Court Opinion

ID: 4200907
Source: CourtListenerOpinion
Date Created: 2017-09-01 19:18:55.965481+00
Date Added: 2024-06-11T07:47:33.930172
License: Public Domain

This opinion is subject to revision before final
                     publication in the Pacific Reporter

                                2017 UT 58

                                   IN THE
       SUPREME COURT OF THE STATE OF UTAH
                           GENOVEVA RUEDA,
                               Appellee,
                                      v.
   UTAH LABOR COMMISSION, JBS USA LLC, AMERICAN ZURICH
    INSURANCE CO., and ZURICH AMERICAN INSURANCE CO.,
                        Appellants.

                             No. 20140043
                            August 31, 2017

         On Certification from the Utah Court of Appeals

                                Attorneys:
             Loren M. Lambert, Midvale, for appellee
         Jaceson R. Maughan, Salt Lake City, for appellant
                     Utah Labor Commission
        Mark R. Sumsion, Cody G. Kesler, Salt Lake City,
  for appellants JBS USA LLC, American Zurich Insurance Co.,
              and Zurich American Insurance Co.

          JUSTICE HIMONAS authored an opinion, in which
                      JUSTICE PEARCE joined.
       CHIEF JUSTICE DURRANT authored an opinion, in which
                      JUSTICE DURHAM joined.
        ASSOCIATE CHIEF JUSTICE LEE authored an opinion.*

   JUSTICE HIMONAS, opinion:

   * Because no Justice holds a majority, the ruling of the lower
tribunal stands.

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                RUEDA v. UTAH LABOR COMMISSION
                       Himonas, J., Opinion

                        INTRODUCTION
    ¶ 1 We confront the effect of the 1991 amendments to the
Occupational Disease Act, UTAH CODE § 34A-3-101 to -113, on the
Workers’ Compensation Act, id. § 34A-2-101 to -905. Lamentably,
we are divided on how to square the acts and are left with a
splintered opinion in which Justice Pearce and I would affirm in
part and reverse in part the final order of the Labor Commission,
Chief Justice Durrant and Justice Durham would affirm, and
Associate Chief Justice Lee would vacate and remand. The result
is that the order stands as issued.1
    ¶2     The facts in this case concern Genoveva Rueda, who
claimed workers’ compensation benefits against her employer,
JBS USA, for injuries she sustained while working in its meat
processing plant from 2007 to 2009. Initially, JBS USA and its
insurers, American Zurich Insurance and Zurich American
Insurance, (collectively, JBS) paid Ms. Rueda’s benefits. But in
2012 they asked for a medical review to determine any further
liability. After this review, JBS determined that either it was no
longer liable to Ms. Rueda or “Ms. Rueda’s condition, while
connected to the employment, did not constitute a compensable
‘accident’ under the Workers’ Compensation Act, but was instead
an occupational disease under the . . . Occupational Disease Act.”
Ms. Rueda petitioned an administrative law judge (ALJ) on the
matter. The ALJ found in favor of Ms. Rueda, concluding that JBS
was subject to ongoing liability for her injuries, which were
caused by a workplace accident under a theory of “cumulative
trauma.” JBS petitioned for review of this decision to the Labor
Commission, which upheld the decision of the ALJ in its final
order. That order is before us on proper appeal by JBS.
    ¶ 3 With an eye trained on our longstanding precedent, I
would affirm in part and reverse in part. The majority of my
colleagues, however, based on no relevant changes to the
Workers’ Compensation Act and only minor, twenty-six-year-old
amendments to the Occupational Disease Act, would now
fundamentally adjust the scope of both acts. While I certainly

   1 What is unmistakable given the fragmented nature of this
decision is that legislative attention to this issue would be of real
benefit. On this there is unanimity.

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                       Himonas, J., Opinion

understand their urge to bring clarity to these muddy waters, and
while I also share many of their policy concerns, I think we forget
the wisdom behind Justice Scalia’s aphorism that legislative
bodies do not “hide elephants in mouseholes” and, in so
forgetting, overstep our authority by making sweeping changes.
Whitman v. Am. Trucking Ass’ns, 531 U.S. 457, 468 (2001).
   ¶ 4 I reject this approach and tackle the questions presented
by this matter as set forth below. First, I address JBS’s contention
that the 1991 amendments to the Occupational Disease Act
abrogated the “cumulative trauma” theory of injury by accident
under the Workers’ Compensation Act. I conclude that they did
not.2
    ¶ 5 Second, I address the challenge by Ms. Rueda that her
injury was improperly classified as the result of “cumulative
trauma” rather than a series of distinct accidents. I conclude that
there was substantial evidence to support the Labor
Commission’s findings that Ms. Rueda suffered a medical
condition affecting her right arm as the result of gradual and
consistent exposure to the regular duties of her employment. And,
thus, I would affirm the finding of the Labor Commission that
Ms. Rueda’s injury was caused by “cumulative trauma.”
    ¶ 6 Third, I conclude that these findings, when viewed
against the legal backdrop of the proper construction of the
interplay between the Occupational Disease Act and the Workers’
Compensation Act, result in a determination that Ms. Rueda’s
condition is an occupational disease. Thus, in my view, we should
reverse the Labor Commission’s determination that Ms. Rueda’s
injury was by accident.
                        BACKGROUND
    ¶ 7 Ms. Rueda began working at JBS USA’s meat processing
plant on July 23, 2007. She first worked as a mock tender trimmer
in the fabrication department, which required her to repeatedly
remove meat from a conveyor belt with a hook and trim the meat
with a knife. Then, for a short time, Ms. Rueda worked in the “hot
boning area,” where she used a knife to “poke into the head of the

   2 Each of the opinions reaches this same conclusion, albeit for
differing reasons.

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                RUEDA v. UTAH LABOR COMMISSION
                       Himonas, J., Opinion

tender” and “clip[ped] the tender to drop out of position.” She
also spent several weeks working as a fat trimmer, “trimming fat
and lean with a straight knife.”
    ¶ 8 As early as August 2007, Ms. Rueda began to experience
“right upper extremity . . . symptoms, including numbness, pain,
wrist discomfort, elbow pain, forearm discomfort, and right
shoulder symptoms.” She also experienced swelling in her right
hand. The swelling in her hand gradually worsened over time and
spread up her right arm; the other pains and symptoms likewise
persisted and progressed throughout her employment at the
plant.
   ¶ 9 On January 1, 2008, Ms. Rueda was trimming mock
tender and pulled product with a hook in order to trim it when
she “felt pain on the left sides of her neck, shoulder and low
back.” Afterward, she was diagnosed with neck, shoulder, and
back strain and began physical therapy in February 2008. On
April 28 and June 3, 2008, Ms. Rueda “reported right medial
elbow soreness and right shoulder and arm pain.” She continued
receiving physical therapy until late November 2008.
     ¶ 10 In February 2009, Ms. Rueda was moved to a new
position as a meat trimmer. She would use her left hand to
position the neck bone and use her right hand to remove the meat
from the bone with a mechanized knife. The physical demands of
the position were “in the [l]ight work category with frequent
lifting up to 20 pounds and carrying objects up to 10 pounds,
reaching with the right [arm] occasionally and the left arm
frequently, handling with the right hand frequently and the left
hand frequently[,] and standing six to eight hours.”
   ¶ 11 On May 11, 2009, Ms. Rueda filed another injury report.
On that day, she felt pain in her right shoulder and in her right
hand as she was removing meat from bones and throwing the
bones onto trays. She “began to hear [her] right shoulder make a
popping noise that she had not heard before.” Ms. Rueda reported
the injury and was placed on light work duty, which consisted of
using a small hand tool to count pieces of product as they fell into
a box.
    ¶ 12 In June and July 2009, Ms. Rueda received physical
therapy for her ailments. An MRI scan revealed a “partial
thickness tear through the supraspinatus and infraspinatus

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                       Himonas, J., Opinion

portions of the rotator cuff.” Ms. Rueda underwent surgery on her
right shoulder in October 2009 and returned to work the next
month. She was assigned to light work duty but was released
from work a week later “due to ongoing right arm pain” and did
not return to work after that.
   ¶ 13 On January 11, 2010, a doctor opined that Ms. Rueda’s
right shoulder condition was “medically stable.” He assessed “a
permanent impairment rating of 4% whole person for
[Ms. Rueda’s] right shoulder condition of which he apportioned
80% to the industrial accident, or 3% whole person, and 20% to
non-industrial.” The following day, January 12, 2010, Ms. Rueda
voluntarily quit her job.
    ¶ 14 After leaving JBS USA, Ms. Rueda continued undergoing
medical evaluations and treatment for her right upper extremity
symptoms for a couple of years. In 2012, JBS requested an
orthopedic evaluation to determine its additional liability, if any,
for Ms. Rueda’s condition. After the evaluation, JBS maintained
that it was no longer liable for Ms. Rueda’s medical expenses and
that it had paid Ms. Rueda all that was required under the
law. Alternatively, JBS contended that Ms. Rueda’s injury was the
result of an occupational disease, rather than an industrial
accident, and that any benefits should be apportioned in
accordance with the medical evidence. Ms. Rueda then filed an
Application for Hearing with the Adjudication Division of the
Utah Labor Commission, claiming entitlement to additional
workers’ compensation benefits.
    ¶ 15 The dispute was heard before an ALJ, who determined
that there was a conflict of medical opinion regarding Ms. Rueda’s
need for ongoing treatment. The ALJ directed the factual medical
questions to a Labor Commission medical panel, which issued a
report on May 16, 2013. Neither party objected to the medical
panel’s report, and it was admitted into evidence. Based on the
earlier hearing and the medical panel’s report, the ALJ ruled in
favor of Ms. Rueda, concluding that Ms. Rueda needed further
treatment for her condition resulting from her “industrial
accident,” and ordered JBS to provide Ms. Rueda additional
workers’ compensation benefits.
  ¶ 16 In response to the ALJ’s order, JBS asked the Labor
Commission for review. The Labor Commission affirmed the

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                RUEDA v. UTAH LABOR COMMISSION
                       Himonas, J., Opinion

ALJ’s order, and JBS subsequently filed a petition to review the
Labor Commission’s decision with the Utah Court of Appeals
under the Utah Administrative Procedures Act. UTAH CODE
§ 63G-4-403. The court of appeals certified the case for transfer to
this court. We have jurisdiction under Utah Code section 78A-3-
102(3)(b).
                   STANDARDS OF REVIEW
    ¶ 17 Appellate courts have authority to review final agency
adjudications on the grounds enumerated in the Utah
Administrative Procedures Act. UTAH CODE § 63G-4-403. A court
may grant relief if “it determines that a person seeking judicial
review has been substantially prejudiced” because “the agency
has erroneously interpreted or applied the law” or “the agency
action is based upon a determination of fact, made or implied by
the agency, that is not supported by substantial evidence when
viewed in light of the whole record before the court.” Id. § 63G-4-
403(4)(d), (g).
    ¶ 18 The first issue in this case is the Labor Commission’s
interpretation of the scope of coverage under the Workers’
Compensation Act and the Occupational Disease Act. Subsection
(4)(d) of Utah Code section 63G-4-403 does not imply a standard
of review, and we therefore turn to our traditional method for
determining the proper standard by reviewing our case law.
Murray v. Utah Labor Comm’n, 2013 UT 38, ¶ 21, 308 P.3d 461. The
Labor Commission’s “interpretation of a statute is a question of
law, which we review for correctness.” Miller v. Utah Dep’t of
Transp., 2012 UT 54, ¶ 23, 285 P.3d 1208 (citation omitted). Thus,
we review the Labor Commission’s interpretation of the
Occupational Disease Act and the Workers’ Compensation Act for
correctness.
    ¶ 19 The second issue is whether Ms. Rueda’s injury was the
result of “cumulative trauma,” as the Labor Commission found,
rather than the result of a series of distinct accidents. The grounds
in section 63G-4-403 “do[] not expressly mandate the standards of
review [courts] must employ when reviewing [agency] actions.”
Murray, 2013 UT 38, ¶ 18. However, we have recognized that
subsection (4)(g) implies a standard of review, permitting the
court to grant relief “only after reviewing the agency’s
determination of fact for a lack of substantial evidence.” Id. ¶ 19.

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                       Himonas, J., Opinion

Therefore, we review the agency’s findings of fact on whether
Ms. Rueda’s injury was the result of “cumulative trauma” for
substantial evidence.
   ¶ 20 Finally, JBS contends that the Labor Commission
misapplied the Workers’ Compensation Act to the facts of
Ms. Rueda’s case. This claim also falls under section 63G-4-
403(4)(d), and we once again turn to our traditional method for
determining the proper standard of review by reviewing our case
law. Id. ¶ 21. Since JBS’s claim “involv[es] application of a legal
standard to a set of facts unique to a particular case,” it is a mixed
question of law and fact. In re Adoption of Baby B., 2012 UT 35,
¶ 42, 308 P.3d 382. In such situations, our standard of review is
“sometimes deferential and sometimes not.” Id. Whether we grant
deference to the administrative body’s findings depends on
       (1) the degree of variety and complexity in the facts
       to which the legal rule is to be applied; (2) the
       degree to which a trial court’s application of the
       legal rule relies on “facts” observed by the trial
       judge, such as a witness’s appearance and
       demeanor, relevant to the application of the law that
       cannot be adequately reflected in the record
       available to appellate courts; and (3) other policy
       reasons that weigh for or against granting
       [deference] to trial courts.
Murray, 2013 UT 38, ¶ 36 (alteration in original) (citation omitted).
    ¶ 21 Here, we determine that the Labor Commission’s
decision to classify Ms. Rueda’s injury as a compensable injury by
accident under the Workers’ Compensation Act is entitled to non-
deferential review. The Labor Commission’s determination that
Ms. Rueda’s facts satisfy the legal requirements of injury by
accident under the Workers’ Compensation Act turns on the legal
effect of the established facts regarding the circumstances
surrounding her injury. Therefore, “the ultimate question is the
legal effect of the facts rather than witness credibility or
demeanor.” Id. ¶ 40. Thus “we are in a better position to analyze
[this question] than the [Labor] Commission.” Id.
                            ANALYSIS
   ¶ 22 First, JBS argues that the 1991 amendments to the
Occupational Disease Act should be read to have expanded its

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                RUEDA v. UTAH LABOR COMMISSION
                       Himonas, J., Opinion

application. Furthermore, JBS argues that this expansion comes at
the expense of the Workers’ Compensation Act, by abrogating the
“cumulative trauma” theory of injury by accident developed by
the courts under the Workers’ Compensation Act. I decline the
invitation to completely abandon the “cumulative trauma” theory
of injury by accident, and clarify the effect of the 1991
Occupational Disease Act amendments on workers’ compensation
in Utah.
   ¶ 23 Second, I reject Ms. Rueda’s contention that the Labor
Commission made an erroneous factual finding when it found
that Ms. Rueda’s injury was caused by “cumulative trauma” and
not by separate, distinct accidents.
   ¶ 24 Finally, I agree with JBS that the Labor Commission
misapplied the Workers’ Compensation Act to Ms. Rueda’s case. I
would hold that Ms. Rueda’s injury is an occupational disease
under the Occupational Disease Act. Therefore, I would reverse
the Labor Commission on this point and remand for further
proceedings consistent with this opinion.
     I. CLASSIFICATION OF WORKPLACE HARM UNDER
         EITHER THE WORKERS’ COMPENSATION ACT
            OR THE OCCUPATIONAL DISEASE ACT
    ¶ 25 JBS contends that this case is an opportunity for the
court to create a more “common sense” demarcation between
injuries by accident and occupational diseases by holding that
proof of “cumulative trauma” can only establish an occupational
disease. Ms. Rueda counters that there is no reason to upset the
status quo between the two. I opt for a middle path. While I
decline to abolish the “cumulative trauma” theory of injury by
accident, I would clarify the state of the law surrounding
occupational diseases and injuries by accident.
   ¶ 26 Utah’s workers’ compensation scheme is outlined by
two separate but related chapters of the Utah Labor Code: the
Occupational Disease Act and the Workers’ Compensation Act.
    ¶ 27 Prior to the enactment of the Occupational Disease Act
in 1941, workers who developed an occupational disease had to
seek recovery under a theory of negligence by their employer
because the Workers’ Compensation Act did not cover
occupational diseases. See Masich v. U.S. Smelting, Ref. & Mining
Co., 191 P.2d 612, 615 (Utah 1948); see also Young v. Salt Lake City,

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                         Himonas, J., Opinion

90 P.2d 174, 176–77 (Utah 1939). The passage of the Occupational
Disease Act brought occupational diseases into the realm of the
workers’ compensation system. See Masich, 191 P.2d at 615. Much
of the wording of the Occupational Disease Act was taken from
the Workers’ Compensation Act, and this court noted that “the
Occupational Disease Act . . . is closely allied to the Work[ers’]
Compensation Act.” Id.
    ¶ 28 However, the original Occupational Disease Act had
limited application in the scheme of workers’ compensation
because it provided a remedy for only twenty-seven specifically
enumerated diseases arising out of a worker’s employment. UTAH
CODE § 42-1a-28 (1943). Most of these enumerated diseases
consisted of poisoning caused by various compounds. Id. § 42-1a-
28(3)–(21). The enumerated diseases also included conditions like
“[s]ynovitis, or tenosynovitis, or bursitis, or cellulitis, of the wrist,
elbow, knee, or hand, due to continual pressure or friction or to
repeated trauma or vibration of tools.” Id. § 42-1a-28(25).
   ¶ 29 The Utah Legislature amended the Occupational Disease
Act in 1949 to include a provision expanding the Act’s coverage.
See UTAH CODE § 35-2-27(28) (1953). In addition to providing
coverage for the twenty-seven enumerated diseases, the
Occupational Disease Act also covered other diseases and injuries
that met six factors. Id.3 These factors required that the disease or

   3   The six factors are
         (1) a direct causal connection between the conditions
         under which the work is performed and the disease
         or injury to health; (2) the disease or injury to health
         can be seen to have followed as a natural incident of
         the work as a result of the exposure occasioned by
         the employment; (3) the disease or injury to health
         can be fairly traced to the employment as to the
         proximate cause; (4) the disease or injury to health is
         not of a character to which the employee may have
         had substantial exposure outside of the
         employment; (5) the disease or injury to health is
         incidental to the character of the business and not
         independent of the relation of the employer and
         employee; and (6) the disease or injury to health
                                                                    (cont.)

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                      Himonas, J., Opinion

injury be related to and caused by employment, as opposed to a
disease that was incident to ordinary life. Id.
   ¶ 30 In 1991, the legislature again amended the Occupational
Disease Act. Now, the Occupational Disease Act provides
remedies for “any disease or illness that arises out of and in the
course of employment and is medically caused or aggravated by
that employment.” UTAH CODE § 34A-3-103 (emphasis added).4
    ¶ 31 On the other end of the workers’ compensation
spectrum lies the Workers’ Compensation Act. The Workers’
Compensation Act, originally passed in 1917, compensates
workers for accidental injuries and excluded “disease[s] except as
[they] shall result from the injury.” COMPILED LAWS OF UTAH
§ 49-3112(5) (1917). The Workers’ Compensation Act governs
compensation for injuries caused “by accident arising out of and
in the course of the employee’s employment.” UTAH CODE
§ 34A-2-401(1). The statute does not define “accident.”5
   ¶ 32 Cognizant of the need to distinguish injuries by accident
from occupational diseases and because this distinction is at issue
in this case, I proceed to provide guidance for determining
whether an injury is by accident under the Workers’
Compensation Act or an occupational disease under the
Occupational Disease Act.

     must appear to have had its origin in a risk
     connected with the employment and to have flowed
     from that source as a natural consequence, though it
     need not have been foreseen or expected before
     discovery.
UTAH CODE § 35-2-27(28) (1953).
   4  The statute was also amended in 1997, but since only minor
stylistic and renumbering changes were made, the statute remains
substantively the same as after the 1991 amendments.
   5  This portion of the Workers’ Compensation Act remains
largely unchanged since its original iteration in 1917. Compare
COMPILED LAWS OF UTAH §§ 49-3112(5), 49-3113 (1917), with UTAH
CODE §§ 34A-2-102(1)(j), 34A-2-401(1).

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    ¶ 33 “When interpreting statutes, our primary goal is to
evince the true intent and purpose of the Legislature. We discern
legislative intent and purpose by first looking to the best evidence
of its meaning, which is the plain language of the statute itself.”
State v. Martinez, 2002 UT 80, ¶ 8, 52 P.3d 1276 (citation omitted)
(internal quotation marks omitted). However, “[t]he legislature is
entitled to invoke specialized legal terms that carry an extra-
ordinary meaning. And when it does so we credit the legal term
of art, not the common understanding of the words.” State v.
Canton, 2013 UT 44, ¶ 28, 308 P.3d 517.
    ¶ 34 In the present case, I cannot evince the legislature’s “true
intent and purpose” for injury classification from the ordinary
meaning of “injury by accident” or “occupational disease.” These
terms are legal terms of art, deeply embedded in more than a
century of precedent, which have taken on a specialized meaning
in the context of workers’ compensation schemes.6 Therefore, to

   6  See Purity Biscuit Co. v. Indus. Comm’n, 201 P.2d 961, 968 (Utah
1949) (concluding that the Utah Legislature “intended to adopt
the construction given to” the words “injury by accident” by
Fenton v. Thorley & Co., [1903] A.C. 433 (HL)); see also Babahmetovic
v. Scan Design Fla. Inc., 176 So. 3d 1006, 1008 (Fla. Dist. Ct. App.
2015) (“[I]t requires the presence of certain elements described . . .
by terms of art such as accident, injury, arising out of work
performed in the course and the scope of employment.”
(emphasis omitted)); Aluminum v. Carkuff, No. 2009-SC-000068-
WC, 2009 WL 3526558, at *2 (Ky. Oct. 29, 2009) (“‘Accident’ and
‘injury’ are legal terms of art . . . .”); O’Regan v. Preferred Enters.,
Inc., 758 So. 2d 124, 131 (La. 2000) (“We have highlighted the
words, ‘accident arising out of and in the course of his
employment’ because they are terms of art in the context of the
Workers’ Compensation Act.”), superseded on other grounds by LA.
REV. STAT. § 1031.1 (2010); Hoard v. ARA Servs., Inc., No. 179213,
1996 WL 33358106, at *3 (Mich. Ct. App. Sept. 20, 1996)
(“‘[O]ccupational disease[]’ [is] a worker’s compensation term of
art.”); Vespers v. Springs Mills, Inc., 275 S.E.2d 882, 884 (S.C. 1981)
(“The term ‘contracted’ is a term of art which has been defined for
compensation purposes in occupational disease cases . . . .”).
Indeed, “occupational disease” has taken on a meaning so distinct
from its constituent parts that dictionaries define it as a collective
                                                                 (cont.)

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                       Himonas, J., Opinion

properly understand the meanings of “injury by accident” and
“occupational disease,” I believe we must undertake “a distinctive
analysis and tracking of pertinent precedents.” Johannesen v.
N.Y.C. Dep’t of Hous. Pres. & Dev., 638 N.E.2d 981, 984 (N.Y. 1994).
To this end, I examine the legal history of the phrases “accident,”
“injury by accident,” and “occupational disease,” as well as
accompanying case law, to derive the meanings of the legal terms
of art at issue in this case.
     ¶ 35 In Utah, as well as the majority of other jurisdictions, the
unexpectedness of the accident and the definiteness of the timing
of the injury’s occurrence have been the most important points of
distinction in determining whether an injury resulted from an
accident or was an occupational disease. See 3 ARTHUR LARSON ET
AL., LARSON’S WORKERS’ COMPENSATION LAW § 42.02 (2017). The
term “by accident” as used in the Utah Workers’ Compensation
Act was first discussed in Tintic Milling Co. v. Industrial
Commission, 206 P. 278 (Utah 1922). After Tintic, Utah courts
developed two lines of cases that defined “accident” differently:
one required proof of an unusual event; the other, represented by
Carling v. Industrial Commission, 399 P.2d 202 (Utah 1965), did not
require such proof. See Allen v. Indus. Comm’n, 729 P.2d 15, 21–22
(Utah 1986). In Allen, this court renounced the unusual-event line
of cases, which had confused the definition of accident, and
reaffirmed the broad definition of accident espoused in Carling.
Id.7

term. See Occupational Disease, BLACK’S LAW DICTIONARY (10th ed.
2010) (“A disease that is contracted as a result of exposure to
debilitating conditions or substances in the course of
employment.”); Illness, WEBSTER’S THIRD NEW INTERNATIONAL
DICTIONARY (2002) (“[A]n unhealthy condition of the body or
mind”);     Occupational   Disease,   WEBSTER’S   THIRD    NEW
INTERNATIONAL DICTIONARY (2002) (“[A]n illness caused by factors
arising from one’s occupation.”).
   7 While Allen renounced the unusual-event line of cases, it
went on to say that under the Workers’ Compensation Act, a
claimant with a preexisting condition is required to show “an
unusual or extraordinary exertion . . . to prove legal causation.”
Allen v. Indus. Comm’n, 729 P.2d 15, 26 (Utah 1986) (emphasis
                                                           (cont.)

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    ¶ 36 Under Carling, the term “accident” “connotes an
unanticipated, unintended occurrence different from what would
normally be expected to occur in the usual course of events.” 399
P.2d at 203. But an injury by accident “is not necessarily restricted
to some single incident which happened suddenly at one
particular time and does not preclude the possibility that due to
exertion, stress or other repetitive cause, a climax might be
reached in such manner as to properly fall within the definition of
accident.” Id. Thus, in Carling, this court recognized that
“cumulative trauma” or “repetitive trauma” can give rise to a
claim under the Workers’ Compensation Act.8 Carling, however,

added). So, the question of an unusual or extraordinary exertion
remains relevant when a claimant with a preexisting condition is
attempting to prove legal causation for an injury under the
Workers’ Compensation Act. See id. at 25–27.
   8  Courts have used this “cumulative trauma” or “repetitive
trauma” theory of injury by accident to find application of the
Workers’ Compensation Act to such injuries as back injuries and
knee injuries. See Specialty Cabinet Co. v. Montoya, 734 P.2d 437, 440
(Utah 1986) (allowing compensation for a cabinet maker’s back
injury and a gym teacher’s torn medial meniscus); Kaiser Steel
Corp. v. Monfredi, 631 P.2d 888, 892 (Utah 1981) (upholding a
determination that a miner’s back injury resulted from an
“accident,” reasoning that the Commission’s finding could
reasonably be based on “a job-induced preexisting condition . . .
hav[ing] reached . . . a ‘climax’ due to ‘exertion, stress, or other
repetitive cause’”) (quoting Carling v. Indus. Comm’n, 399 P.2d 202,
203 (Utah 1965), superseded on other grounds by UTAH CODE § 63-
44b-1 to -22 (1989)); Smith’s Food & Drug, Inc. v. Labor Comm’n,
2011 UT App 67, ¶¶ 1, 14, 250 P.3d 1008 (affirming that a cheese
cook’s spondylosis could be classified as an accident resulting
from “exertion, stress or other repetitive cause”). I note that Chief
Justice Durrant faults me for citing Specialty Cabinet, claiming that
this case upheld an award for a cabinet maker under the Workers’
Compensation Act, despite finding no evidence of a climactic
event under a theory of cumulative trauma injury by accident. I
agree with the Chief Justice that the cited facts for the cabinet
maker’s injuries in that case do not point to a climactic event.
Specialty Cabinet, 734 P.2d at 438. However, I do not cite this case
                                                               (cont.)

