QIRC: usual PFOS injury – significant contributing factor?

Chase v Workers’ Compensation Regulator [2019] QIRC 195

Decision delivered 11 December 2019, Brisbane, by Industrial Commissioner Black

Parties

Chase, Claude

(Appellant)

v

Workers’ Compensation Regulator

(Respondent)

 

Facts & Case History

The appellant was a firefighter with Queensland Fire and Emergency Services between February 1994 to September 2002. He was both a worker and volunteer within the meaning of the Workers’ Compensation and Rehabilitation Act 2003 (Qld) (WCRA).

The appellant’s employment involved fire suppression and extinguishment and training in fire suppression and extinguishment. This involved exposure to carcinogenic substances [3] ‘including smoke, combustion products and fire extinguishment products including Aqueous Foam Fire Fighting Compounds (AFFF) containing the perflouroaklyl chemicals, perfluorooctanyl sulphonate (PFOS) and perfluorooctanoic acid (PFOA).’ The parties agreed the appellant was exposed to such substances, but did not outline the frequency or intensity of such exposure in the agreed statement of facts.

In 2009, the appellant was hospitalised for sepsis following bacterial infection arising during a dental procedure. This was associated with neck lymphadenopathy (lymph node enlargement) and was resolved at the time. The appellant was also a heavy smoker, of twenty per day, for more than thirty years.

Between February and December 2013, ultrasound and MRI scans indicated enlarged/prominent lymph nodes. Biopsies taken in 2014 indicated PTGC (progressive transformation of germinal centres) and reactive hyperplasia. Subsequent PET/CT scans did not show enlargement anywhere else in his body. Dr. Hensen treated the appellant with Mabthera monotherapy, and his lymph nodes returned to a normal size.

Subsequently, in August 2014, the appellant made an application for compensation to WorkCover Queensland.

PTGC is known for its potential to progress to lymphoma, and it was agreed the appellant was in a window where cancer could develop, but at the time of hearing his condition hadn’t transformed into lymphoma.

In February 2015, Dr Hensen provide a work-related diagnosis in response to WorkCover’s of whether the appellant’s “exposure to AFFF whilst employed as a fire fighter” was a significant contributing factor in the causation of the appellant’s work-related diagnosis.’[1]

Dr Hensen diagnosed ‘a work related injury of neck lymphadenopathy caused by PTGC, and opined that an association with occupational exposures seemed “quite likely” given that the location of the lymphadenopathy correlated with the chemical exposure site.’[2] Dr Hensen concluded that, based on research and case studies, there was a “plausible association” between the appellant’s work and his PTGC.

In June 2015, WorkCover rejected the appellant’s claim, and was subsequently confirmed by the Regulator in December 2015. The appellant appealed.

Issues on Appeal

The Commission noted at [29] that ‘The ultimate matter for determination is whether the appellant’s diagnosed condition of florid lymphoid hyperplasia and PTGC is causally connected to his employment pursuant to s 32 of the WCR Act.’

The Commission again noted at [84] that ‘The question to be answered in the appeal is whether, on the balance of probabilities, the appellant’s exposure to occupational carcinogens has caused the development of PTGC.’

In determining this, it was also relevant to consider whether other causes could be responsible for the appellant’s condition, such as his smoking or 2009 bacterial infection (see [26]).

Submissions

The submissions of both parties essentially turned on the expert evidence of both Dr Brant (for the respondent) and Dr Hensen (for the appellant) as to causation i.e. whether the appellant’s exposure to carcinogenic substances significantly contributed to his development of PTGC.

Dr Brant noted that, although the appellant had been exposed to hazardous substances, the existing literature does not establish a causal association between the chemical compounds he was exposed to and his diagnosis. He noted that although the literature does indicate an association between the chemicals and various cancers, it is not associated with PTGC or other lymphatic issues. In essence, although the substances are known to be hazardous, their health effects haven’t been clearly established.

Dr Hensen highlighted the carcinogenic character of the substances and their recognition by SafeWork as a ‘Category 2 Carcinogen’ and there is ‘sufficient evidence to provide a strong presumption that human exposure might result in the development of cancer’, leading to the reasonable conclusion that ‘that it is more a matter of probability than possibility that the appellant’s exposure to PFOS might lead to the development of cancer’. [3] Dr Hensen also noted that although the appellant’s smoking or dental complications could have caused his PTGC, the area of exposure was consistent with the site of pathology (the neck)

Decision on the Issue

The Commission noted that, to date, there had not been any studies examining the association between PTGC its potential causative factors. However, citing the observation of Spigelman CJ in Seltsam Pty Ltd v McGuiness, the Commission concluded that a lack in medical science being able to determine causation does not mean that, legally, causation or a lack thereof automatically exists. Rather, the law may look to epidemiological evidence, and, in any event, where disease aetiology is uncertain, the Courts are not ‘disenabled from making decisions as to causation on the balance of probabilities’.[4]

The Commission then weighed the evidence of the two experts – Dr Brant and Dr Hensen. His Honour concluded that they agreed the literature review did not evidence an association between PTCG and occupational exposure. Dr Brant opined this omission warranted the conclusion that it was unlikely the appellant’s occupation caused his PTGC. However, Dr Hensen opined the lack of evidence was merely a result of a lack of extensive research on the pivotal issue, but that there were ‘sound reasons for a conclusion that occupational exposures were the most likely cause of the appellant’s condition’.[5] As such, His Honour balanced ‘the literature review outcomes on the one side of the scales, and the reasoning of Dr Hensen to the effect that an association between PTGC and occupational carcinogens was sound and defensible, on the other side of the scales’.[6]

Dr Hensen’s views as a haematologist went largely unchallenged and the appellant relied on his expertise as a haematologist. Accordingly, His Honour preferred the evidence of Dr Hensen and accepted that ‘it was more probable than not that the appellant’s diagnosed condition of PTGC was causally connected with his employment as a firefighter.’[7]

The appeal was allowed [145].

David Cormack – Brisbane Barrister and Mediator

Madeleine Bowater – research assistant 

[1] At [18]

[2] At [19]

[3] At [54]

[4] At [94]

[5] At [127]

[6] At [138]

[7] At [144]

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