Case Title: Lockheed Martin Corp. v. Super. Ct.

Citation: 

Docket Number: S088458

State: california

Court: California Supreme Court

Date: 2003-03-03T00:00:00Z

Document:
1
Filed 3/3/03 
 
 
 
IN THE SUPREME COURT OF CALIFORNIA 
 
 
 
 
LOCKHEED MARTIN CORPORATION 
) 
et al., 
) 
 
 
) 
 
Petitioners, 
) 
 
 
) 
S088458 
 
v. 
) 
 
 
) 
Ct. App. 4/2 E025064 
THE SUPERIOR COURT OF SAN 
) 
BERNARDINO COUNTY, 
) 
 
) 
San Bernardino County 
 
Respondent; 
) 
Super. Ct. No. RCV31496 
 
 
) 
ROSLYN CARRILLO et al.,  
) 
 
 
) 
 
Real Parties in Interest. 
) 
___________________________________ ) 
 
) 
BAUMAC CORPORATION, 
) 
 
 
) 
 
Petitioner, 
) 
 
 
) 
 
v. 
) 
 
 
) 
Ct. App. 4/2 E025163 
THE SUPERIOR COURT OF SAN 
) 
BERNARDINO COUNTY, 
) 
 
) 
San Bernardino County 
 
Respondent; 
) 
Super. Ct. No. RCV31496 
 
 
) 
ROSLYN CARRILLO,  
) 
 
 
) 
 
Real Party in Interest. 
) 
___________________________________ ) 
 
2
 
PETRO-TEX CHEMICAL 
) 
CORPORATION et al., 
) 
 
 
) 
 
Petitioners, 
) 
 
 
) 
 
v. 
) 
 
 
) 
Ct. App. 4/2 E025181 
THE SUPERIOR COURT OF SAN 
) 
BERNARDINO COUNTY, 
) 
 
) 
San Bernardino County 
 
Respondent; 
) 
Super. Ct. No. RCV31496 
 
 
) 
ROSLYN CARRILLO et al.,  
) 
 
 
) 
 
Real Parties in Interest. 
) 
___________________________________ ) 
 
 
 
In this action for medical monitoring of the residents of a geographic area 
affected by defendants’ toxic chemical discharge, the question before us is 
whether plaintiffs, in moving for class certification, have met their burden of 
demonstrating that common issues of law and fact predominate.  We conclude 
they have not.  We therefore affirm the judgment of the Court of Appeal. 
BACKGROUND 
 
Plaintiffs Roslyn Carrillo et alia allege that defendants Lockheed Martin 
Corporation et alia, in the course of conducting manufacturing operations in the 
City of Redlands, beginning in 1954, discharged dangerous chemicals that 
contaminated the city’s drinking water with harmful toxins and that this 
contaminated water was used by a large portion of the city’s residents.  In 
December 1996, on behalf of themselves and persons similarly situated, plaintiffs 
filed this action in the San Bernardino County Superior Court.  Plaintiffs pray that 
the court order defendants to fund a court-supervised program for the medical 
monitoring of class members, and for punitive damages. 
 
3
 
Plaintiffs moved for certification of a “medical monitoring” class and a 
“punitive damage” class, defined identically as “People who were exposed to 
water contaminated with any of the following chemicals:  TCE, PCE, TCA, other 
solvents, Ammonium Perchlorate, Perchlorate, other unknown rocket fuel 
components and rocket fuel decomposition products, Beryllium, Carbon 
Tetrachloride, Vinyl Chloride, Hydrazine (and Hydrazine derivatives), 
Nitrosamines (and Nitrosamine derivatives), Epoxides (and Epoxide derivatives), 
Triazines (and Triazine derivatives), at levels at or in excess of the dose equivalent 
of the MCL (Maximum Contaminant Level),[1] or in excess of the safe dose where 
there is no MCL, for some part of a day, for greater than 50% of a year, for one or 
more years from 1955 to the present” within specified geographical limits.  (Fns. 
omitted.)  Plaintiffs’ class definition indicated that review of relevant water quality 
documents was ongoing and that the definition would be amended if additional 
chemicals were identified. 
 
One of plaintiffs’ attorneys declared that estimating the number of persons 
in the class was difficult, because the University of Redlands is located within the 
specified geographic boundaries, and persons residing, working or studying within 
the defined area may qualify as class members.  The attorney’s best estimate was 
that the class includes between 50,000 and 100,000 people. 
 
The trial court certified the classes, finding that plaintiffs had met their 
burden of proof under Code of Civil Procedure section 382:  “The Court finds that 
the plaintiffs have a realistic chance of success on the merits.  [¶] Specifically, the 
Court finds that the plaintiffs have shown that there is a realistic chance that the 
                                             
 
1  
A measure based on the health dangers posed by oral ingestion of 
contaminated water developed by the California Department of Health Services. 
 
4
defendants caused contaminants to be leaked into the water table beneath 
Redlands and that this contaminated water was served to the members of the 
proposed class.”  The court also found that there is an ascertainable class, 
concluding it was “not necessary to determine the levels of toxins received by 
each plaintiff at this time and that the geographic limits placed on the class are 
reasonable and related to the alleged contamination.”  The court concluded, 
finally, that members of the class have a well-defined community of interest and 
that common questions of law and fact predominate in the action. 
 
Parties objecting to certification filed three writ petitions in the Court of 
Appeal, which that court consolidated.  Opining that individual issues raised by 
plaintiffs’ claims “clearly predominate, making class certification inappropriate,” 
the Court of Appeal granted a writ of mandate directing the trial court to vacate its 
order certifying the classes.  We granted plaintiffs’ petition for review. 
DISCUSSION 
I.  Suitability of Medical Monitoring Claims for Class Treatment2 
 
We first addressed the availability of medical monitoring as a form of 
damages in Potter v. Firestone Tire & Rubber Co. (1993) 6 Cal.4th 965 (Potter).  
There, residents of homes located near a landfill at which the dumping of toxic 
substances was prohibited brought, as individual claimants, an action against a tire 
manufacturing company that had dumped toxic waste materials, alleging that their 
water supply had thereby been contaminated.  The plaintiffs sought damages for, 
inter alia, fear of cancer and the costs of medical monitoring.  (See id. at pp. 975-
979.)  Recognizing that “expenditures for prospective medical testing and 
evaluation, which would be unnecessary if the particular plaintiff had not been 
                                             
 
2  
Seven justices join this part of the opinion. 
 
5
wrongfully exposed,” are “ ‘detriment proximately caused’ ” by negligent disposal 
of toxic substances (id. at p. 1005 & fn. 24, quoting Civ. Code, § 3333), we held 
that “the cost of medical monitoring is a compensable item of damages where the 
proofs demonstrate, through reliable medical expert testimony, that the need for 
future monitoring is a reasonably certain consequence of a plaintiff’s toxic 
exposure and that the recommended monitoring is reasonable” (Potter, supra, at 
p. 1009).   
 
“In determining the reasonableness and necessity of monitoring,” we stated, 
“the following factors [(hereafter the Potter factors)] are relevant:  (1) the 
significance and extent of the plaintiff’s exposure to chemicals; (2) the toxicity of 
the chemicals; (3) the relative increase in the chance of onset of disease in the 
exposed plaintiff as a result of the exposure, when compared to (a) the plaintiff’s 
chances of developing the disease had he or she not been exposed, and (b) the 
chances of the members of the public at large of developing the disease; (4) the 
seriousness of the disease for which the plaintiff is at risk; and (5) the clinical 
value of early detection and diagnosis.”  (Potter, supra, 6 Cal.4th at p. 1009.)   
 
We have not previously addressed the prerequisites for class treatment of 
medical monitoring claims.  “Section 382 of the Code of Civil Procedure 
authorizes class suits in California when ‘the question is one of a common or 
general interest, of many persons, or when the parties are numerous, and it is 
impracticable to bring them all before the court.’  The burden is on the party 
seeking certification to establish the existence of both an ascertainable class and a 
well-defined community of interest among the class members.”  (Washington 
 
6
Mutual Bank v. Superior Court (2001) 24 Cal.4th 906, 913 (Washington 
Mutual).)3 
 
Plaintiffs assert that separate litigation of each class member’s medical 
monitoring claim would unnecessarily consume vast judicial resources and time.  
They also urge us to repudiate the Court of Appeal’s suggestion that the presence 
of individual issues generally precludes class certification in mass toxic exposure 
cases, arguing any such categorical foreclosure would render our decision in 
Potter meaningless.  Defendants, on the other hand, emphasize that Potter’s 
proximate cause rationale for recognizing medical monitoring costs as damages 
logically extends only to such “increased or different monitoring” (Potter, supra, 6 
Cal.4th at p. 1009, fn. 27) as a defendant’s conduct actually necessitates.  In light 
of their due process right to litigate each individual plaintiff’s actual toxic dosage 
and relevant personal characteristics, defendants argue, individual issues in the 
case predominate over common ones, such that the community of interest required 
for class certification is lacking. 
 
The certification question is “essentially a procedural one that does not ask 
whether an action is legally or factually meritorious.”  (Linder v. Thrifty Oil Co. 
(2000) 23 Cal.4th 429, 439-440 (Linder).)  “The community of interest 
requirement [for class certification] embodies three factors:  (1) predominant 
common questions of law or fact; (2) class representatives with claims or defenses 
typical of the class; and (3) class representatives who can adequately represent the 
                                             
 
3  
Code of Civil Procedure section 382 provides, in its entirety:  “If the 
consent of any one who should have been joined as plaintiff cannot be obtained, 
he may be made a defendant, the reason thereof being stated in the complaint; and 
when the question is one of a common or general interest, of many persons, or 
when the parties are numerous, and it is impracticable to bring them all before the 
court, one or more may sue or defend for the benefit of all.” 
 
7
class.”  (Richmond v. Dart Industries, Inc. (1981) 29 Cal.3d 462, 470.)  Plaintiffs 
acknowledge it is their burden to establish the requisite community of interest and 
that “the proponent of certification must show, inter alia, that questions of law or 
fact common to the class predominate over the questions affecting the individual 
members.”  (Washington Mutual, supra, 24 Cal.4th at p. 913.) 
 
“The ultimate question in every case of this type is whether . . . the issues 
which may be jointly tried, when compared with those requiring separate 
adjudication, are so numerous or substantial that the maintenance of a class action 
would be advantageous to the judicial process and to the litigants.”  (Collins v. 
Rocha (1972) 7 Cal.3d 232, 238; see also Linder, supra, 23 Cal.4th at p. 435.) 
 