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                       Himonas, J., Opinion

cautioned that courts must still be careful to distinguish such
accidental injuries from occupational diseases, which it
characterized as “gradually developing conditions.” Id.
   ¶ 37 Earlier Utah case law defined occupational disease in a
similar way.
       An accident . . . is distinguished from an
       occupational disease, in that it arises by some
       definite event, the date of which can be fixed with
       certainty, but which cannot be so fixed in the case of
       occupational diseases. . . . We are therefore of the
       opinion that the term occupational disease must be
       restricted to a disease that is not only incident to an
       occupation, but the natural, usual, and ordinary
       result thereof; and held not to include one
       occasioned by accident or misadventure.
Young, 90 P.2d at 176 (internal quotations marks omitted); see also
Tintic, 206 P. at 281 (“If the injury is incurred gradually in the
course of the employment, and because thereof, and there is no
specific event or occurrence known as the starting point, it is held
to be an occupational disease, and not an injury resulting from
accident.”).
   ¶ 38 These definitions track the definitions of “accident” and
“occupational disease” in other jurisdictions and legal works.9

to endorse the awards we granted under the Workers’
Compensation Act, especially if the facts of the injuries do not
meet the requirements of the “cumulative trauma” theory of
injury by accident. Instead, I cite Specialty Cabinet here merely as
part of the history of when the court has granted compensation
under the “cumulative trauma” theory of injury by accident.
   9 See 82 AM. JUR. 2D Workers’ Compensation § 199 (2017) (“An
‘accident’ is an unanticipated, unintended occurrence different
from what would normally be expected to occur in the usual
course of events; the basic and indispensable ingredient of
accident is unexpectedness.”); id. § 284 (“[A] statutory
occupational disease . . . involves disability, the onset of which is
gradual and unheralded by any identifiable occurrence.”); id.
§ 291 (“An occupational . . . disease is a disease or infirmity that
                                                              (cont.)

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                       Himonas, J., Opinion

However, such “[d]efinitions . . . should always be checked
against the purpose for which they were uttered.” 4 ARTHUR
LARSON ET AL., LARSON’S WORKERS’ COMPENSATION LAW § 52.03[1]
(2017). One early purpose of defining “occupational disease” was
to distinguish occupational diseases from accidental injuries. The
usual result of this distinction was to prevent the injured worker
from receiving workers’ compensation because “‘occupational
disease’ was synonymous with the verdict ‘noncompensable.’” Id.
With the advent of occupational disease acts in the realm of
workers’ compensation, this context took on less importance. Id.
This is because in many jurisdictions “it [became] . . . immaterial
which category applie[d]” as the coverage offered for injuries by
accidents and occupational diseases became roughly the same. Id.
§ 50.06. Therefore, the distinctions between the definitions of
accident and occupational disease became less important in the
case law because the categorization of the injury often made little
or no difference to the compensation the employee was to receive
for his or her injury. Id. § 52.03[1]. This was the case in Utah with
respect to the scope of coverage until our decision in Dale T. Smith
& Sons v. Utah Labor Commission, 2009 UT 19, 218 P.3d 580, where

develops gradually and imperceptibly as a result of engaging in a
particular employment and that is generally known and
understood to be a usual incident or hazard of that
employment.”); 99 C.J.S. Workers’ Compensation § 359 (2017) (“[A]n
occupational disease is one which develops over a period of time
as opposed to an injury that is attributable to a one-time event.”);
id. § 334 (“An ‘accident,’ for workers’ compensation purposes, has
also been said to be an unexpected or unforeseen actual,
identifiable, precipitous event happening suddenly or violently,
with or without human fault, and directly producing at the time
objective findings of an injury which is more than simply a
gradual deterioration or progressive degeneration.”); id. § 358
(“The terms ‘accident’ and ‘occupational disease,’ as defined
generally, and in connection with provisions of compensation
acts, are distinguishable in that an accident arises from a definite
event, the time and place of which can be fixed, while the
occupational disease develops gradually over a long period of
time and also in the fact that the accident might easily have been
avoided . . . .”).

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               RUEDA v. UTAH LABOR COMMISSION
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we held that the apportionment provision of the Occupational
Disease Act applies to all forms of compensation under that Act,
including medical benefits.10 Now, because the Workers’
Compensation Act has no similar apportionment provision, the
question of whether an injury qualifies as by accident or as an
“occupational disease” can matter greatly. The distinction means
that the employee will be entitled to receive more or less
compensation depending on which act is applied and that the
employer (or its insurer) will be obligated to pay more or less
compensation depending on how the injury is classified.11

   10The specific language regarding apportionment in the
Occupational Disease Act reads:
         The compensation payable under this chapter
     shall be reduced and limited to the proportion of the
     compensation that would be payable if the
     occupational disease were the sole cause of
     disability or death, as the occupational disease as a
     causative factor bears to all the causes of the
     disability or death when the occupational disease, or
     any part of the disease: (1) is causally related to
     employment with a non-Utah employer not subject
     to commission jurisdiction; (2) is of a character to
     which the employee may have had substantial
     exposure outside of employment or to which the
     general public is commonly exposed; (3) is
     aggravated by any other disease or infirmity not
     itself compensable; or (4) when disability or death
     from any other cause not itself compensable is
     aggravated, prolonged, accelerated, or in any way
     contributed to by an occupational disease.
UTAH CODE § 34A-3-110.
   11  Another context in which the distinction remained highly
relevant in Utah is in the application of the time limits for
bringing a claim. Under the 1943 and 1953 versions of the
Workers’ Compensation Act, a statute of repose operated to cut
off all claims where “no claim for compensation [was] filed with
the Industrial Commission within three years from the date of the
accident or the date of the last payment of compensation.” UTAH
                                                          (cont.)

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    ¶ 39 Today, I would make clear that in keeping with this
court’s long-standing precedent, we should view injuries by
accident and occupational disease as existing along a “spectrum”
with extreme examples of workplace accidents on one end and
similarly extreme examples of occupational diseases on the other.
See Smith’s Food & Drug, Inc. v. Labor Comm’n, 2011 UT App 67,
¶ 14, 250 P.3d 1008. I would also make clear that when
characterizing an impairment along this spectrum, we should take
into consideration the unexpectedness of the accident as well as
the definiteness as to the occurrence of the injury. When an
accident is unexpected and one can trace the occurrence of the
injury to a definite time, then “one has the clearest example of a
typical industrial accident . . . . At the other extreme, if [the
unexpectedness and definiteness] elements are missing, one sees
the typical occupational disease.” 3 ARTHUR LARSON ET AL.,
LARSON’S WORKERS’ COMPENSATION LAW § 42.02 (2017). And
under our statutory scheme, the same injury cannot be both a
workplace accident and an occupational disease at the same time.
See UTAH CODE § 34A-2-102(1)(j)(ii) (“‘Personal injury by accident
arising out of and in the course of employment’ does not include a
disease, except as the disease results from the injury.”).
Consequently, it is at the center of the spectrum where the battle
between classifying an injury as an occupational disease or as a
workplace accident is fought.
    ¶ 40 I recognize that in the past we have spoken loosely
regarding the classification of an accidental injury under the
workers’ compensation scheme. Therefore, I would clarify that
definiteness of time as to the occurrence of (1) the cause of the
injury and (2) the resultant injury are important factors in
determining the categorization of a workplace injury. But the
primary factor by which we should judge whether an injury
results from an accident is whether the cause of the injury or
result of the occurrence is unexpected or unintended. See

CODE § 42-1-92 (1943); see also id. § 35-1-99 (1953). However, under
the Occupational Disease Act, a statute of limitations did not
begin to run until the cause of action arose. Id. § 42-1a-49 (1943);
see also id. § 35-2-48 (1953).

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                 RUEDA v. UTAH LABOR COMMISSION
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3 ARTHUR LARSON ET AL., LARSON’S WORKERS’ COMPENSATION LAW
§ 42.02 (2017); see also Allen, 729 P.2d at 22.12
    ¶ 41 To determine if an occurrence satisfies the
unexpectedness factor of the test, either the cause of the injury or
the result of the occurrence must be unexpected. To determine if
the cause of an injury is unexpected, one will ordinarily look to
whether “something . . . broke, or interjected itself into, the usual
course of the performance of the occupation.” Young, 90 P.2d at
177. In other words, we should look to whether a mishap
occurred. A slip and fall is a classic example of an unexpected
cause. Often, however, the real controversy in this area of law is
whether the result of an occurrence was unexpected, and thus an
injury by accident.13 To determine whether the result of an

   12 This is consistent with the history of workers’ compensation
cases in Utah and the country in general. The phrase “accident” in
American workers’ compensation jurisprudence traces back to the
leading English case of Fenton v. Thorley & Co., [1903] A.C. 433
(HL). 3 ARTHUR LARSON ET AL., LARSON’S WORKERS’
COMPENSATION LAW § 42.02 (2017). As Fenton, and the American
cases that followed, made clear, “[t]he basic and indispensable
ingredient of ‘accident’ is unexpectedness.” Id.; see also Tintic
Milling Co. v. Indus. Comm’n of Utah, 206 P. 278, 282 (Utah 1922)
(acknowledging the unexpected result rule of Fenton).
   13 In a review of our case law, we have consistently held that
an unexpected result may be termed an injury by accident under
the Workers’ Compensation Act. The only case of ours that I have
located to the contrary is Young v. Salt Lake City. 90 P.2d 174, 177
(Utah 1939) (“The unusual or the unexpected circumstance that
classifies the illness as accidental must occur in the events leading
up to the illness.”). Our subsequent case law, however, is
antagonistic to Young on this point. See, e.g., Purity Biscuit, 201
P.2d at 966 (“There is no requirement in the statute that the
accident be the first in the chain of events which ultimately results
in injury . . . . [I]t may be that the only accidental event is the
resulting injury itself.”). In Purity Biscuit, the court explained that
workers’ compensation may be awarded for unexpected results
because “the distinction between accidental cause and accidental
result was over the heads of parliament and of employer and
                                                                 (cont.)

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                        Himonas, J., Opinion

occurrence is unexpected, one ordinarily looks to whether there
was an “unexpected internal failure of [an employee’s] system to
function normally.” Purity Biscuit Co. v. Indus. Comm’n, 201 P.2d
961, 966 (Utah 1949).
    ¶ 42 At the opposite end of the spectrum are occupational
diseases, which are not unexpected. Since occupational diseases
are those “medically caused or aggravated by that employment,”
UTAH CODE § 34A-3-103, they are not unexpected in connection
with an employee’s work.14 In addition, an occupational disease
does not typically arise from a definite event, the time and place
of which can be exactly pinpointed. As far back as Tintic, we
recognized that occupational diseases typically are “incurred
gradually.” 206 P. at 281. Carling reaffirmed that notion, noting
that workplace accidents “must be distinguished from gradually
developing conditions which are classified as occupational
diseases.” 399 P.2d at 203. And Allen reiterated that distinction,
stating that an injury by accident would have no evidence “that it
developed gradually as with an occupational disease.” 729 P.2d at
27. But not every occupational disease must occur gradually, as
expectedness is our primary consideration in this context. This
approach is consistent with the original version of the
Occupational Disease Act. Although some of the twenty-seven

employee, and . . . the average person would consider he had met
with an accident in either case.” Id. at 967. Consequently, I believe
that it is clear from our case law that an injury by accident is either
the unexpected or unintended cause of an injury or result of an
occurrence.
   14 I do not mean to suggest that courts rely on an analysis of
which injuries are simply more likely to occur in a certain line of
work. I focus instead on what medical evidence shows is incident
to the usual performance of the occupation. For example, a
worker may recover under the Workers’ Compensation Act and
not recover under the Occupational Disease Act for a heart attack
where his job involves heavy lifting. Though the frequent exertion
of heavy lifting may make it more likely that the employee has a
heart attack than employees in sedentary lines of work, a heart
attack is not medically understood to be incidental to the
character of the work.

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                RUEDA v. UTAH LABOR COMMISSION
                       Himonas, J., Opinion

enumerated diseases had “rapid harmful effects,” they were not
contrary to the term of art understanding of occupational disease,
as Chief Justice Durrant claims, because they were still not
unexpected. Infra ¶ 116.
    ¶ 43 I note that there is criticism regarding the consideration
of the definiteness of time as a factor when classifying an injury.
See 3 ARTHUR LARSON ET AL., LARSON’S WORKERS’ COMPENSATION
LAW § 42.02 (2017). This criticism, as both Chief Justice Durrant
and Justice Lee have pointed out, is not unfounded—I readily
concede that the legislature can and should draw clearer lines in
the workers’ compensation context. And I agree with many of my
colleagues’ policy arguments. But in the absence of any statutory
change beyond the streamlining accomplished by the 1991
amendments, see infra ¶¶ 45–48, we should adhere to our case law
on this point. And the definiteness of time factor is one that is
entrenched in our case law. See, e.g., Carling, 399 P.2d at 203
(“However, such an occurrence must be distinguished from
gradually developing conditions which are classified as
occupational diseases . . . .”); see also Allen, 729 P.2d at 27
(distinguishing an injury by accident where there was “no
evidence which indicates that [the employee’s] injury was
predictable or that it developed gradually as with an occupational
disease”); Tintic, 206 P. at 281 (“What is termed an accident must
be something . . . definitely located as to time and place. If the
injury is incurred gradually . . . and there is no specific event or
occurrence known as the starting point, it is held to be an
occupational disease . . . .”); Smith’s Food & Drug, 2011 UT App 67,
¶ 13 (“The period of time in which [Claimant] experienced
periodic shoulder pain was short until the pain evolved into
chronic pain thereafter.” (alteration in original)). In reviewing our
case law, I conclude that our courts often look to the definiteness
of time factor to help inform the “unexpectedness” inquiry in
terms of whether a mishap occurred. This is why our cases have
stated that “[t]he basic and indispensable ingredient of ‘accident’
is unexpectedness,” while also looking at the definiteness of time
as to the occurrence or onset of an injury. Allen, 729 P.2d at 22
(citation omitted). I believe the Chief Justice’s criticism that
adopting a test that includes definiteness of time as a factor leads
to an “inequitable standard” is true when the length of time is the
sole basis for determining whether workplace harm is an injury by
accident or an occupational disease. See infra ¶ 89. In Utah,

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                       Himonas, J., Opinion

however, the definiteness of time is a secondary factor in
determining how to classify workplace harm, the primary factor
being unexpectedness of cause of the injury or unexpectedness of
the resultant injury. Indeed, neither JBS nor Ms. Rueda argue
against inclusion of the definiteness of time as a factor in the test,
and, in fact, JBS appears to argue that the definiteness of time
should be the deciding factor in classifying a workplace harm. See
infra ¶ 65 n.19. Given the prevalent inclusion of the definiteness of
time factor in our case law, I am determinedly of the opinion that
we are in no position to eliminate it, either wholly or in
substantial part, from the analysis in classifying workplace harm
based on a relatively minor change to the statutory scheme.
    ¶ 44 And it is the role of the definiteness factor that presents
my principal point of departure from Justice Lee’s opinion.
Primarily for policy reasons, Justice Lee would demote
definiteness to “only circumstantially relevant to the
‘unexpectedness’ of a given causal event.” Infra ¶ 153. But this
treatment represents, as I explain throughout my opinion, a
substantial shift in our case law that cannot be squared with the
legislature’s minor 1991 amendments to the Occupational Disease
Act. To quote Justice Scalia, legislatures do not “hide elephants in
mouseholes” by altering “the fundamental details of a regulatory
scheme in vague terms or ancillary provisions.” Whitman v. Am.
Trucking Ass’ns, 531 U.S. 457, 468 (2001).15
    ¶ 45 Chief Justice Durrant’s approach does even greater
violence to the elephants-in-mouseholes doctrine. First, the Chief
Justice applies inconsistent interpretive principles to the phrase
“injury by accident” by arguing for a plain language

   15 Contrary to Justice Lee’s opinion, I do not believe Young
“unequivocally repudiated the ‘definiteness’ factor.” See infra
¶ 162. Instead, Young rejected the idea, as do we, that definiteness
should be the “governing” factor. But it stated that after
determining whether an illness “is one commonly recognized as
incident to the usual performance of the occupation”—i.e.,
whether it is unexpected—courts should “then ascertain if some
definite circumstance took place of an unexpected or unusual
nature.” 90 P.2d at 177. I believe my analysis tracks Young’s
approach of treating definiteness as a secondary factor.

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                RUEDA v. UTAH LABOR COMMISSION
                       Himonas, J., Opinion

interpretation of “injury” (and “disease”), but a term of art
interpretation of “by accident.” Second, wielding this novel
interpretative approach, he proceeds to view the amendments to
the Occupational Disease Act as creating a sea change in decades’
worth of workers’ compensation law.
    ¶ 46 I find Chief Justice Durrant’s position commendable in
its attempt to bring clarity to an admittedly muddled pair of
statutory schemes. And I agree with the Chief Justice (and
Associate Chief Justice Lee) that this is an area that the legislature
should revisit. But in the absence of legislative clarification, I
cannot agree with the Chief Justice’s approach for two reasons.
First, a plain language analysis is not appropriate where the terms
“injury by accident” and “occupational disease” have developed
specialized meanings and have not been undercut by statutory
changes. Second, as pointed out above, there is no indication that
the legislature intended such a massive shift in the scope of both
the Workers’ Compensation Act and the Occupational Disease Act
when it amended the latter in 1991.16
    ¶ 47 A term of art approach for both “injury by accident” and
“occupational disease” is consistent with principles of statutory
interpretation, our case law, and the workers’ compensation
scheme of the majority of states. Supra ¶ 34 & n.6. Decades of
judicial interpretation in workers’ compensation cases have
“become[] a gloss” on both the Workers’ Compensation Act and
the Occupational Disease Act. Hackford v. Utah Power & Light Co.,
740 P.2d 1281, 1283 (Utah 1987), superseded by statute on other
grounds by UTAH CODE § 30-2-11, as recognized in Benda v. Roman
Catholic Bishop of Salt Lake City, 2016 UT 37, ¶ 12, 384 P.3d 207.
That gloss becomes, “in effect, part of the statute.” Id. The

   16 Chief Justice Durrant also states that a shift away from the
term of art understanding of “occupational disease” occurred in
1941, with the enactment of the Occupational Disease Act.
However, the Chief Justice’s position is ultimately moored to the
1991 amendments. Infra ¶ 124 (“By enacting the 1991 ODA, the
legislature continued to reject our common law term of art
definition of ‘disease’ and also jettisoned its own effort to define
that term by enumerating twenty-seven specific diseases covered
under the act.”); see also infra ¶¶ 99, 108.

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                       Himonas, J., Opinion

legislature is not operating in a vacuum; where it has not erased
that gloss through new definitions, “the subsequent amendments
suggest implicit legislative adoption of the judicially created
definition.” Weyerhaeuser Co. v. Woda, 998 P.2d 226, 230 (Or. Ct.
App. 2000). The Weyerhaeuser court recognized that where—as
here—the legislature has never provided a definition for
“disease,” the occupational disease statute “retains the use of the
term ‘disease,’ which is a term that has acquired a specific
definition that cannot simply be ignored.” Id.
    ¶ 48 In fact, even language that predates the Occupational
Disease Act’s enactment operated to inform the legislature’s word
choice. Our decisions interpreting the Workers’ Compensation
Act, a sister statute to the Occupational Disease Act, go back
nearly a century, providing key insight for what the term
“disease” meant when the legislature enacted the Occupational
Disease Act. See Masich, 191 P.2d at 615 (“The intent, purposes and
objectives of the Occupational Disease Act, which is closely allied
to the Work[ers’] Compensation Act, can be determined by
reliance on former interpretations of the Work[ers’] Compensation
Act . . . .”); see also Tintic, 206 P. at 280–83 (pre-Occupational
Disease Act case discussing “injury by accident” and “disease”).
Our cases after the Occupational Disease Act’s enactment and the
1949 amendment continued our specialized meaning approach by
fleshing out the factors of unexpectedness and timing. See Carling,
399 P.2d at 203 (describing occupational diseases as “gradually
developing conditions”); Allen, 729 P.2d at 27 (noting that
occupational diseases have the characteristics of being
“predictable” and “develop[ing] gradually”).
    ¶ 49 Indeed, the legislature never gave “disease” a definition
inconsistent with our common-law gloss. Notably, it has never
defined “disease” at all. Certainly “nothing in the language of the
amended statute or its enactment history suggests that the
legislature intended to abandon the [common-law] definition of
the term.” Weyerhaeuser, 998 P.2d at 229. Chief Justice Durrant
himself seems to recognize that following the 1941 enactment of
the Occupational Disease Act, our case law has consistently
adhered to a term of art definition. See infra ¶ 85 (citing Allen, 729
P.2d at 18, 22). Our continued use of the term of art meanings
after the 1941 enactment of the Occupational Disease Act and the
1949 and 1991 amendments is evidence that the legislature had

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                RUEDA v. UTAH LABOR COMMISSION
                       Himonas, J., Opinion

not abandoned the common-law definition. We are not in a
position to reject all of our history in this area without a signal
that the legislature intended such a sea change. Because the 1991
amendment to the Occupational Disease Act served primarily to
simplify the Act and is closely aligned to the 1949 version, I
believe we are compelled to continue using the term of art
definitions rather than the Chief Justice’s plain language
approach. Compare UTAH CODE § 35-2-27(28) (1953) (defining
“occupational disease” as “diseases or injuries to health which
directly arise as a natural incident of the exposure occasioned by
the employment” as long as there is a suitable nexus between the
disease and the employment), with UTAH CODE § 34A-3-103 (2015)
(“[A] compensable occupational disease means any disease or
illness that arises out of and in the course of employment and is
medically caused or aggravated by that employment.”).
    ¶ 50 Additionally, Chief Justice Durrant’s conclusion that by
“any disease” the legislature meant to use an “ordinary” meaning
for the term “disease” is based on an incorrect premise. When the
legislature adopted the 1991 amendments, the Occupational
Disease Act did not have a narrow definition of “disease” based
only on the twenty-seven enumerated diseases. Instead, the
Occupational Disease Act listed twenty-seven diseases and
included a broader provision that provided coverage for any
disease that qualified under a six-factor test. When the legislature
jettisoned the specific list and adopted what was essentially a
simplified version of the six-factor test from the previous version
of the Occupational Disease Act, it does not follow that it meant to
then abandon the prior term of art meaning of “occupational
disease.” The Chief Justice’s analysis is further complicated by the
fact that it adopts a plain language interpretation of “injury” and
“disease,” but splits the term “injury by accident” in order to
apply a specialized meaning to “by accident.” Infra ¶¶ 94–97. This
approach contravenes principles of statutory interpretation by
splitting a singular phrase into separate parts and applying
disparate models of statutory interpretation to each part. See Dist.
of Columbia v. Heller, 554 U.S. 570, 586–87 (2008) (rejecting
interpretation that would give a literal interpretation to part of
“keep and bear arms” and an idiomatic interpretation to another
part). We have consistently referred to “injury by accident” as a
cohesive phrase. See Specialty Cabinet Co. v. Montoya, 734 P.2d 437,
439 (Utah 1986) (referring to the term “injury by accident” as a

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                        Himonas, J., Opinion

whole); Allen, 729 P.2d at 17 (same); Purity Biscuit, 201 P.2d at 968
(referring to “the [singular] term ‘injury by accident’”). This
phraseology spans centuries, continents, and countless cases.17
See, e.g., Purity Biscuit, 201 P.2d at 967 (“The English Workmen’s
Compensation Law was adopted in 1897 . . . [and] provided
compensation for ‘injury by accident’ the same as ours.”). We do
not “only inquire into individual words and subsections in
isolation; our interpretation of a statute requires that each part or
section be construed in connection with every other part or
section so as to produce a harmonious whole.” Anderson v. Bell, 2010
UT 47, ¶ 9, 234 P.3d 1147 (internal quotation marks omitted),
superseded on other grounds by UTAH CODE § 20A-1-306. I therefore

   17 Chief Justice Durrant correctly points out that this phrase is
not always analyzed in its entirety. Infra ¶ 96 n.41. That is because,
as often happens in the interpretation of language, one part of a
phrase is more relevant to the analysis. But the Chief Justice’s
focus on courts’ decisions to address only the relevant part of the
phrase—or the separation of “injury” and “by accident” by a
certain number of words—entirely misses the point. The
importance of our treatment of “injury by accident” as a cohesive
phrase is not that it can never be analyzed in part, but that a
cohesive phrase should compel a cohesive interpretation. See
Penunuri v. Sundance Partners, Ltd., 2013 UT 22, ¶ 15, 301 P.3d 984
(“[W]e do not view individual words and subsections in isolation;
instead our statutory interpretation requires that each part or
section be construed in connection with every other part or
section so as to produce a harmonious whole.” (citation omitted)).
Even the four cases the Chief Justice cites to that apply a plain
language analysis do not split the phrase “injury by accident” or
“accidental injury” and apply different interpretive models to
each part. See infra ¶ 124 n.105. In fact, the Chief Justice cites to no
case that takes that tack, nor did my research turn up such a case.
And the separation of “injury” and “by accident” in Utah Code
section 34A-2-401(1) does not imply that different interpretive
models should be applied to each part, especially given that the
definitions section of the Workers’ Compensation Act uses the
cohesive phrase “personal injury by accident.” UTAH CODE
§ 34A-2-102(j).

