Court Opinion

ID: 9890920
Source: CourtListenerOpinion
Date Created: 2023-10-16 20:04:04.57877+00
Date Added: 2024-06-11T13:36:31.196721
License: Public Domain

Filed 10/16/23
                 CERTIFIED FOR PUBLICATION

IN THE COURT OF APPEAL OF THE STATE OF CALIFORNIA

                  SECOND APPELLATE DISTRICT

                            DIVISION SIX

DANA BRANCATI,                          2d Civ. No. B321616
                                    (Super. Ct. No. 16CV03956)
     Plaintiff and Appellant,         (Santa Barbara County)

v.

CACHUMA VILLAGE, LLC,

     Defendant and Respondent.

       Here we decide an expert is qualified to render an opinion
on whether a person’s exposure to toxic mold is harmful.
       Dana Brancati, a former tenant, appeals a judgment of
dismissal following the trial court’s granting a motion in limine
filed by defendant Cachuma Village, LLC (Cachuma), her
landlord. Brancati filed a complaint for, among other things,
personal injuries for exposure to toxic mold. Cachuma moved in
limine to exclude Brancati’s medical expert from testifying about
the medical causation of her illnesses due to mold.
       Because the medical expert was qualified and his opinion
was based on facts and a differential diagnosis, the trial court
erred in excluding his evidence. We reverse.
                               FACTS
       Brancati entered a month-to-month lease with Cachuma to
reside in its premises. She resided there from April 2012 to April
2016. She complained to Cachuma about mold “infestation” and
Cachuma’s failure to correct that problem. In 2016, Insight
Environmental, a company that specialized in mold testing,
determined there were high levels of a variety of dangerous types
of mold at her residence at Cachuma.
       Brancati filed a complaint for breach of the warranty of
habitability, fraud, constructive eviction, and personal injuries
for exposure to toxic mold. She alleged that she had suffered
“respiratory illnesses” because of exposure to the mold. She
sought $50,000 for her injuries.
       Brancati relied on the testimony of Ronald A. Simon, M.D.,
as her expert to prove the cause of her medical illnesses. At his
deposition Simon testified that “as a result of living” in her home
environment with “excess mold growth,” Brancati had “a variety
of adverse health effects that started fairly shortly after she
moved in there.”
       Cachuma moved in limine to exclude Simon from testifying
on causation, or, alternatively, for an Evidence Code section 402
hearing to determine admissibility. Cachuma claimed Simon was
not qualified to testify on medical causation of Brancati’s
illnesses due to mold.
       In her opposition, Brancati claimed, “Dr. Simon’s testimony
is not only based on both his examinations of [Brancati], but his
experience and the scientific literature which establishes that
exposure to damp moldy environments has negative effects on
health.”

                                2.
      At a pretrial hearing, the trial court ruled Simon was not
qualified to testify on the medical causation issue. Brancati was
not able to proceed to trial without Simon’s testimony. The trial
court dismissed this action.
                            DISCUSSION
                         Standard of Review
      Where a trial court grants a motion in limine that prevents
a party’s expert from testifying and leads to a dismissal, we
review that order for an abuse of discretion. (Kelly v. New West
Federal Savings (1996) 49 Cal.App.4th 659, 677; see also Geffcken
v. D’Andrea (2006) 137 Cal.App.4th 1298, 1311 [“ ‘If the court
excludes expert testimony on the ground that there is no
reasonable basis for the opinion, we review the exclusion of
evidence under the abuse of discretion standard’ ”].)
      Where the granting of a motion in limine “precludes an
entire cause of action” or is tantamount to a nonsuit, we may also
conduct our review de novo to determine whether the trial court
erred as a matter of law. (Kinda v. Carpenter (2016) 247
Cal.App.4th 1268, 1279; McMillin Companies, LLC v. American
Safety Indemnity Co. (2015) 233 Cal.App.4th 518, 530.)
      Brancati presented evidence showing her expert is a
qualified medical doctor and a scientific researcher. She was
prepared to present relevant evidence on the cause of her
respiratory illness. The trial court’s ruling prevented her from
having a trial. The court’s order is not consistent with the
standard courts must use to decide whether to exclude an expert
from testifying.
                        Disqualifying Experts
      “Trial judges have a ‘substantial “gatekeeping”
responsibility’ to ensure that an expert’s opinion is based on both