Defendants point to our statement that the Potter factors comprise 
“substantial evidentiary burdens” for plaintiffs (Potter, supra, 6 Cal.4th at 
p. 1009), as if to suggest the factors constitute novel proof requirements applicable 
only in medical monitoring cases.  Not so.  Potter recognizes “not a separate tort 
but simply an item of damages that cannot be awarded until liability is established 
under a traditional tort theory.”  (San Diego Gas & Electric Co. v. Superior Court 
(1996) 13 Cal.4th 893, 914, fn. 18, citing Potter, supra, at pp. 1006-1007.)   So to 
observe does not gainsay the high court’s observation that “limitations and 
cautions [like the Potter factors are] important—and integral—parts of the state-
court decisions that permit asymptomatic plaintiffs a separate tort claim for 
medical monitoring costs.”  (Metro-North Commuter R. Co. v. Buckley (1997) 521 
U.S. 424, 444; see also id. at pp. 440-441, citing, inter alia, Potter, supra, at 
p. 1010, fn. 28.)   
 
As defendants acknowledge, Potter simply specified for the medical 
monitoring context the traditional requirement that a plaintiff prove causation of 
damage.  Thus, while in Potter we “ma[de] it clear that the monitoring must be 
‘additional or different’ ” than that previously required (Gutierrez v. Cassiar 
 
8
Mining Corp. (1998) 64 Cal.App.4th 148, 156), we just as clearly stated that, “if 
additional or different tests and examinations are necessitated as a result of the 
toxic exposure caused by the defendant, then the defendant bears full 
responsibility for their costs” (Potter, supra, 6 Cal.4th at p. 1012, fn. 31).   
 
Defendants assert that “the required proof under Potter” includes “that each 
of the elements of the claims asserted on behalf of proposed class members, and 
all applicable defenses, are capable of common proof.”  Again, not so.  We 
consistently have recognized, before and after Potter, that “the fact that each 
member of the class must prove his [or her] separate claim to a portion of any 
recovery by the class is only one factor to be considered in determining whether a 
class action is proper.”  (Vasquez v. Superior Court (1971) 4 Cal.3d 800, 809.)4 
 
In sum, no per se or categorical bar exists to a court’s finding medical 
monitoring claims appropriate for class treatment, so long as any individual issues 
the claims present are manageable.  Accordingly, we shall review the certification 
ruling before us in light of the established standards for class certification 
generally.  
                                             
 
4  
Defendants also assert that their having pled an affirmative defense of 
untimeliness makes class certification inappropriate.  Notice is the only individual 
issue defendants identify as being raised by that defense, however; i.e., they assert 
that when each plaintiff received actual notice of his or her claim will vary from 
individual to individual.  No California court has declined to certify a class action 
specifically because of a statute of limitations defense.  Defendants ultimately 
concede the point, calling “noncontroversial” the proposition that a limitations 
defense does not categorically preclude class certification. 
 
9
II.  Plaintiffs Demonstrated Presence of Some Common Issues5 
 
As indicated, in granting plaintiffs’ certification motion, the trial court 
expressly found that common questions predominate and determined that any 
individual issues that might arise at the time of trial are manageable.  “Because 
trial courts are ideally situated to evaluate the efficiencies and practicalities of 
permitting group action, they are afforded great discretion in granting or denying 
certification.”  (Linder, supra, 23 Cal.4th at p. 435.)  Nevertheless, “we must 
examine the trial court’s reasons for [granting] class certification.”  (Id. at p. 436; 
see also Washington Mutual, supra, 24 Cal.4th at p. 914.)  In particular, we must 
consider whether the record contains substantial evidence to support the trial 
court’s predominance finding, as a certification ruling not supported by substantial 
evidence cannot stand.  (Linder, supra, at pp. 435-436; see also Richmond v. Dart 
Industries, Inc., supra, 29 Cal.3d at p. 470.)   
 
At the outset, the record reveals that plaintiffs’ claims sound generally in 
negligence, entailing proof of the “well-known elements of any negligence cause 
of action, viz., duty, breach of duty, proximate cause and damages.”  (Artiglio v. 
Corning Inc. (1998) 18 Cal.4th 604, 614.)6  Addressing whether questions 
common to the class predominate over questions affecting members individually, 
therefore, required the trial court to consider these elements. 
 
Whether defendants in disposing of their chemical wastes owed a duty of 
care to the class members, i.e., to the persons who lived for the specified period 
within the specified geographical area, is a question of law for the court.  (Parsons 
                                             
 
5  
Seven justices join this part of the opinion. 
6  
The operative fifth amended complaint purports to state causes of action for 
negligence, negligence per se, strict liability for ultrahazardous activity, 
declaratory relief, and injunctive relief. 
 
10
v. Crown Disposal Co. (1997) 15 Cal.4th 456, 472.)  Defendants proffer no reason 
why a court would need to engage in individualized analysis in order to answer 
that question.  The trial court rationally could conclude that the duty element of 
plaintiffs’ claims will be susceptible to common proof. 
 
Additionally, how and when defendants disposed of toxic chemicals and 
whether defendants’ conduct was negligent are, as the Court of Appeal 
recognized, significant common issues of fact in this case.  The parties already 
have presented extensive evidence (including well sampling and other 
hydrological data) about the pattern and degree of contamination of Redlands 
groundwater with various chemicals and the potential health consequences to 
humans of exposure to those chemicals.  Defendants have conceded that common 
issues are present in the case because defendants’ acts allegedly are the same with 
regard to each plaintiff.  Thus, the record also contains substantial evidence 
supporting the conclusion that the breach of duty element of plaintiffs’ claims will 
be susceptible to common proof.7 
 
As noted, when first recognizing the medical monitoring remedy in Potter, 
we focused on the causation and damages elements of such claims, stating that in 
order to recover plaintiffs must demonstrate, through reliable medical expert 
testimony, both that the need for future monitoring is a “reasonably certain 
consequence” of toxic exposure and that the monitoring sought is “reasonable.”  
(Potter, supra, 6 Cal.4th at p. 1009.)  Defendants take the position that plaintiffs in 
moving for class certification have failed to demonstrate either that the causation 
                                             
 
7  
As the Court of Appeal recognized, moreover, whether defendants’ conduct 
was malicious or otherwise such as to justify an award of punitive damages is a 
significant common issue of fact in the case. 
 
11
(“reasonably certain consequence”) or the damages (“reasonable” monitoring) 
elements of their medical monitoring claims will be susceptible to common proof. 
 
Plaintiffs clearly are in a position to address some aspects of causation and 
damages on a class basis.  Defendants concede, for example, that “the toxicity of 
the chemicals” allegedly discharged and “the seriousness of [any] disease for 
which the plaintiff is at risk”—both factors discussed in Potter, supra, 6 Cal.4th at 
page 1009—would be susceptible to common proof.  And as the Court of Appeal 
noted, “the amount of contaminants that entered the groundwater; and, when, 
where, and at what levels were contaminants pumped by the city’s wells entered 
into the domestic water system” are significant common issues of fact in this case. 
 
Plaintiffs contend that, on the theory of liability they intend to present, each 
individual’s exact dosage of each discharged chemical will not be relevant.  
According to expert testimony already in the record, plaintiffs argue, “anyone 
living or working in the area of contamination for at least six months has a 
plausible claim for medical monitoring.”  Class membership, plaintiffs stress, is 
restricted by definition to persons who have received a specified “medically 
significant” minimum dosage “for some part of a day, for greater than 50% of a 
year, for one or more years from 1955 to the present” within specified 
geographical boundaries.  All who meet that definition, plaintiffs propose to prove, 
“will require a generalized monitoring program for the diseases caused by such 
exposure.”  On such a theory, plaintiffs argue, specific individual dosages above 
the specified minimum are not relevant and, therefore, “the significance and 
extent” of toxic exposure (Potter, supra, 6 Cal.4th at p. 1009) will involve largely 
common proof. 
 
The trial court in ruling on the certification motion apparently took 
plaintiffs’ minimum dosage liability theory into account, stating that “proof of the 
[actual] dosage received [by each plaintiff] is not necessary at this time.”  Strictly 
 
12
speaking, that is correct, as in ruling on certification a court does not “ask whether 
[plaintiffs’] action is legally or factually meritorious.”  (Linder, supra, 23 Cal.4th 
at pp. 439-440.)  Moreover, nothing in Potter precludes liability premised on a 
theory that a defendant’s negligence has necessitated increased or different 
monitoring for all, or nearly all, exposed individuals, as long as the need is “a 
reasonably certain consequence of the exposure.”  (Potter, supra, 6 Cal.4th at 
p. 1006.)  That a class of water consumers could, under particularly egregious 
circumstances, demonstrate that everyone who drank from a polluted municipal 
water system over a specified period is at significant risk for having received a 
dose sufficient to cause serious disease and, therefore, needs special monitoring, is 
not inconceivable.  Thus, on an appropriate theory, even dosage issues may be 
susceptible of common proof. 
 
III.  Plaintiffs Failed to Demonstrate Common Issues Predominate 
 
Plaintiffs’ burden on moving for class certification, however, is not merely 
to show that some common issues exist, but, rather, to place substantial evidence 
in the record that common issues predominate.  (Washington Mutual, supra, 24 
Cal.4th at p. 913.)  As we previously have explained, “this means ‘each member 
must not be required to individually litigate numerous and substantial questions to 
determine his [or her] right to recover following the class judgment; and the issues 
which may be jointly tried, when compared with those requiring separate 
adjudication, must be sufficiently numerous and substantial to make the class 
action advantageous to the judicial process and to the litigants.’ ”  (Id. at pp. 913-
914, quoting City of San Jose v. Superior Court (1974) 12 Cal.3d 447, 460.) 
 
While the record on certification undoubtedly contains substantial evidence 
that many Redlands residents were exposed to toxic chemicals during the class 
period, evidence of exposure alone cannot support a finding that medical 
monitoring is a reasonably necessary response.  (Potter, supra, 6 Cal.4th at 
 
13
p. 1009.)  As defendants emphasize, that all plaintiffs exposed to Redlands water 
received identical dosages of any toxic chemicals it contained is unlikely.  On the 
one hand, duration of exposure to polluted water will vary among class members, 
as the class would include numerous people who lived in Redlands for a relatively 
short period of time during the more than 40-year class period.  On the other hand, 
as the Court of Appeal observed, severity of exposure among class members may 
vary according to the amount of water they used. 
 
Examination of the instant record reveals that plaintiffs have not provided 
substantial evidence that they are in a position to resolve possible dosage issues 
with common proof.  Each class member’s actual toxic dosage would remain 
relevant to some degree even if plaintiffs’ “minimum dosage” liability theory 
ultimately were to prove viable.  Membership in the class as plaintiffs have 
defined it requires, not merely exposure to water contaminated with one or more 
of the chemicals listed in the definition, but exposure “at levels at or in excess of 
the dose equivalent of the MCL (Maximum Contaminant Level), or in excess of 
the safe dose where there is no MCL” for at least the defined minimum period of 
time.  (Fns. omitted.)  But plaintiffs’ experts did not unqualifiedly opine that all 
who resided in Redlands for the defined period likely received such dosages.  Dr. 
Dahlgren was “asked to assume that there [was] a clinically significant exposure to 
these chemicals among members of a group that is geographically defined as 
residing within Redlands.”  (Italics added.)  And Dr. Teitelbaum’s opinion that 
“risk of disease due to the toxins is spread over the whole exposed population” 
was qualified with the observation that “[t]he outcome of the exposure . . . is 
determined by many factors including the dose, and the genetic makeup of the 
target individual.”   
 