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disagree with the Chief Justice’s application of two different
interpretive methods to a singular phrase, and I interpret “injury
by accident” as a whole and as a term of art.
    ¶ 51 Chief Justice Durrant criticizes my opinion for focusing
on “by accident” rather than first classifying an impairment as an
injury. I reject this premise. As I have explained, the term “injury
by accident” is a term of art. My opinion restates and explains that
term of art. Included in this restatement and explanation is a
distinction that is central to the judicial gloss on “injury by
accident” and “occupational disease” that the legislature has
embraced: the distinction between an ailment brought on by a
mishap (an injury by accident) and one medically understood to
be caused by a certain kind of work. The Chief Justice is mistaken
that I read the concept of a mishap into the term “injury by
accident” by focusing only on the phrase “by accident.” Instead, I
read it into the term by focusing on the judicial gloss that has
come to be coextensive with that term’s meaning. I also disagree
with the Chief Justice’s effectively advocating a sweeping change
to both the Occupational Disease Act and the Workers’
Compensation Act. While the Chief Justice’s desire to draw a clear
line between injury by accident and occupational disease is a
laudable one, I do not believe that it is possible to do so in this
context. See 3 ARTHUR LARSON ET AL., LARSON’S WORKERS’
COMPENSATION LAW § 42.02 (2017). Indeed, the line the Chief
Justice wishes to draw would profoundly upset decades of
workers’ compensation precedent by now stating that any
repetitive trauma can be compensated only as an injury by
accident. It is too much to imagine that, in amending the
Occupational Disease Act in 1991, the legislature intended to
effect such a significant change in the workers’ compensation
arena without indicating such an intent or changing the language
of the Workers’ Compensation Act.
    ¶ 52 And Chief Justice Durrant’s attempt to do so directly
contradicts the legislative history. The sponsor of the 1991
amendments to the Occupational Disease Act stated that it was an
update needed to “eliminate[] the unnecessary duplication of
provisions” and streamline the “confusing” act, which did “not
meet the needs of the 1990s.” Utah Occupational Disease Act
Amendments: Hearing on S.B. 9 Before the House, 1991 Gen. Sess.
(statement of Sen. Lane Beattie). Nowhere in the floor votes did

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any legislator indicate an intention to discard the term of art
approach and redraw the lines of compensation in the way the
Chief Justice proposes.
    ¶ 53 Such line drawing, while often valuable in the law
because it creates clear demarcations and obvious outcomes,
inevitably will create winners and losers. The legislature is much
better positioned to draw those lines after hearing testimony than
we are based upon the case before us. The current “line” between
the Workers’ Compensation Act and the Occupational Disease
Act, while admittedly unclear, is based on factors that have
developed in nearly a century of case law. There are weighty
reliance issues at play in this area of the law and in the way that
these cases have played out over such a long period of time. See
Eldridge v. Johndrow, 2015 UT 21, ¶ 22, 345 P.3d 553 (“Our
decisions have identified two broad factors that distinguish
between weighty precedents and less weighty ones . . . . The
second factor encompasses a variety of considerations, including
the age of the precedent . . . and the extent to which people’s
reliance on the precedent would create injustice or hardship if it
were overturned.”). The 1991 amendments to the Occupational
Disease Act were not an invitation by the legislature for us to step
in and overrule a century of precedent, create a new test, and
decide who the new “winners” and “losers” will be in the context
of workers’ compensation.18
   ¶ 54 A final problem with Chief Justice Durrant’s approach is
that it has the perverse implication that a definition that certainly
was not aimed at narrowing the definition of an “occupational
disease” does exactly that. For example, the Occupational Disease
Act consistently listed “bursitis” as an occupational disease until
the 1991 amendments. But bursitis does not fit under the Chief
Justice’s understanding of the ordinary meaning of disease
because it does not “result from exposure to environmental
hazards and foreign agents, such as bacteria, viruses, other germs,

   18  Furthermore, I do not share Chief Justice Durrant’s faith that
his lines, which even he concedes are unclear, will become clearer
over time. Infra ¶ 135. Nor do I think it worth the risk to discard
settled precedent for new precedent that shares the same
fundamental defect as the old.

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                RUEDA v. UTAH LABOR COMMISSION
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poisons, and toxins, or from inherent biological or genetic
defects.” Infra ¶ 130. Thus, the Chief Justice is forced to conclude
that a clarifying amendment to the Occupational Disease Act that
eliminated a specific list of diseases and instead stated simply that
the Occupational Disease Act encompasses “any disease” has the
effect of removing a previously recognized core disease from its
ambit. I cannot accept this.
   ¶ 55 Having clarified the standard for determining whether
an injury is by accident or an occupational disease, I proceed to
address JBS’s contention that the 1991 amendments to the
Occupational Disease Act abrogated the “cumulative trauma”
theory of injury by accident.
      A. The “Cumulative Trauma” Theory of Injury by Accident
    ¶ 56 The 1991 amendments changed the Occupational
Disease Act to provide a remedy for “any disease or illness that
arises out of and in the course of employment and is medically
caused or aggravated by that employment.” UTAH CODE § 34A-3-
103. But that change did not, as JBS argues, abrogate the
“cumulative trauma” theory of injury by accident.
    ¶ 57 JBS asks us to abandon the “cumulative trauma” theory
of injury by accident as articulated in Carling. See 399 P.2d at 203
(injury by accident “is not necessarily restricted to some single
incident which happened suddenly at one particular time”).
Instead of that theory, JBS argues that we should adopt what it
considers a more “common sense” line of demarcation, namely,
that definiteness of time is the sole mechanism by which an injury
should be classified either as by accident or as an occupational
disease. Such a rule, JBS asserts, would give meaning to the 1991
Occupational Disease Act amendments while reining in the
courts’ overly broad definition of workplace accident under the
Workers’ Compensation Act.
    ¶ 58 The “cumulative trauma” theory of injury by accident is
established by longstanding precedent, which we will overrule
only “for the most compelling reasons.” ASC Utah, Inc. v. Wolf
Mountain Resorts, L.C., 2010 UT 65, ¶ 23, 245 P.3d 184 (citation
omitted). JBS, as the party asking us “to overturn prior
precedent[,] ha[s] a substantial burden of persuasion.” Id. (second
alteration in original) (citation omitted). This burden, however, “is
not equal[] . . . in all cases.” Eldridge, 2015 UT 21, ¶ 22.

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       Our decisions have identified two broad factors that
       distinguish between weighty precedents and less
       weighty ones: (1) the persuasiveness of the authority
       and reasoning on which the precedent was
       originally based, and (2) how firmly the precedent
       has become established in the law since it was
       handed down. The second factor encompasses a
       variety of considerations, including the age of the
       precedent, how well it has worked in practice, its
       consistency with other legal principles, and the
       extent to which people’s reliance on the precedent
       would create injustice or hardship if it were
       overturned.
Id.
    ¶ 59 As discussed below, all of these factors are present in
this case, making the “cumulative trauma” theory of injury by
accident “weighty precedent[].” Id. And because JBS has not met
its heavy burden of persuading us to abandon this precedent, I
decline the invitation to do so.
    ¶ 60 The first part of the test for departing from precedent
requires us to consider “the persuasiveness of the authority and
reasoning on which the precedent was originally based.” Id. JBS
does not argue that the “cumulative trauma” theory of injury by
accident was originally erroneous. Indeed, the “cumulative
trauma” theory of injury by accident, or similar “repeated
trauma” or “repetitive trauma” theories appear to be well-
recognized in the law. 4 ARTHUR LARSON ET AL., LARSON’S
WORKERS’ COMPENSATION LAW § 50.04 (2017) (The “repeated-
trauma or cumulative-trauma doctrine appears to have originated
with the House of Lords decision in Burrell & Sons, Ltd. v. Selvage,
[90 L.J. 1340 (H.L. 1921)] . . . [I]t has had considerable acceptance
in this country and accounts for many of the successful cases that
lack brevity of both cause and result.”); see also Tokyo House, Inc. v.
Hsin Chu, 597 So. 2d 348, 350–51 (Fla. Dist. Ct. App. 1992) (stating
that “repetitive trauma theory” exists “apart from occupational
disease theory”); Martin v. Cudahy Foods Co., 646 P.2d 468, 471
(Kan. 1982) (holding “that tenosynovitis when incurred through
repetitive cyclic activities of an employee is an accidental injury
within the meaning of the workmen’s compensation act and not
an occupational disease” because “it is more akin to accidental

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                RUEDA v. UTAH LABOR COMMISSION
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injury from repetitive small traumas than to occupational
disease”); Hash v. Mont. Silversmith, 810 P.2d 1174, 1176 (Mont.
1991) (recognizing “that a ‘tangible happening of a traumatic
nature’ need not be a single isolated incident, but may well be a
‘chain of incidents’ leading to an injury”); Macklanburg-Duncan Co.
v. Edwards, 311 P.2d 250, 255 (Okla. 1957) (holding “that . . . an
injury . . . may be inflicted progressively and over a more or less
lengthy period rather than being confined to infliction on one
definite date and as the result of an isolated or particular event”).
Given the theory’s prevalence in the workers’ compensation
jurisprudence of not only Utah but throughout the country, I am
not convinced that the “cumulative trauma” theory of injury by
accident was originally erroneous.
    ¶ 61 The second part of the test focuses our analysis on “how
firmly the precedent has become established in the law since it
was handed down.” Eldridge, 2015 UT 21, ¶ 22. In this inquiry, we
consider many things, “including the age of the precedent, how
well it has worked in practice, its consistency with other legal
principles, and the extent to which people’s reliance on the
precedent would create injustice or hardship if it were
overturned.” Id.
    ¶ 62 JBS argues that the “cumulative trauma” theory of injury
by accident has become a “legal fiction . . . which has been
stretched beyond all bounds of reasonableness to allow
occupational disease claims to be filed as accidents.” Specifically,
JBS asserts that the legislature intended that the 1991
Occupational Disease Act amendments would expand coverage
under the Occupational Disease Act and diminish coverage under
the Workers’ Compensation Act. But to read into the new
language of the Occupational Disease Act an intention to abrogate
the “cumulative trauma” theory of injury by accident under
Carling and the Workers’ Compensation Act requires too many
inferences. Indeed, it requires an inference that the legislature
meant to upend decades of established precedent regarding our
workers’ compensation jurisprudence without amending a single
word of the Workers’ Compensation Act. This strikes me as a
most extraordinary leap that runs a great risk of usurping the
legislature’s policy-making prerogative. I decline such an
interpretation of the Occupational Disease Act.

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    ¶ 63 This conclusion is supported by all of the Eldridge factors
mentioned above. First, we look to the “age of the precedent.” Id.
The “cumulative trauma” theory of injury by accident established
in Carling is over fifty years old.
   ¶ 64 Next, we examine “how well [the theory] has worked in
practice.” Id. I am of the opinion that the theory appears to have
worked well in practice. Our appellate courts have used it to grant
compensation under the Workers’ Compensation Act in only four
cases. See supra ¶ 35 & n.8; see also Nyrehn v. Indus. Comm’n,
800 P.2d 330, 335 (Utah Ct. App. 1990). This does not strike me as
a theory of injury by accident “stretched beyond all bounds of
reasonableness.” As a result, I conclude JBS’s assertions that the
theory is harmful to the workers’ compensation system are
unfounded.
    ¶ 65 We also must examine the theory’s “consistency with
other legal principles.” Eldridge, 2015 UT 21, ¶ 22. I believe that
the “cumulative trauma” theory of injury by accident is consistent
with the legal principles of workers’ compensation requiring that
injuries by accident be compensated under the Workers’
Compensation Act and occupational diseases be compensated
under the Occupational Disease Act. While JBS argues that the
current test for whether an injury is by accident “defies common
sense and logic” and that the Occupational Disease Act
amendments give us an opportunity to change the way the line
between injuries by accident and occupational diseases has been
drawn, this argument does not support JBS’s argument that the
“cumulative trauma” theory of injury by accident should be
overruled.19 An argument that the current rule is illogical is not

   19 JBS’s proposed rule emphasizes definiteness of time as the
basis for classifying injuries as by accident or occupational
diseases. I worry that the change JBS advocates would bring about
the very harm this court expressed concern over in Young. See
90 P.2d at 176 (considering and rejecting time as the basis for
“determining the accidental nature of the illness”). As we
explained in Young, to adopt this proposed rule “is to adopt a rule
which may, in many cases, be governed by the bodily resistance of
the individual. . . . Were we to adopt such a rule, the dividing line
between an occupational disease and an accident would become
                                                              (cont.)

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evidence that the Occupational Disease Act amendments
abrogated the “cumulative trauma” theory of injury by accident
under the Workers’ Compensation Act. I certainly agree with JBS
that there is a distinction between injuries by accident and
occupational diseases; an injury by accident caused by
“cumulative trauma” resulting in an acute event is not the same as
the gradual onset of an occupational disease. But this is not to say
that an occupational disease can never be caused by “cumulative
trauma” as well. On the contrary, the classification of an injury
caused by “cumulative trauma” depends on the circumstances
surrounding the injury’s unexpectedness and the definiteness of
time as to the occurrence of the injury. There is nothing in the
language of the “cumulative trauma” theory of injury by accident
that requires courts to find that all injuries caused by “cumulative
trauma” are necessarily caused by accident. Instead, the test is
merely recognition that the term “accident” in the Workers’
Compensation Act “does not preclude the possibility that due to
exertion, stress or other repetitive cause, a climax might be
reached in such a manner as to properly fall within the definition
of an accident.” Carling, 399 P.2d at 203. The case goes on to
recognize that “such an occurrence must be distinguished from
gradually developing conditions which are classified as
occupational diseases.” Id. The line between injuries by accident
and occupational diseases is clearly contemplated and preserved
under the language of the “cumulative trauma” theory of injury
by accident. Therefore, it is up to courts and other adjudicative
bodies to ensure that the line between injuries by accident and
occupational diseases is preserved by analyzing the workplace
harm for its unexpectedness and definiteness of time and
classifying it accordingly. See supra ¶¶ 38–42.
   ¶ 66 Finally, we consider whether overturning the
“cumulative trauma” theory of injury by accident now would
create injustice or hardship in the realm of workers’
compensation. See Eldridge, 2015 UT 21, ¶ 22. I conclude that it

extremely hazy as the periods of time for each approached unity.”
Id. Such a result is contrary to the purposes of the Workers’
Compensation Act, which intends to compensate employees for
workplace accidents only. See Carling, 399 P.2d at 203.

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would. Undoubtedly, people have relied on this theory when
deciding whether to file their claims under the Workers’
Compensation Act or under the Occupational Disease Act. As
stated above, there is no language in the 1991 amendments to the
Occupational Disease Act that supports our overturning this
precedent and at least one case has relied on this theory in making
its ruling subsequent to the amendments. See Smith’s Food & Drug,
2011 UT App 67, ¶¶ 12, 14. To overturn the precedent now,
without any supporting statutory language and despite its age
and the fact that litigants and courts continue to rely on it, would
create injustice and hardship.
   ¶ 67 Therefore, although the 1991 amendments changed the
language of the Occupational Disease Act, that language did not
abrogate the “cumulative trauma” theory of injury by accident.
JBS did not argue that the “cumulative trauma” theory of injury
by accident was originally erroneous or that its original reasoning
was unpersuasive. And, based on “the age of the precedent, how
well it has worked in practice, its consistency with other legal
principles, and the extent to which people’s reliance on the
precedent would create injustice or hardship if it were
overturned,” I would not overrule the “cumulative trauma”
theory of injury by accident. Eldridge, 2015 UT 21, ¶ 22. In
conclusion, JBS has failed to meet its heavy burden of convincing
us to abandon the “cumulative trauma” theory of injury by
accident.
         II. SUBSTANTIAL EVIDENCE SUPPORTS THE
             LABOR COMMISSION’S FINDING THAT
             MS. RUEDA’S INJURY RESULTED FROM
                   “CUMULATIVE TRAUMA”
    ¶ 68 Ms. Rueda argues that the Labor Commission
improperly classified her injury as a “cumulative trauma” injury.
The Labor Commission, like the ALJ, largely adopted the medical
panel’s findings, determining that “Ms. Rueda’s right-shoulder
condition was a culmination of progressive cumulative trauma
from her repetitive work duties.” Ms. Rueda contends that this
classification by the medical panel and the ALJ was “superfluous”
and that the injuries “can more precisely be deemed specific
individual workplace accidents with specific identifiable injuries.”

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    ¶ 69 Under the Utah Administrative Procedures Act, we
review the order of the Labor Commission and not the underlying
decision by the ALJ or the medical panel. See UTAH CODE § 63G-4-
403(1) (granting this court “jurisdiction to review all final agency
action resulting from formal adjudicative proceedings”). The
standard of review for the Labor Commission’s factual
determination that Ms. Rueda was injured as a result of
“cumulative trauma” is implicit in the language of the
Administrative Procedures Act: we may “grant relief only if . . .
the agency action is based upon a determination of fact, made or
implied by the agency, that is not supported by substantial
evidence when viewed in light of the whole record before the
court.” Id. § 63G-4-403(4)(g); see Murray v. Utah Labor Comm’n,
2013 UT 38, ¶ 19, 308 P.3d 461 (explaining that subsection (4)(g)
“implies a ‘substantial evidence’ standard”). We therefore
consider whether the Labor Commission’s finding of fact
regarding Ms. Rueda’s injury is supported by substantial evidence
in the record. I conclude that it is.
   ¶ 70 The Labor Commission found that “Ms. Rueda’s
condition as of May 11, 2009, represented a culmination of
progressive ‘cumulative trauma’ to her right shoulder” resulting
from her work duties that began in 2007. This finding was
adopted from the ALJ’s order, which, in turn, was based largely
on the medical panel’s report. Ms. Rueda has not challenged the
validity or accuracy of the report, contending only that the finding
regarding progressive “cumulative trauma” was “superfluous.”
The Labor Commission, however, deemed the medical panel’s
analysis to be a “thorough and well-reasoned report.”
    ¶ 71 In its report, the medical panel concluded that
“Ms. Rueda suffered from a cumulative process that appears to
have started in late 2007 and progressed slowly over time to the
point of such severity that she ultimately was sent to have an
injury formally reported on 5/11/09.” The panel determined that
the injury was “not specifically attributable to any event on
5/11/09.” Instead, the panel attributed Ms. Rueda’s injuries to
“work activity that occurred over many months prior to
5/11/09.” It determined that “[a]s a result of this longstanding,
progressive ‘cumulative trauma,’” Ms. Rueda’s symptoms
eventually became severe enough to warrant filing a claim, “even
though no specific pathology can be identified to have occurred

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on 5/11/09.” Moreover, Ms. Rueda told the medical panel that
her pain began “within days of starting employment . . . and it
progressively got worse . . . [for] nearly 2 years” until she was sent
to a doctor on May 11, 2009. She also “insisted to th[e] medical
panel that she had no incident or specific injury on 5/11/09 and
that th[e] pain had been present and worsening since 2007.”
   ¶ 72 I find that this evidence provides substantial support for
the Labor Commission’s finding that Ms. Rueda’s shoulder injury
on May 11, 2009, resulted from “a culmination of progressive
cumulative trauma.”
               III. MS. RUEDA’S INJURY IS AN
            OCCUPATIONAL DISEASE UNDER THE
               OCCUPATIONAL DISEASE ACT
    ¶ 73 Although I decline to abrogate the “cumulative trauma”
theory of injury by accident, and would affirm the Labor
Commission’s findings that Ms. Rueda’s injury was caused by
“cumulative trauma,” I would hold that the Labor Commission
incorrectly classified Ms. Rueda’s injury as a workplace accident.
As stated above, this is a mixed question of law and fact to which
we give nondeferential review. See supra ¶¶ 19–21; see also Murray
v. Utah Labor Comm’n, 2013 UT 38, ¶ 36, 308 P.3d 461. And based
on the medical panel’s report and the Labor Commission’s
findings, I would hold that Ms. Rueda’s injury is an occupational
disease.
    ¶ 74 As we cautioned in Carling v. Industrial Commission,
decision-makers must distinguish accidental injuries from those
“gradually developing conditions which are classified as
occupational diseases.” 399 P.2d 202, 203 (Utah 1965). The case at
hand presents an example where the injury is such that this
“cumulative trauma” crosses the threshold from an injury by
accident caused by “cumulative trauma” into the realm of
occupational disease resulting from a cumulative or gradual
process. Ms. Rueda’s symptoms began in late 2007 when she
started working for JBS and “progressed slowly over time to the
point of such severity that [Ms. Rueda] ultimately was sent to
have an injury formally reported on 5/11/09.” “[N]o specific
pathology [was] identified to have occurred on 5/11/09.” Indeed,
Ms. Rueda “insisted . . . that she had no incident or specific injury
on 5/11/09” but instead her pain “progressively got worse to the

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point that ultimately . . . ‘they finally sent [her] to the doctor.’”
The medical panel was careful to clarify whether the pain
Ms. Rueda experienced on May 11, 2009, was different from
before and whether a climactic event happened on that day. But
Ms. Rueda “clearly stated . . . that nothing new happened” and
that “[t]here was no new pain or different pain on 5/11/09 to that
which she claim[ed] was present since 2007.” While she stated
that she heard a new popping noise in her shoulder that she had
not previously heard, she insisted that the pain she experienced
that day “was essentially the same as it had been for months.”
    ¶ 75 Ms. Rueda’s injury is thus different from the other
injuries that our courts have found to be injuries by accident
caused by “cumulative trauma” in the unexpectedness of the
injury’s occurrence and the gradualness of its occurrence.
Ms. Rueda’s injury was not reasonably unexpected. The job
Ms. Rueda performed was “highly repetitive.” And, as a result of
her job, Ms. Rueda experienced almost constant pain for the two
years she was employed at JBS. Nothing different happened to her
on May 11, 2009, other than that her symptoms reached their
logical conclusion and she was sent to a doctor. In contrast, the
cheese cook’s injury in Smith’s Food & Drug, Inc. v. Labor
Commission “was qualitatively different from the intermittent pain
she had experienced” previously, and evidence supported the
conclusion that “an ‘acute event’ caused [the cheese cook’s]
injury.” 2011 UT App 67, ¶ 13, 250 P.3d 1008. While an accident
“is not necessarily restricted to some single incident which
happened suddenly at one particular time,” an accident must be
unexpected or unintended and thus often manifests itself as an
“acute event.” Carling, 399 P.2d at 203; see also Smith’s Food &
Drug, 2011 UT App 67, ¶¶ 3, 4, 11, 13. Here, Ms. Rueda
experienced right upper extremity pain shortly after she began
her job at JBS, and after two years of repetitive motions with her
right arm she experienced symptoms severe enough to have them
examined by a doctor. It cannot be the case that her ultimate
injury was unexpected after such a long period of time
performing the same repetitive work tasks while subject to such
chronic pain.
    ¶ 76 Other cases that found an injury to be a compensable
injury by accident caused by “cumulative trauma” occurred over
a period of mere months. For example, in Smith’s Food & Drug, the

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cheese cook’s pain occurred “over a period of several months”
and “[t]he period of time in which [she] experienced periodic
shoulder pain was short.” 2011 UT App 67, ¶ 13. In Nyrehn v.
Industrial Commission, the stock room clerk’s back injury resulted
from “two and a half months” of repetitive work activities.
800 P.2d 330, 335 (Utah Ct. App. 1990). Finally, in Specialty Cabinet
Co. v. Montoya, the gym teacher’s knee injury progressed over a
period of a few months from January to April 1983. 734 P.2d 437,
438 (Utah 1986).20 Ms. Rueda’s injury, which occurred over a
period of two years, was not reasonably unexpected and too
gradual to be classified as an injury by accident; as a result, on the
spectrum of work-related injuries, her injury is more
appropriately viewed as an occupational disease.
   ¶ 77 In conclusion, because Ms. Rueda’s injury was gradual
and—in light of Ms. Rueda’s history of pain under the work
conditions—not unexpected, the injury more appropriately falls
on the occupational disease side of the workers’ compensation
spectrum than on the injury by accident side.
                          CONCLUSION
   ¶ 78 JBS has not, in my view, met its burden to convince us
that the 1991 amendments to the Occupational Disease Act
abrogated the “cumulative trauma” theory of injury by accident.
Furthermore, I am of the opinion that there was substantial
evidence supporting the Labor Commission’s finding that
Ms. Rueda’s injury was caused by “cumulative trauma.” Finally, I
would conclude that Ms. Rueda’s injury should be classified as an
occupational disease under the Occupational Disease Act.
Therefore, I would affirm the factual findings of the Labor
Commission in its final order, but would reverse its determination
that Ms. Rueda’s injury was compensable under the Workers’
Compensation Act.

   20 I cite this case only to the extent it describes the gym
teacher’s injury as progressing over a period of a few months.

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   CHIEF JUSTICE DURRANT, opinion:
    ¶ 79 The Workers’ Compensation Act (WCA) provides
compensation to employees for any “injury by accident arising
out of and in the course of employment.”1 The Occupational
Disease Act (ODA), in contrast, provides compensation for “any
disease or illness that arises out of and in the course of
employment and is medically caused or aggravated by that
employment.”2 The WCA specifically does not provide
compensation for “disease[s],”3 while the ODA specifically states
that it does not provide compensation for injuries covered by the
WCA.4 Thus, the legislature has made clear that for purposes of
the WCA and ODA a particular type of harm to an employee
cannot be both an injury and a disease. It is one or the other. This
difference is an important one because compensation for a disease
under the ODA is often reduced in cases where compensation for
an injury under the WCA would not be.5
    ¶ 80 We are charged, then, with distinguishing between the
sets of harms covered by the WCA—injuries by accident—and
those covered by the ODA—occupational diseases. Because we
have not yet addressed the scopes of these two acts in light of the
recent amendments to the ODA, this is a question of first
impression. It is a question that is complicated by the fact that the
legislature has not fully defined the terms “injury,” “disease,” or
“accident,” as used in these two compensation acts. And it is
further complicated by the fact that the legislature has offered no
rationale for compensating an employment-caused disease at a
lower rate than an employment-caused injury. Nor can I think of
one. Regardless, we are charged with distinguishing between
those harms covered by the WCA and the ODA.

   1   UTAH CODE § 34A-2-102(1)(j)(i)–(ii); id. § 34A-2-401(1).
   2   Id. § 34A-3-103.
   3   Id. § 34A-2-102(1)(j)(ii).
   4   Id. § 34A-3-111.
   5   See supra ¶ 38.

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    ¶ 81 Below, I begin by reviewing Justice Himonas’s approach
and some of the practical problems that I see with it. I then discuss
the two relevant statutes in turn, reviewing Justice Himonas’s
interpretation of each one and explaining why I believe that
interpretation is erroneous. I also describe what I believe to be the
proper way of interpreting and harmonizing the two statutes,
relying on both the plain meaning and the history of the statutes
to conclude that the WCA covers all “injuries” while the ODA
covers all “diseases” as those terms are commonly understood.
Under this standard, I conclude that Ms. Rueda’s harm should be
categorized as an “injury” and should be evaluated under the
WCA. And because I agree with Justice Himonas that we should
not abandon the cumulative trauma theory that is part of the term
of art “by accident” and that the Labor Commission’s findings
were supported by substantial evidence, I would affirm the
Commission’s ruling.
           I. Justice Himonas’s Approach Fails to Make the
                 Proper Distinction Between the Scopes
                         of the WCA and ODA
    ¶ 82 Justice Himonas and I agree that the scope of the WCA
and the scope of the ODA are primarily to be understood in
contrast to one another, i.e., that whatever is covered under one
act cannot be covered under the other. This conclusion follows
from the express provisions of the statutes. First, the WCA states
that it covers “injur[ies] by accident” but specifically excludes
from its scope “disease[s],”6 which we have interpreted as
“occupational diseases.”7 Thus, whatever the WCA covers, it
cannot include “occupational diseases.” The ODA, on the other
hand, covers “occupational diseases,”8 but expressly states that it
does not compensate the “injuries by accident” that are covered

   6 See UTAH CODE § 34A-2-102(1)(j)(ii). As I discuss below,
although not all harms that fall within the scope of the WCA may
be compensable, the scope of the statute reaches all “injuries”—
everything except “diseases.”
   7See Pinyon Queen Mining Co. v. Indus. Comm’n, 204 P. 323, 326
(Utah 1922).
   8   UTAH CODE § 34A-3-103.