                                3.
reliable material and sound reasoning.” (Bader v. Johnson &
Johnson (2023) 86 Cal.App.5th 1094, 1104.) “ ‘The trial court’s
preliminary [or gatekeeping] determination whether the expert
opinion is founded on sound logic is not a decision on its
persuasiveness.’ ” (Id. at p. 1105.) “ ‘The court must not weigh
an opinion’s probative value or substitute its own opinion for the
expert’s opinion.’ ” (Ibid.) “ ‘Rather, the court must simply
determine whether the matter relied on can provide a reasonable
basis for the opinion or whether that opinion is based on a leap of
logic or conjecture.’ ” (Ibid.) “ ‘The court does not resolve
scientific controversies.’ ” (Ibid.)
       In determining evidence of causation, the court applies a
substantial factor standard. “ ‘The substantial factor standard is
a relatively broad one, requiring only that the contribution of the
individual cause be more than negligible or theoretical.’ ”
(Bockrath v. Aldrich Chemical Co., Inc. (1999) 21 Cal.4th 71, 79.)
       “As a general rule, the factual basis of an expert opinion
goes to the credibility of the testimony, not the admissibility, and
it is up to the opposing party to examine the factual basis for the
opinion in cross-examination.” (Bonner v. ISP Technologies, Inc.
(8th Cir. 2001) 259 F.3d 924, 929.) “Only if the expert’s opinion is
so fundamentally unsupported that it can offer no assistance to
the jury must such testimony be excluded.” (Id. at pp. 929-930.)
       Medical doctors are experts who are in the best position to
determine the nature of illnesses experienced by patients. (San
Jose Neurospine v. Aetna Health of California, Inc. (2020) 45
Cal.App.5th 953, 960.)
       Doctor Simon testified that Brancati’s “adverse health
effects” were the result of her living at the Cachuma residence
where she was exposed to “excess mold growth.” The trial court

                                 4.
ruled Simon was not qualified to make a diagnosis of mold as the
cause of her illnesses. But Simon’s opinion was based on facts,
not on a “leap of logic or conjecture.” (Bader v. Johnson &
Johnson, supra, 86 Cal.App.5th at p. 1105.)
           Evidence of Toxic Mold at Brancati’s Residence
       The 2016 Insight Environmental testing report showed
Brancati’s residence at Cachuma showed “high levels” of
“aspergillus” and “penicillium” mold growth near her shower. Air
samples from her hallway showed “elevated levels of
Aspergillus/Penicillium and Stachybotrys mold growth.” (Italics
added.) Insight Environmental said that stachybotrys,
aspergillus, and penicillium produce “fungal metabolites that
may be toxic” when “inhaled.” These are the types of mold that
“produce mycotoxins.” It also determined that the “mold spores”
at her residence “pose an immediate threat of occupant exposure.”
(Italics added.) Included within that report were color
photographs that showed large concentrations of mold growth in
various parts of Brancati’s Cachuma residence.
       Stachybotrys chartarum, aspergillus, and penicillium are
toxic molds. (Jarman & Felstiner, Mold Is Gold: But, Will it be
the Next Asbestos (2003) 30 Pepperdine L.Rev. 529, 549.)
Stachybotrys chartarum “has killed animals.” (Id. at p. 542.) It
is “especially harmful to small children.” (Id. at p. 533.) Health
professionals have linked it to sudden infant death syndrome.
(Ibid.) “[E]xcessive exposure to mold has been a health issue for
humans for many years.” (Id. at p. 534.)
          Methods to Prove Mold as the Cause of an Illness
       There are two methods used to prove mold is the cause of
an illness. An expert may testify using a “methodology generally
recognized in the scientific community” to determine mold as the