Moreover, regardless of how a particular medical monitoring class might be 
defined, a plaintiff must demonstrate that “the need for future monitoring is a 
 
14
reasonably certain consequence of [the] toxic exposure” (Potter, supra, 6 Cal.4th 
at p. 1009), i.e., that the plaintiff faces a “significant but not necessarily likely risk 
of serious disease” (id. at pp. 1008-1009).  For the following reasons, we conclude 
plaintiffs have not placed in the record sufficient evidence to warrant the trial 
court’s concluding that they are likely to be able to make that demonstration with 
common proof. 
 
Plaintiffs’ class definition refers to at least 12 different toxic substances, 
and plaintiffs contend that, as a consequence of defendants’ toxic dumping, each 
class member now requires special monitoring for numerous potential medical 
conditions.  In linking their class definition to the toxic dumping and water 
pollution evidence submitted in support of the certification motion, plaintiffs 
relied primarily on the testimony of two medical experts, Dr. James Dahlgren and 
Dr. Daniel Teitelbaum.  We previously have held that reliable medical expert 
testimony may establish the reasonableness and necessity of medical monitoring.  
(Potter, supra, 6 Cal.4th at p. 1009.)  “Expert medical opinion, however, does not 
always constitute substantial evidence . . . .”  (Place v. Workmen’s Comp. App. Bd. 
(1970) 3 Cal.3d 372, 378; see, e.g., Mann v. Cracchiolo (1985) 38 Cal.3d 18, 40 
[medical malpractice action]; Kerr v. Bock (1971) 5 Cal.3d 321, 324 [res ipsa 
loquiter case]; Zemke v. Workmen’s Comp. App. Bd. (1968) 68 Cal.2d 794, 798 
[disability apportionment appeal].)  No reason appears why in the medical 
monitoring context we should depart from our settled understanding that “[a]n 
expert’s opinion which rests upon guess, surmise or conjecture, rather than 
relevant, probative facts, cannot constitute substantial evidence” (Garza v. 
Workmen’s Comp. App. Bd (1970) 3 Cal.3d 312, 318, fn. 3).   
 
Dr. Dahlgren testified in conclusionary fashion that “[a]ll persons who are 
at risk . . . should be in [a] monitoring program.”  He testified generally that 
“chemical exposure in Redlands has resulted in an excess of certain cancers” and 
 
15
“[e]arly diagnosis and treatment for these cancers would improve the prospect of 
cure or long term remissions,” but he acknowledged that “[t]he precise dose of 
exposure experienced by each person cannot be determined exactly because of 
variability in the delivery of the water.”  (Italics added.)  He also conceded that 
“safe levels of exposure in such a setting are not known precisely . . . .”  (Italics 
added.) 
 
Dr. Teitelbaum opined that “any person who fulfills the class definition 
proposed in this case is at greater risk of developing cancer and other serious 
illness which is known by medical scientists and toxicologists to be associated 
with the chemicals at issue in this case.”  But neither Dr. Dahlgren nor Dr. 
Teitelbaum categorically stated that mere qualification under the class definition 
demonstrates a need for medical monitoring irrespective of actual chemical 
dosages received. 
 
We previously have noted that courts confronting medical monitoring 
claims may consider “the relative increase in the chance of onset of disease in the 
exposed plaintiff as a result of the exposure, when compared to (a) the plaintiff’s 
chances of developing the disease had he or she not been exposed, and (b) the 
chances of the members of the public at large of developing the disease” (Potter, 
supra, 6 Cal.4th at p. 1009).  Indisputably, a member of the public’s chances of 
developing any particular disease would be susceptible to common proof, but each 
individual plaintiff’s chances of developing that particular disease, had he or she 
not been exposed as alleged, may not be. 
 
Taken as a whole, the medical expert testimony plaintiffs presented in 
support of their motion for class certification is too qualified, tentative and 
conclusionary to constitute substantial evidence that plaintiffs, by adopting a 
liability theory that makes actual dosages and variations in individual response 
irrelevant, will be able to prove causation and damages by common evidence.  As 
 
16
the record stands, therefore, the causation and damages issues raised by plaintiffs’ 
claims must be counted among those that would be litigated individually, even if 
the matter were to proceed on a class basis.  Especially when considered in light of 
the trial court’s finding that the class consists of an estimated 50,000 to 100,000 
people, that conclusion fatally undermines the trial court’s predominance 
calculation. 
 
In light of the foregoing, we conclude that the trial court’s predominance 
finding is not supported by the record.  The questions respecting each individual 
class member’s right to recover that would remain following any class judgment 
appear so numerous and substantial as to render any efficiencies attainable through 
joint trial of common issues insufficient, as a matter of law, to make a class action 
certified on such a basis advantageous to the judicial process and the litigants.  
(Washington Mutual, supra, 24 Cal.4th at pp. 913-914.) 
IV.  Conclusion 
 
Although the Court of Appeal erred to the extent it stated or implied that no 
action in which plaintiffs seek medical monitoring as a remedy may ever 
appropriately be certified for class treatment, we agree with the court that the trial 
court abused its discretion in granting the instant certification motion.  (Linder, 
supra, 23 Cal.4th at pp. 435-436.) 
DISPOSITION 
 
The judgment of the Court of Appeal is affirmed. 
 
 
 
 
 
 
 
WERDEGAR, J. 
I CONCUR: 
KENNARD, J. 
1 
 
 
 
  
 
 
 
 
 
CONCURRING OPINION BY BROWN, J. 
 
I agree that there is “no per se or categorical bar” to the class treatment of 
medical monitoring claims (lead opn., ante, at p. 8), and that there are some 
common issues (see lead opn., ante, at pp. 9-12).  I also agree that “the trial court 
abused its discretion in granting the instant certification motion” because plaintiffs 
failed to establish that the common issues predominate.  (Id. at p. 16.)  Thus, I join 
in parts I and II of the lead opinion and its disposition.  I, however, cannot join 
part III of the lead opinion because it fails to adequately convey the complexity of 
plaintiffs’ claims and, as a result, fails to acknowledge many of the individual 
issues that must be resolved in order to decide the proposed class action.  Indeed, 
upon considering the full breadth of plaintiffs’ claims in light of the record, I do 
not believe any court could reasonably conclude that they are suitable for class 
treatment. 
I 
To fully appreciate the complexity of plaintiffs’ proposed class action, I 
recount in greater detail the relevant facts. 
In 1954, Grand Central Rocket Company (GCRC) constructed a facility 
used for the production, testing and disposal of rocket propellants (the rocket 
facility) in the Redlands/Crafton area.  In 1958, defendant Petro-Tex Chemical 
Corporation (Petro-Tex)—which was jointly owned by defendants Food 
Machinery and Chemical Corporation (FMC) and Tennessee Gas Transmission 
2 
Corporation (now El Paso Tennessee Pipeline Co.; Tenneco)—acquired GCRC 
and the rocket facility.  In a series of transactions from 1960 to 1961, defendant 
Lockheed Martin Corporation (Lockheed) acquired GCRC and the facility.  
Lockheed manufactured, assembled and tested solid fuel rockets at the facility—
which covered approximately 400 acres—until 1974.  From the opening of the 
rocket facility in 1954 to its closing in 1974, these defendants discharged toxic 
substances throughout the facility’s 400-acre property and contaminated the water 
used by surrounding residents. 
In 1979, Lockheed leased 66 acres of the property to Seven W Enterprises, 
Inc. (Seven W).  Seven W then acquired another 24 acres of adjacent property 
from the City of Redlands and constructed an industrial park.  Since the creation 
of this park, tenants—specifically, defendants Baumac Corporation (Baumac), 
Highland Supply Corporation (Highland) and Palco Communications, Inc. 
(Palco)—have discharged toxic substances around the park and further 
contaminated the water used by surrounding residents. 
As a result of this discharge of toxic substances, plaintiffs filed this class 
action against seven defendants—Petro-Tex, FMC, Tenneco, Lockheed, Baumac, 
Highland and Palco.  Plaintiffs did not seek compensatory damages.  Instead, they 
limited their recovery to “[s]pecial damages . . . to establish a fund for periodic 
medical monitoring and medical testing for each Plaintiff and Class member” and 
“punitive and exemplary damages.”  Consistent with this limitation, plaintiffs 
identified two potential classes—a medical monitoring class and a punitive 
damages class.   
In their motion to certify, plaintiffs defined the class as “[p]eople who were 
exposed to water contaminated with” certain toxic substances “at levels at or in 
excess of the dose equivalent of the MCL (Maximum Contaminant Level), or in 
excess of the safe dose where there is no MCL, for some part of a day, for greater 
3 
than 50% of a year, for one or more years from 1955 to the present, within” certain 
“geographical boundaries” which encompassed the City of Redlands.  Plaintiffs 
estimated the class contained 50,000 to 100,000 members and identified over 12 
toxic substances discharged by defendants, including TCE, PCE, TCA, 
ammonium perchlorate, perchlorate, beryllium, carbon tetrachloride, vinyl 
chloride, hydrazine (and hydrazine derivatives), nitrosamines (and nitrosamine 
derivatives), epoxides (and epoxide derivatives) and triazines (and triazine 
derivatives).  Plaintiffs also identified over 40 different medical conditions that 
may require medical monitoring due to exposure to those substances.1 
The trial court certified both the medical monitoring and punitive damages 
classes.  The Court of Appeal reversed, concluding that the individual issues raised 
by plaintiffs’ claims “clearly predominate” over the common issues. 
                                             