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                RUEDA v. UTAH LABOR COMMISSION
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by the WCA.9 Thus, each statute covers a mutually exclusive set of
harms.
    ¶ 83 Justice Himonas has made a yeoman effort to define the
key terms of the statutes—“injury,” “accident,” and “occupational
disease”—and to harmonize the WCA and ODA. And in doing so
he has attempted to be consistent with our very inconsistent
caselaw. But I believe that Justice Himonas’s approach is
fundamentally flawed because it rests on the premise that the
distinction between the scope of the WCA and the scope of the
ODA turns on the difference between “injuries by accident” and
“occupational diseases” as those terms have been understood in
our caselaw. This premise requires Justice Himonas to fashion a
test for distinguishing the scopes of the statutes that is unclear,
and, in my mind, both unsupported by the statutory language
and potentially inequitable. Instead, I believe that the proper
distinction to be made is between the ordinary meaning of
“injuries” and “diseases,” which distinction is both compelled by
the statutory language and has long been recognized by other
states.
        A. Justice Himonas’s Approach Relies on the Distinction
                 Between the Common Law Terms of Art
           “Injury by Accident” and “Occupational Disease”
   ¶ 84 According to Justice Himonas, the appropriate analysis
contrasts “injuries by accident”10 with “occupational disease” as
those terms have been understood in our caselaw. Under Justice
Himonas’s approach, potentially compensable harms fall along a

   9 Id. § 34A-3-111 (providing that compensation is not available
under the ODA “in all cases when injury results by reason of an
accident arising out of and in the course of employment”).
   10 Justice Himonas phrases the harms covered by the WCA as
alternatively “injuries by accident,” “workplace accidents,” or
simply “accidents.” See supra ¶¶ 34–39. But Justice Himonas never
defines “injuries” apart from “accidents” and bases his discussion
of the scope of the WCA on its definition of “accidents.” See supra
¶¶ 34–39. For simplicity’s sake, I will simply use the term “injury
by accident” to refer to Justice Himonas’s understanding of the
harms covered by the WCA.

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spectrum. At one end are those harms covered by the WCA—
“injuries by accident.” At the other are those covered by the
ODA—“occupational diseases.” In order to determine where on
the spectrum a particular harm lies, Justice Himonas looks to the
factors established in our caselaw interpreting the terms “injury
by accident” and “occupational disease.”
    ¶ 85 In our caselaw, the term “by accident” is defined to
encompass “either the cause or the result of an injury,”11 and may
refer to a harm arising from a “single incident which happened
suddenly at one particular time” or may refer to a harm emerging
more gradually “due to exertion, stress or other repetitive cause
[that reaches] a climax.”12 An occupational disease, on the other
hand, has been defined as a “gradually developing condition[].”13
Justice Himonas has distilled these two term-of-art meanings into
two factors that determine whether a harm in a given case falls
more on the “injury by accident” or the “occupational disease”
side of its compensation spectrum. First, Justice Himonas looks to
“the unexpectedness of the [harm],” which can be found in either
the “cause of the injury or result of the occurrence.” Second, he
looks to “the definiteness as to the occurrence of the [harm],”14
which looks to the time it takes for the harm to develop, and
whether the harm can be identified as resulting from discrete
events.
    ¶ 86 So the same ultimate condition can be either an injury by
accident or an occupational disease depending on how it
develops, how long it takes to develop, and whether it “result[s]
in an acute event.”15 If the harm is unexpected—i.e., either caused
by an unexpected event (or series of events) or is the unexpected
result of ongoing stress—and has a more definite occurrence—i.e.,
it can be traced to specific incidents or it arose over a relatively
short period of time—it is an “injury by accident” and

   11 Allen v. Indus. Comm’n, 729 P.2d 15, 22 (Utah 1986).
   12   Id. at 18 (citation omitted).
   13   Id. (citation omitted).
   14   Supra ¶ 39.
   15   Supra ¶ 65.

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compensable under the WCA. If, on the other hand, the harm is a
more expected result of ongoing stress that either cannot be easily
traced to discrete incidents or emerged over a longer period of
time, it is an “occupational disease” and compensable under the
ODA.
    ¶ 87 Justice Himonas’s construct for distinguishing between
injuries by accident and occupational diseases leads to perplexing
results. The cheese cook whose shoulder pain occurs over a period
of several months,16 the stock room clerk whose back injury
emerged over two and a half months,17 and the gym teacher
whose knee injury progressed over a period of a few months18 are
all compensated at a higher rate than they would be if, like Ms.
Rueda, they had soldiered on for two years. Ms. Rueda’s pain,
which would be deemed an “unexpected” result for the first few
months and therefore an accident, eventually, at some point over
the course of two years, became “not reasonably unexpected,”19
“too gradual to be classified as an injury by accident,” and

   16 See Smith’s Food & Drug, Inc. v. Labor Comm’n, 2011 UT App
67, ¶ 13, 250 P.3d 1008.
   17See Nyrehn v. Indus. Comm’n, 800 P.2d 330, 335 (Utah Ct.
App. 1990).
   18 See Specialty Cabinet Co. v. Montoya, 734 P.2d 437, 438 (Utah
1986).
   19 Justice Himonas stops short of stating that Ms. Rueda’s harm
was expected, stating instead only that it was “not reasonably
unexpected.” Supra ¶¶ 74–75. This description seems to blur the
line between “unexpected” and “expected,” leading to an
inherently ambiguous test to be applied in future cases. I see no
principled basis to distinguish Ms. Rueda’s shoulder pain from all
of the other individuals’ pains described above; all of the
individuals’ harms resulted from repeated motions made at work,
and their pain “reached [its] logical conclusion” when the
individual determined that they could no longer stand working
with the pain and received treatment. See supra ¶ 75. It would
seem that, under Justice Himonas’s framework, either all of these
individuals’ harms should be considered injuries by accident or
they should all be considered occupational diseases.

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accordingly somehow morphed into a disease.20 Although Justice
Himonas recognizes that “under our statutory scheme, the same
injury cannot be both a workplace accident and an occupational
disease at the same time,”21 his test ultimately does permit the
same harm—be it a torn rotator cuff or silicosis—to be categorized
as either an injury by accident or an occupational disease in
different cases based on hard-to-define factors.
    ¶ 88 I believe that Justice Himonas, despite his insistence to
the contrary, has “adopt[ed] a rule . . . governed by the bodily
resistance of the individual.”22 Indeed, though Justice Himonas
attempts to describe the consideration of the time a particular
harm took to emerge as only “a secondary factor,” with “the
primary factor being unexpectedness of cause of the injury or
unexpectedness of the resultant injury,”23 his application of his
own standard belies his assertion.
    ¶ 89 Under Justice Himonas’s approach, the only way I see to
distinguish between an unexpected harm emerging from
repetitive motion—an injury by accident—and a “not reasonably
unexpected” harm emerging from repetitive motion—an
occupational disease—is to look either to the length of time
involved or to whether there was some “definite time”24 or
“definite event”25 when the harm emerged or worsened. The
problem with the former distinction is that it makes the length of
time an individual suffered before seeking medical attention
determinative of compensation—a result everyone agrees is
erroneous. The problem with the latter distinction is that some of
our prior cases—cases reaffirmed by Justice Himonas today—
have required no such definite occurrence in awarding

   20   Supra ¶ 76.
   21   Supra ¶ 39.
   22 Young v. Salt Lake City, 90 P.2d 174, 176 (Utah 1939); see also
supra ¶ 43.
   23   Supra ¶ 43.
   24   Supra ¶ 39.
   25   Supra ¶¶ 37, 42.

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compensation for injuries under the WCA.26 Thus, we have an
unclear and, in my view, potentially inequitable standard based
on inconsistent caselaw.
    ¶ 90 Again, I do not fault Justice Himonas for his attempt to
bring some order both to a statutory scheme that is far from clear
and to our caselaw, which is also less than a model of clarity. But I
would approach the task differently, in a way that I believe better
follows the statutory language and is in harmony with other
states’ approaches to this issue. Below I address each statute,
beginning with the WCA, in order to explain both why Justice
Himonas’s approach—which relies on the terms of art “by
accident” and “occupational disease”—does not align with the
legislative intent expressed in the two statutes and why a plain
language approach is necessary.
         B. The Language of the Statutes Reveals that Their Scopes
        Depend on the Ordinary Meaning of “Injury” and “Disease”
    ¶ 91 Justice Himonas approaches the task of defining the two
sets of mutually exclusive harms created by the statutes by
envisioning a spectrum between the WCA and ODA, classifying

   26 For example, Justice Himonas supports his argument that
Ms. Rueda’s harm was an occupational disease with Specialty
Cabinet Co. v. Montoya, 734 P.2d 437 (Utah 1986), wherein we held
that a cabinet maker’s back pain, which “did not result from any
specific event or activity [but] developed in the course of [the
employee’s] routine work of designing and building cabinets,”
was an injury by accident because it was “the unexpected and
unintended result of exertions which occurred at work and in the
course of . . . employment.” Id. at 438–39. Justice Himonas states
that he cites this case “only to the extent it describes the . . . injury
as progressing over a period of a few months,” but by so doing,
Justice Himonas has reinforced that the only distinguishing factor
between Specialty Cabinet and Ms. Rueda’s case is the time
involved. Supra ¶ 76 n.20. Both involve injuries resulting from
routine workplace exertions, but one injury is “unexpected”
because it emerged over “a few months,” while the other injury—
Ms. Rueda’s—is “not reasonably unexpected” because it was
more gradual. Supra ¶ 76.

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harms as “injuries by accident” or “occupational diseases” based
on certain factors derived from our caselaw. I disagree. I believe
that the statutes require a categorical approach, where a harm is
categorized at a threshold level as either falling within the scope
of the WCA or the ODA. And, unlike Justice Himonas, I think the
central distinction between the two statutes’ scopes—and thus the
key to the categorization—is found in the difference between the
ordinary meaning of the terms “injury” and “disease,” not in the
difference between the term of art understandings of “injury by
accident” and “occupational disease,” as Justice Himonas
suggests. Although the statutes could be clearer, I believe their
language and history requires this approach, which is the same
approach taken by a majority of other states that have considered
this issue.27

   27  Of the five states to address the distinction between a
“disease” and an “injury” under statutory schemes similar to
ours, four have taken a plain language approach. See, e.g., Luttrell
v. Indus. Comm’n, 507 N.E.2d 533, 541–42 (Ill. App. Ct. 1987) (using
a plain language approach to describe how “‘injury’ is
distinguished from a ‘disease’”); Duvall v. ICI Ams., Inc., 621
N.E.2d 1122, 1124–26 (Ind. Ct. App. 1993) (same); Noble v. Lamoni
Prods., 512 N.W.2d 290, 294–95 (Iowa 1994) (same); Pee v. AVM,
Inc., 543 S.E.2d 232, 234–37 (S.C. Ct. App. 2001) (same), aff’d, 573
S.E.2d 785 (S.C. 2002). The fifth state, Oregon, rejected a plain
meaning approach and instead employed a term of art approach
consistent with Justice Himonas’s opinion today. See Weyerhaeuser
Co. v. Woda, 998 P.2d 226, 227–31 (Or. Ct. App. 2000). In
Weyerhaeuser, the Oregon Court of Appeals reasoned that because
Oregon courts had adopted the common law term of art definition
of “occupational disease” in the context of its workers’
compensation statute, and because “since the adoption of that
definition by the Supreme Court, the legislature has not defined
the term differently and has not enacted language that is
inconsistent with the judicially created definition,” but rather had
implicitly adopted that definition, it would continue to use the
term of art and not a plain language understanding. Id. at 230. As
discussed below, infra ¶ 114, the Weyerhaeuser court’s logic is
inapposite here because our legislature has specifically adopted a
statutory definition of “occupational disease” that conflicts with
                                                              (cont.)

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1. The WCA Covers “Injuries,” Not “Injuries by Accident”
    ¶ 92 The WCA covers “injur[ies] by accident arising out of
and in the course of employment” and excludes only
“disease[s].”28 Justice Himonas reads the phrase “injury by
accident” as a single, indivisible concept. He accordingly explains
the scope of the WCA according to what he describes as the term
of art understanding of “injury by accident.” In my view, though I
agree that the term “by accident” is indeed a term of art with the
meaning described by Justice Himonas, I do not believe that term
defines the scope of the WCA. Instead, the phrase “by accident,”
in conjunction with the phrase “arising out of and in the course of
employment” defines only whether an “injury”—a harm that has
been categorized as falling within the scope of the WCA—is
compensable.
    ¶ 93 First, I agree with Justice Himonas that the phrase “by
accident” or “accident,” is a term of art within the context of the
WCA that has been incorporated into the statute. When the WCA
was first enacted, it contained the same “by accident” language at
issue today.29 As Justice Himonas has discussed, we have a long
line of cases interpreting this phrase. There are two aspects of our
interpretation of “accident” relevant today. First, as Justice
Himonas points out, we have adopted a broad interpretation of
the term, holding “that an accident is an unexpected or
unintended occurrence that may be either the cause or the result of
an injury.”30 Second, and as part of that broad interpretation of the
term “accident,” we have adopted the “cumulative trauma”
theory of accident. Under this theory, an “accident” “is not
necessarily restricted to some single incident which happened
suddenly at one particular time,” but instead includes

the common law term of art understanding of that phrase.
Accordingly, there is no basis for rejecting a plain meaning
approach in Utah.
   28   UTAH CODE § 34A-2-102(1)(j)(i)–(ii); see also id. § 34A-2-401(1).
   29   See Chandler v. Indus. Comm’n, 184 P. 1020, 1021 (Utah 1919).
   30   Allen, 729 P.2d at 22.

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“accident[s]” that emerge over time “due to exertion, stress or
other repetitive cause [that reach] a climax.”31
    ¶ 94 Because the legislature has amended and reenacted the
WCA many times over the past century without amending or
changing the “by accident” language, we presume it has
approved of and adopted our interpretation.32 Thus, the term
“accident” in the WCA is no longer understood according to its
ordinary meaning, but as a term of art as described above. But
although Justice Himonas and I agree that the phrase “by
accident” in the WCA is to be understood as a term of art, we
disagree as to the stage at which that understanding becomes
applicable. Justice Himonas relies on the term of art “by accident”
at the threshold, categorization stage to determine the scope of the
WCA. I, on the other hand, believe that the term of art does not
apply to the threshold question of what harms are covered by the
WCA, but rather goes only to whether a harm that has already
been classified as falling within the scope of the WCA—an
“injury”—is compensable.
    ¶ 95 Although the legislature has not clearly defined the
extent of the statute’s scope, its language guides the inquiry that
we must make. The WCA repeatedly states that it applies to
“injuries,”33 and our caselaw confirms that its scope is focused on

   31   Id. at 18 (citation omitted).
   32 See Christensen v. Indus. Comm’n, 642 P.2d 755, 756 (Utah
1982) (“[W]here a legislature amends a portion of a statute but
leaves other portions unamended, or re-enacts them without
change, the legislature is presumed to have been satisfied with
prior judicial constructions of the unchanged portions of the
statute and to have adopted them as consistent with its own
intent.”).
   33  See UTAH CODE § 34A-2-401(1)(a) (compensating “loss
sustained on account of . . . injury”); id. § 34A-2-401(1)
(compensating “[a]n employee . . . who is injured . . . wherever
such injury occurred”); id. § 34A-2-102(1)(j)(i) (including within
the scope of the act “an injury caused by the willful act of a third
person”); id. § 34A-2-105(1) (“The right to recover compensation
pursuant to this chapter for injuries sustained by an employee . . .
                                                             (cont.)

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“injuries”34 and not “injuries by accident.”35 Justice Himonas’s
focus on the “by accident” language mistakes the relevant
standard by conflating compensability with categorization. The
WCA states that it covers “injur[ies] by accident arising out of and
in the course of employment.”36 And as other states have
recognized when interpreting similar statutory schemes, the
WCA’s definition of its scope implicitly requires “threshold proof
of [injury]” as a “prerequisite to recovery.”37 It “assumes that the
employee suffers from [an ‘injury’] and focuses on whether the

is the exclusive remedy against the employer . . . .” (emphasis
added)).
   34 See, e.g., Wash. Cty. Sch. Dist. v. Labor Comm’n, 2015 UT 78,
¶ 1, 358 P.3d 1091 (discussing “the scope of the Utah Workers’
Compensation Act” as it related to “an initial workplace injury
and a subsequent non-workplace injury”).
   35 Our cases have long recognized that the “by accident”
language is only a “prerequisite[] for a finding of a compensable
injury,” not a description of the type of harms covered by the
WCA, as Justice Himonas has treated it. Murray v. Utah Labor
Comm’n, 2013 UT 38, ¶ 44, 308 P.3d 461 (describing the Workers’
Compensation Act as covering injuries and noting that the
“statute creates two prerequisites for a finding of a compensable
injury” (emphasis added) (citation omitted)); Allen, 729 P.2d at 18
(same); see also Salt Lake City v. Indus. Comm’n, 74 P.2d 657, 659
(Utah 1937) (“A mere accident does not impose the duty to pay.”).
   36   UTAH CODE § 34A-2-102(1)(j)(i); see also id. § 34A-2-401(1).
   37 See Noble, 512 N.W.2d at 294 (“[T]he statutory criteria upon
which [the claimant] relies presume the existence of a disease. The
factors cited relate solely to proof of causation. Were threshold
proof of disease not a prerequisite to recovery under [the ODA],
many disabilities arising from clearly traumatic injuries would
also meet [the ODA’s] requirements. Such a circumstance would
contravene the clear intent of [the WCA and ODA] to make
recovery under the two chapters mutually exclusive.”).

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[injury] is causally connected to workplace conditions”38 and is
“by accident.”39
    ¶ 96 Because the WCA’s scope is tied to the existence of an
“injury,” the statutory definition of the act’s scope is incomplete.
It presumes the existence of an injury and discusses only the
requirements for an injury to be compensable—that it be “by
accident” and “aris[e] out of and in the course of employment.”40 I
believe the proper way to resolve this issue is to use our usual
tools of statutory interpretation to interpret the key term “injury.”
And because the legislature has not indicated that the term
“injury” should be understood in a technical way, we should rely
on our usual plain language approach to interpret “injury”
according to its ordinary meaning.41

   38   Duvall, 621 N.E.2d at 1125.
   39   UTAH CODE § 34A-2-102(1)(j)(i).
   40 Id.; see Noble, 512 N.W.2d at 294 (“The commissioner wisely
observed that the statutory criteria upon which [the claimant]
relies presume the existence of a disease. The factors cited relate
solely to proof of causation.”).
   41  Justice Himonas claims this approach involves “splitting a
singular phrase into separate parts and applying disparate models
of statutory interpretation to each.” Supra ¶ 50. But our cases have
not “consistently” treated the words “injury by accident” as a
“singular phrase.” Supra ¶ 50. To the contrary, we have often
analyzed the words “by accident” in isolation. See Specialty Cabinet
Co., 734 P.2d at 439 (“These cases . . . both involve the troublesome
problem of determining whether internal failures satisfy the ‘by
accident’ standard of [Section 34A-2-401].”); Allen, 729 P.2d at 22
(“[W]here either the cause of the injury or the result of an exertion
was different from what would normally be expected to occur, the
occurrence was unplanned, unforeseen, unintended and therefore
‘by accident.’”); Hone v. J.F. Shea Co., 728 P.2d 1008, 1011 (Utah
1986) (“Whether the claimant had a preexisting condition is
relevant to the issue of causation, but is not determinative of
whether the injury occurred ‘by accident.’”). Indeed, the text of
Utah Code section 34A-2-401(1) is inconsistent with the notion
that “injury by accident” constitutes a “singular phrase.” It
                                                                (cont.)

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   ¶ 97 Ultimately, because the scope of the WCA is not defined
by the term of art “by accident,” an analysis of that term of art is
simply irrelevant to the threshold issue we decide today—which
compensation act applies to Ms. Rueda’s harm. Only after the

provides that “[a]n employee described in Section 34A-2-104 who
is injured and the dependents of each such employee who is
killed, by accident arising out of and in the course of the
employee’s employment, wherever such injury occurred, if the
accident was not purposely self-inflicted, shall be paid” certain
compensation. Notably, the terms “injur[y]” and “by accident” are
separated by ten words, the “by accident” term appears in a
phrase that is set off by commas, and the word “injury” appears a
second time unaccompanied by the words “by accident.”
    Justice Himonas also argues that cases from other jurisdictions
“that apply a plain language analysis do not split the phrase
‘injury by accident’ or ‘accidental injury’ and apply different
interpretive models to each part.” Supra ¶ 50 n.17. But a review of
cases from those states reveals the opposite is true. These courts
have assessed whether a harm is properly categorized as an
“injury” or a “disease,” according to the plain meaning of those
terms, separately from whether the harm occurred “by accident,”
treating the phrase “by accident” as a legal term of art. See Duvall,
621 N.E.2d at 1125–27 (analyzing whether carpal tunnel syndrome
is an “injury” or a “disease” separately from whether it is “by
accident,” entitling the claimant to compensation); Pee, 543 S.E.2d
at 236 (noting, after separately assessing whether the harm in
question was a disease or an injury, that “[t]o be compensable
under the [Workers’ Compensation] Act, the injury must be an
‘injury by accident arising out of and in the course of the
employment’”) (emphasis added) (citation omitted); Luttrell, 507
N.E.2d at 541–42 (noting, separately from any discussion of the
“accidental” nature of the injury, that “it is quite generally
recognized that an ‘injury’ is distinguished from a ‘disease’ by
virtue of the fact that an injury has its origin in a specific,
identifiable trauma or physical occurrence or, in the case of
repetitive trauma, a series of such occurrences. A disease, on the
other hand, originates from a source that is neither traumatic nor
physical . . . .”); Noble, 512 N.W.2d at 295 (quoting Luttrell in
explaining the distinction between an “injury” and a “disease”).

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threshold determination has been made that a harm is an “injury”
and covered by the WCA should we look to whether the injury
was “by accident” to determine whether that injury is
compensable. Justice Himonas’s approach, which relies on the
term of art “by accident” to define the scope of the WCA,
conflates the separate inquiries of categorization and
compensability. I turn now to a discussion of the ODA and the
definition of “disease.”
2. The ODA Covers “Diseases,” Not “Occupational Diseases”
    ¶ 98 The ODA covers “any disease or illness that arises out of
and in the course of employment and is medically caused or
aggravated by that employment.”42 As noted above, the WCA
covers “injur[ies],” but expressly excludes from its scope
“disease.”43 So the key term in determining the scope of the ODA
is “disease.”44

   42   UTAH CODE § 34A-3-103.
   43See id. § 34A-2-102(1)(j)(ii) (“‘[I]njury by accident arising out
of and in the course of employment’ does not include a disease.”).
   44  The statute defines an “occupational disease” as “any
disease or illness.” Because there does not appear to be a relevant
distinction between “disease” and “illness,” and due to the
WCA’s statutory exclusion of “diseases,” I will follow Justice
Himonas’s example and simply use the word “disease” to refer to
the harms excluded from the scope of the WCA and covered by
the ODA. See Illness, THE AMERICAN HERITAGE DICTIONARY OF THE
ENGLISH LANGUAGE (5th ed. 2011) (“1a. Poor health resulting from
disease of body or mind; sickness. b. A disease.”); Illness, BLACK’S
LAW DICTIONARY (10th ed. 2014) (“2. A disease of the body or
mind; disorder of health.”).
    Justice Lee argues that the canon of independent meaning
suggests that “illness” should be given a broad meaning so as to
add something that “disease” does not convey. Infra ¶ 180. But
that canon, like all canons, must yield to contrary indications in
the statutory scheme. Here, Justice Lee’s argument is that “illness”
should be read so broadly as to encompass “any malady” or any
“unhealthy condition of body or mind.” Infra ¶ 180. But this
interpretation suffers from the same deficiency as Justice
                                                              (cont.)

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  ¶ 99 Justice Himonas interprets this key term in both the
WCA45 and the ODA46 as incorporating the common law term of

Himonas’s approach—it threatens to permit the same type of
harm to fall within the purview of both the WCA and the ODA, a
result that, as I explain, is contrary to the legislature’s clear intent
to create two independent compensation schemes with no
overlap. For example, consider two employees who suffer lead
poisoning. The first is a painter who routinely uses lead paint at
work. The second is an office worker who comes in contact with a
tainted shipment of office supplies. Each suffers lead poisoning
from exposure to materials in the course of their work. According
to Justice Lee, the painter has suffered an occupational disease
and we must look to the ODA to determine the applicable
compensation, but the office worker has suffered an injury by
accident, which is to be evaluated under the WCA. The inequity
of this result is manifest, and it is not called for by the text of the
statutes. Justice Lee responds that his scheme “merely divides the
two acts on a ground that turns on the mechanism of causation.”
Infra ¶ 180 n.7. But what textual basis is there for dividing the acts
on that basis, where the WCA excludes “disease[s]” and the ODA
covers “any disease”? Because the distinction between the
schemes turns on whether the harm is a “disease,” it would seem
textually impermissible that two employees who suffer the same
ailment be compensated under different acts. Yet Justice Lee’s
approach would mandate just that result. My approach does not
simply “presume[] that the legislature divided the acts into
categories of harm”; rather, it is my view that “give[s] effect to the
legislative judgments expressed in the statute’s text,” where the
text uses the word “disease” to divide the scope of the statutes. Cf.
infra ¶ 180 n.7. It is Justice Lee who is forced to look beyond the
text to explain why the same bodily condition is sometimes a
disease, and sometimes not.
   45  See UTAH CODE § 34A-2-102(1)(j) (defining injury as
“includ[ing] an injury caused by the willful act of a third person”
but “not includ[ing] a disease, except as the disease results from
the injury”).
   46See id. § 34A-3-103 (defining an occupational disease as “any
disease”).

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art “occupational disease.” I agree that “occupational disease” has
historically been a technical term of art. I further agree that this
term of art was grafted into the WCA in the past, as discussed
more fully below. But I disagree as to the proper understanding of
the term of art and that the legislature intended to incorporate
Justice Himonas’s understanding of “occupational disease”—an
understanding based in pre-ODA caselaw—into either statute
after the enactment of the ODA in 1941. I believe that the ODA is
clear that the legislature has rejected the common law term of art
understanding of “occupational disease.” In addition, by
amending the ODA in 1991 to eliminate specifically identified
diseases from the definition of “occupational disease,” the
legislature jettisoned its previous statutory definitions of
“occupational disease.” As such, in place of our precedent’s term
of art understanding of “occupational disease” and its own
previous statutory definitions of the term, the legislature has
defined “occupational disease” to simply mean “any disease,” a
phrase that should be interpreted according to its plain meaning.
   a. The language of the ODA contradicts a term of art
      understanding of “occupational disease”
    ¶ 100 As Justice Himonas correctly articulates, when the
legislature has “invoke[d] specialized legal terms that carry an
extra-ordinary meaning[,] . . . we credit the legal term of art, not
the common understanding of the words.”47 But there must be
something in the statute or its history that “clearly show[s] that
the language was used in a sense different from its natural and
ordinary meaning.”48 Further, “when the construction of a section
involves technical words and phrases which are defined by
statute, the provision must be construed according to such
peculiar and appropriate meaning or definition.”49 Thus, if the
terms at issue are defined by statute in a way that differs from the
term of art meaning, we cannot rely on the non-statutory

   47   State v. Canton, 2013 UT 44, ¶ 28, 308 P.3d 517.
   48   Miles v. Wells, 61 P. 534, 536 (Utah 1900).
   49   Cannon v. McDonald, 615 P.2d 1268, 1270 (Utah 1980).

