Estate of Worker v. Employer, 2024 CanLII 29983

20240010, ESTATE OF WORKER

REPRESENTED by:

HEARD by:

DATED:

L.CIRILLO, appeals resolution officer

JANUARY 30, 2024

ISSUE

The estate objects to the Adjudicator’s decisions dated May 25, 2017 and September 16, 2021, which denied initial entitlement for prostate cancer as being related to the worker’s employment exposures.

BACKGROUND

This claim was established in April 2016 based Dr. Noel Kerin’s, Occupational Health Clinics for Ontario Workers (OHCOW) report dated March 16, 2016, which opined that the worker developed prostate cancer related to multiple agent exposures in the workplace. The worker was 52 years of age at the time of diagnosis and had worked in various roles with the employer from 1989 to 2015.

The medical reveals that the worker initially saw their physician in July 2014 and underwent routine blood work, which revealed the presence of an elevated PSA. As a result, they were referred for further investigation. The histopathology report dated October 10, 2014 indicated that the prostate biopsy revealed the presence of invasive prostatic adenocarcinoma. The date of injury was determined to be July 1, 2014.

Note is made that the worker was a previous smoker, having smoked 1 pack per day for 25 years and having quit 1 year prior to their diagnosis.

Following review of the worker’s employment and exposure history as well as their medical records, the Adjudicator referred the file to a WSIB Occupational Hygienist (OH) for an opinion on the worker’s potential for occupational exposures throughout their employment history. Following the OH’s review, the file was referred to an Occupational Medical Consultant (OMC) in order to obtain an opinion on whether the worker’s employment exposures significantly contributed to the development of their prostate cancer.

It was ultimately concluded that given the prevalence of prostate cancer in North America, the multifactorial nature of prostate cancer causation, the lack of well-established workplace risk factors, and the absence of occupational hygiene information demonstrating elevated exposure to prostate carcinogens, there was insufficient evidence that the workplace played a role in the development of the worker’s condition. As a result, initial entitlement was denied. The decision was communicated to the worker in correspondence dated May 25, 2017.

The record reveals that the worker passed away on May 27, 2018.

In correspondence dated February 22, 2021, the estate’s representative objected to the denial of initial entitlement for prostate cancer and referred to information as follows:

The report entitled “Using Scientific Evidence and Principles to Help Determine the Work-Relatedness of Cancer” authored by Dr. Paul Demers dated January 9, 2020;
A report entitled “We Can’t Breathe” A Retrospective Exposure Profile of the Company A (1986-1996) prepared by Dale DeMatteo, BA. MHSc and Robert DeMatteo, BA, MA, DOHS with UNIFOR Local 1987 Exposure Advisory Committee: Unifor local President Mark Clapper, Past President Rose Wickman, along with Dave Gooley, Jackie Dufty, Cecil Firlotte, Karen Quesnel, and Rick McDougal for OHCOW (“DeMatteo Report”) submitted on January 7, 2020, which outlines that over 130 chemicals were used by the employer in plastics production, which included 24 carcinogenic chemicals;
He argued that in the Demers report, you can see that Dr. Demers determines and confirms that there is an additive and/or synergistic effect of exposures to multiple carcinogens and the resulting elevated risks of developing cancer;
Further, he stated that this information along with the DeMatteo report pertaining to the employer are both vital information to be utilized in tandem to determine causality in the worker’s prostate cancer diagnosis

Following receipt of the above, the operating contacted the employer to obtain additional details with respect to the worker’s employment/exposure history from September 1989 to December 1996. The employer submitted information pertaining to the worker’s employment history, company medical records, Material Safety Data Sheets (MSDS), statements/interviews with the Manufacturing Supervisor as well as a co-worker.

In further correspondence dated July 26, 2021, the estate’s representative referred to various operational policies and argued the following in part:

The DeMatteo report provides an analysis of “retrospective exposure profiles of the work processes at Company A facility”;
The workers at the employer were routinely subjected to a plethora of chemicals and solvents, the vast majority of which are deemed carcinogenic or endocrine disrupting chemicals (EDC) and that they had “additive or even synergistic effects” ;
She requests that the WSIB use the same “whole person” view be the lens through which the report be weighed as;
She states that the report thoroughly assessed different departments, starting on page 38;
The worker’s career was in three of the five departments analysed;
The report is a detailed and extensive review of working conditions under which the worker spent 29 years; they were consistently exposed to multiple carcinogens and EDCs;
She submits that the worker’s exposures would be similar to a firefighter and firefighter’s have presumptive legislation, creating a two-tiered compensation system since firefighters have a lower threshold to satisfy, whereas this worker is held to higher adjudicative standard that fails to consider cumulative effects;
The representative is not suggesting that operational policy 23-02-01 be invoked, but requests recognition that there is not one sole cause of prostate cancer;
In her view, the cumulative effect of exposure provides presumption that it is related to prostate cancer after 15 years. In this case, the worker was employed for 29 years, which is more exposure than a firefighter and/or volunteer firefighter;
She further argued that the report reviewed the lack of Personal Protective Equipment (PPE) in the early years, issues with air quality, limitations of testing and Ministry of Labour (MOL) investigations;
In conclusion, she argues that the entitlement decision ought to include this report and centric conclusion that there are additive and/or synergistic effects of exposure to multiple carcinogens; in the alternative, she submits that operational policy supports “exercising the ‘precautionary principle’… by giving the worker the benefit of the doubt

Following review of the above, the operating area re-visited the entitlement decision; however, ultimately concluded that the decision to deny entitlement remained upheld. The Adjudicator noted that while there were several new documents submitted to the record, there was no new information per se. Further, while the DeMatteo report provided insight on some of the job duties that the worker was involved with, it did not provide information, which was previously unknown. In addition, while the Demers report provided guidance to the WSIB on how to continue to build scientific and research capacity to determine work relatedness for occupational cancers at the system level, it did not pertain to this specific claim. The reconsideration decision was communicated to the estate in correspondence dated September 16, 2021.

