Filed 2/26/18
                             CERTIFIED FOR PUBLICATION

                IN THE COURT OF APPEAL OF THE STATE OF CALIFORNIA

                               FIRST APPELLATE DISTRICT

                                       DIVISION FIVE


CITY OF SOUTH SAN FRANCISCO,
        Petitioner,
v.
WORKERS’ COMPENSATION                              A151857
APPEALS BOARD and CITY OF
PACIFICA,                                          (W.C.A.B. No. ADJ2151993)
        Respondents.


        Richard Johnson worked successively as a firefighter for the City of South San
Francisco (CSSF) and for the City of Pacifica (Pacifica). He developed a nasopharyngeal
cancer. Labor Code section 3212.1 1 establishes a presumption that cancer manifesting
during and for a specified period following employment in certain public safety positions,
including firefighters, arose out of and in the course of that employment. Section 5500.5,
subdivision (a) (section 5500.5(a)), however, limits employer liability for a cumulative
injury to the employer who employed the applicant during the one year preceding the
earliest of (1) the date of injury or (2) the last date of injurious exposure to the hazards
that caused the injury. Thus, either CSSF or Pacifica would be potentially responsible for
compensation for the entire injury, dependent upon the proper application of
section 5500.5(a).
        CSSF settled a workers’ compensation claim by Johnson for this injury and
petitioned for contribution from Pacifica. An arbitrator denied the petition, ruling that
evidence of the latency period for the cancer suffered by Johnson showed the injurious

        1
            Undesignated statutory references are to the Labor Code.


                                               1
exposure under section 5500.5(a) occurred during Johnson’s earlier employment with
CSSF. The Workers’ Compensation Appeals Board (WCAB) upheld and adopted the
arbitrator’s order.
       CSSF petitioned for review, contending the WCAB, in adopting the arbitrator’s
determination, erroneously utilized a more lenient preponderance evidentiary standard in
applying section 5500.5(a), rather than the more stringent cancer presumption rebuttal
standard provided in section 3212.1. We have granted review, but affirm the
determination of the WCAB.
                                   I.     BACKGROUND
       Johnson worked as a firefighter for CSSF from March 1973 to October 2001, and
for Pacifica from November 2001 on. He was exposed to known carcinogens during
each period of employment. In 2007, he was diagnosed with nasopharyngeal cancer,
which had metastasized and caused a growth in his neck. The cancer was found to have
initially manifested itself during 2005, when Johnson first noted symptoms of nasal
obstruction. The disability was found to have occurred in 2007, during Johnson’s
employment with Pacifica. 2
       Johnson filed a workers’ compensation claim against Pacifica. He invoked the
presumption of section 3212.1 that cancer manifesting during (or within certain periods
following) employment as a firefighter that involves exposure to known carcinogens
arose out of and in the course of that employment. (§ 3212.1, subd. (b).) 3 The


       2
         “The date of injury in cases of occupational diseases or cumulative injuries is
that date upon which the employee first suffered disability therefrom and either knew, or
in the exercise of reasonable diligence should have known, that such disability was
caused by his present or prior employment.” (§ 5412.)
       3
           Section 3212.1 provides in relevant part: “(a) This section applies to all of the
following: [¶] (1) Active firefighting members, whether volunteers, partly paid, or fully
paid, of all of the following fire departments: [¶] (A) A fire department of a city, county,
city and county, district, or other public or municipal corporation or political subdivision.
[¶] . . . [¶] (b) The term ‘injury,’ as used in this division, includes cancer, including
leukemia, that develops or manifests itself during a period in which any member
described in subdivision (a) is in the service of the department or unit, if the member

                                              2
presumption may be rebutted if the employer shows the primary site of the cancer has
been identified and “the carcinogen to which the member has demonstrated exposure is
not reasonably linked to the disabling cancer.” (§ 3212.1, subd. (d).) Pacifica denied
liability and joined CSSF as a party to the case. 4 CSSF eventually settled with Johnson
for all of his cancer-related compensation, and it then sought contribution from Pacifica.
       The contribution case was submitted to arbitration based on a documentary record.
(See § 5275, subd. (a)(2).) CSSF and Pacifica stipulated to “a single cumulative trauma
period for purposes of assessing liability. The effect of this is that one party will bear full
responsibility for the benefits paid . . . .” The issues submitted to the arbitrator concerned
application of sections 3212.1 and 5500.5. Section 5500.5 provides that, in Johnson’s
circumstances, “liability for . . . cumulative injury claims . . . shall be limited to those
employers who employed the employee during a period of [one year] immediately
preceding either [(1)] the date of injury, as determined pursuant to Section 5412, or
[(2)] the last date on which the employee was employed in an occupation exposing him
or her to the hazards of the . . . cumulative injury, whichever occurs first.”