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understanding.50 Ultimately, a statutory definition of a word or
phrase trumps any differing term of art understanding. And as
discussed below, there is no indication in the language of these
statutes that the legislature intended to define the scopes of the
two acts using the term of art understandings of “by accident” or
“occupational disease” as suggested by Justice Himonas. Thus, we
should employ our traditional plain language approach.
   ¶ 101 The WCA states that “‘injury by accident arising out of
and in the course of employment’ does not include a disease.”51
Similarly, the ODA defines “a compensable occupational disease”
as “any disease.”52 It is telling that in neither statute, either at
present or at any point in the statutes’ histories, did the legislature
choose to use the actual term of art “occupational disease” to
define either compensation act’s scope.53 To paraphrase another

   50 See State v. Bagnes, 2014 UT 4, ¶ 13, 322 P.3d 719 (looking first
to whether a statutory term was defined by statute and, only after
finding no such definition, determining that “[w]e must
accordingly look elsewhere to derive its meaning—to either the
ordinary meaning of the word, or to its technical sense as a legal
term of art” (footnote omitted)).
   51   UTAH CODE § 34A-2-102(1)(j)(ii) (emphasis added).
   52  Id. § 34A-3-103 (emphasis added). Although the ODA
continues by stating that the disease must “arise[] out of and in
the course of employment and [be] medically caused or
aggravated by that employment,” these requirements go to the
issue of whether a particular disease would be compensable, not
whether a harm should be categorized at the first stage as either a
disease or injury.
   53 The WCA, since its enactment in 1917, has only referenced
“diseases.” It was this court that interpreted that reference as
“occupational disease.” The ODA, although it has always
provided compensation for “occupational diseases,” has also
always separately and specifically defined “occupational disease,”
either by reference to specific diseases or by using the general
term “disease,” thus showing no indication that the legislature
intended to rely on the term of art understanding to define the
ODA’s scope. And we have never, until today, interpreted the
                                                            (cont.)

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case in which we rejected reliance on a term of art definition to
interpret a phrase that was not the term of art:
         Had the Legislature intended a restrictive meaning
         it could have used the term of art [“occupational
         disease”] in place of the term [“disease”]. Unlike the
         term [“disease,”] a restrictive reading of the term
         of art [“occupational disease”] is supported by
         several cases where the term [“occupational
         disease”] is distinguished from [other diseases and
         injuries] . . . . 54
 Although it may be true that “occupational disease” has a long
history as being understood in a particular way in the caselaw of
both this state and our sister states, that caselaw is irrelevant
unless the legislature chooses to incorporate it.55 And here there is
no indication that “the language was used in a sense different
from its natural and ordinary meaning.”56
   ¶ 102 Justice Himonas fails to address this issue. He never
explains what statutory language leads him to conclude that by
specifically adopting the phrase “any disease” as the definition of
“occupational disease,” the legislature intended to adopt our term

general term “disease” as incorporating the term of art
understanding of “occupational disease.” Thus, at no point in the
two acts’ histories has the legislature relied on the term of art
“occupational disease” to define the two acts’ scopes.
   54 MacFarlane v. Utah State Tax Comm’n, 2006 UT 25, ¶ 15, 134
P.3d 1116 (bracketed words added in place of the phrases “income
tax,” a term of art, and “on income,” a phrase that was interpreted
to not incorporate the term of art understanding of “income tax”).
   55 See In re Estate of Hannifin, 2013 UT 46, ¶ 20, 311 P.3d 1016
(“By enacting a Probate Code with a specific definition of ‘child’
that excludes those ‘equitably’ adopted, the legislature preempted
common law doctrines that are in conflict with the results those
definitions require.”).
   56   Miles, 61 P. at 536.

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of art understanding of “occupational disease.”57 The closest
Justice Himonas comes to doing so is his focus on the causation
language found in section 34A-3-103, which states that an
occupational disease is compensable if it “arises out of and in the
course of employment and is medically caused or aggravated by
that employment.” Justice Himonas reads this language to define
an occupational disease as those harms that are “not unexpected”
and that “do[] not typically arise from a definite event.”58 I believe
this is a strained reading of the text for two reasons.
   ¶ 103 First, as with the WCA discussed above, the ODA’s
definition of “occupational disease” “assumes that the employee
suffers from a ‘disease’ and focuses on whether the disease is

   57 Justice Lee agrees with Justice Himonas’s view that the 1991
Utah legislature intended to adopt the pre-ODA term of art
understanding of “occupational disease” in amending the ODA.
Infra ¶¶ 178, 189. Accordingly, Justice Lee’s arguments overlap
with Justice Himonas’s in their inability to explain why the
legislature—after rejecting the common law term of art
understanding of “occupational disease” through the enactment
of the 1941 ODA—would decide, fifty years later, to adopt that
term of art understanding. Contrary to Justice Lee’s contention,
the common law understanding of “occupational disease” did not
“remain[] unaltered for many decades,” and it certainly never
became “deeply embedded in our law.” Infra ¶¶ 190–91. Rather,
the legislature rejected our court’s pre-ODA understanding of
“occupational disease” in 1941, and that previous understanding
has been lying abandoned ever since. Justice Lee offers no
explanation for why, in using the phrase “any disease” in the 1991
ODA amendments, the legislature intended to revive an
interpretation of the term “occupational disease” that had been
displaced fifty years earlier. Instead, he, like Justice Himonas,
conflates a statutory causation requirement—that the disease or
injury to health “can be seen to have followed as a natural
incident of the work as a result of the exposure occasioned by the
nature of the employment”—as being a limit on the scope of
harms that are to be assessed under the ODA, rather than simply
a limit on what is compensable under the ODA. See infra ¶ 189.
   58   Supra ¶ 42.

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causally connected to workplace conditions.”59 The statutory
definition requires “threshold proof of disease” as a “prerequisite
to recovery.”60 Thus, the language of causation provides no
insight as to what constitutes a disease, as it only tells us when a
harm that has already been categorized as a “disease” is
compensable. Once again, relying on the language of causation
conflates the threshold inquiry of categorization with the
secondary inquiry of compensability.
    ¶ 104 Second, even if we are to assume that this causation
language helps describe the statute’s scope, the language is in
large part repeated in the WCA to describe a compensable
injury.61 I see no basis to interpret the “arising out of” language in
the ODA as importing notions of an expected gradually occurring
condition while refusing to interpret the nearly identical language
of causation in the WCA to do the same. This contradicts our
normal approach of interpreting the same language in two closely
related statutes similarly.62

   59   Duvall, 621 N.E.2d at 1125.
   60 See Noble, 512 N.W.2d at 294 (“[T]he statutory criteria upon
which [the claimant] relies presume the existence of a disease. The
factors cited relate solely to proof of causation. Were threshold
proof of disease not a prerequisite to recovery under [the ODA],
many disabilities arising from clearly traumatic injuries would
also meet [the ODA’s] requirements. Such a circumstance would
contravene the clear intent of [the WCA and ODA] to make
recovery under the two chapters mutually exclusive.” (citation
omitted)).
   61  See UTAH CODE § 34A-2-401(1) (providing compensation to
any “employee . . . who is injured . . . by accident arising out of and
in the course of the employee’s employment” (emphasis added)).
   62 See Spring Canyon Coal Co. v. Indus. Comm’n, 277 P. 206, 211
(Utah 1929) (“[T]he same meaning will be given to a word or
phrase used in different parts of a statute.”); see also State v.
MacGuire, 2004 UT 4, ¶ 15, 84 P.3d 1171 (“[T]he plain language of
a statute is to be read as a whole, and its provisions interpreted in
harmony with other provisions in the same statute and with other
statutes under the same and related chapters.” (citation omitted));
                                                               (cont.)

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    ¶ 105 So although Justice Himonas criticizes my approach
for looking to the plain meaning of “injury,”63 I believe he has
failed to explain why our usual tools of statutory interpretation
are inadequate. Justice Himonas never explains why we must
assume that when the legislature said “any disease,” it really
meant to say “occupational disease.”64 To be sure, as I have
acknowledged, the legislature has instructed us to interpret
“technical words and phrases, and such others as have acquired a
peculiar and appropriate meaning in law, or are defined by
statute, . . . according to such peculiar and appropriate meaning or
definition.”65 But the term “any disease” has not acquired a term
of art understanding.
    ¶ 106 Indeed, by using the phrase “any disease” to define
“occupational disease,” the legislature has specifically adopted a
definition that directly contradicts the understanding in our
caselaw. As Justice Himonas states, our caselaw created a term of
art definition of “occupational disease,” defining the term as a

Masich v. U.S. Smelting, Ref. & Mining Co., 191 P.2d 612, 619 (Utah
1948) (“In passing to Section 42–1a–3, the Occupational Disease
Statute, attention is again directed to the fact that the wording
used by the legislature is exactly the same as the wording used in
the Accidental Injury Act, Section 42–1–57. This court, prior to the
enactment of the Occupational Disease Statute, having construed
the provisions of the Compensation Act to have abrogated the
common law rights of employees, we see no reason to place a
different interpretation on the same provision of the Occupational
Disease Act unless the legislature by clear and unmistakable
language has indicated a contrary interpretation. We find no such
language in the statutes.”).
   63   Supra ¶¶ 47–50.
   64 “[Justice Himonas’s] interpretation of the term ‘disease,’ as
used in [section 34A-3-103], gives it the same meaning as the term
‘occupational disease’ as generally used in our case law. [Justice
Himonas] is essentially defining the term ‘occupational disease,’
as used in [the ODA], by using the term ‘occupational disease.’”
Weyerhaeuser, 998 P.2d at 232 (Deits, C.J., dissenting).
   65   UTAH CODE § 68-3-11.

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“gradually developing condition[].”66 But the current statutory
definition of “occupational disease,” adopted in 1991, is simply
“any disease or illness.” There is no indication in the statute that
by “any disease,” the legislature intended “any gradually
occurring disease.” Indeed, such a reading requires us to ignore
the statutory definition and interpret the statutes to contradict
their plain meaning, which we cannot do.67
    ¶ 107 Ultimately, I see nothing in the language of either
statute that reveals a legislative intent to define the statutes’
scopes by incorporation of the common law understanding of the
term of art “occupational disease.” Because we presume that the
legislature is aware of legal terms and their meanings, it is wholly
inappropriate for us to “re-engraft[] by judicial decision” a term of
art meaning that the legislature has deliberately excluded.68
Accordingly, because the legislature has not revealed an intent to
adopt the common law understanding of “occupational disease,”
and has instead required that we define the term as “any disease,”
we should interpret the term “disease” using our traditional
approach to statutory interpretation and rely on the ordinary

   66 Supra ¶ 36 (quoting Carling v. Indus. Comm’n, 399 P.2d 202,
203 (Utah 1965)).
   67 See O’Keefe v. Utah State Ret. Bd., 956 P.2d 279, 281 (Utah
1998) (“A fundamental rule of statutory construction is that
statutes are to be construed according to their plain language. . . .
Furthermore, unambiguous language may not be interpreted to
contradict its plain meaning.”).
   68 Christensen v. Christensen (In re Estate of Christensen), 655 P.2d
646, 649 (Utah 1982) (“Even though ‘contemplation of marriage’
figured prominently in prior statutes and case law, the Uniform
Probate Code makes no mention of that legal requirement. In a
statute so carefully drafted, that omission must have been
deliberate. We think it would therefore be inappropriate for the
‘contemplation of marriage’ requirement to be re-engrafted by
judicial decision.”).

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meaning of the terms.69 This approach is only confirmed as we
look to the history of the ODA.
   b. The history of the ODA shows that a term of art approach was not
      intended by the legislature
    ¶ 108 Justice Himonas states that my approach creates a sea
change in the way we distinguish between the harms covered by
the WCA and those covered by the ODA, essentially overruling
decades of caselaw interpreting these statutes. I believe that my
framework correctly recognizes that “occupational disease” was a
term of art that had been given specific meanings over time by the
legislature. It is the legislature’s prerogative to change the
definition of “occupational disease,” and its choice to do just that
in 1991 effected the sea change in workers’ compensation in Utah.
    ¶ 109 As I discuss below, our caselaw correctly interpreted
the WCA to incorporate the term of art “occupational disease.”
Since that time, however, our muddled caselaw has generally
failed to recognize the impact of the legislature’s choice to define
and redefine that term of art through the years. The scope of the
WCA has not changed over time—it has always covered
“injuries,” and has never covered “diseases.” What has changed is
the scope of the statutorily mandated carve-out of “diseases.”

   69 Justice Lee argues that the legislature’s intent to adopt the
common law understanding of “occupational disease” can be
inferred from its “circular” definition of “occupational disease” as
“any disease.” Infra ¶ 188. According to this argument, this
circularity “emphasizes that the legislature is ‘convey[ing] its
acceptance of a term of art with a widely shared meaning.’” Infra
¶ 188 (quoting Hughes Gen. Contractors, Inc. v. Utah Labor Comm’n,
2014 UT 3, ¶ 14, 322 P.3d 712). But as I have discussed, Justice Lee,
like Justice Himonas, relies on the definition of “occupational
disease” contained in caselaw that predated the 1941 ODA, see
infra ¶ 189 (quoting Young v. Salt Lake City, 90 P.2d 174 (Utah
1939)—a definition that was expressly rejected by the original
1941 ODA. This alleged circularity therefore provides no
indication that the legislature intended to adopt the common law
definition of occupational disease that it had rejected in 1941 and
continued to reject in the intervening years.

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That carve-out depends on the definition of “occupational
disease,” which was first defined by this court and then defined
and redefined by the legislature in the ODA. Thus, any change to
the definition of “occupational disease” by the legislature—such
as the 1991 amendment to the ODA—necessarily requires a
change in how compensation cases are decided.
    ¶ 110 Therefore, our prior precedent, which interpreted prior
versions of the statutes, has been rendered irrelevant by the
legislature’s decision to change a fundamental aspect of the
statutes—the definition of a key term that determines the scopes
of the two statutory schemes. In addition, previous versions of the
ODA, which have given different definitions for the term
“occupational disease,” have likewise been rendered irrelevant.
Thus, we should not focus on defunct precedent or versions of the
ODA rendered inoperative by the legislature, but on the plain
language of the current version of the ODA.
    ¶ 111 The history of the ODA begins with the WCA. When
the WCA was first passed in 1917, it contained the same exclusion
of “diseases” that is at issue in this case.70 Our first few cases
dealing with the scope of the WCA struggled to understand what,
exactly, the legislature intended by this exclusion. We found it
clear that “occupational diseases”—a term of art consistent with
Justice Himonas’s definition of disease—were excluded.71 We
noted that other courts had interpreted similar statutory schemes
that excluded “diseases” as an exclusion of “occupational
diseases.”72 We concluded that “[s]uch obviously was also the
purpose of the Legislature of this state when disease was
excluded in the definition of injury by accident.”73 After we

   70   See COMPILED LAWS OF UTAH § 1-49-3112(5) (1917).
   71 See, e.g., Pinyon Queen Mining Co., 204 P. at 326; Young,
90 P.2d at 175–76.
   72See Pinyon Queen Mining Co., 204 P. at 326 (“The [Iowa] court
held that the manifest design of the General Assembly in
providing that the term ‘personal injuries’ should not include a
disease was to eliminate occupational diseases.”).
   73   Id.

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concluded that the exclusion of “disease” in the WCA covered at
least “occupational diseases,” there still remained the question of
whether other diseases, those not classified as “occupational
diseases” but still contracted in the course of employment, were
also excluded from the WCA.74 Our cases contained contrary
language,75 and the issue was not resolved until 1940.
   ¶ 112 In Andreason v. Industrial Commission, Mr. Andreason,
who worked for the Colorado By-Products Company “skinning
and butchering animals,” died from an “uncommon” disease
“acquired from contact with diseased animals or diseased meat.”76
We had to decide whether Mr. Andreason’s “non-occupational”
disease was covered by the WCA. Although we recognized that
the language of the statute suggested “that, unless infection set in
through some wound or abrasion in the skin acquired in the
course of one’s employment, the resultant disease could not be
considered an accidental injury,”77 we held that, based on “the
absurdity of making compensation depend[]”78 on whether the

   74 See Chase v. Indus. Comm’n, 17 P.2d 205, 208 (Utah 1932)
(“[T]he question of whether a disease contracted in the course of
employment is or is not compensable . . . . is an open one in this
jurisdiction.”).
   75  Compare id. (“The words . . . ‘[personal injury by accident]
shall not include a disease except as it shall result from the injury’
would seem to indicate a legislative intent that the contraction of a
disease to be compensable must be brought about by some injury
other than merely conveying disease germs to the employee.”
(second alteration in original)), with Pinyon Queen Mining Co., 204
P. at 326 (stating that “the purpose of the Legislature of this state”
in excluding “disease” from “the definition of injury by accident”
“was to eliminate occupational diseases”), and Young, 90 P.2d at
176 (“A disease contracted as a direct result of unusual conditions
connected with the work, and not as an ordinary or reasonably to
be anticipated result of pursuing the work, is to be considered an
accidental injury.” (citation omitted)).
   76   100 P.2d 202, 203–04 (Utah 1940) [Andreason I].
   77   Id. at 205.
   78   Id. at 205–06.

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disease was the result or cause of an injury,79 “a disease may be an
accidental injury” and thus compensable under the WCA.80 Thus
we settled that the WCA’s exclusion of “disease” meant
“occupational disease” and only “occupational disease.” And, at
the time, there was no statutory definition of “occupational
disease,” which led us to define “occupational disease” according
to the common law understanding of the term: “a diseased
condition arising gradually from the character of the employee’s
work.”81
    ¶ 113 Justice Himonas and I agree that we properly
interpreted “disease” in the WCA to mean “occupational disease.”
We also agree that, at least at the time, “occupational disease” was
to be understood by its common law term of art meaning. Where I
ultimately believe that Justice Himonas’s analysis comes up short
is that he has failed to recognize that the common law term of art
understanding of “occupational disease” that we adopted in these
early cases was superseded by the legislature’s enactment of the
ODA in 1941, and that the legislature, in 1991, rejected any prior
technical or statutory understanding of “occupational disease.”
    ¶ 114 When Andreason I was decided, there was no statutory
definition of “occupational disease,” so we relied on our judgment
and other jurisdictions’ caselaw to define it as a “gradually
developing condition.”82 The very next year, in 1941, the
legislature enacted the ODA, which defined “occupational
disease” as a specific list of twenty-seven ailments. In doing so,
the legislature did not alter the WCA’s exclusion of “diseases.”
“[W]here a legislature amends a portion of a statute but leaves
other portions unamended, or re-enacts them without change, the

   79   As the dissent in Andreason I described, a disease is
compensable under the statute if it results from an injury, but not
if the injury results from a disease. See id. at 206–07 (McDonough,
J., dissenting).
   80Andreason v. Indus. Comm’n, 102 P.2d 894, 895 (Utah 1940)
[Andreason II] (denying petition for rehearing).
   81   Young, 90 P.2d at 176 (citation omitted).
   82   See Carling, 399 P.2d at 203; Young, 90 P.2d at 175–77.

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legislature is presumed to have been satisfied with prior judicial
constructions of the unchanged portions of the statute and to have
adopted them as consistent with its own intent.”83 Accordingly,
we must presume that the legislature was both aware and
approved of our interpretation of “disease” as used in the WCA to
mean “occupational disease.”84
    ¶ 115 It is only logical, then, that by enacting the ODA and
including within it a specific definition of an “occupational
disease,” the legislature intended to replace our definition of that
term with its own. There was no indication at that time—and
there remains no indication today—that the understanding of
“occupational disease” incorporated into the WCA should be any
different than the definition of “occupational disease” found in
the ODA.85 I believe that by enacting the ODA in 1941 with a
specific definition of “occupational disease,” the legislature
superseded the common law understanding of “occupational
disease” with its own specific definition of that term of art.
   ¶ 116 This is made clear as we review the different versions
of the ODA. The original version of the ODA enacted in 1941
defined an “occupational disease” in section 28 of that Act as
twenty-seven specifically enumerated diseases, many of which

   83   Christensen, 642 P.2d at 756.
   84 It is true, as Justice Himonas notes, that the legislature never
defined “disease.” Supra ¶ 49. But as I explain, by not amending
the WCA after our construction that the word “disease” in the
WCA means “occupational disease,” the legislature can be
presumed to have embraced that interpretation. So when the
legislature subsequently included a definition of “occupational
disease” in the 1941 ODA as a specific list of twenty-seven
enumerated conditions, it was also necessarily defining the scope
of the word “disease” in the WCA to mean only that list of
conditions.
   85  See Grayson Roper Ltd. P’ship v. Finlinson, 782 P.2d 467, 471–72
(Utah 1989) (“[S]eparate parts of an act should not be construed in
isolation from the rest of the act and the terms of related code
provisions should be construed in a harmonious fashion.”
(citation omitted)).

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were diseases caused by poisoning from various compounds.86
Clearly, such a highly specific and narrow definition of
“occupational disease” did not invoke our pre-ODA caselaw’s
term of art understanding of “occupational disease.” Further, the
diseases listed in the ODA as defining “occupational disease” did
not match the common law understanding of “occupational
disease.” For example, the ODA covered poisoning by both
cyanide and chlorine.87 The harm resulting from either could
occur suddenly or develop gradually, depending on the extent of
exposure.88 Among the non-poisoning conditions covered by the
Act were anthrax and silicosis. Anthrax has rapid harmful
effects,89 while silicosis can have either abrupt or more gradual
effects.90 None of these conditions can be reasonably said to be
categorized as a disease by the legislature based upon whether
their onset was sudden or gradual, or whether they were expected
or unexpected. In fact, as described below, the legislature
specifically excluded consideration of whether a disease was
expected when determining whether an occupational disease was

   86   1941 Utah Laws 79.
   87   See id. at 83.
   88  See Facts About Cyanide, CENTERS FOR DISEASE CONTROL &
PREVENTION, https://emergency.cdc.gov/agent/cyanide/basics/
facts.asp (last visited July 21, 2017); Facts About Chlorine, CENTERS
FOR          DISEASE         CONTROL           &         PREVENTION,
https://emergency.cdc.gov/agent/chlorine/basics/facts.asp (last
visited July 21, 2017).
   89 See Type of Anthrax, CENTERS FOR DISEASE CONTROL &
PREVENTION, https://www.cdc.gov/anthrax/basics/types/
index.html (last visited July 21, 2017).
   90 Acute silicosis can potentially arise after exposure to a single
or limited number of extremely high concentrations of silica,
while chronic silicosis “occurs after 15–20 years of moderate to
low exposures to respirable crystalline silica.” See Fact Sheet,
Crystalline Silica Exposure Health Hazard Information,
OCCUPATIONAL        SAFETY     &      HEALTH        ADMIN.     (2002),
https://www.osha.gov/OshDoc/data_General_Facts/crystalline
-factsheet.pdf.

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compensable. Thus, the legislature had unmistakably supplanted
the common law understanding of “occupational disease” with its
own definition.
    ¶ 117 It is worth noting that in two other separate sections of
the original ODA, 13 and 27, the legislature made compensation
depend on whether the employee became totally disabled91 and
whether there was a sufficient causal connection between the
work and the disease.92 So the compensability requirements—i.e.,
causation—were considered separate and distinct from the
definition of “occupational disease,” meaning the legislature did
not intend for causation to operate as the definition of
“occupational disease.” But even if the causation language is
treated as part of the definition of “occupational disease”—as
Justice Himonas’s approach requires—the statute’s discussion of
causation contained no language referencing a “gradually
occurring condition” and expressly rejected consideration of
“expectedness” by stating that “[t]he disease need not have been
foreseen or expected.”93 Thus, no matter which way you approach

   91  1941 Utah Laws 83–84 (imposing “upon every employer a
liability for the payment of compensation to every employee who
becomes totally disabled by reason of an occupational disease”
and defining the twenty-seven occupational diseases).
   92 See id. at 83 (“The occupational diseases hereinafter defined
shall be deemed to arise out of the employment, only if there is a
direct causal connection between the conditions under which the
work is performed and the occupational disease, and which can
be seen to have followed as a natural incident of the work as a
result of the exposure occasioned by the nature of the
employment, and which can be fairly traced to the employment as
the proximate cause, and which does not come from a hazard to
which workmen would have been equally exposed outside of the
employment. The disease must be incidental to the character of
the business and not independent of the relation of employer and
employee. The disease need not have been foreseen or expected
but after its contraction it must appear to have had its origin in a
risk connected with the employment, and to have flowed from
that source as a natural consequence.”).
   93   Id.

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the issue, the original version of the ODA rejected the common
law term of art understanding of “occupational disease.”
    ¶ 118 The legislature then amended the ODA in 194994 to
cover the same twenty-seven diseases as well as a catch-all for
“other diseases or injuries to health.”95 The statute stated that
these other diseases “shall be compensable only in those instances
where it is shown” that they “directly ar[o]se as a natural incident
of the exposure occasioned by the employment,” which required
the claimant to satisfy six separate elements, each of which related
to causation.96 Justice Himonas contends that “the 1991
amendment to the Occupational Disease Act served primarily to
simplify the Act and is closely aligned to the 1949 version,” which
he argues incorporated the common law term of art meaning of
“occupational disease.”97
    ¶ 119 But the 1991 amendments make no reference to the
prior six-part test that was part of the 1949 definition of
“occupational disease.” The 1991 amendments also eliminate
reference to the twenty-seven specifically enumerated diseases,
instead defining “occupational disease” to mean “any disease or
illness.”98 In making these changes, the legislature gave no
indication that it intended to use either the common law term of
art meaning of “occupational disease” or its own prior definitions
of that term.99 The practical effect of the legislature’s failure to

   94This version of the statute would last until the 1991
amendments, which are at issue today.
   95   UTAH CODE § 35-2-27(28) (1953).
   96   See id.
   97   Supra ¶ 49.
   98   UTAH CODE § 34A-3-103.
   99  Justice Himonas argues that the legislative history of the
1991 amendments does not reveal “an intention to discard the
term of art approach.” Supra ¶ 52. But that is not the right
question. The first question we must ask is whether we can find
legislative intent to incorporate a special meaning, before we can
ask whether there is evidence of intent to discard one. But even if
we were to begin the search by looking for an intent to reject the
                                                             (cont.)

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adopt the term of art meaning in 1941, 1949, and 1991 is that we
must engage in a plain language analysis to determine what
constitutes a “disease” under the ODA.100 A plain meaning
analysis is the first tool in our statutory interpretation toolbox,
and there is little reason to believe the legislature would assume
that we would ignore it here.
    ¶ 120 The current version of the ODA provides an
incomplete definition for “disease,” defining the term solely in
terms of causation while presupposing the existence of a
“disease.” This incomplete definition requires us to employ our
usual tools of statutory interpretation to define “disease,”
beginning with a plain language approach. And because there is
no indication in the language of the 1991 ODA (or, as discussed
above, of the 1949 ODA) of any legislative intent to adopt our
caselaw’s term of art understanding of “occupational disease,”
there is no indication that the legislature ever intended a meaning
of “disease” that differed from the ordinary meaning of that term.
In summary, previous statutory and caselaw definitions of

common law term of art meaning, as I have explained, we can
easily find that intent in the text of the 1941 ODA. See supra ¶ 117
& nn.91–93 (explaining that the 1941 ODA expressly stated that
“[t]he disease need not have been foreseen or expected”). Because
the legislature had so long ago rejected the common law
understanding of this term, the presence or absence of an intent to
discard that understanding in the 1991 legislative history is
simply irrelevant. It really should come as no surprise that the
legislature expressed no such intent to discard, because it had no
occasion to do so.
   100 Because the legislature never indicated an intent to adopt
our common law understanding with any of these iterations of the
statute, my approach is not, as Justice Himonas asserts,
“ultimately moored to the 1991 amendments” to the ODA. Supra
¶ 46 n.16. My point is that for us to properly elevate the term
“occupational disease” to a term of art and give it the particular
meaning it had acquired in our caselaw before 1941, there must be
some legislative indication to incorporate that special meaning.
And I simply cannot see any, and neither Justice Himonas nor
Justice Lee identifies any.