                                5.
cause (B.T.N. v. Auburn Enlarged City School Dist. (N.Y.App.Div.
2007) 845 N.Y.S.2d 614) and may rely on epidemiological studies
to show a statistical link between exposure to the substance and
the cause of the illness. (Johnson & Johnson Talcum Powder
Cases (2019) 37 Cal.App.5th 292, 326.) Alternatively, a doctor
who examines a patient may use a medical “differential
diagnosis” to determine mold as the cause of a diagnosed illness.
(B.T.N., at p. 1340; see also Cooper v. Takeda Pharmaceuticals
America, Inc. (2015) 239 Cal.App.4th 555, 586; Cottle v. Superior
Court (1992) 3 Cal.App.4th 1367, 1384-1385.) Here Simon, as a
medical doctor and a researcher, attempted to use both methods.
    Simon’s Ability as a Medical Doctor to Diagnose Toxic Mold
            as the Cause of Brancati’s Respiratory Illness
       Medical doctors who examine patients may reach the most
probable diagnosis for a patient’s condition through a process of
elimination. (Cottle v. Superior Court, supra, 3 Cal.App.4th at
pp. 1384-1385.) They are expected to identify the “source of a
patient’s illness” (Finn v. G.D. Searle & Co. (1984) 35 Cal.3d 691,
704) and diagnose “the nature of [the] disease . . . from a study of
its symptoms.” (Ibid.) Doctors may consider exposure to toxic
substances as a factor causing an illness. (Davis v. Honeywell
Internat. Inc. (2016) 245 Cal.App.4th 477, 495.)
       Simon, a medical doctor, examined Brancati. He was board
certified in allergy and immunology and was qualified to testify
about the impact of natural toxic substances on Brancati’s
respiratory tract (San Jose Neurospine v. Aetna Health of
California, Inc., supra, 45 Cal.App.5th at p. 960); the symptoms
she suffered (Finn v. G.D. Searle & Co., supra, 35 Cal.3d at
p. 704); and, as an “allergist,” he could identify the symptoms
consistent with toxic mold exposure.

                                 6.
       Simon testified that he conducted “a differential diagnosis”
to determine the cause of Brancati’s illness. This is a standard
method doctors use to eliminate potential causes of illness to be
able to reach a diagnosis. (Cooper v. Takeda Pharmaceuticals
America, Inc., supra, 239 Cal.App.4th at p. 586.) This process
does not require doctors to eliminate all hypothetical causes
before making a diagnosis. (Ibid.) A “proper differential
diagnosis is adequate to support [an] expert medical opinion on
causation.” (Westberry v. Gislaved Gummi AB (4th Cir. 1999) 178
F.3d 257, 263; Kennedy v. Collagen Corp. (9th Cir. 1998) 161 F.3d
1226, 1230.)
       Simon knew Brancati’s Cachuma residence was
contaminated with toxic mold. He determined that she had the
typical combination of “respiratory symptoms” of mold exposure
that included “nasal congestion, runny nose, coughing, sneezing,”
and the “exacerbation of her migraine headaches.” She also was
“not . . . able to sleep” due to “respiratory” illness. Simon
presented evidence to show these are the symptoms that have
been identified as being caused by mold exposure. “Testimony
regarding objectively verifiable physical symptoms leading to a
medical diagnosis is admissible as garden variety expert
testimony.” (Ramona v. Superior Court (1997) 57 Cal.App.4th
107, 121.) Medical theories of causation of illnesses are
admissible when based on standard diagnostic methods. (Roberti
v. Andy’s Termite & Pest Control, Inc. (2003) 113 Cal.App.4th
893, 903.)
       Simon considered the timing of Brancati’s symptoms. He
determined the onset of her symptoms was consistent with her
time in the Cachuma residence. Brancati did not have the
“respiratory tract symptoms” until she moved to Cachuma. Her