demonstrates that he or she was exposed, while in the service of the department or unit, to
a known carcinogen as defined by the International Agency for Research on Cancer, or as
defined by the director. [¶] . . . [¶] (d) The cancer so developing or manifesting itself in
these cases shall be presumed to arise out of and in the course of the employment. This
presumption is disputable and may be controverted by evidence that the primary site of
the cancer has been established and that the carcinogen to which the member has
demonstrated exposure is not reasonably linked to the disabling cancer. Unless so
controverted, the [WCAB] is bound to find in accordance with the presumption.” (Italics
added.)
       4
         CSSF was also potentially subject to the section 3212.1 presumption because the
presumption applies “following termination of service for a period of three calendar
months for each full year of the requisite service, but not to exceed 60 months in any
circumstance.” (§ 3212.1, subd. (d), as amended by Stats. 2000, ch. 887, § 1, p. 6528; cf.
Stats. 2010, ch. 672, § 1, p. 3656 [increasing maximum to 120 months].) Johnson
worked for CSSF for 28 full years and was entitled to the maximum extension of
60 months or five years (28 x 3 = 84 months or 7 years) following the end of his CSSF
employment in October 2001, i.e., through October 2006. The 2005 manifestation of
cancer fell within this presumptive period.


                                               3
(§ 5500.5(a).) 5 The arbitrator determined the date of injury was in 2007. The dispositive
issue was whether the last injurious exposure resulting in the injury occurred during
CSSF or Pacifica employment.
       The medical evidence before the arbitrator consisted of written reports and
deposition testimony by Ira Fishman, M.D., the agreed medical examiner in Johnson’s
case against Pacifica. 6 Fishman acknowledged there was little epidemiological literature
regarding occupational risks for nasopharyngeal cancer, firefighting had “only a possible
link” to the cancer, 7 the cause of the cancer was unknown, and no studies established a
latency period for the cancer. However, he testified that the latency period for exposure-
related solid tumors generally was a minimum of 10 years. 8 Based on that latency period,
he opined that Johnson’s last harmful carcinogen exposure occurred in 1996 or 1997, and
that Johnson’s six-year employment with Pacifica was not causally linked to his cancer.
       The arbitrator found Fishman’s evidence credible and persuasive. He found that
Fishman “made a convincing case” that the CSSF exposure was the causative factor in

       5
            Section 5500.5 provides in relevant part: “(a) Except as otherwise provided in
Section 5500.6, liability for occupational disease or cumulative injury claims . . . shall be
limited to those employers who employed the employee during a period of [one year]
immediately preceding either the date of injury, as determined pursuant to Section 5412,
or the last date on which the employee was employed in an occupation exposing him or
her to the hazards of the occupational disease or cumulative injury, whichever occurs
first. . . . [¶] . . . [¶] If, based upon all the evidence presented, the [WCAB] or workers’
compensation judge finds the existence of cumulative injury or occupational disease,
liability for the cumulative injury or occupational disease shall not be apportioned to
prior or subsequent years . . . .”
       6
           Fishman was board certified in internal medicine.
       7
         Fishman concluded that without application of the cancer presumption for
firefighters, there was insufficient epidemiological literature to conclude with reasonable
medical probability that Johnson’s occupation as a firefighter led to the development of
nasopharyngeal cancer.
       8
         Fishman testified a further delay occurred between appearance of Johnson’s
nasopharyngeal tumor and its metastasis, causing the growth in Johnson’s neck, but he
could not quantify that delay. He also testified it was unknown whether ongoing
exposure to a carcinogen contributes to the development of cancer after a tumor initially
appears.