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“occupational disease” were rendered inoperable by the 1991
ODA.
   ¶ 121 Further, even if Justice Himonas is correct that the
causation language should be read as defining “occupational
disease,” a point I disagree with, then the legislature’s rejection of
the common law term of art understanding of “occupational
disease” is even more apparent. The legislature created a highly
specific six-part test for causation that was taken nearly word for
word from the causation requirements found in the original
version of the ODA enacted in 1941. These requirements, as
discussed above, contained no language referencing a “gradually
occurring condition” and expressly rejected consideration of
“expectedness” by stating that the disease “need not have been
foreseen or expected.”101 So even using Justice Himonas’s reliance
on the language of causation to define the scope of the ODA, I can
only conclude that the legislature again rejected the pre-ODA
common law term of art understanding of “occupational disease.”
    ¶ 122 Ultimately, I see no legislative intent to codify the pre-
ODA term of art meaning of “occupational disease” in either of
the prior iterations of the ODA. The legislature’s enumeration of
certain diseases and later provision of a catch-all did not
encompass the common law term of art understanding espoused
by Justice Himonas. In fact, under Justice Himonas’s logic, the
legislature’s discussion of causation directly and specifically
excluded incorporation of the term of art. The legislature’s
rejection of the common law term of art has only continued in the
current version, when in 1991 it scrapped the twenty-seven
conditions and the more general catch-all. By simply defining
“occupational disease” as “any disease or illness,” it again rejected
any technical definition of “occupational disease.” Previous
iterations of the ODA and our precedent are no longer good law.
The legislature discarded those approaches to compensation for
occupational diseases. We should thus look solely to the plain
language of the current version of the ODA when applying its
provisions. For the reasons discussed above, I believe that the
term “disease” as used in both the ODA and WCA should not be
viewed as having incorporated the term of art understanding of

   101   UTAH CODE § 35-2-27(28) (1953).

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“occupational disease.” Because the legislature superseded the
common law understanding of “occupational disease” by
adopting a statutory definition of the term, our cases that relied
on that common law understanding are no longer viable, and we
should no longer rely on cases interpreting prior versions of the
statutes.102 No term of art understanding should apply when the
legislature has specifically defined the term. And the 1991
amendments to the ODA make clear that the legislature has
rejected any prior technical or statutory understanding of
“occupational disease.” Now, it simply means “disease.” Without
a more technical or statutory definition of the term “occupational
disease,” what we are left with is the plain meaning.
    ¶ 123 Justice Himonas argues that my approach “has the
perverse implication” of “narrowing” the definition of
“occupational disease,” because my approach would, according to
Justice Himonas, exclude bursitis—a condition specifically listed
in previous versions of the ODA.103 Even if my approach were to
have the effect of eliminating bursitis from the ODA, there is

   102 I admit that Justice Himonas’s approach better aligns with
our caselaw, but I believe that that the legislature’s intent, as
expressed in its amendment to the text of the statute, supersedes
our prior cases and renders them wholly irrelevant. The scope of
the WCA has always depended on the statutory exclusion of
“disease.” The legislature has no duty to comport with our
precedent defining that term and is free to redefine it as it deems
appropriate. As part of our duty to adhere to the legislature’s
intent, we read and interpret statutes in harmony with each other,
especially when they are as intertwined as the WCA and ODA.
An interpretation of the ODA—including the legislature’s most
recent    amendments         thereto—necessarily    implicates   an
interpretation of the WCA, because the ODA’s definition of
“occupational disease” determines what constitutes a “disease”
for purposes of the WCA. So a change to the ODA may require a
change to our understanding of the WCA. This is what I believe
happened with the 1991 ODA amendments. Our best tool for
performing the work of following the legislature’s intent,
especially in this context, is a plain language approach.
   103   Supra ¶ 54.

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nothing “perverse” about removing from the scope of the ODA a
condition that is not, according to common understanding, a
“disease.” The elimination of bursitis from the ODA is the result
of the legislature’s decision to jettison bursitis, along with the
other specifically enumerated harms found in prior versions of the
ODA. Contrary to Justice Himonas’s suggestion, nothing indicates
that bursitis is a “core disease.”104 Simply because the legislature
chose to define “occupational disease” to include bursitis in a
prior version of the ODA does not mean that it is a “core disease.”
In fact, a more logical inference to draw from the legislature’s
decision to jettison the list—bursitis included—is that upon
further consideration it may not have considered all of the items
on that list to be occupational diseases.
    ¶ 124 To summarize my discussion of the WCA and ODA,
the terms of the WCA and ODA require us to distinguish between
“injuries” and “disease,” an approach that aligns with the course
taken by other states.105 And whether a harm is an “injury” or
“disease” is a threshold inquiry as to which statute applies. The
phrase “by accident”—a term of art that has specific meaning in
the context of workers’ compensation schemes—does not define
what an “injury” is and thus does not guide us in determining the
scope of the WCA. Instead, it only informs us as to whether a
harm categorized as an “injury” is compensable. Relatedly, the
common law term of art understanding of “occupational disease”
has long been superseded by the legislature, has no basis in the
language of any version of the ODA, and thus has no relevance to
the issue we decide today, leaving us with only the term
“disease.” And we should not define that term by looking to
previous versions of the ODA. By enacting the 1991 ODA, the
legislature continued to reject our common law term of art
definition of “disease” and also jettisoned its own effort to define
that term by enumerating twenty-seven specific diseases covered

   104   Supra ¶ 54.
   105 See, e.g., Luttrell, 507 N.E.2d at 541–42 (using a plain
language approach to describe how “‘injury’ is distinguished
from a ‘disease’” for purposes of statutory schemes similar to
Utah’s); Duvall, 621 N.E.2d at 1124–26 (same); Noble, 512 N.W.2d
at 294–95 (same); Pee, 543 S.E.2d at 234–37 (same).

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under the Act. Now, we should, as with any other statute, focus
on the plain language of the current version of the ODA.
    ¶ 125 Justice Himonas’s focus on these terms of art stems
from his reliance on cases that either pre-date the ODA or failed to
consider the legislative intent in enacting a specific definition of
“occupational disease.” His attempt to reconcile this caselaw,
while understandable, is in my opinion misplaced in light of the
legislature’s amendment to the ODA. We simply cannot look to
past cases’ interpretations of the ODA or the WCA to understand
what the legislature intended by redefining the fundamentally
key term “occupational disease” when the legislature has, by the
plain language of the statute, repudiated those cases’
interpretations.
    ¶ 126 Thus, in my view, it is neither the timing of the harm,
nor its unexpectedness—factors derived from the common law
term of art understandings of “accident” and “occupational
disease”—that determine whether a harm is an injury or a disease.
We should not focus on our prior caselaw’s discussion of what
constitutes an “accident” in order to describe how an “accident”
differs from an “occupational disease,” because those terms of art
are not relevant to the threshold question of which compensation
scheme applies and only confuse the issue we must decide.
Instead, we should focus on the terms that define the statutes’
scopes, “injury” and “disease,” and interpret them according to
their ordinary meaning.
         II. The Plain Language of the Statutes Provides Clear
              Guidelines and Requires that We Categorize
                    Ms. Rueda’s Harm as an “Injury”
   ¶ 127 As noted above, in employing a plain language
approach to the threshold question of how we distinguish a
“disease” from an “injury,” I would join the majority of states that
have addressed this issue. Four states, Illinois,106 Indiana,107

   106See Luttrell v. Indus. Comm’n, 507 N.E.2d 533, 541–42 (Ill.
App. Ct. 1987).
   107See Duvall v. ICI Ams., Inc., 621 N.E.2d 1122, 1124–26 (Ind.
Ct. App. 1993).

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Iowa,108 and South Carolina,109 used a plain language approach to
determine the difference between an “injury” and a “disease.”
Each court recognized that an “injury” is commonly understood
as related to or synonymous with “trauma.”110 They noted that
“none of the commonly understood meanings for the word
‘disease’ trace the cause of disease to a trauma”111 and concluded
“that a disease is commonly understood to result when the body
is invaded by outside agents such as bacteria, virus, poison, toxin,
or germs.”112 Thus, as the Illinois court stated:
         In this regard, it is quite generally recognized that an
         “injury” is distinguished from a “disease” by virtue
         of the fact that an injury has its origin in a specific,
         identifiable trauma or physical occurrence or, in the
         case of repetitive trauma, a series of such
         occurrences. A disease, on the other hand, originates

   108   See Noble v. Lamoni Prods., 512 N.W.2d 290, 294–95 (Iowa
1994).
   109 See Pee v. AVM, Inc., 543 S.E.2d 232, 234–37 (S.C. Ct. App.
2001), aff’d, 573 S.E.2d 785 (S.C. 2002).
   110 See Luttrell, 507 N.E.2d at 541–42 (“[I]t is quite generally
recognized that an ‘injury’ is distinguished from a ‘disease’ by
virtue of the fact that an injury has its origin in a specific,
identifiable trauma or physical occurrence or, in the case of
repetitive trauma, a series of such occurrences.”); Duvall, 621
N.E.2d at 1126 (“Thus, by definition, the term trauma is
synonymous with injury, and the cumulative effect of more than
one trauma is likewise an injury.”); Noble, 512 N.W.2d at 295
(agreeing that an injury results from “external traumatic forces”);
Pee, 543 S.E.2d at 235–36 (agreeing with other courts that injury is
synonymous with trauma).
   111   Pee, 543 S.E.2d at 235; see also Noble, 512 N.W.2d at 295.
   112Noble, 512 N.W.2d at 294–95; see also Luttrell, 507 N.E.2d at
542 (“A disease, on the other hand, originates from a source that is
neither traumatic nor physical . . . .”); Duvall, 621 N.E.2d at 1125
(holding that an occupational disease results from “exposure to
workplace conditions”).

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         from a source that is neither traumatic nor
         physical . . . .113
Each of the courts relied on this plain language approach to
conclude that carpal tunnel syndrome, a condition not unlike
Ms. Rueda’s in that it stems from repetitive stress or trauma over
a long period of time, could not be classified as a disease, but was
rather an injury for purposes of compensation.
    ¶ 128 I believe that these courts’ analysis is persuasive, as it
comports with my own review of dictionary definitions of the
terms “injury” and “disease,” and should be adopted in Utah. As
we have often noted, dictionary definitions are helpful as a
starting point in describing the range of meanings a term may
have.114 Of course, this range of dictionary meanings is not
conclusive in and of itself as it “often fail[s] to dictate ‘what
meaning a word must bear in a particular context,’” thus requiring
us to “select[] the best meaning among a range of options, based
on other indicators of meaning.”115
  ¶ 129 “Injury” is defined broadly, encompassing all harm or
damage,116 and is closely related to “trauma.”117 Thus, an “injury”

   113   Luttrell, 507 N.E.2d at 541–42.
   114   State v. Canton, 2013 UT 44, ¶ 13, 308 P.3d 517.
   115   Id. (citations omitted).
   116 See Injury, THE AMERICAN HERITAGE DICTIONARY OF THE
ENGLISH LANGUAGE (5th ed. 2011) (“Damage or harm done to or
suffered by a person or thing”); Injury, MERRIAM-WEBSTER ONLINE,
https://www.merriam-webster.com/dictionary/injury           (last
visited July 21, 2017) (“hurt, damage, or loss sustained”).
   117 See Trauma, THE AMERICAN HERITAGE DICTIONARY OF THE
ENGLISH LANGUAGE (5th ed. 2011) (“Serious injury to the body, as
from physical violence or an accident”); Trauma, MERRIAM-
WEBSTER               ONLINE,                https://www.merriam-
webster.com/dictionary/trauma (last visited July 21, 2017) (“an
injury (such as a wound) to living tissue caused by an extrinsic
agent”); Trauma, WEBSTER’S THIRD NEW INTERNATIONAL
DICTIONARY (1961) (“an injury or wound to a living body caused
by the application of external force or violence”).

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is a condition that results from physical trauma.118 The word
“disease” has both a broad and a more narrow definition. Its
broad definition suggests that any abnormal or injurious
condition would qualify as a disease.119 Its more narrow definition
focuses on conditions resulting not from trauma, but from other
sources, such as exposure to environmental hazards (e.g., poisons,
toxins, or radiation), the invasion of foreign infectious agents (e.g.,
bacteria or viruses), or inherent biological or genetic defects.120

   118 This definition of “injury” is sufficiently broad to capture a
category of harms—referred to as “internal failures”—that our
precedent has consistently treated as falling within the WCA’s
scope, so long as these failures are coupled with an identifiable
physical trauma. See Allen v. Indus. Comm’n, 729 P.2d 15, 18 n.3
(Utah 1986); cf. infra ¶ 195. These harms, which include “heart
attacks, hernias, and back injuries,” constitute injuries if they
result from identifiable physical trauma acting upon the body.
   119     See       Disease,     MERRIAM-WEBSTER           ONLINE,
https://www.merriam-webster.com/dictionary/disease              (last
visited Aug. 11, 2017) (“[A] condition of the living animal or plant
body or one of its parts that impairs normal functioning and is
typically manifested by distinguishing signs and symptoms[.]”);
Disease, BLACK’S LAW DICTIONARY (10th ed. 2014) (“[s]pecial
classes of pathological conditions with similar traits, such as
having similar causes and affecting similar organs”).
   120 See Disease, THE AMERICAN HERITAGE DICTIONARY OF THE
ENGLISH LANGUAGE (5th ed. 2011) (“An abnormal condition of a
part, organ, or system of an organism resulting from various
causes, such as infection, inflammation, environmental factors, or
genetic defect, and characterized by an identifiable group of signs,
symptoms, or both.”); Disease, WEBSTER’S THIRD NEW
INTERNATIONAL DICTIONARY (1961) (“an impairment of the normal
state of the living animal or plant body or of any of its
components that interrupts or modifies the performance of the
vital functions, being a response to environmental factors (as
malnutrition, industrial hazards, or climate), to specific infective
agents (as worms, bacteria, or viruses), to inherent defects of the
organism (as various genetic anomalies), or to combinations of
these          factors”);        Disease,         DICTIONARY.COM,
                                                             (cont.)

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Within the context of the WCA and ODA, it is clear that the more
narrow definition of “disease” was intended by the legislature.
    ¶ 130 Because the definition of “injury” is broad, with no
narrower understanding of the term than “damage or harm,” a
broad definition of “disease” would lead to substantial overlap
between the statutes. And as the ODA was and is intended to
cover the subset of harms not already covered by the WCA, the
legislature would not have intended “disease” to be understood
as essentially synonymous with “injury.” Thus, I agree with the
courts discussed above that a “disease” is to be understood
narrowly, not as those conditions that result from physical trauma
or force, but rather those that would ordinarily be understood as a
disease, which often result from exposure to environmental
hazards and foreign agents, such as bacteria, viruses, other germs,
poisons, and toxins, or from inherent biological or genetic
defects.121 An injury would be those harms experienced as a result
of trauma, whether the trauma occurs all at once or over time.

http://www.dictionary.com/browse/disease (last visited Aug.
11, 2017) (“1. a disordered or incorrectly functioning organ, part,
structure, or system of the body resulting from the effect of
genetic or developmental errors, infection, poisons, nutritional
deficiency or imbalance, toxicity, or unfavorable environmental
factors; illness; sickness; ailment. 2. any abnormal condition in a
plant that interferes with its vital physiological processes, caused
by     pathogenic      microorganisms,      parasites,  unfavorable
environmental, genetic, or nutritional factors, etc.”).
   121 The ODA’s recognition that compensation is available for
“[p]hysical, mental, or emotional diseases related to mental stress
arising out of and in the course of employment” does not
contradict my proposed understanding of disease. UTAH CODE
§ 34A-3-106(1) (emphasis added). Cf. infra ¶ 181. Mental and
emotional diseases can easily be viewed as falling within the
larger category of all diseases, because they are understood in
common usage to be “diseases,” and because they share the
common trait of having an origin not based in physical trauma. It
is thus completely consistent with my view that the legislature
chose to include within the scope of the ODA mental and
emotional diseases alongside other ailments that similarly do not
                                                            (cont.)

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    ¶ 131 It is worth emphasizing that in none of the
understandings of “injury” or “disease” discussed above is the
unexpectedness of a harm or the time a harm takes to manifest a
defining feature. Indeed, the common understanding of “disease”
is that it can occur by sudden onset, or it can develop gradually.
So too with an injury. And a disease may be every bit as
unexpected as an injury. As discussed above, the original version
of the ODA defined “occupational disease” by listing specific
ailments that both would be commonly understood as diseases
and could occur gradually or suddenly, expectedly or
unexpectedly. Thus, the distinction between “injuries” and
“diseases” cannot be based on the expectedness of the harm, the
discreteness of incidents giving rise to the harm, or the time it
takes for a harm to emerge.
    ¶ 132 So in my view, our threshold inquiry should focus on
whether the ultimate harm at issue is an injury or a disease. An
“injury” is the result of trauma, whether great or small, repeated
or singular. A “disease,” on the other hand, is a non-traumatic
harm, which includes those conditions that typically emerge as
the result of exposure to environmental hazards or foreign
agents.122 Only after this categorization has been made would we

arise out of physical trauma. Justice Lee suggests that my
approach entails “two different dividing lines,” infra ¶ 181 n.8, but
in reality, these are just two sides of the same coin. Conditions
that are commonly understood as diseases do not arise from
physical trauma and often, though not always, involve the
etiologies—e.g., foreign agents or inherent defects—that I
describe.
   122 Although the term “disease” as used in the ODA would
encompass those conditions that emerge both from exposure to
environmental factors or foreign agents as well as those that arise
as a result of inherent biological or genetic defects, the latter
group—inherent defects—is far less likely to be compensable. For
example, the various forms of cancer would certainly be
categorized as “diseases” because they result not from trauma,
but from exposure to environmental hazards or inherent defects.
But this classification does not mean that the cancer will
ultimately be compensable; the employee must still prove the
                                                            (cont.)

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look to the questions of compensability—e.g., whether the injury
was “by accident”123 or whether the disease was “medically
caused or aggravated by that employment.”124 As discussed
above, while these issues of causation define whether an injury is
compensable under the WCA or a disease is compensable under
the ODA, the primary distinction between the WCA and the ODA
is whether the harm at issue is an injury or a disease. Justice
Himonas’s framework, focusing on the difference between
“accidents” and “occupational diseases” as discussed above,
conflates these two separate inquiries.
    ¶ 133 For the reasons discussed above, we should interpret
these two statutory schemes such that the WCA remains the
default compensation statute, covering all “injuries,” including
those that emerge over time, and excluding only “diseases”—
which are covered by the ODA—as the statute requires. The
statutory scheme makes clear that a particular type of harm
cannot be both a “disease” and an “injury.” Because prior cases
interpreting “occupational disease” are no longer relevant, and
because previous versions of the ODA no longer define the scope
of the current statutory scheme, we should use our traditional
method of statutory interpretation and define “disease” in the
current version of the ODA using its ordinary meaning. Thus,
those conditions that are commonly understood as diseases are
the only harms excluded from the WCA and covered by the
ODA.125

necessary causal link between the employment and the disease.
Thus, though something like cancer may be considered a disease
at the threshold level, it will only be compensated to the extent the
employee can show that it resulted from employment, which will
be easiest in cases where there is a specific environmental hazard
or foreign agent causing the cancer.
   123   UTAH CODE § 34A-2-401(1).
   124   Id. § 34A-3-103.
   125 As JBS states in its opening brief, “[t]he current expansive
interpretation of the Workers’ Compensation Act allows
compensation to be paid to workers for any condition, no matter
how incurred, where the requisite causal connection to the
                                                             (cont.)

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    ¶ 134 Now it must be said that this approach may not yield
completely satisfying results in every case. But any problematic
distinction arises from the legislature’s inequitable and
unexplained decision to compensate injuries caused by
employment more favorably than diseases caused by
employment. Any test we could devise would necessarily involve
some inequitable distinctions and difficulties in line-drawing. It
would certainly seem a better and more rational approach to
compensate injuries in the same way as diseases, as many other
states have done, but that is a matter for the legislature, not this
court. I join Justice Himonas’s suggestion that the legislature
should revisit these statutes in order to resolve the confusion and
inequity inherent in drawing lines between the WCA and ODA.126
I would note that, because of these inequities, in a borderline case
where the harm could reasonably be categorized as either an
injury or a disease as those terms are commonly understood, I
would favor categorizing the harm as an injury in order to
provide the harmed worker the most coverage possible.127

workplace can be shown.” JBS criticizes this approach for
“render[ing] inoperative, or at minimum, greatly minimiz[ing] the
need for and applicability of the [Occupational Disease] Act.” I see
it differently. Though I agree that the scope of the WCA is indeed
broad, based on its use of the term “injury” to define its scope,
because the WCA carves out “diseases” from its definition of
injury, there exists a set of harms that are not covered under the
WCA, creating a coverage gap for harmed workers. The ODA
covers that gap by providing compensation for diseases. And by
interpreting the ODA to cover only diseases, as I suggest, we avoid
expanding the ODA to encroach upon the set of harms already
covered by the more worker-friendly WCA.
   126   Supra ¶ 43.
   127 When we face a question of whether an employee should
receive compensation at all, “any doubt respecting the right to
compensation [is resolved] in favor of [the] injured employee.”
Salt Lake City Corp. v. Labor Comm’n, 2007 UT 4, ¶ 16, 153 P.3d 179.
The inequity inherent in the interplay of these statutes suggests to
me that we should extend this policy to circumstances where
                                                              (cont.)

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    ¶ 135 Further, although there may be some initial
uncertainty under my approach, over time it will lead to clear
categories of “injuries” and “diseases.” As cases begin to establish
what harms qualify as an injury or disease, both workers and
employers will have clear expectations as to what compensation is
available.128 I believe this is a better approach both as a matter of
statutory interpretation, as discussed above, and as a matter of
efficiency and predictability. It establishes bright-line categories
instead of Justice Himonas’s multi-factor test, which necessarily
requires a case-by-case evaluation.
   ¶ 136 Justice Himonas expresses doubt over the bright-line
nature of my approach,129 but the experience of other courts
reveals that the plain language approach leads to consistent
results over time. For example, as discussed above, courts that
have adopted a plain language approach have consistently
categorized carpal tunnel syndrome as an injury.130 This suggests

there is doubt as to whether a harm is properly understood as a
“disease” or an “illness.”
   128 Justice Lee agrees with the notion that our decision in this
case should be one that furthers clarity and predictability in this
historically convoluted area of the law. Yet he argues that the
standard I propose is impermissible because it would frustrate
“settled reliance interests” in this area. Infra ¶ 193. This criticism is
at odds with Justice Lee’s own recognition that “[t]he law in this
area is in disarray and in need of overhaul.” Infra ¶ 157 n.2. It is
inconsistent to recognize in one breath that the legal landscape is a
morass and in the next to claim that individuals can somehow
develop settled reliance interests despite the shifting sands. Justice
Lee’s approach is a thoughtful attempt to clarify a very muddled
area of the law, but it can hardly be said to be consistent with firm
reliance interests, given that he is jettisoning one “element of the
legal test” that a line of cases in our precedent has recognized. See
infra ¶ 203.
   129   Supra ¶ 53 n.18.
   130E.g., Luttrell, 507 N.E.2d at 541. See also Stenrich Grp. v.
Jemmott, 467 S.E.2d 795, 802 (Va. 1996) (“[A]n impairment
                                                           (cont.)

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that the plain language approach I would adopt does not have the
“same fundamental defect” that Justice Himonas’s approach
retains.131
    ¶ 137 Justice Lee likewise argues that my standard is “fuzzy”
and “indeterminate.”132 But as I have noted, my approach will
become clearer and more certain as time passes and courts engage
in future iterations of the interpretive framework I propose. And
even at its starting point, I believe my approach is clearer than the
approach Justice Lee advocates. His approach would categorize
maladies as being either “injuries by accident” or “occupational
diseases” depending on the “unexpectedness” of the malady. His
opinion purports to articulate a bright line—a malady is an
“injury by accident” if it is either (1) the result of an unexpected
causal event, i.e., a mishap, or (2) a condition that is unexpected in
that it is not “incident” to the performance of “a given line of
work.”133 But to impose such a standard is to simply kick the
indeterminacy can down the road.
    ¶ 138 How will one know whether a given malady is
“unexpected,” that is, “not incident to,” “a given line of work”?
Surely experts will be required to opine on the subject. But in
addition to the unpredictability caused by the factual
disagreements that are sure to arise, Justice Lee’s approach also
spawns numerous unanswered legal questions. As an initial
matter, at what level of generality are we to define the applicable
“line of work”? Is “manual laborer” the appropriate way to
describe the line of work? Or is “construction worker” more
appropriate? Or perhaps, “crane operator.” The level of generality
at which one defines the relevant field of work is bound to have
an outcome-determinative effect on whether a type of harm is
“incident” to performance in that field.

resulting from cumulative trauma caused by repetitive motion . . .
must be classified as an injury, not a disease . . . .”).
   131   Supra ¶ 53 n.18.
   132   Infra ¶ 194.
   133   Infra ¶¶ 199–200.

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    ¶ 139 Next, even assuming that we could ascertain the
relevant “line of work” with some predictability, it is by no means
clear just how common a malady must be to become “incident” to
that line of work. At what point does a malady cease to be
expected? Does expectedness require that more than 50% of
employees in the particular field will suffer the malady in a given
year? What if 20% will experience the malady at some point
during the entire span of their career?
    ¶ 140 Justice Lee does not offer any answers to these
questions, and it’s not clear where courts and litigants should look
when attempting to apply his standard. A simple example
illustrates the point. Consider a city employee who suffers a burn
in the course of rescuing a family from a burning building. The
employee might argue that “first responders” is the relevant “line
of work,” and that it is highly uncommon, and thus unexpected,
for first responders to suffer burns on the job. The employer
would likely counter that the relevant line of work is firefighter,
and that burns are expected in the course of—that is, incident to—
working as a firefighter.
    ¶ 141 Setting this uncertainty aside, we could assume that
firefighter is the relevant “line of work.” Then we can expect the
employer to put on an expert who will testify that no firefighter
can reasonably expect to perform the job for a year without
suffering at least one burn. Under Justice Lee’s approach, there is
a strong argument that the employee’s burn is an occupational
disease because it does not fit into either category of “injury by
accident” that Justice Lee recognizes. First, the burn is not a
“mishap.” The employee deliberately chose to enter the burning
building, with full knowledge of the dangers posed. So it cannot
be said that the burn was brought about “through carelessness,
unawareness,” or “ignorance” on the part of the employee.134
    ¶ 142 Under Justice Lee’s second category of injury by
accident, we would next need to assess whether burns are
incident to being a firefighter. But attempting to engage in that
analysis reveals yet another level of a complexity—and thus
uncertainty—lurking in his approach. It seems that we can’t stop

   134   Infra ¶ 199 n.15.

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at asking whether a “burn” is incident to working as a firefighter.
Instead, we have to assess whether a burn of this severity is
incident to working as a firefighter. That is, it may be the case that
first-degree burns are a near daily occurrence for all firefighters,
but third-degree burns are quite rare. Perhaps the vast majority of
all firefighters spend an entire career without suffering a burn of
this severity. If that is the case, then, under Justice Lee’s approach,
the firefighter’s first-degree burns are occupational diseases, but
the same worker’s third-degree burns are injuries by accident. The
severity problem seems inextricably bound up in the
“expectedness” inquiry—the more severe a harm, the fewer
employees in a given field will suffer it—which further suggests
that Justice Lee’s approach is far from a bright line. And as this
hypothetical reveals, Justice Lee’s approach would have the
troubling effect of converting many conditions that common
language usage and common sense suggest should be considered
injuries into diseases.135 Under my approach, this is an easy case.