 
1  
According to plaintiffs, exposure to these substances may increase the risk 
for developing the following medical conditions:  “1. Cancer of all types.  2. 
Respiratory effects including asthma, COPD, rhinitis, sinusitis, and bronchitis.  3. 
Neurological deficits including headache syndromes, encephalopathy, neuropathy, 
movement disorders, color blindness, learning disabilities and emotion lability.  4. 
Reproductive damage including sperm damage, miscarriages, infertility and birth 
defects.  5. Immunologic problems including scleroderma, systemic lupus, 
erythematosis, rheumatoid arthritis, Raynaud’s phenomenon, inflammatory bowel 
disease, mixed connective tissue disease and fibromyalgia.  6. Neuroendocrine 
dysregulation including hypothyroidism, menstrual irregularities, decreased libido, 
chronic fatigue syndrome and multiple chemical sensitivity.  7. Psychiatric 
problems including post traumatic stress disorder, depression and anxiety.  8. Skin 
problems including eczema, chloracne, contact dermatitis, defatting dermatitis and 
allergic dermatitis.  9. Cardiac effects including arteriosclerosis, dysrhythmias, 
cardiac malformations and cardiomyopathy.  10. Hematologic damage including 
thrombocytopenia, anemia and leukopenia.” 
4 
II 
Plaintiffs seek to certify a class consisting of all people exposed to a 
specified dose of one of at least 12 different toxic substances for a certain period 
of time from 1955 to the present, within a geographical area encompassing the 
City of Redlands.  They allege that each class member—estimated to number 
50,000 to 100,000—may require medical monitoring for over 40 medical 
conditions.  Plaintiffs seek to recover medical monitoring damages from seven 
different defendants that dumped these chemicals in various locations on a 400-
plus-acre property over a time period of 40-plus years.  Given the size and 
complexity of these class claims, I do not believe a court could reasonably 
conclude that the common issues predominate and certify the proposed class. 
“[T]he cost of medical monitoring is a compensable item of damages where 
the proofs demonstrate, through reliable medical expert testimony, that the need 
for future monitoring is a reasonably certain consequence of a plaintiff’s toxic 
exposure and that the recommended monitoring is reasonable.”  (Potter v. 
Firestone Tire & Rubber Co. (1993) 6 Cal.4th 965, 1009 (Potter).)  Under this 
standard, a plaintiff may not obtain medical monitoring “based ‘solely upon a 
showing of an increased but unquantified risk resulting from exposure to toxic 
chemicals.’ ”  (Ibid.)  Rather, “toxic exposure plaintiffs may recover ‘only if the 
evidence establishes the necessity, as a direct consequence of the exposure in 
issue, for specific monitoring beyond that which an individual should pursue as a 
matter of general good sense and foresight.’ ”  (Ibid., italics added.)  The 
availability of monitoring therefore depends on the particular need of a particular 
plaintiff.  (See ibid.) 
Thus, a member of plaintiffs’ proposed class may obtain medical 
monitoring damages for a medical condition only if that member’s exposure to the 
chemicals dumped by defendants necessitate more monitoring than he or she 
5 
would otherwise need.  (See Potter, supra, 6 Cal.4th at p. 1009.)  To order 
additional medical monitoring, a trier of fact must therefore determine:  (1) the 
extent of monitoring that the class member would have required for that medical 
condition absent exposure; and (2) whether the class member needs any additional 
monitoring due to exposure to the substances discharged by defendants. 
Applying this standard of causation, the majority concludes that “the 
medical expert testimony plaintiffs presented in support of their motion for class 
certification is too qualified, tentative and conclusionary to constitute substantial 
evidence that plaintiffs, by adopting a liability theory that makes actual dosages 
and variations in individual response irrelevant, will be able to prove causation 
and damages by common evidence.”  (Lead opn., ante, at p. 15.)  In reaching this 
conclusion, the majority focuses on plaintiffs’ failure to show that dosages issues 
and the need for medical monitoring are susceptible to common proof.  (See lead 
opn., ante, at pp. 13-15.)  I agree with the majority so far as it goes.  But the 
majority fails to fully consider the extraordinary complexity of plaintiffs’ claims in 
its analysis and, as a result, understates the deficiencies of plaintiff’s showing in 
support of class certification. 
As a threshold matter, determining each defendant’s liability to the class for 
medical monitoring damages requires the resolution of a staggering number of 
complex individual issues.  First, determining the extent of monitoring required by 
each class member absent exposure poses a highly individualized inquiry.  A class 
member’s risk of developing a medical condition depends on numerous factors 
unique to that member, such as age, gender, lifestyle, fitness, preexisting 
conditions, exposure to hazardous substances not released by defendants, etc.  
Given that plaintiffs identify over 40 medical conditions that may necessitate 
additional monitoring for approximately 50,000 to 100,000 individuals, the 
number and complexity of these individual determinations is overwhelming. 
6 
Second, determining whether each class member requires additional 
monitoring due to exposure requires individual litigation of numerous and 
substantial questions.  A class member’s need for additional monitoring hinges on 
the particular traits or characteristics of each class member.  As plaintiffs’ own 
experts acknowledge, human reaction to environmental and other hazards varies 
from individual to individual.  It is directly affected not only by the individual’s 
dosage or extent of exposure, but also by preexisting conditions, genetic makeup, 
age, gender, size, nutrition, adaptation and acclimatization to geographic and 
climatological factors, lifestyle, family history, social history, occupational history 
and personal health history.  Thus, whether an individual class member needs 
additional medical monitoring depends heavily on numerous factors specific to 
that individual—and not just the dosage of toxic substances received.  Moreover, 
the clinical value of early detection and diagnosis may vary significantly 
depending on the medical condition at issue and the individual characteristics of 
each class member.  Given the number of hazardous substances involved, the 
number of medical conditions implicated, and the size of the class, resolution of 
the many individual issues necessary to establish each individual class member’s 
entitlement to additional monitoring due to exposure would be a herculean task.  
Because determining “the basic issue of defendant[s’] liability to the purported 
class” requires the resolution of countless issues specific to each class member, 
class treatment is not appropriate.  (City of San Jose v. Superior Court (1974) 12 
Cal.3d 447, 463 (City of San Jose).) 
Aside from the individualized inquiries necessary to establish liability, the 
individualized inquiries necessary to establish the extent of additional medical 
monitoring required by those class members who prove liability are also numerous 
and substantial.  To determine the extent of monitoring required, the court would 
have to ascertain the significance and extent of each member’s exposure to the 
7 
chemicals dumped by defendants.  Because of the number of chemicals involved, 
their potential synergistic effects, the duration of dumping, the size of the area in 
which the dumping occurred, and the intricacies of hydrogeology, this task 
depends on the resolution of numerous questions specific to each class member.  
Consequently, individual questions dominate such a determination.  Finally, the 
resolution of various affirmative defenses—i.e., statute of limitations—also 
requires separate adjudication for each class member. 
Viewed altogether, the individual questions that must be resolved in order 
to resolve plaintiffs’ claims are staggering in both number and complexity.  
Indeed, “subsequent to the rendering of any class judgment which determined in 
plaintiffs’ favor whatever questions were common to the class,” the trial court in 
this case would have to conduct tens of thousands of complex individualized trials 
over causation, damages and affirmative defenses.  (Vasquez v. Superior Court 
(1971) 4 Cal.3d 800, 809.)  Invocation of the class action mechanism under these 
circumstances would not promote efficiency.  Rather, it would “deprive either the 
defendant[s] or the members of the class—or both—of a fair trial.”  (See City of 
San Jose, supra, 12 Cal.3d at p. 462.) 
The possible creation of subclasses makes no difference in this case.  While 
subclasses may sufficiently minimize the individual issues in certain cases, we 
have long recognized that “there are limits outside of which the subclassification 
system ceases to perform a sufficiently useful function to justify the maintenance 
of the class action.”  (City of San Jose, supra, 12 Cal.3d at p. 463, fn. 10.)  This is 
such a case.  Plaintiffs allege that seven different defendants dumped over 12 
chemicals at multiple locations on a 400-plus-acre property over 40-plus years.  In 
doing so, these defendants allegedly harmed 50,000 to 100,000 people with 
different characteristics by placing them at greater risk for contracting over 40 
possible medical conditions.  “Given the number of variables involved in this 
8 
case,” the potential number of subclasses is mind-boggling.  (Kennedy v. Baxter 
Healthcare Corp. (1996) 43 Cal.App.4th 799, 813.)  Class certification under 
these facts would therefore defeat “the purposes served by class action litigation.”  
(Ibid.) 
In this respect, O’Connor v. Boeing North American, Inc. (C.D.Cal. 2000) 
197 F.R.D. 404 (O’Connor II) is instructive.  In O’Connor v. Boeing North 
American, Inc. (C.D Cal. 1998) 184 F.R.D. 311, 316 (O’Connor I) and  
O’Connor II, the plaintiffs alleged that the defendants discharged radioactive and 
nonradioactive hazardous substances at four facilities.  (See O’Connor I, at p. 
316.)  This discharge allegedly created a continuing health hazard for people 
living near these facilities.  (Id. at pp. 316-317.)  The plaintiffs sought to certify 
three classes.  As relevant here, class I consisted of “ ‘[a]ll persons:  (1) who 
presently reside or work in the Contamination Area or who, at any time since 
1946, have resided or worked in the Contamination Area; and (2) who have not 
been diagnosed with a type of cancer or other serious illness or disease which may 
be attributed to exposure to the radioactive contaminants and/or hazardous, non-
radioactive substances released from’ ” the facilities.  (Id. at p. 317.)  Like 
plaintiffs, the O’Connor plaintiffs sought to establish a medical monitoring 
program for the class funded by the defendants.  (Ibid.) 
Although the federal district court initially certified the medical monitoring 
class (see O’Connor I, supra, 184 F.R.D. at p. 339), it later decertified the class 
(see O’Connor II, supra, 197 F.R.D. at p. 413).  In doing so, the court not only 
cited the “individualized focus of the statute of limitations defense” (ibid.), but 
also admitted that it had “underestimated the difficulty of applying the 
individualized factors required by” Potter “to the Class I medical monitoring 
claim in its” order certifying the class (id. at p. 413, fn. 6). 
9 
These conclusions are especially cogent in this case, given that plaintiffs’ 
class claims and the class claims in O’Connor II are analogous in their breadth and 
complexity.  Moreover, the reasoning of the court in O’Connor II is even more 
persuasive here because plaintiffs’ proposed medical monitoring class is even 
broader than the class proposed in O’Connor II.  (See O’Connor I, supra, 184 
F.R.D. at p. 317 [the plaintiffs’ class expressly excluded those persons who have 
been diagnosed with a medical condition attributable to exposure].)  Indeed, other 
courts have refused to certify medical monitoring classes in analogous cases using 
similar reasoning.  (See, e.g., Goasdone v. American Cyanamid Corp.  (Goasdone) 
(N.J. Super. 2002) 808 A.2d 149, 172-173 [refusing to certify a medical 
monitoring class consisting of all people who worked at a textile plant for 30 days 
or more from 1946 until 1983 and were exposed to benzidine-related dyes 
resulting in an increased risk of contracting bladder cancer because the individual 
issues predominated].) 
The federal cases cited by plaintiffs in support of class certification are 
inapposite.  Even assuming these cases are still persuasive (see Goasdone, supra, 
808 A.2d at p. 169), all of them involved simpler facts and claims.2  By contrast, 
                                             