                                7.
symptoms “lessened when she moved out.” A “temporal
connection” may be a “reliable indicator of a causal relationship.”
(Bonner v. ISP Technologies, Inc., supra, 259 F.3d at p. 931;
Westberry v. Gislaved Gummi AB, supra, 178 F.3d at p. 265,
italics added [a “temporal relationship between exposure to a
substance and the onset of a disease or a worsening of symptoms
can provide compelling evidence of causation”]; Martin v. Chuck
Hafner’s Farmers’ Market, Inc. (N.Y. 2006) 814 N.Y.S.2d 442,
443-444 [evidence that respiratory illness occurred after exposure
to mold supported a triable issue of fact on causation].)
        Brancati resided at Cachuma for four years. The
“ ‘ “length, frequency, proximity and intensity of exposure” ’ ” to a
toxic substance are factors “that a medical expert may rely upon
in forming his or her expert medical opinion.” (Davis v.
Honeywell Internat. Inc., supra, 245 Cal.App.4th at p. 495.) Here
the level of exposure to the toxic molds was high and long term.
Simon’s determination that there was “excessive” mold is
supported by the photographs in the mold testing report.
        Before reaching his differential diagnosis of mold exposure,
Simon prepared two medical reports where he eliminated several
potential causes for Brancati’s respiratory illness. He reviewed
her “collateral allergic history” and found it was “totally
noncontributory.” He reviewed a “four page allergy, asthma and
immunology review form with her.” That is a standard procedure
to “rule out other possible causes” in mold cases. (New Haverford
Partnership v. Stroot (Del. 2001) 772 A.2d 792, 800.)
        Simon reviewed her current symptoms and past history of
symptoms. He considered her medications. He reviewed her
history of “past adverse drug reactions.” He considered whether
her symptoms could be caused by laryngopharyngeal reflux

                                 8.
(LPR). But he rejected that as the cause because Brancati’s
symptoms “are not the most typical LPR symptoms.” He
considered her pre-existing conditions. He said Brancati had a
“pre-existing” condition involving migraine headaches. But he
determined her home environment had an aggravating impact on
that condition because it “got much, much worse in the home” in
Cachuma.
       Simon determined whether Brancati would fall within the
tiny percentage of people who are hypersensitive and have toxic
allergic reactions to mold. He relied on a 2016 allergic skin
testing report by Doctor Tubiolo who had examined Brancati.
Simon concluded Brancati did not fall within that group.
Brancati was normal and within the “99 percent” of the
population who do not have such extreme toxic allergic reactions.
In an allergy skin test report, Tubiolo found Brancati’s
“inhalants” included “aspergillus” and other molds. That
aspergillus finding supported the conclusion that she had been
breathing toxic mold.
       Simon also conducted an “environmental survey.”
Potential causes of allergic reactions may include smoking or pet
allergies. (New Haverford Partnership v. Stroot, supra, 772 A.2d
at p. 800.) But Simon eliminated those causes. He reviewed
Brancati’s “smoking history” and found it was not relevant. He
considered her history with cats and found that was not
applicable in terms of allergies. He determined that she was
“[n]egative for atopic disorders” and that she was physically “well
developed.” He decided her “pulmonary function” was “within
normal limits.” He found that her 2016 CT scan was, in relevant
part, normal. He considered her “social history” and her “family
history.” He excluded exposure to outdoor mold as a cause of her

                                9.
illness because outdoor mold “get[s] dissipated” by the
atmosphere. That is not the case with indoor mold. Simon could
reasonably make these findings to exclude a number of potential
causes in order to make a diagnosis. (Cooper v. Takeda
Pharmaceuticals America, Inc., supra, 239 Cal.App.4th at p. 586;
Wendell v. GlaxoSmithKline LLC (9th Cir. 2017) 858 F.3d 1227,
1237 [“when an expert establishes causation based on a
differential diagnosis, the expert may rely on his or her clinical
experience as a basis for ruling out a potential cause of the
disease”].)
       Simon considered the 2016 mold testing report of Brancati’s
residence. It indicated that mold spores there posed an
immediate threat of exposure. The air testing in that report was
relevant on causation. A method “typically used to prove specific
causation in mold cases is air sampling.” (Kanemoto, Scientific
Expert Admissibility in Mold Exposure Litigation (2003) 26
Hawaii L.Rev. 99, 129; New Haverford Partnership v. Stroot,
supra, 772 A.2d at p. 800.) The air sampling, combined with a
2016 medical report finding that she was breathing toxic mold,
provided support for Simon’s theory.
       A medical expert may also rely on published scientific
studies showing odds ratios (OR) of 2.0 or more that show a
causal effect between exposure to a substance and illness
symptoms. (Johnson & Johnson Talcum Powder Cases, supra, 37
Cal.App.5th at p. 326.) Simon relied on published studies. One
study from Japan showed an OR of 4.36 for eye symptoms, 3.70
for nose symptoms, and 3.45 for throat and respiratory symptoms
for persons living in indoor environments containing dampness
and visible mold growth. (Hope & Simon, Excess dampness and
mold growth in homes: An evidence-based review of the