                                              4
Johnson’s development of cancer, given the latency period involved, and that CSSF,
while emphasizing deficiencies in Fishman’s opinions, had not offered any contrary
medical opinion. The arbitrator further found that Fishman’s opinion provided
“substantial evidence” on the question of latency, and that “the weight of the evidence
shows [CSSF] employment as being within the latency period, and there is no medical
evidence showing that either [CSSF] fell outside the injurious period vis-à-vis latency or
that the Pacifica employment was the proper time frame given the latency period for
nasopharyngeal cancer.”
       The arbitrator denied CSSF’s petition for contribution. In doing so, he
distinguished between the enhanced burden an employer must meet under section 3212.1
to rebut liability to the employee for the injury (i.e., establishing the absence of a
“reasonable link” between the cancer and the industrial exposure to the carcinogen), and
what he found to be the applicable preponderance of the evidence standard in a
contribution action between employers (i.e., whether it is more likely that the cancer
arose from one or another period of employment). The arbitrator wrote: “Had [Johnson]
only been employed by Pacifica, with no prior public safety employment, it is likely that
on this record of six years employment with Pacifica, the exposure to carcinogens and the
operation of the presumption, that he would have established a compensable injury case
as to Pacifica. . . . [However, t]he fact that there is exposure with both [CSSF] and
Pacifica shifts the factual determination solely to which employment is injurious . . . .
[¶] . . . [B]etween Pacifica and [CSSF], the stronger case is that the latency period
implicates the [CSSF] employment.”
       CSSF petitioned for reconsideration. The arbitrator wrote a report and
recommendation defending his original award (Award) and recommending denial of the
petition. The WCAB adopted the arbitrator’s report and recommendation and denied
CSSF’s petition for reconsideration. CSSF petitioned for review (§ 5950), arguing that
(1) the arbitrator acted in excess of his power by failing to apply the “no reasonable link”
standard of proof for rebuttal of the section 3212.1 cancer presumption; and (2) the



                                               5
arbitrator’s findings of fact and award are unreasonable and not supported by substantial
evidence. 9
                                    II.    DISCUSSION
       “When considering a petition for a writ of review on a decision of the WCAB,
‘ “ ‘ “[we] must determine whether the evidence, when viewed in light of the entire
record, supports the award of the WCAB. [We] may not reweigh the evidence or decide
disputed questions of fact,” ’ ” ’ ” unless we determine the WCAB’s factual findings to
be “ ‘ “ ‘ “unreasonable, illogical, improbable or inequitable when viewed in light of the
overall statutory scheme.” ’ ” ’ ” (City of Long Beach v. Workers’ Comp. Appeals Bd.
(Garcia) (2005) 126 Cal.App.4th 298, 310.) “[U]nless clearly erroneous[,] the WCAB’s
interpretation of the workers’ compensation laws is entitled to great weight.” (Genlyte
Group, LLC v. Workers’ Comp. Appeals Bd. (2008) 158 Cal.App.4th 705, 714; Griffith v.
Workers’ Comp. Appeals Bd. (1989) 209 Cal.App.3d 1260, 1263–1264
[“contemporaneous administrative construction of a statute by the [WCAB], as the
administrative agency charged with its enforcement and interpretation, while not
necessarily controlling, is of great weight; and courts will not depart from such
construction unless it is clearly erroneous or unauthorized”].) “Nevertheless, issues of
statutory interpretation and questions of law are subject to our independent review, and
we need not defer to the WCAB’s legal determinations where they are contrary to the
plain meaning of the statute or prevailing case law.” (Contra Costa County v. Workers’
Comp. Appeals Bd. (2015) 240 Cal.App.4th 746, 756.)
A.     The Arbitrator’s Factual Findings
       The arbitrator found the expert medical testimony credible. Based on evidence of
the latency period for nasopharyngeal cancer, he concluded that “the weight of the
evidence” established that Johnson’s injurious exposure occurred during his CSSF
employment, and not during his Pacifica employment—i.e., that Johnson’s cancer was
caused by his CSSF exposure.