 
2  
(See, e.g., Friends for All Children, Inc. v. Lockheed Aircraft Corp. (D.C. 
Cir. 1984) 746 F.2d 816, 819-820 [alleging that a single defendant negligently 
manufactured an aircraft that crashed, potentially causing a single neurological 
development disorder in no more than 149 children and seeking the creation of a 
medical monitoring fund for approximately 40 children]; Day v. NLO (S.D.Ohio 
1994) 851 F.Supp. 869, 874-875 [alleging that a plant exposed visitors and 
workers to hazardous materials and seeking to certify a class of “workers and 
frequenters” to the plant]; Yslava v. Hughes Aircraft Co. (D.Ar. 1993) 845 F.Supp. 
705, 707-708, 712 [alleging that a single defendant disposed of hazardous wastes 
in a single location over 29 years and identifying “24 separate subgroups 
representing precise geographic areas where plaintiffs lived, worked or went to 
school”]; Boggs v. Divested Atomic Corp. (S.D.Ohio 1991) 141 F.R.D. 58, 60-62 
[alleging that a single plant released radioactive substances and seeking to certify a 
 
(footnote continued on next page) 
10 
plaintiffs’ class claims are incredibly complex even for a mass tort action.  
Permitting certification under these facts would, as a practical matter, make all 
medical monitoring claims subject to class treatment.  Such a result would open 
the “floodgates of litigation” notwithstanding our carefully crafted decision in 
Potter.  (Potter, supra, 6 Cal.4th at p. 1009.)  Rather than do so, I believe other 
procedures traditionally used to manage complex litigation, like consolidation and 
coordination, may be more appropriate.  (See Rose v. Medtronics, Inc. (1980) 107 
Cal.App.3d 150, 155 [“consolidation of actions is the preferred procedure for 
disposition of ” mass tort cases].) 
Accordingly, I join the lead opinion in affirming the judgment of the Court 
of Appeal. 
 
 
 
 
 
 
 
BROWN, J. 
WE CONCUR: 
 
 
BAXTER, J. 
 
CHIN, J. 
                                                                                                                                                              
(footnote continued from previous page) 
class numbering in the thousands of persons “who were residents, property owners 
or lessees of property within a radius of six miles from” the plant]; but see Boggs 
v. Divested Atomic Corp. (S.D.Ohio Mar. 24, 1997, No. C-2-90-840) 1997 WL 
33377790 [subsequently decertifying the class].) 
 
1
 
 
 
 
 
 
 
 
CONCURRING AND DISSENTING OPINION BY MORENO, J. 
 
I join Parts I and II of the lead opinion, holding that there is no per se bar to 
class treatment of medical monitoring claims, and concluding that plaintiffs have 
demonstrated some common issues as a class.  However, I dissent from the lead 
opinion’s holding in Parts III and IV that the trial court abused its discretion in 
finding that common issues predominate and in certifying the class in this case.  
Contrary to the majority, I conclude that the trial court did not abuse its discretion 
in certifying the class of plaintiffs seeking damages for the cost of future medical 
monitoring.  
Plaintiffs in the present case allege that defendants caused contaminants, 
including toxic rocket fuel (ammonium perchlorate) and trichloroethylene (a 
carcinogenic solvent) to be leaked into the water table in Redlands and that this 
contaminated water was consumed by members of the proposed class.  Plaintiffs 
brought a claim seeking damages for the cost of a court-supervised medical 
monitoring program, and punitive damages.  The trial court determined that 
plaintiffs had a realistic chance of success on the merits.  In addition, the trial 
court found that common issues predominate in this action and that plaintiffs could 
pursue their claims as a class.   
The decision of a trial court to certify a class action is reviewed for abuse of 
discretion.  “Because trial courts are ideally situated to evaluate the efficiencies 
and practicalities of permitting group action, they are afforded great discretion in 
 
2
granting or denying certification.”  (Linder v. Thrifty Oil Co. (2000) 23 Cal.4th 
429, 435 (Linder).)  The majority disregards this deferential standard of review 
and instead engages in its own examination of the record to decide that, while 
there are some common issues in this case, these issues do not predominate.  The 
majority concludes, therefore, that the trial court erred in certifying the class.  I 
believe that substantial evidence supports the trial court’s certification order.  
Because I would uphold the trial court’s decision to certify the class in this case, I 
dissent. 
I. 
A.  Applicable Standard of Review 
The lead opinion briefly summarizes the standard for reviewing a trial 
court’s decision to certify a class.   (See lead opn., ante, at p. 9.)  This short 
discussion, however, does not fully acknowledge the level of deference given to a 
trial court.  The lead opinion cites our opinion in Linder, supra, 23 Cal.4th at page 
436, for the proposition that “we must examine the trial court’s reasons for 
[granting] class certification.”  The lead opinion does not mention, however, that 
in the following sentence in Linder we clarify that “ ‘Any valid pertinent reason 
stated will be sufficient to uphold the order.’ ”  (Ibid.)  Thus, while the lead 
opinion is correct in stating that reviewing courts may overturn a trial court ruling 
on certification if it is not supported by substantial evidence, it misses the point 
that any valid pertinent reason is sufficient to uphold an order for certification.  
This is an extremely deferential standard of review.   
Further, we have stated that “a trial court ruling [on certification] supported 
by substantial evidence generally will not be disturbed ‘unless (1) improper 
criteria were used [citation]; or (2) erroneous legal assumptions were made 
[citation]’ ” (Linder, supra, 23 Cal.4th at pp. 435-436.)  For example, in 
Washington Mutual Bank v. Superior Court (2001) 24 Cal.4th 906, 927 
 
3
(Washington Mutual), we reversed a Court of Appeal decision upholding the trial 
court’s certification order because the order was “premised upon [a] faulty legal 
assumption.”  In the present case, however, the majority does not conclude that the 
trial court used improper criteria in granting the certification order, nor do they 
find that the trial court made erroneous legal assumptions.  In such a case, “the 
sole question is whether the court abused its discretion.”  (Occidental Land, Inc. v. 
Superior Court (1976) 18 Cal.3d 355, 361.)   
In addition, an appellate court’s review of a certification order should not 
consider the merits of the underlying suit.  As we have said, “we view the question 
of certification as essentially a procedural one that does not ask whether an action 
is legally or factually meritorious.”  (Linder, supra, 23 Cal.4th at pp. 439-440.)  In 
reviewing a certification order, then, we assume that the plaintiffs’ theories of 
liability are viable.  Any challenge to the viability of the plaintiffs’ claims should 
be left for a pleading or motion that considers the merits of these claims.  As we 
have stated, “[w]hen the substantive theories and claims of a proposed class suit 
are alleged to be without legal or factual merit, the interests of fairness and 
efficiency are furthered when the contention is resolved in the context of a formal 
pleading (demurrer) or motion (judgment on the pleadings, summary judgment, or 
summary adjudication) that affords proper notice and employs clear standards.  
Were we to condone merit-based challenges as part and parcel of the certification 
process, similar procedural protections would be necessary to ensure that an 
otherwise certifiable class is not unfairly denied the opportunity to proceed on 
legitimate claims.”  (Id. at pp. 440-441.) 
B.  Trial Court’s Certification Order 
In the certification order at issue here, the trial court explained that while it 
recognized that this case presents some individual issues, these issues were 
“manageable.”  The trial court found that plaintiffs’ case derived from a common 
 
4
nucleus of facts and that common issues predominate.  Because we review the 
certification order for abuse of discretion, I set forth in detail its relevant contents. 
In granting the certification order, the trial court stated that its ruling was 
interlocutory: “This order may be rescinded or modified as the changed 
circumstances of the class, its representatives, or particular actions require.”  After 
concluding that plaintiffs have a realistic chance of success on the merits, and 
recognizing that plaintiffs allege that they were exposed as a class to water 
contaminated by toxic chemicals, the court noted: “This court further finds that 
although there is no evidence of the dosage of toxins that were received by the 
members of the proposed class, proof of dosage received is not necessary at this 
time.”  Additionally, the court found that “it is not necessary to determine the 
levels of toxins received by each plaintiff at this time.”   
Most importantly, the trial court found that “[t]he issues of law and fact in 
this case all evolve from a common nucleus of facts and these common questions 
of law and fact predominate over those that are individual to the plaintiffs.  [¶]  
The court recognizes that there are individual issues that will have to be dealt with 
at the time of trial, however, the court finds these individual issues to be 
manageable.”   
Turning to the benefits of class treatment, the trial court found that 
“proceeding with this action as a class action will substantially benefit the court 
and the litigants because it will provide a superior method of dealing with the 
common questions of law and fact that exist in this case.”  The trial court noted 
that it had “considered other methods of proceeding with this litigation” but found 
that “the class action is the superior method.”   
In addition, the trial court found that the prerequisites for a class action set 
forth in Federal Rules of Civil Procedure, rule 23(a) (28 U.S.C.), were satisfied.  
We have stated that in determining whether a class action proponent has 
 
5
demonstrated a predominance of common issues and manageability of the class, 
“we may look to the procedures governing federal class actions under rule 23 of 
the Federal Rules of Civil Procedure (28 U.S.C.) . . . for guidance.”  (Washington 
Mutual, supra, 24 Cal.4th at p. 922.)  The trial court in this case found that “(1) 
The class consists of an estimated 50,000 – 100,000 people and therefore, the 
members of the class are so numerous that joinder of members of the class as 
individual plaintiffs is impracticable; (2) The common questions of law and fact 
predominate over those that are individual to the plaintiffs; (3) The claims of the 
persons representing the class are typical of the class generally; (4) The persons 
acting as class representatives are able to fairly and adequately protect the interest 
of all members of the class and class counsel is able to adequately represent the 
class.”   
II. 
Applying the standard of review to the trial court’s certification order, it is 
clear that the trial court did not abuse its discretion in certifying the class in this 
case.  Contrary to the majority, I conclude that substantial evidence supports the 
trial court’s determination that common issues predominate and that any 
individual issues in this case are manageable. 
A.  Duty and Breach 
In reviewing the factors that plaintiffs will have to prove at trial to recover 
medical monitoring damages, there is substantial evidence to support the trial 
court’s conclusion that common issues predominate.  Part II of the lead opinion 
recognizes that it is undisputed that several key issues at trial will be proven by 
evidence that is common to all class members.  (Lead opn., ante, at pp. 9-12.)  As 
the lead opinion states, because plaintiffs’ claims sound generally in negligence, 
plaintiffs will have to prove duty, breach of duty, proximate cause, and damages.  
(Artiglio v. Corning Inc. (1998) 18 Cal.4th 604, 614.)  The lead opinion 
 
6
acknowledges that the issue of whether defendants owed a duty of care to the 
proposed class members is susceptible to common proof.  (Lead opn., ante, at pp. 
9-10.)  In addition, the lead opinion states that the issue of defendants’ breach of 
this duty of care is also one that will be proven by evidence common to all class 
members.  (Lead opn., ante, at pp. 9-10.)   
The trial court, in its certification order, explained that it found that 
common issues predominate because “[t]he issues of law and fact in this case all 
evolve from a common nucleus of facts.”  This conclusion is supported by 
substantial evidence since the central question of whether defendants acted 
negligently is common to all class members.  In order to establish defendants’ 
liability, plaintiffs will present common evidence attempting to show that 
defendants negligently disposed of toxic chemicals that contaminated the 
groundwater of Redlands.  Evidence of how these chemicals were discharged, and 
in what amounts, and how they entered into the domestic water system, will be 
common to all class members.  In fact, all of defendants’ actions will be proven by 
common evidence.    
B.  Proximate Cause and Damages: The Potter Factors 
In addition to establishing defendants’ duty of care and their breach of this 
duty, plaintiffs will also have to show that their injuries were proximately caused 
by defendants’ actions and that they are entitled to damages as compensation for 
these injuries.  Plaintiffs in this case, however, do not seek traditional 
compensatory damages.  Instead, they seek to recover damages for the cost of 
medical monitoring of future injuries.  As we explained in Potter, “[i]n the context 
of a toxic exposure action, a claim for medical monitoring seeks to recover the 
cost of future periodic medical examinations intended to facilitate early detection 
and treatment of disease caused by a plaintiff’s exposure to toxic substances.”  
 