   135 The cases that Justice Lee cites from the “robust body of
law” that purportedly supports his approach contain similar
failings. Infra ¶ 200 n.17. These cases are from jurisdictions that,
unlike Utah since 1941, excluded occupational diseases from any
form of compensation, and the desire of judges to shoehorn
maladies into their states’ compensation acts goes a long way
toward explaining the lengths to which they have gone to find
maladies to be “injuries by accident.” See Indus. Comm’n v. Ule, 48
P.2d 803, 804 (Colo. 1935) (concluding that the death of a
woodworker caused by poisoning from a substance that he
worked with routinely was an injury by accident, not an
occupational disease); Downey v. Kansas City Gas Co., 92 S.W.2d
580, 582, 587 (Mo. 1936) (concluding that an employee who
developed an “infection” (“acute conjunctivitis”) in his eye due to
repeated, prolonged exposure to harmful substances found in
chimney soot “suffered an injury compensable under the
Workmen’s Compensation Act[,] . . . . not an occupational
disease”). In any event, these cases cannot guide our analysis here
because they come from jurisdictions operating under entirely
different statutory schemes, so they shed little insight into the
proper interpretation of Utah’s unique statutory history in this
field. Cf. Downey, 92 S.W.2d at 584–85 (“It will be observed that
                                                             (cont.)

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A burn, no matter its severity, arises from physical trauma and fits
squarely into the category of an injury, which is the more
commonsensical and predictable result.
    ¶ 143 In this case, the harm sustained by Ms. Rueda is a
rotator cuff tear. Applying the standard discussed above, this
should be categorized at the threshold level as an injury. It is not a
disease, because the harm was the result of trauma—repeated
stress to her rotator cuff. It did not result from exposure to some
environmental hazard or an invasion of a foreign substance into
her body. No toxin or germ caused the harm. It was also not the
result of inherent biological or genetic defects. Thus, it does not
fall within the narrow definition of “disease” discussed above. I
would therefore affirm the labor commission’s decision to treat
Ms. Rueda’s harm as an injury and so within the scope of the
WCA.
    ¶ 144 Of course, this threshold level categorization of her
harm as an injury does not determine whether Ms. Rueda is
ultimately entitled to compensation. It determines only which
statutory framework we apply, which in turn sets forth the
compensation requirements. Because her harm should be
categorized as an injury, the WCA applies, which means that
Ms. Rueda must show that her injury was “by accident arising out
of and in the course of [her] employment.”136
    ¶ 145 The only question in this regard is whether her injury
can be considered to be “by accident,” as there is no question that
it arose out of her employment. In determining whether her injury
was “by accident,” we must address two issues: whether we
should abandon the cumulative trauma theory of accident and

our statute limits the rights created to ‘any illness or disease
peculiar to the work or process carried on, or which subjects the
employee to the danger of illness or process carried on, or which
subjects the employee to the danger of illness or disease incident
to such work . . . .’ ‘We are therefore of the opinion that the term
“occupational disease” must be restricted to a disease that is not
only incident to an occupation, but the natural, usual, and
ordinary result thereof . . . .’” (citations omitted)).
   136   UTAH CODE § 34A-2-401(1).

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whether the Commission’s determination that Ms. Rueda’s injury
was a cumulative trauma injury was supported by substantial
evidence.
    ¶ 146 As discussed above, the cumulative trauma theory of
accident is part of our courts’ understanding of the term of art “by
accident.” It permits the Commission or a court to determine that
an injury that emerged over time—as opposed to emerging as the
result of a single, discrete incident—may still be considered to be
“by accident” as required by the WCA in order to be a
compensable injury.137 This theory has long been part of our
interpretation of the phrase “by accident,”138 has effectively
become part of the statute, and I agree with Justice Himonas that

   137   Carling v. Indus. Comm’n, 399 P.2d 202, 203 (Utah 1965).
   138  I note that because Justice Himonas views the harms
covered by the WCA and the ODA as falling along a spectrum of
expectedness, definiteness, and time, a harm that emerges over
time may be considered the result of cumulative trauma and still
be considered an “occupational disease.” Under Justice Himonas’s
view, cumulative trauma appears to simply be the way to describe
harms that emerge over time, which harms may be classified as
either “injuries by accidents” or “occupational diseases” based on
other factors. Under this view, the theory is not limited to the
consideration of whether an injury is “by accident.” I disagree
with this approach both because I believe that the WCA and ODA
do not establish a spectrum but rather a bright-line test, as
discussed above, and because Justice Himonas’s interpretation of
the cumulative trauma theory extends it far beyond where we
have always understood it in our caselaw—as part of the
definition of the phrase “by accident.” See, e.g., Allen, 729 P.2d at
18 (stating that the term “by accident” is defined as “an
unanticipated, unintended occurrence different from what would
normally be expected to occur in the usual course of events. . . .
[T]his is not necessarily restricted to some single incident which
happened suddenly at one particular time and does not preclude
the possibility that due to exertion, stress or other repetitive cause,
a climax might be reached in such manner as to properly fall
within the definition of an accident as just stated above.”
(alterations in original) (citation omitted)).

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there is no good reason to abandon it now.139 JBS’s best argument
to do so is that this theory blurs the line between an occupational
disease and an injury by accident. Although I agree with JBS that
Justice Himonas’s retention of the cumulative trauma theory of
accident and the common law term of art understanding of
occupational disease would lead to confusing and inconsistent
results, those results are absent under my approach.140 So I agree
with Justice Himonas that there is no need to overrule our
precedent on this issue, though I base my decision on different
reasons than those articulated by Justice Himonas.
    ¶ 147 The final issue related to the compensability of
Ms. Rueda’s injury is whether the Commission’s determination
that Ms. Rueda’s injury was “by accident” under the cumulative
trauma theory of accident is supported by substantial evidence.
Justice Himonas has thoroughly addressed this issue in his
opinion,141 and I agree with his conclusion that the Commission’s
order was supported by substantial evidence. But because of the
different approaches Justice Himonas and I propose, our
agreement on these issues leads to different results.
    ¶ 148 Justice Himonas accepts that either an injury by
accident or an occupational disease can be caused by cumulative
trauma. So his conclusion that the cumulative trauma theory
survives and that the Commission’s finding of cumulative trauma
in this case was supported by substantial evidence leads to the

   139   Supra ¶¶ 56–67.
   140 Under my approach, the theory does not go to the threshold
question of whether a harm is an injury because it only helps to
define “by accident,” and I would not look to whether a harm is
“by accident” to determine whether it falls within the scope of the
WCA. Instead, I would employ a bright-line test based on the
ordinary meaning of the terms “injury” and “disease.” So at least
under my approach, there is no confusion created by the retention
of the cumulative trauma theory.
   141   Supra ¶¶ 68–72.

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question of whether Ms. Rueda’s injury should be compensated
under the WCA or the ODA. He answers this question by
concluding that, although her harm was the result of cumulative
trauma, it was too gradual to be considered an injury by accident
and must be categorized as an occupational disease. I disagree
with this approach as I have discussed above. Under my
approach, categorization of harms is a threshold matter, and the
question of whether the Commission’s finding of cumulative
trauma was supported by substantial evidence goes only to the
secondary issue of compensability. And because I believe that Ms.
Rueda’s harm should be classified as an injury at the threshold
level, and that the Commission’s determination that her injury
was “by accident” under the cumulative trauma theory was
supported by substantial evidence at the compensability level, I
would conclude that the Commission was correct to award Ms.
Rueda compensation under the WCA.
    ¶ 149 In conclusion, I believe that Justice Himonas fails to
make the proper distinction between the WCA and the ODA and
incorrectly relies on the term of art understandings of “by
accident” and “occupational disease” to distinguish the two
statutes’ scopes. This failure leads to his confusing, multi-factor
balancing test. I believe the proper approach would be to, as a
threshold matter, determine whether the employee’s harm
qualifies as an injury or a disease. And in my view, the text and
history of the statutes require us to employ a plain language
approach to interpret these terms. Applying this threshold test to
Ms. Rueda’s case, I conclude that her harm should be categorized
as an injury and so the terms of the WCA should apply. I agree
with Justice Himonas that we should not abandon the cumulative
trauma theory of accident and that the Commission’s order was
supported by substantial evidence. I would, therefore, affirm the
Commission’s decision.

   ASSOCIATE CHIEF JUSTICE LEE, opinion:
   ¶ 150 In this case we are asked to delineate the boundary
between the Workers Compensation Act (WCA) and the
Occupational Disease Act (ODA). That seemingly simple task
turns out to be a difficult one, as the governing language of these

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two statutes is far from clear, and our cases complicate the matter
by our own inconsistencies and imprecisions over the years.
    ¶ 151 My colleagues have made a valiant attempt to bring
order and clarity to this fuzzy field of jurisprudence. I applaud
their efforts and find elements of their opinions that I agree with. I
agree with Justice Himonas, for example, that the WCA and ODA
use words in their legal term-of-art sense, and that the standard
we apply here should consider the meaning of those words set
forth in the law. Yet I also share Chief Justice Durrant’s concerns
about the indeterminacy of the “spectrum” envisioned by Justice
Himonas’s balancing test, and agree with the goal of seeking a
bright line in this area.
    ¶ 152 That leads me back to the drawing board—in search of
a test that is consistent with the terms of the statutes and lends
itself to consistent application while maintaining some fealty to
precedent. With this in mind, I would apply a standard that
draws the line between the WCA and the ODA based on whether
a given workplace harm is “unexpected.” And I would define
“unexpectedness” to encompass either an unexpected causal
event in the workplace (a “mishap”) or an unexpected malady
(one that is not an occupational “disease,” defined as a malady
that is incident to the worker’s employment). These alternative
notions of unexpectedness are set forth in our cases. And the
standard is consistent with the operative language of the two
statutory schemes—which treats workplace harms occurring “by
accident” as falling under the WCA, UTAH CODE § 34A-2-401(1),
and workplace harms amounting to “occupational disease” as
falling under the ODA, id. § 34A-3-103.
   ¶ 153 This approach follows Justice Himonas’s standard to
some extent. But it defines “accident” purely in terms of
“unexpectedness” instead of making that a factor to be balanced
along with the “definiteness” of the onset of the worker’s injury. I
acknowledge that our cases have sometimes spoken of the
“definiteness” inquiry in the way that Justice Himonas does. But I
would reject this “factor” because it finds no basis in the statutory
scheme as I understand it and introduces too much

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unpredictability into our law. See infra ¶¶ 170–72.1 Thus, I would
treat “definiteness” as only circumstantially relevant to the
“unexpectedness” of a given causal event—the more definite (not
gradual) the onset of a workplace harm the greater the likelihood,
all else being equal, that the harm came about as a result of a
mishap at work. But I would not consider “definiteness” an
element of the test, for reasons set forth long ago by this court. See
Young v. Salt Lake City, 90 P.2d 174, 176 (Utah 1939) (rejecting
definiteness; noting that “to stress the length of time as a basis of
determining the accidental nature of the illness is to adopt a rule
which may, in many cases, be governed by the bodily resistance of
the individual”).
    ¶ 154 The test that I propose would require a remand
because the Labor Commission has not had a chance to apply it to
the facts of this case. For that reason I dissent from the lead
opinion because I disagree with its disposition of the case
(affirmance in part and reversal in part) even though I agree with
part of the test that it endorses.
   ¶ 155 I explain the basis for my approach in the paragraphs
below. First I explain the grounds for my departure from the
approach advanced by Justice Himonas. Then I outline some
common ground and also some conflict with the standard
proposed by Chief Justice Durrant. Next I offer a more fulsome
explanation of the basis for my proposed test. And finally I close
by applying my proposed test to the facts of this case.
                                  I
    ¶ 156 Justice Himonas acknowledges some difficulties in our
caselaw in this area. He concedes that our cases “have spoken
loosely” in articulating the operative standard—identifying
factors of relevance to the distinction between injury by accident
and occupational disease (the “unexpectedness of the accident”
and the “definiteness as to the occurrence of the injury”) but
without consistently establishing the precise role these factors
play in the analysis. Supra ¶¶ 39–40. Thus, Justice Himonas notes

   1  My approach is not driven “[p]rimarily” by “policy”
concerns. See supra ¶ 44. It is rooted in my view of the text of the
relevant statutes and our cases.

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that our cases have not consistently specified what it is that must
be “unexpected” or “definite” to satisfy the legal test, and have
also failed to clarify the relationship between these two factors.
See supra ¶ 39.
    ¶ 157 Justice Himonas does not ultimately try to defend all of
our decisions in this area. Nor does he purport to preserve all
articulations of the operative test set forth in each of our prior
cases. Instead, he seeks to “clarify” the law by distilling principles
that he finds essential.2 See supra ¶ 40. Those principles result in a
legal standard that envisions a “spectrum” of workplace injuries
rather than a bright line. “[W]hen characterizing an impairment
along this spectrum,” Justice Himonas proposes to “take into
consideration the unexpectedness” of the event giving rise to the
worker’s injury or illness “as well as the definiteness as to [its]
occurrence.” Supra ¶ 39. Specifically, Justice Himonas proposes to
treat unexpectedness as the “primary” factor and definiteness as
“secondary.” Supra ¶¶ 40, 43. As to unexpectedness, Justice
Himonas says that we should look to whether “‘something . . .
broke, or injected itself into, the usual course of the performance
of the occupation’” (a “mishap”), supra ¶ 41 (quoting Young,
90 P.2d at 177), or whether there was “an ‘unexpected internal
failure of [an employee’s] system to function normally,” supra
¶ 41 (alteration in original) (quoting Purity Biscuit Co. v. Indus.
Comm’n, 201 P.2d 961, 966 (Utah 1949)). And he says that the
definiteness inquiry concerns both the “cause of the injury” and
“the resultant injury” itself. Supra ¶ 40.
   ¶ 158 Justice Himonas also acknowledges “criticism
regarding the consideration of the definiteness of time as a factor
when classifying an injury.” Supra ¶ 43 (citing 3 ARTHUR LARSON
ET AL., LARSON’S WORKERS’ COMPENSATION LAW § 42.02 (2017));

   2  For this reason I do not think any member of the court is in a
position to claim to be deciding this case on stare decisis grounds.
This is the most splintered decision I have seen in my years on
this court. But we all agree on one thing: The law in this area is in
disarray and in need of overhaul. My overhaul is admittedly more
aggressive than Justice Himonas’s. But we all are engaged in an
exercise of revision and reformulation. None of us is really
clarifying.

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also citing the Chief Justice’s critique “that adopting a test that
includes definiteness of time as a factor leads to an ‘inequitable
standard,’” supra ¶ 89). Yet he declines to repudiate this element
on the ground that it is “entrenched in our case law” as a
“secondary factor in determining how to classify workplace
harm,” with “the primary factor being unexpectedness of cause of
the injury or unexpectedness of the resultant injury.” Supra ¶ 43.
And he also stops short of specifying the precise relationship
between the “primary” and “secondary” factors—what result is
dictated when they point in opposite directions.
    ¶ 159 For these and other reasons I agree with much of the
Chief Justice’s critique of Justice Himonas’s approach. I am
troubled by a test that would “permit the same harm . . . to be
categorized as either an injury by accident or an occupational
disease in different cases based on hard-to-define factors.” Supra
¶ 87. And that also seems untenable under the governing
statutory scheme. A claim for a harm suffered in the workplace
must ultimately be covered by “one or the other”—either WCA or
ODA; it “cannot be both.” Supra ¶ 79.
    ¶ 160 Unlike Justice Himonas, moreover, I do not find the
lead opinion’s standard to be dictated by precedent. See supra
¶ 47. Nor do I find it impossible to articulate a “clear line between
injury by accident and occupational disease.” Supra ¶ 51. The line
that I would draw, as noted above, is one that would treat
“unexpectedness” as the line between the WCA and the ODA.
That standard, as explained more in Part III below, is a bright line
that avoids the difficulties rightly decried by Chief Justice
Durrant. And in my view, my approach is not foreclosed by
precedent.
    ¶ 161 The cases cited by Justice Himonas do not ultimately
support his assertion that definiteness is embedded in our law. In
Young, our court held that definiteness was not the “governing
factor” for determining whether a malady is an occupational
disease. 90 P.2d at 176 (“[I]f the illness is one commonly
recognized as incident to the particular occupation, it is an
occupational disease. The time taken for the effects of the
occupation to become serious is not the governing factor.”). And
Young is particularly powerful precedent on this issue because it
presents a close parallel to the question presented here—as to the

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boundary between workplace accident and occupational disease,3
and the role of expectedness and definiteness in that inquiry.
    ¶ 162 The plaintiff in Young was a painter who died of lead
poisoning only three weeks after beginning work as a painter. See
id. at 175–76. Everyone recognized that lead poisoning was an
expected disease for painters at the time. But the timing of the
plaintiff’s demise from such poisoning was extraordinarily quick.
See id. And that prompted litigation over the question whether the
“definite” onset of the plaintiff’s condition brought him into the
workers compensation statute, or whether the “expected” nature
of the lead poisoning condition left him subject to any available
tort remedies for occupational disease. The Young court took the
latter route. And in so doing it unequivocally repudiated the
“definiteness” factor (and the notion of a balancing test and the
“spectrum” notion that it would lead to).
    ¶ 163 “From the fact that Mr. Bailey succumbed to the lead
poisoning in the vapor in a comparatively short time,” the court
reasoned that “we should not conclude that the illness was
accidental.” Id. at 176. “Were we to adopt such a rule,” the court
observed, “the dividing line between an occupational disease and
an accident would become extremely hazy as the periods of time
for each approached unity.” Id. This is the central holding of
Young. It has never been overruled. In my view, it should be
followed here.
   ¶ 164 As Justice Himonas notes, our decision in Carling v.
Industrial Commission, 399 P.2d 202 (Utah 1965), refers to
occupational diseases as “gradually developing conditions.” Id. at
203. But I view that as merely descriptive dicta—language

   3 The question presented in Young differed from that presented
here only in that at the time of Young there was no Occupational
Disease Act. In the Young era, occupational diseases were the
domain of the tort law. So the question presented in Young was
whether the claimant’s injury was covered by workers
compensation or instead was subject to tort law. But as explained
more below, see infra ¶¶ 185–89, the common law notion of
occupational disease overlaps substantially with the statutory
principle. So Young is an important precedent.

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describing the typical occupational disease—suggesting only that
the timing of onset of an injury may be circumstantially relevant
to the key inquiry into expectedness. Nothing in Carling overrides
Young. Nowhere does Carling hold that definiteness is an element
of the test or “factor” to be balanced on a “spectrum.”
   ¶ 165 The Carling opinion is not a model of clarity. But the
apparent premise of Carling’s case was that he had suffered an
“unexpected” accident in the “mishap” sense—that he suffered a
sudden loss of hearing as a result of something that went awry in
the workplace. See id. It appears from the opinion that there was
no direct evidence of a workplace mishap. So Carling was left to
present circumstantial evidence. That was the evident point of the
gradualness evidence that Carling presented. Carling asserted
that “after he had been pounding the pipes with [an] air gun for
about 20 to 30 minutes, he suddenly became aware that his
perception of other noises around him became dulled.” Id. And he
suggested that the sudden timing of his hearing loss indicated
that there had been an unexpected event—a mishap—entitling
him to workers compensation.
    ¶ 166 Yet there was contrary evidence in the record. “An
acoustical engineer testified that noise from the air gun under the
conditions shown was within the limits of tolerance of ordinary
ears.” Id. And Carling’s medical records revealed “a long prior
history of deficient hearing” documented “as early as 14 years”
prior to the alleged incident. Id. The medical evidence suggested
that circumstances alleged by Carling were “not the usual pattern
of a hearing loss suffered in the manner [Carling] contend[ed the]
loss occurred.” Id. The doctors examining Carling’s records “were
of the opinion that there had been a gradual and continuous
regression of his hearing . . . [and] that the type of hearing loss he
suffered could be due to a number of factors, including heredity.”
Id.
    ¶ 167 The commission rejected Carling’s theory, concluding
that “[t]he medical evidence strongly suggest[ed] occupational
disease due to long exposure to loud noise or heredity.” Id. at 204.
And the commission accordingly determined that the record
“d[id] not support a finding that the specific incident . . . caused
the alleged loss of hearing.” Id. The holding of Carling is an
affirmance of that decision. Carling never states that definiteness is
an element of the test to be balanced with unexpectedness. It

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simply refers to evidence of gradual onset in concluding that the
commission did not act arbitrarily and capriciously in holding
that there was no unexpected event causing Carling’s hearing
loss. Id. at 203–04.
    ¶ 168 That approach is consistent with the framework that I
would apply. The Carling opinion makes reference to definiteness
and gradualness. But this is dicta describing typical injuries by
accident (which usually come on as a result of a definite event)
and typical occupational diseases (which usually come on
gradually). And the court’s dicta referring to this evidence is
easily understood as treating definiteness as only of
circumstantial relevance.
    ¶ 169 Indeed the Carling opinion affirmatively reaffirms
Young in an important respect. It does so in its recognition of the
cumulative trauma theory—in noting that an accident may arise
over time, and need not be the result of a single time-definite
incident. Carling, 399 P.2d at 203.
    ¶ 170 This highlights the centrality of the unexpectedness
inquiry. A typical accident is one that happens at a distinct,
definite time. But the legal test for establishing an accident does
not require definiteness. Definiteness is merely descriptive of the
typical accident—and thus of circumstantial relevance in a case in
which it is unclear whether an accident occurred. Thus, a worker
may suffer a series of mishaps over time, and such a series would
certainly qualify for workers compensation under Carling. See also
Allen v. Indus. Comm’n, 729 P.2d 15, 18–22 (Utah 1986) (holding
that the legal test for an “accident” does not require proof of a
definite causal event or mishap so long as the resulting malady is
“unexpected”).
    ¶ 171 Justice Himonas cites the Larson treatise as additional
authority for his contrary view. See supra ¶¶ 35, 39–40 & n.12. But
the Larson treatise seems to me to cut against Justice Himonas’s
approach in a couple of respects. It states that “[t]he basic and
indispensable ingredient of ‘accident’ is unexpectedness.”
3 ARTHUR LARSON ET AL., LARSON’S WORKERS’ COMPENSATION LAW
§ 42.02 (2017). And it expressly rejects the use of definiteness as an

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element in a statutory scheme, like Utah’s, which requires a
showing of “injury by accident.”4
    ¶ 172 Admittedly, the Larson treatise characterizes
definiteness as an element of the test in “the majority of other
jurisdictions.”5 Yet the treatise documents a shift in the courts
towards minimizing the role of definiteness evidence. 6 To that

   4   See 3 ARTHUR LARSON ET AL., LARSON’S WORKERS’
COMPENSATION LAW § 42.02 (2017) (asserting that where “the
phrase ‘accidental injury’ is used, or the equivalent phrase ‘injury
by accident,’ there is no occasion, as a matter of grammar, to read
the phrase as if it referred to ‘an accident’ and then proceed to
conduct a search for ‘the accident’”); id. § 50.01 (asserting that
where the statute “speak[s] of ‘accidental injury’ or ‘injury by
accident,’ the necessity for definite time rests on more
questionable grounds”); see also UTAH CODE § 34A-2-401(1)
(providing compensation for an employee who is “injured” or
“killed” “by accident”); id. § 34A-2-102(1)(j)(i) (defining
“[p]ersonal injury by accident”).
   5  Supra ¶ 35; 3 ARTHUR LARSON ET AL., LARSON’S WORKERS’
COMPENSATION LAW § 42.02 (2017) (acknowledging that
definiteness “has been added [as an element] in most
jurisdictions”).
   6  The jurisdictions that adopted definiteness as an element
have also developed a myriad of doctrines and exceptions for
satisfying the definiteness requirement in cases involving gradual
injuries—greatly diminishing the role of definiteness in
establishing injury by accident. See, e.g., 3 ARTHUR LARSON ET AL.,
LARSON’S WORKERS’ COMPENSATION LAW § 50.01 (2017) (“A
relatively brief exposure to fumes, dust or cold may lead to
protracted period during which the victim gradually succumbs to
disease; conversely, months or years of exposure to poisons, jolts
or strains may lead to a sudden collapse on a particular day. In
either case it is relatively easy to satisfy the definite-time
requirement by merely accepting the view that suddenness may
be found in either cause or result. When, however, both the cause
and effect are gradual, as when protracted exposure leads to
protracted deterioration or disease, many courts have still been
                                                            (cont.)

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extent, the Larson treatise only strengthens my view that
definiteness is not an appropriate element of the legal standard.
Requiring proof of definiteness is inconsistent with the terms of
Utah’s WCA and is increasingly out of step with the law of other
jurisdictions that once incorporated definiteness as an element.
   ¶ 173 For these reasons I do not see a basis for establishing
definiteness as an element of the test for an injury by accident.
And the decision to introduce that element into our law can only
bring confusion and indeterminacy into this important field. I
turn to that problem now.
                                 II
   ¶ 174 The Chief Justice, as noted, rightly decries the
indeterminacy of the standard proposed by Justice Himonas. He
shows how the lead opinion’s “construct . . . leads to perplexing
results”—with the definiteness factor allowing some claimants to
be “compensated at a higher rate than they would be if, like Ms.
Rueda, they had soldiered on for two years.” Supra ¶ 87. And he
helpfully highlights the unpredictability of the balancing test
implicated by the “hard-to-define factors” put forward by Justice
Himonas. Supra ¶ 87.
    ¶ 175 For these reasons I agree that the “spectrum”
envisioned by the lead opinion’s balancing test is untenable. Our
cases may not always have drawn a clear line between these two
statutory schemes. But the legislature clearly envisions such a line.
A given claim for harm suffered in the workplace cannot be
susceptible to categorization under both statutory schemes. The
legislature has expressly stated as much in both the WCA and the
ODA. See UTAH CODE § 34A-2-102(1)(j)(ii) (workers compensation
claims do not extend to an occupational “disease”); id. § 34A-3-111
(ODA compensation is not “payable” if “compensation is
payable” under the WCA). We must accordingly police that line;
we override the terms of the operative statutes if we condone a
balancing test that allows the same workplace harm to be covered
under either the WCA or the ODA.

able to find ‘accident’ by treating each impact or inhalation as a
miniature accident in itself, leading ultimately to disability.”).