       9
           The WCAB declined to file an answer to CSSF’s petition.


                                             6
       Pacifica argues that “the arbitrator specifically found that the [section] 3212.1
presumption was rebutted” and thus “did not use a different legal standard to adjudicate
the contribution claim.” (Italics added.) We disagree with that reading of the arbitrator’s
opinions.
       Pacifica relies upon the following language from the arbitrator’s summary of
rulings at the beginning of the Award: “Was there injurious exposure with Pacifica under
. . . section 5500.5 considering the latency period of applicant’s cancer? NO [¶] . . . If the
. . . section 3212.1 presumption applies as to Pacifica, is it rebutted by evidence of
latency? YES.” However, the arbitrator articulated no such finding in the body of the
written Award. Moreover, in his report and recommendation, the arbitrator revised the
summary of rulings to read: “Was there injurious exposure with Pacifica under . . .
section 5500.5 considering the latency period of applicant’s cancer? YES [¶] . . . If the
. . . section 3212.1 presumption applies as to Pacifica, is it rebutted by evidence of
latency? NO.” In light of these inconsistencies in the summaries, we consider only the
fully-articulated reasoning in the body of the opinions.
       In addition, the Award clearly indicates the arbitrator was inclined to find Pacific
had not rebutted the section 3212.1 presumption. “While Pacifica’s [evidence] may have
been insufficient to defeat an injury claim by an injured worker, here, . . . the question of
latency is . . . determined by weighing the evidence presented by the parties. [¶] As we
know from Garcia[, supra, 126 Cal.App.4th 298], . . . [t]he employer has the affirmative
burden of disproving the link [between the exposure and the cancer], but as noted above,
that is for the limited question of determining whether applicant sustained a compensable
industrial injury.” The arbitrator’s report and recommendation similarly indicates
application of the preponderance of evidence standard to the injurious exposure issue
rather than the section 3212.1 presumption rebuttal standard, and that the arbitrator likely
would not have found the presumption rebutted had he applied the section 3212.1
standard.
       Therefore, we reject Pacifica’s argument that the arbitrator made a factual finding
that Pacifica rebutted the section 3212.1 presumption.


                                              7
B.     The Legal Standard
       CSSF argues the arbitrator applied the wrong legal standard to determining which
of the employers was liable for Johnson’s cumulative injury. We disagree.
       1.     The Section 3212.1 Employer Rebuttal Standard
       “ ‘In the usual workers’ compensation case, before an employer can be held liable,
the worker must show not only that the injury arose out of and in the course of
employment’ but also that the injury was proximately caused by the employment.
[Citations.] The burden is on the employee to show proximate cause by a preponderance
of the evidence. [Citations.] However, in the case of certain public employees who
provide ‘vital and hazardous services’ to the public [citation], the Labor Code contains a
series of presumptions of industrial causation. These presumptions provide that when
specified public employees develop or manifest particular injuries or illnesses, during
their employment or within specified periods thereafter, the injury or illness is presumed
to arise out of and in the course of their employment.[10] [Citations.] These presumptions
are a reflection of public policy. [Citations.] Their purpose is to provide additional
compensation benefits to employees who provide vital and hazardous services by easing
their burden of proof of industrial causation.” (Garcia, supra, 126 Cal.App.4th at
pp. 310–311.)
       As originally enacted, section 3212.1, the cancer presumption, “imposed on the
employee the burden of demonstrating . . . that the carcinogen [to which the employee
was exposed] was reasonably linked to the disabling cancer.” (Garcia, supra,
126 Cal.App.4th at p. 312, fn. omitted.) Because this standard placed an unreasonable
burden on employees, the statute was amended in 1999 to require the employer to prove
the carcinogen of exposure was not reasonably linked to the disabling cancer. (Id. at
pp. 312–313.) “The inescapable conclusion is that the Legislature intended to remove the



       10
         See, e.g., § 3212 et seq. (hernia, heart trouble, pneumonia, tuberculosis, blood-
borne infectious diseases, meningitis, skin cancer, Lyme disease, lower back
impairments).