                               10.
aeroirritant effect and its potential causes (May–June 2007) 28
(No. 3) Allergy & Asthma Proceedings 264 (Hope & Simon), citing
Saijo et al., Symptoms in relation to chemicals & dampness in
newly built dwellings (2004) Internat. Archives of Occupational
and Environmental Health.) Simon could rely on such studies to
properly support his diagnosis and opinion.
       Cachuma’s experts, who did not examine Brancati, claimed
there might be causes for her illness other than indoor mold, such
as her contact with horses. But a 2016 allergy skin test did not
show any positive finding for Brancati inhaling “horse dander.”
Simon prepared a medication plan for Brancati, and, as a
treating doctor, he was in the best position to determine the cause
of her illness (San Jose Neurospine v. Aetna Health of California,
Inc., supra, 45 Cal.App.5th at p. 960) and to exclude other
potential causes. (Wendell v. GlaxoSmithKlien LLC, supra, 858
F.3d at p. 1237.)
       Moreover, “[c]ausation is generally a question of fact for the
jury, unless reasonable minds could not dispute the absence of
causation.” (Lombardo v. Huysentruyt (2001) 91 Cal.App.4th 656,
666.) Here there is a significant dispute. (See, e.g., Watters v.
Dept. of Social Service (La.Ct.App. 2003) 849 So.2d 724, 733
[genuine issue of material fact where in a dispute between
experts, one doctor said mold was “capable of compromising the
immune system”].)
       As a medical doctor, Simon could rule out other causes with
his differential diagnosis and reach a probable diagnosis of toxic
mold exposure as the cause of Brancati’s respiratory illnesses.
(Roberti v. Andy’s Termite & Pest Control, Inc., supra, 113
Cal.App.4th at pp. 901-902; Cottle v. Superior Court, supra, 3
Cal.App.4th at pp. 1384-1385.)

                                11.
   Simon’s Ability as a Scientific Researcher to Testify about the
  General Acceptance of His Theory in the Scientific Community
       In addition to being a medical doctor, Simon is also a
scientific researcher. His experience in that area provided
additional support for his differential diagnosis that exposure to
mold caused Brancati’s respiratory illness.
       Simon researched the “aeroirritant” impact of moldy
environments on health. He and another author published a
peer-reviewed study on the aeroirritant effects of exposure to
damp indoor environments. (Hope & Simon, supra, Allergy &
Asthma Proceedings, at pp. 262-270.) In this published study,
Simon said, “[E]pidemiological studies support the link between a
damp indoor environment and mold growth with upper airway
irritant symptoms.” (Id. at p. 269.) Epidemiological studies may
show a statistical correlation between exposure to a substance
and the cause of an illness. (Johnson & Johnson Talcum Powder
Cases, supra, 37 Cal.App.5th at p. 326.)
       Scientific researchers may opine on the scientific
acceptance of their theories and the epidemiological factors and
studies they relied on to reach their conclusions. (Bockrath v.
Aldrich Chemical Co., supra, 21 Cal.4th at p. 79; Johnson &
Johnson Talcum Powder Cases, supra, 37 Cal.App.5th at p. 326;
Centex-Rooney Construction Co., Inc. v. Martin County (Fla. 1997)
706 So.2d 20, 26.)
       The trial court cited Geffcken v. D’Andrea, supra, 137
Cal.App.4th 1298. There we held two scientific tests to link mold
to illness had not achieved scientific acceptance, and an expert
was not qualified to testify about a causal link between, among
other things, mold and lung cancer. We noted that the plaintiffs’
theory was not supported by a single peer-reviewed scientific