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                                  A
   ¶ 176 That said, I cannot agree with the standard proposed
by the Chief Justice. In my view, the WCA and the ODA do not
use the terms “injury” and “disease” in their “ordinary” sense.
Like Justice Himonas, I understand the legislature to have
embraced the legal term-of-art understanding of “injury by
accident” and “occupational disease” as the dividing line between
the WCA and the ODA.
    ¶ 177 The Chief Justice acknowledges that the terms
“injury,” “disease,” and “illness” may each be defined in a
manner that encompasses a wide range of maladies or harms.
Supra ¶ 129. But he rejects that reading because he views it as
creating an impermissible overlap between the WCA and the
ODA. And he cites that overlap as a basis for adopting a narrower
sense of “disease.” Supra ¶ 130.
   ¶ 178 I see a simpler way out of the thicket. The overlap
problem can easily be resolved by reference to the term-of-art
understanding of “injury by accident” and “occupational
disease.” If the legislature was thinking of that understanding of
these terms—and I see no reason to conclude otherwise—then it
would make perfect sense to give the terms “injury,” “disease,”
and “illness” a broad meaning encompassing all forms of
workplace harm.
    ¶ 179 For that reason I see no basis in the operative statutes
to require a narrow construction of “disease” or “illness.” If
anything the ODA seems to direct us to a broad reading. It speaks
of “any disease or illness.” See UTAH CODE § 34A-3-103. The “any”
modifier seems to suggest a broad understanding. And the
alternative “disease or illness” formulation reinforces that
understanding.
    ¶ 180 The Chief Justice finds no “relevant distinction
between ‘disease’ and ‘illness.’” Supra ¶ 98 n.44. But at least one of
the cases he cites in support of his approach finds an important
distinction. Luttrell v. Industrial Commission, 507 N.E.2d 533 (Ill.
App. Ct. 1987), notes that “illness” is among the terms the
legislature “could have used to better convey” an intention to
“provide compensation for any malady” under Illinois’s
Occupational Disease Act. Id. at 541. That highlights a significant
strike against the Chief’s reading of our statute. The Utah ODA

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covers “any disease or illness.” And under the canon of
independent meaning we should presume that “illness” adds
something. See, e.g., Lancer Ins. Co. v. Lake Shore Motor Coach Lines,
Inc., 2017 UT 8, ¶ 13, 391 P.3d 218. That canon suggests a basis for
finding a broad meaning of “illness” even if we adopt a narrow
understanding of “disease.” And the broad notion of “illness,” as
the Luttrell court concludes, is easily sufficient to cover “any
malady.” See WEBSTER’S THIRD NEW INTERNATIONAL DICTIONARY
1127 (2002) (defining “illness” as “an unhealthy condition of body
or mind: MALADY”).7

   7 The Chief Justice responds by asserting that a decision to give
independent meaning to “illness” is inconsistent with the
“statutory scheme” because “it threatens to permit the same type
of harm to fall within the purview of both the WCA and the
ODA.” Supra ¶ 98 n.44. But that response is circular. My approach
does not create overlap between the statutory schemes; it merely
divides the two acts on a ground that turns on the mechanism of
causation—not the nature of the harm. See infra ¶ 184. The Chief
Justice presumes that the legislature divided the acts into
categories of harm. But that construct fails because it is
inconsistent with the text and structure of the statute and the
canon of independent meaning. See supra ¶¶ 178–183.
    The Chief Justice also criticizes my approach as creating an
inequity. He notes that two employees who experience the same
workplace harm via distinct causal mechanisms would be
compensated differently under my framework. Supra ¶ 98 n.44.
But I see no inequity. I see good reasons for compensating the
same malady differently depending on the mechanism of
causation. In the Chief Justice’s example, an employee called upon
to work with lead paint on a daily basis is likely receiving higher
compensation in the form of hazard pay because of the known
risks associated with that employment. By contrast, an office
worker is not ordinarily presented with the risks of lead
poisoning, so an employee in this field is likely compensated in
accordance with the low risks associated with office employment.
In any event, our interpretation of statutory language does not
turn on our own sense of equity. We should give effect to the
legislative judgments expressed in the statute’s text.

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    ¶ 181 The Chief Justice’s approach would make trauma-
based maladies the exclusive domain of the WCA, see supra
¶¶ 129, 132, with the ODA left to cover only maladies arising out
of exposure to “bacteria, virus, poison, toxin, or germs,” supra
¶ 127. But these premises seem incompatible with the terms and
structure of these statutes. The ODA’s exclusive remedy provision
speaks of “compensation under this chapter for diseases or injuries
to health sustained by a Utah employee.” UTAH CODE § 34A-3-
102(3) (emphasis added). And elsewhere the ODA provides for
compensation for “[p]hysical, mental, or emotional diseases related
to mental stress arising out of and in the course of employment.”
Id. § 34A-3-106(1) (emphasis added).8 These provisions seem to me
to make it impossible to limit the ODA to maladies arising from
exposure to microbes or toxins. Clearly the statute encompasses
other “injuries to health,” including at a minimum those arising
from “mental stress.”
     ¶ 182 I likewise find no basis for treating “injury” as limited
to harms arising from physical trauma. The ordinary sense of
“injury” does not contemplate such a limit. See supra ¶ 129 n.116
(listing definitions of “injury” as comprising “harm” or
“damage”); supra ¶ 130 (conceding that “the definition of ‘injury’
is broad, with no narrower understanding of the term than

   8  The Chief Justice claims that mental- or emotional–stress-
related maladies fall within his definition of disease because they
do not result from physical trauma. See supra ¶ 130 n.121. But this
makes the Chief’s standard even murkier. Do we evaluate
whether a harm is a disease as ordinarily defined to determine
whether it is compensable under the ODA? See supra ¶ 130
(defining a disease as a malady resulting from “exposure to
environmental hazards and foreign agents, such as bacteria,
viruses, other germs, poisons, and toxins, or from inherent
biological or genetic defects”). Or do we look exclusively to
whether a malady results from physical trauma? See supra ¶ 130
n.121. These are two different dividing lines. I am unsure which
one the Chief Justice proposes to adopt. In any case, I see nothing
in the statute’s text that indicates that either the ordinary
definition of trauma or disease divide the boundaries of the ODA
and WCA.

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‘damage or harm’”). And our longstanding precedent likewise
contradicts it. See, e.g., Allen, 729 P.2d at 18 n.3 (identifying an
“internal failure” as compensable under the WCA); Tintic Milling
Co. v. Indus. Comm’n, 206 P. 278, 281–83 (Utah 1922) (concluding
that a malady resulting from exposure to fumes was compensable
under the WCA).
    ¶ 183 I would reject the trauma-based conception of “injury”
on the above grounds. If the ordinary and term-of-art
understanding of “injury” are broad, we should not limit the term
by judicial fiat. We should respect the settled understanding of the
statutory language, which has remained intact (unamended) since
the statute’s first enactment in 1917. Compare 1917 Utah Laws 322,
with UTAH CODE § 34A-2-102(1)(j). Surely the settled
understanding of “injury” has sustained important reliance
interests over the years. And in my view those interests are more
weighty than the contrary standards embraced in caselaw in other
jurisdictions.
                                   B
   ¶ 184 The difference between the WCA and the ODA has
long been understood to turn on the mechanism of causation and
not on the nature of the harm to the worker. Specifically, our law
has long deemed the line between the WCA and ODA to turn on
whether the worker’s malady resulted “by accident” (triggering
the WCA) or is instead an “occupational disease” (triggering the
ODA).
    ¶ 185 Significantly, as Justice Himonas notes, our cases have
“consistently referred to ‘injury by accident’ as a cohesive
phrase.” Supra ¶ 50. Our law has never extracted the term
“injury” out of this legal phrase, or deemed the injury/disease
distinction to be controlling. For that reason it seems perilous to
do so here. The law has long treated legal words transplanted
from legal fields to bring their “soil” with them. See, e.g., Nielsen v.
State, 2016 UT 52, ¶ 18, 391 P.3d 166; State v. Canton, 2013 UT 44,
¶ 28, 308 P.3d 517; Maxfield v. Herbert, 2012 UT 44, ¶ 31, 284 P.3d
647. It upsets important reliance interests to ignore that soil and to
parse legal language in a manner crediting “ordinary” or “plain”
meaning of statutory terms.
   ¶ 186 The Chief Justice claims to find support for his
approach in the 1991 amendments to the ODA. Because the 1991

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amendments define “occupational disease” as “any disease or
illness that arises out of and in the course of employment and is
medically caused or aggravated by that employment,” UTAH
CODE § 34A-3-103, and “jettison[] . . . previous statutory
definitions of ‘occupational disease,’” the Chief Justice concludes
that “the legislature has rejected the . . . term of art understanding
of ‘occupational disease.’” Supra ¶ 99. In other words, Chief
Justice Durrant concludes that the 1991 amendments provide that
“occupational disease” means simply “any disease.” Supra ¶ 99.
And he therefore asserts that “‘any disease[]’ . . . should be
interpreted according to its plain meaning.” Supra ¶ 99.
   ¶ 187 I disagree. The cited provision of the 1991 amendments
does not provide a definition of “occupational disease”; it defines
“compensable occupational disease.” UTAH CODE § 34A-3-103
(emphasis added). That strikes me as significant. The point of
section 103, as I see it, is not to define the scope of “occupational
disease” but to articulate a causation standard—to require that the
disease or illness arise out of employment and be medically
caused thereby. The operative terms of section 103 bear that out.
They do not define or restrict “occupational disease” in any way;
by articulating a causation standard they simply define which
occupational diseases are “compensable.”
   ¶ 188 To the extent section 103 defines “occupational
disease” it does so in terms that are circular—that define
occupational disease as “any disease.” And “circular terminology”
in a “statutory definition[] drives home a key to its meaning.”
Hughes Gen. Contractors, Inc. v. Utah Labor Comm’n, 2014 UT 3,
¶ 14, 322 P.3d 712. It emphasizes that the legislature is
“convey[ing] its acceptance of a term of art with a widely shared
meaning.” Id.
    ¶ 189 It is true, as the Chief Justice observes, that the 1991
legislature failed to preserve longstanding statutory definitions of
“occupational disease.” Supra ¶ 99. But I do not see how we can
conclude that this was an intentional “jettison[ing]” of the legal
term-of-art understanding of this phrase. The notion of
occupational disease is deeply embedded in our law. The term has
common law roots, tracing back to our decision in Young v. Salt
Lake City, 90 P.2d 174 (Utah 1939). Young defined occupational
disease as a malady “commonly recognized as incident to the
usual performance of [an] occupation.” Id. at 177. That notion of

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occupational disease was also carried forward by statute for many
decades. Although for a time covered occupational diseases
included only those expressly set forth by statute,9 our law has
also long required proof that a given malady is one that “can be
seen to have followed as a natural incident of the work as a result
of the exposure occasioned by the nature of the employment.”
1941 Utah Laws 83; see also id. at 97 (requiring, among other
elements, proof that “the disease or injury to health can be seen to
have followed as a natural incident of the work as a result of the
exposure occasioned by the employment”).
   ¶ 190 This was the state of the law of occupational diseases
when the legislature enacted the 1991 amendments to the ODA. In
both the common law and by statute our law had always deemed
“occupational disease” to refer to conditions that are understood
to be a “natural incident” to a given line of work. That principle
remained unaltered for many decades. And the legislature
enacted the 1991 amendments against that backdrop.
    ¶ 191 For these reasons I would interpret the legislature’s
circular reference to “compensable occupational disease” as
encompassing “any disease or illness” that arises out of
employment and is medically caused thereby as an acceptance of
the longstanding legal notion of “occupational disease.” The
legislature apparently thought it didn’t need a more precise
definition because this principle was so deeply embedded in our
law.10

   9  See 1941 Utah Laws 83 (stating that “[f]or purposes of this act
only the diseases enumerated in this section shall be deemed to be
occupational diseases” and setting forth a list of twenty-seven
conditions covered by the statute). This provision was amended
in 1949 to include “other diseases” meeting a series of criteria. See
id. at 97–98.
   10 I concede that the 1941 ODA departed from the common law
definition of occupational disease by identifying a limited number
of compensable maladies. See supra ¶ 118 & n.95. But I see no basis
for the conclusion that the 1941 amendments “reject[ed]” those
aspects of the standard, first articulated in Young, that seem
inherent in the statute’s circular definition of occupational disease.
                                                               (cont.)

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    ¶ 192 Young has never been overruled. And “[t]he age-old
principle is that words undefined in a statute are to be interpreted
and applied according to their common-law meanings.”11 I would
follow that “age-old principle” here. I would conclude that the
legislature embraced the Young notion of “occupational disease,”
and did not intend to “jettison” it in the circular reference in
section 103.
   ¶ 193 Chief Justice Durrant’s contrary conclusion threatens
to undermine settled reliance interests in this field.12 Thus, the
Chief Justice’s proposed standard is a linguistically permissible
one. We can speak of “injury” and “illness” in the way that he

Supra ¶ 102 n.57; see supra ¶ 107 n.68. The Chief Justice fails to
respond to the argument that my standard is entirely consistent
with the text of the 1941 and 1949 versions of the ODA. See supra
¶ 189.
   11 See ANTONIN SCALIA & BRYAN A. GARNER, READING LAW: THE
INTERPRETATION OF LEGAL TEXTS 320 (2012); see also Neder v. United
States, 527 U.S. 1, 23 (1999) (applying this “age-old” principle to
the meaning of “defraud”; stating that “under the rule that
Congress intends to incorporate the well-settled meaning of the
common-law terms it uses, we cannot infer from the absence of an
express reference to materiality that Congress intended to drop
that element from the fraud statutes”); Gilbert v. United States, 370
U.S. 650, 655 (1962) (“[I]t is important to inquire . . . into the
common-law meaning of forgery at the time the 1823 statutes was
enacted. For in the absence of anything to the contrary it is fair to
assume that Congress used that word in the statute in its
common-law sense.”).
   12 Elsewhere, as the Chief Justice notes, I lament the state of
disarray in our law in this field. See supra ¶ 135 n.128 (citing supra
¶ 157 n.2). But that does not mean that there are no settled points
of law in this area, or that reliance interests are entirely irrelevant.
Certainly our cases have vacillated on the proper standard for
distinguishing “injury by accident” and “occupational disease.”
Yet one point has long been clear: These are legal terms of art.
And the Chief Justice’s approach would introduce an entirely new
regime for dividing cases between the ODA and the WCA.

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proposes. Yet I doubt that any litigant or lawyer in this field
would have anticipated the standard proposed in his opinion. It is
more likely that the 1991 amendments have been understood as
continuing the longstanding legal term-of-art notion of
“occupational disease.”
                                 C
    ¶ 194 The Chief Justice’s proposed standard also seems to me
to be vulnerable to the same charge he (rightly) levels at Justice
Himonas’s approach—that it is too fuzzy and indeterminate to
yield predictable results. Even a “narrow” notion of “disease” will
require difficult line-drawing. We can accept that “disease”
cannot mean any “injury.” But we still have to decide what
conception of “disease” to adopt. And the choice among various
“narrow” notions of disease seems arbitrary (and not dictated by
anything that is apparent in “plain” meaning).
    ¶ 195 Even after selecting a particular definition of disease,
many ailments will be difficult to categorize. First, our cases have
consistently had to deal with a class of maladies referred to as
“internal failure[s].” Allen, 729 P.2d at 18 n.3. These conditions
typically involve “general organ or structural failure” and include
“heart attacks, hernias, and back injuries.” Id. The internal nature
of these conditions will likely make it difficult to place them into
either the “physical trauma” or “exposure” category.13
    ¶ 196 Second, the WCA’s exclusion of occupational disease is
subject to an exception. The WCA covers diseases when “the
disease results from the injury.” UTAH CODE § 34A-2-102(1)(j)(ii).
Over seventy years ago, our court interpreted the term “disease”
in this exclusion to mean “occupational disease.” See Andreason v.
Indus. Comm’n, 100 P.2d 202, 205–06 (Utah 1940). The court’s
interpretation was based, in part, on the fact that an alternative
holding would inject both fuzziness and arbitrariness into the law.

   13 The Chief Justice states that these types of maladies would
fall under his definition of injury “if they result from identifiable
physical trauma acting upon the body.” Supra ¶ 129 n.118. But
again the Chief provides no standard for determining what counts
as “trauma.” And that is what leaves this category of cases in
doubt.

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Specifically, this reading would make “compensation [under the
WCA] dependable upon the practically impossible task of proving
which of two possible avenues of entry was used by the germs.”
Id. If the contagion entered the body through a cut or other injury
due to physical trauma, then it would be compensable under the
WCA. See id. But if the bacteria entered the system through some
other means of exposure—dissociated from a physical trauma—
then the disease would be compensable as an occupational
disease. Cf. id. This concern is no less significant today, and no less
problematic under the Chief Justice’s formulation.
    ¶ 197 If the legislature unambiguously directed us to use the
ordinary meaning of injury and disease to divide harm between
the WCA and the ODA, then the fuzziness and arbitrariness
associated with the Chief Justice’s approach would not be reasons
to second-guess that standard. But the better view is that the ODA
directs us to fall back on the longstanding legal term-of-art
meaning of “occupational disease”—to harms or maladies that are
understood as “inherent” in a given line of work. Perhaps the
statute is not as clear as it might be in directing us to that
definition. But that definition seems dictated by longstanding
canons of construction. And adopting it furthers the goal of
policing a clear line between the WCA and the ODA.
                                  III
   ¶ 198 The operative statutory terms in my view go to the
mechanism of causation of a given workplace harm. If a worker’s
malady results “by accident,” it is covered by the WCA. If it is an
“occupational disease,” it is covered by the ODA. These are two
pieces of a puzzle in this field. We can understand the coverage of
the WCA only if we also understand the coverage of the ODA.
Our precedents have not always considered both pieces of the
puzzle in their analysis; and that is part of the reason we are left
with such a difficult question in this seemingly simple case.14

   14  The most egregious example is Specialty Cabinet Co., Inc. v.
Montoya, 734 P.2d 437 (Utah 1986). In that case, we expressly
declined to examine “whether the injuries of [the plaintiffs]
satisf[ied] the definition of ‘occupational disease’ under [the
ODA]” because we had already concluded that the maladies fell
                                                            (cont.)

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   ¶ 199 The legal test for differentiating “injury” and
“occupational disease” is “unexpectedness.” There are two
notions of unexpectedness—one going to the incident that caused
the worker’s malady and the other going to the malady itself. And
these two notions of unexpectedness follow from two alternative
senses of “by accident.” Sometimes we use “accident” to refer to a
“mishap.”15 When workplace harm results from a mishap we can
say it happened “by accident,” and thus is covered by the WCA.
    ¶ 200 The other notion of “accident” is “by chance.”16 This is
where the ODA notion of “occupational disease” comes into play.
Cf. Young, 90 P.2d at 177 (outlining a framework for dividing
workplace harm between injury by accident and occupational
disease similar to the one I propose). Some maladies are
“expected” in a given line of work in the legal term-of-art sense of
“occupational disease”—they are understood to be “incident to” a

within our cases’ broad understanding of injury by accident. Id. at
440. In my view, the two issues cannot be interpreted in
isolation—in every case the ODA and the WCA need to be
assessed in relation to each other.
   15  See, e.g., Tintic, 206 P. at 280 (identifying one relevant sense
of accident as an “unlooked for mishap, or an untoward event,
which is not expected or designed by the workman himself”
(citation omitted)); Allen, 729 P.2d at 17–22 (identifying an
“unusual event” as one way, but not the only way of proving
injury by accident); see also WEBSTER’S THIRD NEW INTERNATIONAL
DICTIONARY 11 (2002) (defining “accident” as “2a usu. sudden
event or change occurring without intent or volition through
carelessness, unawareness, ignorance, or a combination of causes
and producing an unfortunate result”).
   16 Andreason, 100 P.2d at 205–06 (noting that “Webster defines
‘accidental’ as ‘happening by chance, or unexpectedly’, and
‘accident’ as an unexpected event” and holding that the WCA’s
coverage extends to an employee’s contraction of a rare disease
during the course of his employment); see also WEBSTER’S THIRD
NEW INTERNATIONAL DICTIONARY 11 (2002) (defining “accident” as
“1a: an event or condition occurring by chance or arising from
unknown or remote causes”).

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given line of work. Id. If a malady is expected in an employee’s
line of work, it cannot be said to have occurred “by chance.” And
that malady would be compensable only under the ODA. See id.
Alternatively, if a malady results from the usual course of the
employment, i.e. without the occurrence of a mishap, but it is not
within the class of maladies that are “incident to” the employee’s
line of work then it has occurred “by chance” and would be
compensable under the WCA. 17 See id.
    ¶ 201 I would treat either of these notions of accident as
sufficient to trigger coverage under the WCA. And I would not
treat “definiteness” as an element of the legal test. The timeframe
of onset of a given malady has no direct bearing on whether it
came about “by accident” or was instead “incident to” a given line
of work. See id. at 176–77. And adding that “factor” to the legal
framework raises all sorts of complications that the lead opinion
declines to answer—as to the interplay between the two factors,
and what to do if they point in opposite directions. See id.

   17  The Chief Justice criticizes my proposed standard as
introducing similar fuzziness. He chides me for not clearly
establishing a basis for determining whether a given malady was
incident to an employee’s employment. See supra ¶¶ 137–41. But
the difference between my test and the Chief Justice’s is that mine
taps into well-established legal terms of art. And there exists a
robust body of law—in cases from other jurisdictions and
treatises—applying these terms in a manner consistent with my
opinion. See, e.g., Indus. Comm’n of Colo. v. Ule, 48 P.2d 803, 804
(Colo. 1935) (applying an “incident to his employment” standard
for occupational disease); Downey v. Kansas City Gas Co., 92 S.W.2d
580, 584 (Mo. 1936) (applying an “incident to” employment
standard to define occupational disease); In re Mack v. Rockland
Cty., 128 A.D.2d 922, 922 (N.Y. App. Div. 1987) (applying an
“incident to” employment standard for occupational disease); see
also 4 ARTHUR LARSON ET AL., LARSON’S WORKERS’ COMPENSATION
LAW § 52 (2017) (“Jurisdictions having general coverage of
occupational disease now usually define the term to include any
disease arising out of exposure to harmful conditions of the
employment, when those conditions are present in a peculiar or
increased degree by comparison with employment generally.”).

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(warning of this precise problem over seventy years ago). That is
the trouble with multi-factored balancing tests. They enhance
flexibility but at the expense of determinacy. I think our law in
this field needs determinacy. And I find no mandate in the statute
or in our cases for the indeterminacy (flexibility) of a balancing
test.
     ¶ 202 This is not to say that “definiteness” (or its converse,
“gradualness”) should be entirely irrelevant. In close cases where
it is unclear whether there was a mishap, it seems to me that the
definiteness of the onset of an injury could be circumstantially
relevant. All else being equal, a distinct onset of an injury would
suggest that something went wrong at work—that the worker was
not just doing his job as required by his employer. 18 Conversely, a
gradual onset could suggest—again, all else equal—that there
may not have been a mishap but instead that the injury or illness
came about as a result of the worker doing his job.19
    ¶ 203 My standard admittedly rejects the “definiteness”
inquiry as an independent element of the legal test. But I am not
repudiating the inquiry entirely; I am treating “definiteness” as
circumstantial evidence, with “unexpectedness” as the core test.
Our cases since Young, moreover, have never been clear on the
role of “definiteness” in the inquiry. When we have referred to

   18 See Tintic, 206 P. at 282 (quoting authority from Indiana
discussing the circumstantial relevance of acute onset of
symptoms as evidence that the employee was exposed to an
unusual risk or a mishap).
   19  See supra ¶¶ 164–69 (discussing the circumstantial role of
gradualness evidence in the Carling case). This latter point is not
inevitable, however. Certainly there could be a series of
mishaps—slips and falls, for example—that over time could result
in harm. See Carling, 399 P.2d at 203 (recognizing the cumulative
trauma theory). And when that happens, it would be apparent
that the worker is entitled to workers compensation, since an
injury by a series of accidents is still an injury by accident. This
underscores the point that gradualness is not the test, or even a
factor to be balanced. It is at most a circumstantial indicator (in
close cases where unexpectedness is in doubt) of unexpectedness.

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occupational diseases as gradually developing, moreover, we
have done so in cases in which the ODA question was not before
us—in cases in which we were asking only about WCA coverage.
See supra ¶¶ 164–71. And our recognition of the cumulative
trauma theory of injury by accident further bolsters the conclusion
that definiteness is not a governing factor. See supra ¶¶ 164–71.
    ¶ 204 Under my approach, cumulative trauma will continue
to function as it has in the past. It is a theory for explaining how a
given malady, not traceable to a single workplace event or strain,
may constitute an injury compensable under the WCA. See
Carling, 399 P.2d at 203. But in such cases, the claimant must still
show that the malady was “unexpected” in the sense set forth
above. See id. (noting that even in cases asserting cumulative
trauma a plaintiff must still show that the malady is not an
occupational disease).
                                 IV
    ¶ 205 The WCA and the ODA are two pieces of a puzzle. We
cannot define the scope of the WCA without accounting for the
terms of the ODA, and we cannot define the ODA’s reach without
accounting for the WCA. Thus, to be covered by the WCA a given
workplace harm must arise out of an “accident” in the course of
employment and not constitute an “occupational disease” covered
by the ODA. The terms “accident” and “disease” are the operative
terms. And they should be defined in accordance with the
meaning they have been given in the law—a meaning that
dovetails with the “unexpectedness” factor identified in our
caselaw, encompassing both an unexpected causal event
(a “mishap”) and an unexpected harm (not an “occupational
disease”).
    ¶ 206 Our cases have long ignored the ODA piece of the
puzzle. I would repudiate the strands of analysis in our cases that
do so. I would reformulate the legal standard in terms set forth in
this opinion.
   ¶ 207 And I would decide this case under this test. First I
would conclude that there was no evidence of a mishap in
Ms. Rueda’s work for JBS USA. For reasons set forth in Justice
Himonas’s opinion I would hold that there is no basis in the
record for concluding that the harm suffered by Ms. Rueda came
about as a result of anything other than her simply doing her job

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over time. And for that reason I would hold that her malady did
not come about “by accident” in the first sense of the causal event
being “unexpected.”
    ¶ 208 That leaves the question of the second sense of
unexpectedness—whether Ms. Rueda’s shoulder condition itself is
“unexpected,” or in other words not an “occupational disease.” I
would examine this question under the standard from Young,
which goes to whether Ms. Rueda’s shoulder condition is one that
is “commonly recognized as incident to the usual performance of
[her] occupation.” Young, 90 P.2d at 177.
    ¶ 209 This is the point on which I deem a remand necessary.
The Labor Commission did not consider this question. That is
understandable given that our cases have not clearly formulated
the test in the manner in which I would apply it. Having now
clarified the test, I would remand the case to allow the Labor
Commission to consider this question in the first instance, upon
briefing, evidence, and argument submitted by the parties.

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