                                             8
burden from employees and enable them to obtain benefits even when it was not possible
to prove the cancer was linked to the particular carcinogen.” (Id. at p. 315.)
       While other workers’ compensation presumption statutes allow employers to rebut
the presumption with any “ ‘other evidence,’ ” section 3212.1 “requires the link be
controverted only in a specific and limited way: by proof of the cancer’s primary site and
the absence of a reasonable link.” (Garcia, supra, 126 Cal.App.4th at p. 315.) Garcia
holds that “an employer demonstrates the absence of a reasonable link if it shows no
connection exists between the carcinogenic exposure, or that any such possible
connection is so unlikely as to be absurd or illogical. . . . [T]he statute does not require
the employer to prove ‘the absence of any possible link.’ . . . [¶] [On the other hand, a]n
employer does not meet its burden merely by showing that no studies exist showing a
positive link between the exposure and the particular form of cancer. . . . The absence of
medical evidence linking a known carcinogen with a particular form of cancer simply
represents a void of information, and cannot be considered proof a reasonable link does
not exist.” (Garcia, at p. 316, fn. omitted; see Faust v. City of San Diego (2003)
68 Cal.Comp.Cases 1822 [WCAB en banc decision reaching similar conclusion].)
Garcia acknowledges this burden is high, but observes, “There appears to be no inherent
reason why the employee, rather than the employer, should bear the burden of an absence
of scientific knowledge.” (Garcia, at p. 316.)
       2.     Section 5500.5
       As noted ante, section 5500.5 provides that liability for a cumulative injury is
limited to those employers who employed the employee during one year preceding the
earlier of (1) the date of injury per section 5412 (here in 2007, during Pacifica
employment), or (2) “the last date on which the employee was employed in an occupation
exposing him or her to the hazards of the occupational disease or cumulative injury.”
(§ 5500.5(a).) Although the second phrase appears to refer to any exposure to the
hazards during a period of employment, this court has held that other provisions in the
workers’ compensation statutory scheme require proof of proximate causation before
liability may be imposed. (Scott Co. v. Workers’ Comp. Appeals Bd. (1983)


                                               9
139 Cal.App.3d 98, 104–105, citing §§ 3600, subd. (c), 3208, 3208.1.) Thus, an
employer is not liable under section 5500.5(a) absent evidence that exposure during that
employment was a contributing cause of the disease or injury, i.e., that the exposure was
injurious. (Scott Co., at pp. 101, 104.)
       The purpose of section 5500.5(a) is “to provide greater certainty to insurers in
anticipating costs and necessary reserves, to simplify the proceedings by reducing the
number of employers and insurers required to be joined as defendants, and to reduce the
burden placed on the entire system by the former procedures. [Citations.] The insurance
industry favored these amendments and reasoned that the total burdens and benefits upon
employers and insurers would more or less even out, for while they might be required to
assume a larger liability in some cases, they would also be absolved of liability in other
cases.” (Flesher v. Workers’ Comp. Appeals Bd. (1979) 23 Cal.3d 322, 328; see Scott
Co. v. Workers’ Comp. Appeals Bd., supra, 139 Cal.App.3d at p. 105 [quoting Flesher’s
statement of § 5500.5’s legislative purpose].) The statute also ensures that “an employee
disabled by a progressive occupational disease may obtain an award for his entire
disability against any one or more of his successive employers or insurance carriers and
that those held liable have the burden of seeking apportionment [in subsequent
proceedings].” (Flesher, at p. 327.)
       3.     Analysis
       Johnson was exposed to the hazards of the occupational disease or suffered
cumulative injury during his final employment with Pacifica. 11 His cancer manifested
itself during that employment. The section 3212.1 presumption would establish the
existence of an industrial injury for which Pacifica would be liable absent rebuttal by
evidence of no reasonable link between the carcinogens to which Johnson was exposed
and the disabling cancer. To rebut the presumption, Pacifica would be required to
“explicitly demonstrate that medical or scientific research has shown that there is no

       11
          The agreed medical examiner, Fishman, questioned whether there was sufficient
evidence of Pacifica exposure to trigger the presumption. The parties’ stipulation made
this issue moot.


                                             10
reasonable inference that exposure to the specific known carcinogen or carcinogens is
related to or causes the development of the cancer,” i.e., evidence of reasonable medical
probability that a reasonable link does not exist. (Faust v. City of San Diego, supra,
68 Cal.Comp.Cases at p. 1832.) But, because the cancer manifested itself within five
years after he left employment with CSSF (in October 2001), CSSF was subject to the
same presumption. (§ 3212.1, subd. (d).) As the arbitrator noted, “[W]e have two
employers with injurious exposure and two employers who are bound by the 3212.1
presumption.” 12
       The issue is not whether Johnson was entitled to compensation for his injury. He
was, and has been. The only question is, as between two otherwise individually liable
employers, who pays? CSSF contends that application of section 5500.5(a) is a
straightforward process of applying a one-year time frame to any period of employment
causally linked to the cumulative injury, and that the section 3212.1 presumption
establishes that link unless adequately rebutted. In other words, the last public safety
employer presenting any carcinogen exposure would bear the sole responsibility in that
circumstance. 13 But Scott Co. v. Workers’ Comp. Appeals Bd., supra, 139 Cal.App.3d at
pages 104–105, establishes that employers may be held liable under section 5500.5(a)
only if their employment is causally linked to the employee’s cumulative injury. 14 The