                               12.
reference and that the test results to prove causation were
unreliable. There was no forensic investigation, there were chain
of custody errors that invalidated the integrity of the sampling
results, and samples had been inaccurately transposed. We also
said our decision was fact specific and “[did] not constitute
precedent for the exclusion” of evidence “under materially
different factual scenarios.” (Id. at p. 1312, fn. 4.)
       Brancati does not rely on the testing or theories mentioned
in Geffcken and she does not claim mold causes cancer. The trial
court’s reliance on Geffcken was misplaced. Our decision was not
intended to prevent medical doctors who examine their patients,
as here, from performing a differential diagnosis to determine
and opine on the cause of the patient’s illness. Moreover, as
Brancati notes, there have been new scientific studies about mold
that were not in existence in 2006 when we decided Geffcken.
               Scientific Studies on Mold and Illness
       Simon declared recent studies confirmed the scientific
accuracy and acceptance by the scientific community of his
opinion about the link between respiratory diseases and exposure
to mold.
       In 2016, in a statement on building dampness, mold, and
health, the State Department of Public Health determined that
“visible mold” or “mold odor” indicates “an increased risk of
respiratory disease for occupants.” (Environmental Health
Laboratory Branch, State Dept. of Pub. Health, Statement on
Building Dampness, Mold, and Health (Feb. 2016) p. 1, italics
added.)
       In 2011, an Environmental Health Perspectives report
determined “[t]here is sufficient evidence of an association
between indoor dampness-related factors and a wide range of

                               13.
respiratory or allergic health effects.” (Mendell et al., Respiratory
and Allergic Health Effects of Dampness, Mold, and Dampness-
Related Agents: A Review of the Epidemiologic Evidence (June
2011) 119 (No. 6) Environmental Health Perspectives 755, italics
added.)
      A World Health Organization (WHO) report in 2009 found
a connection between exposure to mold and “increased
prevalence[] of respiratory symptoms.” (WHO guidelines for
indoor air quality: dampness and mould (Jan. 2009) <http:/
/www.who.int/publications/i/item/9789289041683> [as of Oct. 16,
2023], archived at <https://perma.cc/5SHE-7Z6M>.)
      In 2017, a review in the International Journal of Hygiene
and Environmental Health determined that “indoor mold growth
must be considered as a potential health risk.” (Hurrass et al.,
Medical diagnostics for indoor mold exposure (2017) p. 306.)
      A 2004 Institute of Medicine of the National Academies
report, titled “Damp Indoor Spaces and Health,” concluded: 1)
“There is sufficient evidence of an association between exposure
to a damp indoor environment and upper respiratory tract
symptoms,” and 2) “There is sufficient evidence of an association
between the presence of ‘mold’ . . . in a damp indoor environment
and upper respiratory tract symptoms.” (Id. at p. 194, italics
added.)
      A September 2017 report by the National Center for
Environmental Health, Centers for Disease Control and
Prevention, titled “Mold and Your Health,” concluded that for
people sensitive to molds, “molds can cause nasal stuffiness,
throat irritation, coughing or wheezing, eye irritation, or, in some
cases, skin irritation.”

                                 14.
       The United States Environmental Protection Agency (EPA)
recently stated, “Research on mold and health effects is ongoing.”
(U.S. EPA, Mold and Health (2023) <http:/
/www.epa.gov/mold/mold-and-health> [as of Oct. 16, 2023],
archived at <https://perma.cc/YB8N-UL8J>.) But it noted,
“Molds have the potential to cause health problems. Molds
produce allergens (substances that can cause allergic reactions)
and irritants. . . . [¶] [M]old exposure can irritate the eyes, skin,
nose, throat, and lungs of both mold-allergic and non-allergic
people.” (Ibid.) “Inhaling or touching mold or mold spores may
cause allergic reactions in sensitive individuals. Allergic
responses include hay fever-type symptoms, such as sneezing,
runny nose, red eyes, and skin rash.” (Ibid.)
       In addition to these studies, in a published article, Simon
relied on additional scientific studies showing OR ratios well
exceeding 2.0 for documented causal connections between
exposure to damp and mold environments and various specific
illness symptoms. (Hope & Simon, supra, Allergy & Asthma
Proceedings, at pp. 264-265.) These were published studies from
researchers in various countries, including Sweden, Taiwan, and
Japan. (Ibid.) These studies used a scientific statistical method,
considered similar causal factors, involved significantly large
population groups, and their findings could be peer reviewed and
duplicated. (Ibid.) Such studies, with such ratios, provided
factual support for Simon’s theory about the causal link between
mold and respiratory illness. (Johnson & Johnson Talcum
Powder Cases, supra, 37 Cal.App.5th at p. 326.)
       Simon’s theory about mold exposure has “support in
existing data, studies or literature.” (Marsh v. Smyth
(N.Y.App.Div. 2004) 785 N.Y.S.2d 440, 446.) General acceptance