7
(Potter v. Firestone Tire &  Rubber Co. (1993) 6 Cal.4th 965, 1004-1005 
(Potter).) 
Damages for medical monitoring are unlike a traditional damages remedy 
because in order to recover medical monitoring damages, a plaintiff need not 
demonstrate a present physical injury or even show proof that injury is reasonably 
certain to occur in the future.  We have determined that “medical monitoring may 
be called for as a result of defendant’s tortious conduct, even in the absence of 
actual physical injury.”  (Potter, supra, 6 Cal.4th 965, 1007.)  “[R]ecovery of 
medical monitoring damages should not be dependent upon a showing that a 
particular cancer or disease is reasonably certain to occur in the future.”  (Id. at p. 
1008.)  To recover medical monitoring damages, a plaintiff must show that “the 
need for future monitoring is a reasonably certain consequence of a plaintiff’s 
toxic exposure and that the recommended monitoring is reasonable.”  (Id. at p. 
1009.) 
As the lead opinion explains, we set forth five factors in our decision in 
Potter (the Potter factors) that are relevant to a court’s determination of the 
reasonableness and necessity of medical monitoring.  (Potter, supra, 6 Cal.4th at 
p. 1009; see lead opn., ante, at p. 5.)  The five Potter factors are not novel 
evidentiary burdens; they are simply meant to give courts guidance in determining 
whether plaintiffs seeking medical monitoring have met the traditional tort 
requirements of causation and damage.  (See lead opn., ante, at p. 7.)  Thus, 
plaintiffs will need to present evidence relating to the Potter factors in order to 
prove the elements of proximate causation and damages.  
As with the elements of duty and breach, I agree with the majority that 
some of the Potter factors are clearly subject to common proof.  The majority 
recognizes that two of the five Potter factors—the toxicity of the chemicals 
 
8
allegedly discharged and the seriousness of a disease for which the plaintiffs are at 
risk—will involve common proof.   
Furthermore, the lead opinion acknowledges that “[s]trictly speaking,” the 
trial court was correct in ruling that the first Potter factor—the significance and 
extent of plaintiffs’ exposure to chemicals—is subject to common proof, since 
under plaintiffs’ theory of liability, the exact dosage of each discharged chemical 
received by each individual plaintiff is irrelevant.  (Lead opn., ante, at pp. 11-12.)  
Part III of the lead opinion, however, ultimately rejects plaintiffs’ theory of 
liability and concludes that the first Potter factor is not subject to common proof.  
It is largely this determination, that the issue of plaintiffs’ exposure is not subject 
to common proof, that leads the majority to reject the trial court’s conclusion that 
common issues predominate.  For this reason, I will focus on this factor to explain 
why I believe that the issue of exposure is subject to common proof, and that the 
trial court did not err in concluding that common issues predominate. 
The lead opinion refers to Potter for the proposition that “evidence of 
exposure alone cannot support a finding that medical monitoring is a reasonably 
necessary response.”  (Lead opn., ante, at p. 12, citing Potter, supra, 6 Cal.4th at 
p. 1009.)  This statement is, of course, correct.  A plaintiff cannot recover the cost 
of medical monitoring merely because he or she has been exposed to toxic 
chemicals.  Instead, a plaintiff must show the need for medical monitoring in light 
of the other Potter factors, including the toxicity of these chemicals and the 
seriousness of the diseases for which plaintiff is at risk as a result of the exposure 
to these chemicals. 
The lead opinion is incorrect, however, in concluding from our statements 
in Potter that the issue of plaintiffs’ exposure to toxic chemicals cannot be subject 
to common proof.  We did not decide in Potter whether evidence of exposure 
could be presented on a class-wide basis.  We merely said that one factor relevant 
 
9
in determining whether a plaintiff could recover the cost of medical monitoring 
was the significance and extent of plaintiff’s exposure to the toxic chemicals.  We 
did not say whether or not plaintiffs could present evidence of exposure on a class-
wide basis by alleging that all plaintiffs in a proposed class have received a certain 
minimum level of exposure to the chemicals. 
Plaintiffs’ theory of liability is that all individuals who meet the class 
requirements are entitled to medical monitoring.  Plaintiffs allege that everyone 
exposed to defendants’ discharged chemicals over specified minimum safety 
levels “for some part of a day, for greater than 50% of a year, for one or more 
years from 1955 to the present” will require specialized monitoring for diseases 
caused by such exposure.  Class membership, therefore, is restricted by definition 
to persons who have received a specified, medically significant minimum level of 
exposure to the allegedly contaminated water.  Plaintiffs claim that individual 
class members need only establish their residency and/or employment in the 
contaminated area for at least six months to be eligible for medical monitoring.  
Thus, under plaintiffs’ theory of liability, the significance and extent of toxic 
exposure is susceptible to common proof.  While plaintiffs may or may not be able 
to succeed in proving this theory, the trial court was correct in accepting this 
theory for purposes of a certification motion.   
The majority concludes, however, that plaintiffs cannot prove exposure on 
a class-wide basis because each plaintiff received different dosages of toxic 
chemicals.  (See lead opn., ante, at p. 13.)  Of course, whether someone is exposed 
to toxic chemicals is not the same issue as what dosage of the chemical he or she 
received.  I agree with the majority that any relevant questions relating to 
variations in actual chemical dosage received by individual members of the 
plaintiff class are likely not susceptible to common proof.  Plaintiffs, however, 
 
10
have constructed their theory of liability to make these questions of individual 
dosage largely irrelevant.   
The majority errs in examining the record in this case to determine whether 
plaintiffs’ experts’ declarations support plaintiffs’ theory of liability.  The lead 
opinion finds that “the medical expert testimony plaintiffs presented in support of 
their motion for class certification is too qualified, tentative, and conclusionary to 
constitute substantial evidence that plaintiffs, by adopting a liability theory that 
makes actual dosages and variations in individual response irrelevant, will be able 
to prove causation and damages by common evidence.”  (Lead opn., ante, at p. 
15.)  This type of reevaluation of the record and critique of expert testimony is 
inappropriate in the context of a certification motion.   
In reviewing a certification order, we are not called upon to determine 
whether plaintiffs’ experts’ declarations demonstrate the reasonableness and 
necessity of medical monitoring.1  Whether the evidence submitted in support of 
certification is adequate to support plaintiffs’ theories on their merits is not before 
us, since certification may not be “conditioned upon a showing that class claims 
for relief are likely to prevail.”  (Linder, supra, 23 Cal.4th at p. 443.)   
By rejecting the viability of plaintiffs’ theory of liability—that all plaintiffs 
in the proposed class are entitled to medical monitoring based on a threshold level 
                                             
 
1  
I note, however, that the record does contain evidence to support plaintiffs’ 
theory of liability.  Plaintiffs’ expert Dr. Teitlebaum opined that “even small doses 
of environmental carcinogens . . . such as those present in Redlands, [and] their 
breakdown products delivered to the population, are quite capable of interacting 
with the human genome to produce malignant outcomes.”  Dr. Teitlebaum further 
stated that “any person who fulfills the class definition proposed in this case is at 
greater risk of developing cancer and other serious illness which is known by 
scientists and toxicologists to be associated with the chemicals at issue in this 
case.”   
 
11
of exposure—the majority is effectively ruling on the substantive merits of 
plaintiffs’ claims in the context of a procedural motion for certification.  Such a 
conclusion should not be made in the context of a certification motion but rather 
should be made in the context of a formal pleading or motion that affords proper 
notice to the parties and follows clear standards of review.  By ruling on the merits 
of plaintiffs’ claims in the context of a certification motion, the majority denies 
plaintiffs the procedural protections to which they are entitled.  (Linder, supra, 23 
Cal.4th at p. 440.)   
In addition, the majority’s search of the record for evidence to support 
plaintiffs’ theory of liability risks making a motion for certification a more 
complicated and burdensome procedure.  As we have cautioned, “[s]ubstantial 
discovery . . . may be required if plaintiffs are expected to make meaningful 
presentations on the merits.  All of that is likely to render the certification process 
more protracted and cumbersome, even if . . . trial courts were prohibited from 
resolving factual disputes.  Such complications hardly seem necessary when 
procedures already exist for early merit challenges.”  (Linder, supra, 23 Cal.4th at 
p. 441, fn. omitted.) 
Furthermore, the majority ignores the fact that the nature of the remedy 
requested in this case reduces the importance of each plaintiff’s individual 
exposure.  If plaintiffs had sought to recover compensatory damages, the issue of 
each individual’s exposure clearly would have been relevant to each individual’s 
recovery.  In seeking medical monitoring damages, however, plaintiffs need not 
prove present or future individual injury.  Instead, they need only show that 
medical monitoring is reasonably necessary as a result of exposure to the toxic 
chemicals.  Plaintiffs allege that all class members, having received a threshold 
level of exposure, are entitled to the same remedy because they are all at a greater 
risk of disease.  This is the approach taken in Yslava v. Hughes Aircraft Co. 
 