       12
          The arbitrator’s reference to “injurious exposure” including Pacifica is
somewhat confusing in that exposure is only “injurious” if it “causes disability or need
for medical treatment.” (§ 3208.1.) The reference is, however, consistent with the
arbitrator’s view that the parties might have hypothetically “developed a case for two
periods of cumulative trauma—one for each employer in that the presumption applied to
each.”
       13
         It is, strictly speaking, a misnomer to characterize this as a “contribution”
action. Contribution seeks equitable sharing of liability between co-obligors. (See
Crowley Maritime Corp. v. Boston Old Colony Ins. Co. (2008) 158 Cal.App.4th 1061,
1067 [co-insurers].) This is more accurately a proceeding to allocate singular
responsibility between two employers. (See § 5500.5, subd. (e) [employer action to
determine “apportionment of liability or right of contribution”].)
       14
        We also question whether Johnson’s injury is properly characterized as
“cumulative” in this context, although the parties here stipulated to a single period of

                                             11
ordinary causation test is proximate causation, established by a preponderance of the
evidence. (Garcia, supra, 126 Cal.App.4th at p. 310; § 3202.5.)
       Section 3212.1 does not eliminate the requirement that an industrial injury be
proximately caused by the hazardous exposure. Instead, it applies presumptions of a
causal link between exposure to the industrial hazard (a known carcinogen) and the
manifested injury (cancer), unless the employer disproves the existence of such a link.
Absent such proof, the WCAB is “bound to find in accordance with the presumption.”
(§ 3212.1, subd. (d).) “These presumptions are a reflection of public policy . . . to
provide additional compensation benefits to employees who provide vital and hazardous
services by easing their burden of proof of industrial causation.” (Garcia, supra,
126 Cal.App.4th at pp. 310–311; see id. at p. 315.) We agree with the arbitrator’s
conclusion that “[t]he purpose [of section] 3212.1 . . . was to protect the injured worker
and not to protect one employer over another.”
       We simply do not find that same worker protection policies embodied in
section 3212.1 implicated in allocation of liability between employers. CSSF argues that
applying a lower rebuttal standard to contribution proceedings would encourage
employers to deny presumptive claims and would result in additional denials and
litigation of presumptive cases. CSSF does not explain why it would be less probable,
rather than more, that a public safety employer subject to the presumption would seek to
join any other potentially liable employer in the employee claim proceeding if the




cumulative trauma for purposes of assessing liability. “An injury may be either:
(a) ‘specific,’ occurring as the result of one incident or exposure which causes disability
or need for medical treatment; or (b) ‘cumulative,’ occurring as repetitive mentally or
physically traumatic activities extending over a period of time, the combined effect of
which causes any disability or need for medical treatment . . . .” (§ 3208.1.) Johnson had
cumulative exposure to carcinogens over the course of his successive periods of
employment, but Fishman could not say whether continuing exposure to carcinogens
could contribute to the development of cancer even after it first manifests. The arbitrator
here was required to make a binary determination as to which period of exposure was
injurious.