                                 15.
“does not require unanimity, a consensus of opinion, or even
majority support by the scientific community.” (People v. Leahy
(1994) 8 Cal.4th 587, 601.) The trial court may permit the
introduction of “ ‘ “competing principles or methods in the same
field of expertise.” ’ ” (Cooper v. Takeda Pharmaceuticals
America, Inc., supra, 239 Cal.App.4th at p. 590.)
       Judicial Decisions on Mold Exposure Causing Illnesses
       Courts have found that “the scientific community has
generally accepted the principle that a connection exists between
the presence of mold and health.” (Mondelli v. Kendel Homes
Corp. (Neb. 2001) 631 N.W.2d 846, 856, italics added.)
“[N]umerous publications accepted in the scientific community”
recognize “the link between exposure to” highly “toxigenic molds”
and “adverse health effects.” (Centex-Rooney Construction Co.,
Inc. v. Martin, supra, 706 So.2d at p. 26, italics added.) Although
courts have been cautious about linking mold to a variety of
illnesses, they have recognized that studies have linked “toxic
effects as a result of mold exposure . . . to upper and lower
respiratory tract symptoms.” (Young v. Burton (D.C. 2008) 567
F.Supp.2d 121, 138.)
       Consequently, courts have admitted expert evidence
showing the specific causal link between molds and illnesses
suffered by parties. (B.T.N. v. Auburn Enlarged City School
Dist., supra, 845 N.Y.S.2d at p. 615 [epidemiology evidence
showed “atypical molds found to be present in the school building
can cause plaintiffs’ symptoms”]; Martin v. Chuck Hafner’s
Farmers’ Market, supra, 28 A.D.3d at p. 1067; Watters v. Dept. of
Social Services, supra, 849 So.2d at p. 733; New Haverford
Partnership v. Stroot, supra, 772 A.2d at pp. 797, 801 [expert
testimony properly admitted to show cognitive defect symptoms

                                16.
were the result of “exposure to atypical” mold]; Davis v. Fisher
Single Family Homes, Ltd. (Ky.Ct.App. 2007) 231 S.W.3d 767,
779 [expert permitted to testify about the “scientifically” valid
“short-term health effects of mold exposure”]; Pauluk v. Savage
(9th Cir. 2016) 836 F.3d 1117, 1119 [doctors’ depositions
“corroborated that [employee] was ill and that the illness was
caused by mold”]; Caldwell v. Curioni (Tex.Ct.App. 2004) 125
S.W.3d 784, 793 [treating doctors’ affidavits stating plaintiffs’
physical problems were caused “by exposure to mold infestation”
were sufficient to overturn summary judgment for defendant
landlord]; Genna v. Jackson (Mich.Ct.App. 2009) 781 N.W.2d
124, 130 [extremely high levels of mold “can cause” children’s
symptoms of coughing, wheezing, vomiting, lack of oxygen,
nosebleeds, and diarrhea].)
       The scientific acceptance of the link between molds and
illness has also been part of this state’s health public policy.
California courts long ago found a link between mold and adverse
health symptoms. (Miller v. Lakeside Village Condominium
Assn. (1991) 1 Cal.App.4th 1611, 1634 (conc. opn. of Johnson, J.)
[“Mold in the condominium was the cause of all the symptoms”].)
The California Toxic Mold Protection Act of 2001 requires
landlords to disclose “the presence of toxic mold.” (Jarman-
Felstiner, Mold is Gold: But, Will it be the Next Asbestos, supra,
30 Pepperdine L.Rev. at p. 549.) Lawmakers enacted it to
“[p]rotect the public’s health.” (Health & Saf. Code, § 26131,
subd. (a)(2).) In 2016, the Legislature added major “visible mold”
growth, confirmed by health officials, as a factor in classifying a
premises as “substandard.” (Id., § 17920.3, subd. (a)(13).)
Landlords are not shielded from liability for the presence of “mold
infestation on the premises.” (Burnett v. Chimney Sweep (2004)