12
(D.Ariz. 1993) 845 F.Supp. 705, where the court determined that for a class action 
seeking medical monitoring, “[a]ll persons who were exposed to [a certain] level 
for at least a year would qualify for medical monitoring. Thus, proof of an exact or 
individual amount of exposure or particular risk level is not necessary. The core 
issues of liability and exposure are common to all class members.” (Id. at p. 713, 
italics added.) 
Ultimately, the majority, in rejecting plaintiffs’ theory of liability, fails to 
give proper deference to the findings of the trial court.  The trial court accepted 
plaintiffs’ theory of liability for purposes of the certification order.  As the trial 
court concluded, “although there is no evidence of the dosage of toxins that were 
received by the members of the proposed class, proof of the dosage received is not 
necessary at this time.”  Moreover, the certification order was interlocutory.  Thus, 
should plaintiffs’ theory of liability prove to be not viable at a later date, the trial 
court retained the option of decertifying the class.  (See O’Connor v. Boeing North 
American, Inc. (2000) 197 F.R.D. 404, 408-409 [while trial court initially certified 
class seeking damages for medical monitoring, the court decertified the class after 
its summary judgment rulings].)  At this early point in the proceedings, however, 
the trial court assumed, as it should, that plaintiffs’ theory of liability was viable.  
Under this theory, the first Potter factor—plaintiffs’ exposure to the toxic 
chemicals—is subject to common proof. 
Turning to the remaining Potter factors, the lead opinion briefly states that 
proof of each individual plaintiff’s chances of developing a particular disease, had 
he or she not been exposed, may not be subject to common proof.  I agree with the 
lead opinion that an individual’s preexisting conditions are, by definition, not 
susceptible to common proof.  I am not convinced, however, that predisposition to 
a disease should preclude a plaintiff who has been exposed to toxic chemicals 
from receiving medical monitoring for diagnostic purposes.  As we stated in 
 
13
Potter, “While there is no question that a defendant ought not to be liable for 
medical monitoring of a plaintiff’s preexisting condition that is unaffected by a 
subsequent toxic exposure negligently caused by the defendant, we see no reason 
why the defendant should not be held responsible for any increased or different 
monitoring of the preexisting condition (whether or not the preexisting condition 
is caused by the plaintiff’s voluntary conduct) where necessitated as a direct result 
of the subsequent exposure.”  (Potter, supra, 6 Cal.4th at p. 1009, fn. 27.)  Thus, 
neither the possibility nor the actuality of preexisting medical conditions 
constitutes a bar to medical monitoring liability.   Furthermore, screening for 
preexisting conditions, while individualized, is irrelevant to an initial 
determination of defendants’ liability.  Such screening for preexisting conditions 
can be done postjudgment, perhaps as an initial part of the monitoring process.  
Finally, the lead opinion does not discuss the fifth Potter factor, the clinical 
value of early detection and diagnosis.  (Potter, supra, 6 Cal.4th at p. 1009.)  
Presuming that the clinical value of early detection and diagnosis varies among 
diseases, whether monitoring has clinical value in a particular case would seem to 
depend, at least in part, on the specific toxicity of the chemicals allegedly 
discharged.  As previously discussed, the lead opinion agrees that such toxicity 
may be susceptible to common proof.   
Part I of the lead opinion states that even if one Potter factor is not subject 
to common proof, this should not prove fatal to a certification motion.  The lead 
opinion explicitly rejects defendants’ argument that Potter requires that each of 
the five factors is capable of common proof.  (See lead opn., ante, at p. 8.)  I agree 
with this conclusion and determine that even though some factors may not involve 
common proof, certification of a class action may still be appropriate.  As we have 
stated, “the fact that each member of the class must prove his [or her] separate 
claim to a portion of any recovery by the class is only one factor to be considered 
 
14
in determining whether a class action is proper” and “[t]he requirement of a 
community of interest does not depend upon an identical recovery.” (Vasquez v. 
Superior Court (1971) 4 Cal.3d 800, 809 (Vasquez).)  Even “that each class 
member might be required ultimately to justify an individual claim does not 
necessarily preclude the maintenance of a class action.”  (Collins v. Rocha (1972) 
7 Cal.3d 232, 238; see also Vasquez, supra, at p. 815.)   
Here, the trial court concluded that class treatment was the superior method 
since the case arose out of a common nucleus of facts and common issues 
predominate.  In my view, substantial evidence supports this conclusion.  I agree 
with the majority that the issues of defendants’ duty and breach of this duty is 
susceptible to common proof.  In addition, I conclude that most, if not all, of the 
Potter factors will involve proof that is common to all class members.  Therefore, 
unlike the majority, I cannot conclude that the trial court abused its discretion in 
determining that common issues predominate.   
III. 
While the majority concludes that there is no per se bar to class treatment of 
medical monitoring claims, I am concerned that by reversing the trial court’s 
decision to certify the class in this case, the effect of our ruling will be a de facto 
bar on class treatment of medical monitoring claims.  Plaintiffs’ theory of liability 
is that all plaintiffs who meet a threshold level of exposure should recover 
damages for the cost of medical monitoring.  The majority rejects this theory, 
agreeing with defendants that proof of exposure alone is insufficient to show 
causation and damages.  Since the majority believes that each plaintiff will have to 
show the specific dosage of toxic chemicals he or she received, they conclude that 
the trial court erred in certifying this case as a class action.  My concern with this 
holding is that it essentially precludes plaintiffs from constructing a claim for 
medical monitoring damages that minimizes questions of individual exposure.  If 
 
15
plaintiffs are required to show evidence of dosage on an individual basis, and such 
a requirement of individualized proof will prove fatal to a certification motion, 
then essentially no claim for medical monitoring damages can be treated on a 
class-wide basis. 
In every potential class action for medical monitoring damages, exposure 
will be individualized in some sense.  A group of plaintiffs seeking medical 
monitoring based on their exposure to asbestos in the workplace, for example, will 
have been employed for varying amounts of time.  Even for those plaintiffs 
employed for the same length of time, contact with hazardous substances may 
vary from plaintiff to plaintiff.  Under the majority’s holding, these employees 
could not bring a class action for medical monitoring damages because each class 
member did not receive an identical exposure to the asbestos.  Even if the 
employees attempted to bring an action for medical monitoring damages based on 
a minimum level of exposure, the majority would require each plaintiff to prove 
his or her individual level of exposure, and would conclude that, as a result, 
common issues do not predominate and the class could not be certified.  
Ultimately, by rejecting plaintiffs’ theory of liability in the present case and 
concluding that common issues do not predominate, the majority risks barring 
class treatment for any medical monitoring claim.  (Compare Lamb v. United Sec. 
Life Co. (S.D. Iowa 1972) 59 F.R.D. 25, 33 [to reject class actions for securities 
fraud merely because of the existence of the individual reliance issue would 
“wholly eviscerate Rule 10b-5”].) 
IV. 
Contrary to the majority, I believe that this case is ideally suited for class 
treatment.  The majority’s failure to uphold the trial court’s decision to certify the 
class in this case is contrary to the public policy of this state.  As we have said, 
“this state has a public policy which encourages the use of the class action 
 
16
device.”  (Richmond v. Dart Industries, Inc. (1981) 29 Cal.3d 462, 473.)  Class 
actions “ ‘serve an important function in our judicial system.  By establishing a 
technique whereby the claims of many individuals can be resolved at the same 
time, the class suit both eliminates the possibility of repetitious litigation and 
provides small claimants with a method of obtaining redress for claims which 
would otherwise be too small to warrant individual litigation.’ ”  (Id. at p. 469.) 
By allowing plaintiffs to pursue their claims as a class, the trial court’s 
certification order may advance a number of public policies.  In Potter, we found 
that “recovery of medical monitoring costs is supported by a number of sound 
public policy considerations.”  (Potter, supra, 6 Cal.4th at p. 1008.)  We listed 
four public policy reasons supporting medical monitoring damages: (1) the 
“important public health interest in fostering access to medical testing for 
individuals whose exposure to toxic chemicals creates an enhanced risk of disease, 
particularly in light of the value of early diagnosis and treatment for many cancer 
patients”; (2) the “deterrence value in recognizing medical surveillance claims” 
because allowing plaintiffs to recover the cost of care could deter the irresponsible 
discharge of toxic chemicals; (3) the mitigation of future illness and therefore the 
reduction of overall costs that could result from providing medical monitoring 
before the consequences of exposure are manifest; (4) the fact that “it would be 
inequitable for an individual wrongfully exposed to dangerous toxins, but unable 
to prove that cancer or disease is likely, to have to pay the expense of medical 
monitoring when such intervention is clearly reasonable and necessary.”  (Ibid.)  
I agree with the trial court that plaintiffs’ claims for medical monitoring 
damages are most effectively and efficiently presented as a class action.  Plaintiffs 
allege that they were injured by defendants as a class.  As claimed by plaintiffs, 
defendants negligently disposed of toxic rocket fuel, which seeped into the 
groundwater of Redlands and contaminated the city’s drinking water.  The 
 
17
majority holds that notwithstanding this class-wide injury, plaintiffs cannot 
recover as a class.  Instead, they must pursue their claims on an individual basis.  
In order to recover the cost of medical monitoring for diseases that were allegedly 
caused by defendants’ negligent actions, each plaintiff will have to prove the 
elements of a damages claim.  Each plaintiff will have to show that defendants had 
a duty of care, that defendants breached this duty by negligently disposing of toxic 
chemicals, and that the chemicals contaminated the groundwater.  He or she will 
additionally have to show the amount of contaminants that entered the 
groundwater, and when, where, and at what levels the contaminants were pumped 
by the city’s wells and introduced into the domestic water system.  Each plaintiff 
will have to prove the toxicity of the chemicals, and the diseases he or she is at 
risk of contracting as a result of exposure to the chemicals.  Each plaintiff will 
have to show that medical monitoring of future potential diseases is a reasonably 
necessary response based on the risk of disease due to exposure to the chemicals.   
Absent class treatment, therefore, each individual plaintiff will present the 
same or essentially the same arguments and evidence (including expert testimony) 
on these numerous complicated issues.  Any Redlands resident who wishes to 
recover the cost of medical monitoring will have to go to great expense to prove 
defendants’ liability and his or her right to recover.  The result will be a 
multiplicity of trials conducted at enormous cost to both the judicial system and 
the litigants.  As Chief Judge Weinstein observed in In re “Agent Orange” 
Product Liability Litigation (E.D.N.Y. 1983) 100 F.R.D. 718, 720, “if [mass 
injury] claims are dealt with individually, the result might [be] ‘a tedium of 
repetition lasting well into the next century.’ ”  “It would be neither efficient nor 
fair to anyone, including defendants, to force multiple trials to hear the same 
evidence and decide the same issues.”  (Boggs v. Divested Atomic Corporation 
 
18
(S.D. Ohio 1991) 141 F.R.D. 58, 67 (Boggs).)2  Class treatment here therefore 
promotes judicial efficiency and economy.   
More importantly, it is unlikely that, on an individual basis, plaintiffs will 
pursue such a remedy.  Class claims for medical monitoring damages typically 
present a large body of plaintiffs who, individually, do not expect a large recovery, 
but, as a class, expect a significant recovery.  “Where it is not economically 
feasible to obtain relief [in separate suits] . . . , aggrieved persons may be without 
any effective redress unless they may employ the class-action device.”  (Deposit 
Guarantee Nat. Bank v. Roper (1980) 445 U.S. 326, 339.)  As we have stated, 
“[w]hile the mere denial of certification does not, as a legal matter, terminate the 
right of any plaintiff to pursue claims on an individual basis, it is likely to have 
that net effect when there has been injury of insufficient size to warrant individual 
action.”  (Linder, supra, 23 Cal.4th at p. 441.)  In the present case, the cost of 
litigating defendants’ liability undoubtedly will be greater than any expected 
individual recovery in the form of damages for the cost of medical monitoring.  
For “exposure only” plaintiffs individually to pursue even plainly meritorious 
medical monitoring claims may be economically infeasible. 
Furthermore, class treatment of plaintiffs’ claims would secure uniform 
results for any viable medical monitoring claims pled herein.  To the extent a class 
                                             
 
2  
Boggs, supra, 141 F.R.D. 58, involved claims by neighbors of an industrial 
facility that hazardous materials released from the facility had contaminated their 
properties.  In certifying a medical monitoring class, the federal district court 
“rejected defendants’ view of the individualized nature of the plaintiffs’ claims” 
(id. at p. 67), which parallel defendants’ arguments here (see id. at pp. 64-65).  
The court noted that “[c]ommon issues of liability, causation, and remedies not 
only predominate but overwhelm individualized issues.  If these claims were tried 
separately, the amount of repetition would be manifestly unjustified.”  (Id. at 
p. 67.) 
 