                                             12
section 3212.1 presumption applied to a contribution claim. 15 But litigation between
employers subject to the section 3212.1 presumption does not require participation by the
employee, and an employer’s unreasonable delay or refusal to pay benefits is subject to
sanction. (See § 5814.) “Section 5500.5 is long and complex, but its design is
reasonably clear. It is intended to allow an employee to recover for his entire cumulative
injury from one or more employers of his choosing for whom he worked within the
preceding five years, even though a portion of his injury was incurred in prior
employments. The employer or employers against whom compensation is awarded are in
turn authorized to seek contribution from other employers in the five-year period.”
(Flesher v. Workers’ Comp. Appeals Bd., supra, 23 Cal.3d at pp. 325–326, fn. omitted.)
A proceeding to determine an apportionment of liability or right of contribution between
employers “shall not diminish, restrict, or alter in any way the recovery previously
allowed the employee or his or her dependents, but shall be limited to a determination of
the respective contribution rights, interest or liabilities of all the employers joined in the
proceeding . . . .” (§ 5500.5, subd. (e).)
       In the Award, the arbitrator cited City of Huntington Beach v. Workers’ Comp.
Appeals (Dalbey) (2016) 81 Cal.Comp.Cases 740 as authority for “placing liability on the
earlier employer even though the [cumulative injury] manifested during the subsequent
employ[ment] [and] even though the presumption was operative against the subsequent
employer as well as the earlier employer.” In that case, a public safety officer invoked
different presumptions (§§ 3212, 3212.5) that his cardiovascular injuries were caused by
successive employment for the City of Huntington Beach and Orange County. (Dalbey,
at p. 741.) Although the presumptions applied to both employers the workers’
compensation judge made a factual finding, based on medical testimony, that the actual
date of injury was during the earlier Huntington Beach employment, even though it did
not manifest until his subsequent employment with Orange County. While not discussing


       15
         As CSSF notes in its petition for review, section 3212.1 “makes rebuttal of a
cancer claim difficult if not impossible.”


                                              13
the applicable standard of proof, the WCAB adopted the workers’ compensation judge’s
findings, rejecting Huntington Beach’s claim that section 5500.5 required liability to be
imposed based upon the last one year of harmful exposure. Dalbey certainly assumes
that injury causation as an issue of fact remains the relevant question in a section 5500.5
allocation.
       Nothing expressed in section 5500.5 imposes the rebuttal proof standards of
section 3212.1, and we find nothing implied, either in that statute or in the statutory
scheme. As the Garcia court observed, “section 3212.1’s burden-shifting paradigm
differs from that contained in other workers’ compensation presumption statutes. Nearly
all the other presumption statutes state that the presumption may be controverted ‘by
other evidence.’ [Citations.] Section 3212.1, on the other hand, requires the link be
controverted only in a specific and limited way: by proof of the cancer’s primary site and
the absence of a reasonable link.” (Garcia, supra, 126 Cal.App.4th at p. 315.)
C.     Substantial Evidence
       The arbitrator made a factual determination, based on medical opinion of the
latency period of the cancer, that the date of Johnson’s injury was during his CSSF
employment. CSSF insists that this determination lacks support in substantial evidence.
“ ‘[S]ubstantial evidence’ means evidence ‘which, if true, has probative force on the
issues. It is more than a mere scintilla, and means such relevant evidence as a reasonable
mind might accept as adequate to support a conclusion . . . . It must be reasonable in
nature, credible, and of solid value . . . .” (Braewood Convalescent Hospital v. Workers’
Comp. Appeals Bd. (1983) 34 Cal.3d 159, 164, italics omitted.)
       “When considering a petition for a writ of review on a decision of the WCAB,
‘ “ ‘ “[t]his court must determine whether the evidence, when viewed in light of the entire
record, supports the award of the WCAB. This court may not reweigh the evidence or
decide disputed questions of fact. [Citations.] However, this court is not bound to accept
the WCAB’s factual findings if determined to be unreasonable, illogical, improbable or
inequitable when viewed in light of the overall statutory scheme.” ’ ” ’ ” (Garcia, supra,
126 Cal.App.4th at p. 310.) CSSF premises its challenge largely on the assumption that