                                17.
123 Cal.App.4th 1057, 1067.) They must provide safe and
habitable premises. (Knight v. Hallsthammar (1981) 29 Cal.3d
46, 52.)
       Federal courts have recognized the link between toxic mold
and illness may constitute an “obvious health” hazard for the
public. They have held that: 1) because apartments
contaminated with mold constitute a threat to health, they may
be condemned (Elsmere Park Club, L.P. v. Town of Elsmere (3d
Cir. 2008) 542 F.3d 412, 419); and 2) “[b]ecause removing an
obvious health hazard is a matter of safety and not policy, the
government’s alleged failure to control the accumulation of toxic
mold in the Bangor commissary cannot be protected under the
discretionary function exception” to the Federal Tort Claims Act.
(Whisnant v. United States (9th Cir. 2005) 400 F.3d 1177, 1183,
italics added.)
       The trial court did not consider the deposition testimony of
Cachuma defense expert Marion J. Fedoruk, M.D. Fedoruk
testified, “[M]old as being considered unhealthy in a building,
obviously, generally, I would agree with that, yes.” From Simon’s
experience, his medical diagnosis, and the recent scientific
literature, he could reasonably conclude that environments with
high levels of aspergillus and stachybotrys, as here, form
“aeroirritants” that had an adverse impact on Brancati’s
respiratory health.
       Cachuma claims that Simon’s research and theories are
outside the mainstream and that his theory about “aeroirritant
effects” is not based on traditional scientific wisdom and cannot
be used to support his testimony at trial. But this claim has been
rejected. (Centex-Rooney Construction Co., Inc. v. Martin County,
supra, 706 So.2d at p. 26.)

                                18.
       Moreover, on a motion in limine, the trial court “does not
resolve scientific controversies” and it does not weigh the
opinion’s “probative value.” (Bader v. Johnson & Johnson, supra,
86 Cal.App.5th at p. 1105.) Those are matters for the jury at
trial. Even if a theory involves a matter of scientific controversy,
history shows new theories often replace the conventional
scientific wisdom. Substances that were once thought to be
harmless have later been determined to be dangerous, i.e.,
smoking, asbestos, lead paint, cyclamates, saccharin, Camp
Lejeune drinking water, talcum powder, etc.
                            Other Issues
       Cachuma claims in Simon’s deposition he gave opinions
about “MVOC” (microbial volatile organic compounds), but he
was not an expert in that area, and he opined about a number of
other factors based on speculation. Where an expert gives
testimony in areas beyond his or her expertise, or provides
speculation, that testimony may be excluded. (Jennings v.
Palomar Pomerado Health Systems, Inc. (2003) 114 Cal.App.4th
1108, 1117; People v. Hogan (1982) 31 Cal.3d 815, 852, overruled
on another ground by People v. Cooper (1991) 53 Cal.3d 771.) But
Cachuma’s effort to completely prevent Simon from testifying in
the various areas where he has expertise is unwarranted.
       Cachuma contends Simon did not consider evidence of
Brancati’s preexisting conditions before she moved into Cachuma.
Her medical records show she was treated for an “upper
respiratory infection” in 2009. But whether that infection is a
preexisting condition or contradicts Brancati’s evidence on
causation are matters for the trier of fact to resolve at trial.

                                19.
                         DISPOSITION
     The judgment dismissing the action and disqualifying
Doctor Simon from testifying is reversed. Costs on appeal are
awarded to appellant.
           CERTIFIED FOR PUBLICATION.

                                     GILBERT, P. J.
We concur:

             BALTODANO, J.

             CODY, J.

                               20.
                   Timothy J. Staffel, Judge

            Superior Court County of Santa Barbara

                ______________________________

      Richard I. Wideman for Plaintiff and Appellant.
      Mullen & Henzell, Rafael Gonzalez and Sean Stratford-
Jones for Defendant and Respondent.