19
action “ ‘ “eliminates the possibility of repetitious litigation” ’ ” of common issues 
(Linder, supra, 23 Cal.4th at p. 435), it also eliminates the possibility of 
inconsistency in their adjudication.   
Not only is the nature of plaintiffs’ claims well suited for class treatment, 
but also the remedy requested here is one that is most effectively administered to a 
class of plaintiffs.  If plaintiffs receive the medical monitoring remedy as a class, 
one unitary monitoring program with clear standards and procedures can be 
established.  An initial screening can be utilized to detect any preexisting 
conditions, and to identify any specific risk factors.  Diseases may be easier to 
identify through class treatment of medical monitoring plaintiffs as well, because 
doctors monitoring a class of plaintiffs exposed to the same toxic chemicals may 
see similar symptoms in a number of individuals.   
In addition, the maintenance of a class action for medical monitoring 
damages serves as a deterrent for corporate polluters.  “Absent a class suit a 
wrongdoing defendant [may] retain the benefit of its wrongs.”  (Vasquez, supra, 4 
Cal.3d at p. 810.)  “ ‘Allowing plaintiffs to recover the cost [of medical 
monitoring] deters irresponsible discharge of toxic chemicals by defendants.’ ” 
(Metro-North Commuter R. Co. v. Buckley (1997) 521 U.S. 424, 451 (conc. & dis. 
opn. of Ginsburg, J.).)   Since the cost of litigating cases on an individual basis 
may be prohibitive, a class action may be the only way to establish defendants’ 
liability for the cost of medical monitoring.  In fact, unless defendants are held 
liable for the cost of medical monitoring, they may escape liability altogether.  As 
one court has noted, “The difficulty of proving causation, where the disease is 
manifested years after exposure, has caused many commentators to suggest that 
tort law has no capacity to deter polluters, because the costs of proper disposal are 
often viewed by polluters as exceeding the risk of tort liability. [Citations.] 
However, permitting recovery for reasonable pre-symptom, medical-surveillance 
 
20
expenses subjects polluters to significant liability when proof of the causal 
connection between the tortious conduct and the plaintiffs' exposure to chemicals 
is likely to be most readily available.”  (Ayers v. Jackson Tp. (1987) 106 N.J. 557, 
604.) 
Thus, while “ ‘[a]ny valid pertinent reason stated [would] be sufficient to 
uphold the [certification] order’ ” (Linder, supra, 23 Cal.4th at p. 436), the trial 
court’s certification order in this case is supportable on several grounds:  
responsible public health policy, efficiency in the expenditure of judicial 
resources, uniformity of adjudication, effective administration of the remedy, and 
deterrence of wrongdoing by potential polluters. 
V. 
Part I of the lead opinion states that medical monitoring claims may be 
treated as a class “so long as any individual issues the claims present are 
manageable.”  (Lead opn., ante, at p. 8.)  In reviewing the evidence to be proven at 
trial, it is clear that the trial court was well within its discretion in concluding that 
any individual issues in this case are manageable.  The majority errs in reweighing 
the balance of common versus individual issues in this case and determining that 
common issues do not predominate.  This is a conclusion we need not reach.  
Instead, the weighing of individual versus common factors and the decision on the 
manageability of the class is an exercise left to the sound discretion of the trial 
court.  A trial court’s class certification determination is discretionary because “ ‘it 
is “a practical problem, and primarily a factual one with which a [trial] court 
generally has a greater familiarity and expertise than does a court of appeal[].” ’ ”  
(Boughton v. Cotter Corporation (10th Cir. 1995) 65 F.3d 823, 828.)  
 
The majority essentially disregards the trial court’s conclusion that the 
individual issues in this case are manageable and that common issues predominate.   
 
21
Rather than reviewing the certification order for abuse of discretion, the majority 
rejects plaintiffs’ theory of liability after a merit-based analysis of plaintiffs’ 
claims.  Our role as a reviewing court, however, is not to determine whether or not 
we agree with the trial court’s conclusion that common issues predominate but 
only to see whether this conclusion was an abuse of discretion.  Unless this 
decision was an abuse of discretion, it should be upheld.   
Plaintiffs allege that they were injured as a class by defendants.  They ask 
that defendants be held responsible for the cost of medical monitoring, which can 
detect, and prevent, future illness.  The trial court determined that class treatment 
of plaintiffs’ claims was the superior method of dealing with the common 
questions of law and fact that exist in this case.  Substantial evidence supports this 
determination, and so I conclude that the trial court did not abuse its discretion in 
certifying the class in this case.  Therefore, I dissent. 
 
 
 
 
 
 
 
MORENO, J. 
I CONCUR: 
GEORGE, C. J. 
 
1
See last page for addresses and telephone numbers for counsel who argued in Supreme Court. 
 
Name of Opinion Lockheed Martin Corporation v. Superior Court 
__________________________________________________________________________________ 
 
Unpublished Opinion 
Original Appeal 
Original Proceeding 
Review Granted XXX 79 Cal.App.4th 1019 
Rehearing Granted 
 
__________________________________________________________________________________ 
 
Opinion No. S088458 
Date Filed: March 3, 2003 
__________________________________________________________________________________ 
 
Court: Superior 
County: San Bernardino 
Judge: Ben T. Kayashima 
 
__________________________________________________________________________________ 
 
Attorneys for Appellant: 
 
Holme, Roberts & Owen, Linnea Brown; Gibson, Dunn & Crutcher, Robert S. Warren, Robert W. Loewen 
and Daniel S. Floyd for Petitioners Lockheed Martin Corporation and Highland Supply Corporation. 
 
Payne & Fears, David Sweet, Alan G. Ross; Law Offices of Terry Bridges and Terry Bridges for Petitioner 
Highland Supply Company. 
 
Bowman & Brooke, Anthony S. Thomas; Seyfarth, Shaw, Fairweather & Geraldson, John D. Dwyer, 
Steven B. Katz and Carrie L. Daughters for Petitioner FMC Corporation. 
 
Wood, Smith, Henning & Berman, David F. Wood, Ann G. Zuckerman, James C. MacDonald; Brunick, 
Alvarez & Battesby and Leland P. McElhaney for Petitioner Baumac Corporation. 
 
Zevnik Horton Guibord McGovern Palmer & Fognani, John D. Fognani, Michael John Miguel and           
K. Eric Adair for Petitioners PETRO-TEX Chemical Corporation and El Paso Tennessee Pipeline Co. 
 
Nossman, Guthner, Knox & Elliott and Patrick J. Richard as Amici Curiae on behalf of Petitioners. 
 
Hugh F. Young, Jr., and Harvey M. Grossman for The Product Liability Advisory Council, Inc., as Amicus 
Curiae on behalf of Petitioners. 
 
Atlantic Legal Foundation and Martin S. Kaufman for Ronald E. Gots, Leonard Hamilton, Ronald Hart, 
Clark W. Heath, Michael Gough, A. Alan Moghissi, Rodney W. Nichols, Frederick Seitz, Barry H. Smith, 
James Wilson and Richard Wilson as Amici Curiae on behalf of Petitioners. 
 
Crowell & Moring, Victor E. Schwartz and Luther Zeigler for The Coalition for Asbestos Justice, Inc., as 
Amicus Curiae on behalf of Petitioners. 
 
Horvitz & Levy, David M. Axelrad, Lisa Perrochet and Mary-Christine Sungaila for American Chemistry 
Council, Chemical Industry Council of California, ExxonMobil Corporation and Union Oil Company of 
California dba UNOCAL as Amici Curiae on behalf of Petitioners. 
 
 
2
 
 
 
Page 2 - counsel continued - S088458 
 
 
Attorneys for Appellant: 
 
 
Sedgwick, Detert, Moran & Arnold and Frederick D. Baker for Defense Research Institute as Amicus 
Curiae on behalf of Petitioners. 
 
Spriggs & Hollingsworth, Donald W. Fowler, Rebecca A. Womeldorf, Marc S. Mayerson; National 
Chamber Litigation Center and Robin S. Conrad for United States Chamber of Commerce as Amicus 
Curiae on behalf of Petitioners. 
 
Robie & Matthai, Pamela E. Dunn and Natalie A. Kouyoumdjian for State Farm General Insurance 
Company and United Services Automobile Association as Amici Curiae on behalf of Petitioners. 
 
Crosby, Heafy, Roach & May, James C. Martin, Michael K. Brown; Daniel J. Popeo and Paul D. Kamenar 
for Washington Legal Foundation as Amicus Curiae on behalf of Petitioners Lockheed Martin Corporation 
and Highland Supply Company. 
 
__________________________________________________________________________________ 
 
Attorneys for Respondent: 
 
No appearance for Respondent. 
 
Engstrom, Lipscomb & Lack, Walter J. Lack, Gary A. Praglin, Richard P. Kinnan; Masry & Vititoe, 
Edward S. Masry; Girardi & Keese, Thomas V. Girardi, Howard B. Miller; Ward & Ward and Alexandra 
S. Ward for Real Parties in Interest. 
 
 
 
 
 
 
3
 
 
 
 
Counsel who argued in Supreme Court (not intended for publication with opinion): 
 
Robert S. Warren 
Gibson, Dunn & Crutcher 
333 South Grand Avenue 
Los Angeles, CA  90017-3197 
(213) 229-7000 
 
Howard B. Miller 
Girardi & Keese 
1126 Wilshire Boulevard 
Los Angeles, CA  90017-1904 
(213) 977-0211