                                             14
the section 3212.1 rebuttal standard applies. We review the evidence in light of what we
have determined to be the applicable preponderance standard.
       Garcia notes that one method of meeting the employer’s burden, even under
section 3212.1, is to show “it is highly unlikely the cancer was industrially caused
because the period between the exposure and the manifestation of the cancer is not within
the cancer’s latency period.” (Garcia, supra, 126 Cal.App.4th at p. 317.) Garcia cites
Riverview Fire Protection Dist. v. Workers’ Comp. Appeals Bd. (1994) 23 Cal.App.4th
1120 as an example. (Garcia, at p. 317.) In Riverview, which applied the former version
of section 3212.1 that required the employee to prove a reasonable link between the
demonstrated exposure and the cancer (Riverview, at p. 1124), the court held that the
employee failed to prove a reasonable link where no medical studies showed an increased
risk of stomach cancer in firefighters and the available medical evidence showed cancers
generally appeared decades after chemical exposure and the relevant employment period
was less than 10 years (id. at pp. 1128–1129). WCAB panels have repeatedly found the
presumption rebutted with medical evidence of a latency period for the particular type of
cancer suffered by the employee. 16 (See, e.g., Suarez v. Dept. of Forestry and Fire
Protection (Jan. 15, 2015, ADJ8691488) 2015 Cal.Wrk.Comp. P.D. Lexis 11, *7 [five-
year latency period for leukemia; employment began 2011 and manifestation/diagnosis in
2012]; Oyler v. County of Sonoma (Apr. 15, 2015, ADJ8518473) 2015 Cal.Wrk.Comp.
P.D. Lexis 228, *14–*15 [11- to 30-year latency period for kidney cancer; employment
began 2007 and manifestation/diagnosis in 2012].) In contrast, the panel in Bigelow v.
City of Paso Robles (Nov. 7, 2013, ADJ7949972) 2013 Cal.Wrk.Comp. P.D. Lexis 532
ruled that “discussion of latency periods for cancers in general” was not sufficient to
rebut the presumption. (Id. at p. *14, italics added ; see id. at pp. *15–*17.) The
employee in Bigelow had contracted colon cancer (id. at p. *4), and the expert “admitted
. . . there are no studies showing a specific latency period for colon cancer. . . . [H]e

       16
          WCAB panel decisions are “citable authority, especially as an indication of
contemporaneous interpretation and application of workers’ compensation laws.”
(Griffith v. Workers’ Comp. Appeals Bd., supra, 209 Cal.App.3d at p. 1264, fn. 2.)


                                              15
looked at the latency period for other cancers where ‘you have a fighting chance to
identify a latency period,’ and relied upon those latency periods for other cancers to opine
that it is ‘not unreasonable to think of 15, 20 years of latency’ for applicant’s colon
cancer to develop. [¶] . . . [He] acknowledged that no carcinogen has been identified as
causative of colon cancer and without that information the latency period for colon
cancer cannot be determined.” (Id. at p. *15.) The panel held this evidence did not meet
the rebuttal standard because “thinking that there likely is a latency period for colon
cancer is much different from proving that applicant’s colon cancer is not reasonably
linked to his exposure to carcinogens at work.” (Id. at pp. *15–*16, italics added.)
       Here, Fishman acknowledged that Johnson suffered a fairly rare form of cancer of
uncertain etiology. He testified in his deposition that no specific latency period had been
established for nasopharyngeal cancer by peer reviewed scientific studies, but based his
opinion on the general latency period for exposure-related solid tumors in humans.
Citing medical literature, he opined: “For most tumors, . . . the latency interval is
approximately 12–25 years . . . [and] exposure related solid tumors in humans appear to
require a minimum of 10–12 years and often longer latency from exposure to clinical
evidence of cancer.” Fishman testified that he was aware of no shorter latency period for
hard tumors, and in his medical opinion, there would be a minimum 10-year latency in
this case. CSSF presented no contrary medical evidence, and the arbitrator found
Fishman’s expert medical testimony to be credible and persuasive. The findings based on
that testimony are not “ ‘ “ ‘ “unreasonable, illogical, improbable or inequitable,” ’ ” ’ ”
and we consequently do not reweigh the evidence or decide disputed questions of fact.
(Garcia, supra, 126 Cal.App.4th at p. 310.) Applying what we find to be proper
preponderance standard, we find that the evidence, viewed in light of the entire record,
supports the award of the WCAB.
                                    III.   DISPOSITION
       The June 5, 2017 WCAB order denying CSSF’s petition for reconsideration is
affirmed. CSSF shall bear Pacifica’s costs on appeal.



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                                 _________________________
                                 BRUINIERS, J.


WE CONCUR:


_________________________
JONES, P. J.


_________________________
SIMONS, J.




A151857


                            17
Richard, Thorson, Graves & Royer, Daniel E. Graves and Henry J. Gage III for
Petitioner.

No appearance for Respondent Workers’ Compensation Appeals Board.

Thomas, Lyding, Cartier, Arnone & Daily and Mark A. Cartier for Respondent City of
Pacifica.




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