The estate objected to the denial of initial entitlement for prostate cancer however, the decision remained unchanged and as a result, the matter was referred to the Appeals Services Division for further consideration.

Estate’s Position:

In correspondence dated May 23, 2023, the estate’s representative provided a claim background, which will not be repeated. She referred to legislation and operational policy (Merits and Justice & Benefit of Doubt) and argued the following in part:

The significance of the Demers report was discussed in her previous submission;
The significance of the DeMatteo report was discussed in her previous submission;
She referred to previous case law, which she states supports that synergistic and additive effects need to be factored into exposure quantifications. She notes that case law 1391/221 considers the DeMatteo report (relevant to the case at hand) and the Demers report;
She submits that the worker’s rate of exposure as well as their deemed exposures ought to be considered cumulatively;
The representative recognized that the worker was over the age of 50 at the time of diagnosis and that they had a confirmed smoking history having quit 2 years [sic] to being diagnosed; however, in weighing the totality of evidence, she submits the non-occupational risk factors ought not dissuade the WSIB from granting entitlement as they are of moderate significance at best;
She re-refers to the OHCOW report and notes that none of the worker’s first-generation relatives were diagnosed with prostate cancer. Further, she states that the worker was only 51 [sic] years of age at the time of diagnosis and literature supports that the likelihood of developing the disease at this age is least likely compared to the age range of 60-69;
The representative argues that little weight ought to be given to the employer’s submission, as there were repeated deficiencies with the information that was provided. In addition, she states the credibility and reliability of the information provided by the interviewees is difficult to determine as their commentary could not be cross-examined and their statements lack specific details. She submits this information is hearsay;
In her view, the standard of causation is not that of medical certainty nor is the threshold beyond a reasonable doubt. She argues the occupational exposures were more likely than not to have significantly contributed to the worker’s diagnosis;
She refers to the Toxicant and Disease Database from the Collaborative on Health and the Environment, which she states confirms causes of prostate cancer grouped by strength, as were identified in the OHCOW report – i.e. includes aromatic amines (n-Nitrosamines), polycyclic aromatic hydrocarbons (PAHs) and solvents having strong evidence and bisphenol A, cadmium, diesel exhaust, estrogens/DES and trichloroethylene (TCE) having limited evidence;
In considering Dr. Kerin’s report, she submits that it is more likely than not that the worker’s prostate cancer was significantly contributed to by their occupational exposures;
She further argues that the WSIB OH review is very limited and ought to be given little weight. In addition, she states it does not consider additive or synergistic effects, the effect of endocrine disrupting chemicals, the work environment as a whole as it relates to PPE, ventilation and safety culture;
In conclusion, she submits the worker’s exposure to asbestos, PAHs, cadmium, and solvents directly contributed to their diagnosis. As did their exposure to MEK, phosphate acids, formaldehyde, and bisphenol-A. Their rate of exposure was contributed to by poor safety culture, poor ventilation and lack of full PPE;
For these reasons, she requests that initial entitlement be allowed

Employer’s Position:

In correspondence dated November 18, 2023, the employer argues the following in part:

They provide an explanation as to why there are no “company” records prior to 1999 other than employee files;
Therefore, in order to provide the information requested by the WSIB, they had to interview current employees/mangers, who described former business operations in the early days of the RIM and paint processes in the manufacturing environment and they did so in good faith to the best of their recollection;
The estate’s representative criticized the reliability of the interviewees who each have been employed for 36 years, most of the time as managers, and have worked diligently to seek out any information they could to assist the adjudication of this claim;
They (along with other employees who have now retired) have provided facts and observations of the workplace as they know them for our consideration and do not agree with the harsh description of the workplace by the OHCOW, the estate’s representative and the two referenced reports;
The employer submits that they did have reasonable controls in place, especially for isocyanates and in the Paint Department where PPE was always mandatory to protect the health and safety of their employees in accordance with accepted workplace practices and compliance with industry standards in place at that time;
It is not disputed that the worker had proper PPE available to them at all times; they were diligent in wearing the PPE and often encouraged their co-workers to do the same;
Additionally, since 2001 there were continuous improvements made to the facility to comply with industry standards;
Information was provided with respect to the Chemical Monitor’s start up procedures (i.e. procedure checklist and photographs) in order to demonstrate an understanding of a typical day for the worker as a Chemical Monitor;
The employer states that according to the employer’s records, the worker worked on their family farm where they may have been exposed to pesticides or other chemicals used on the farm that may have contributed to their cancer;
They attached articles that suggest a strong link of increased risk factors from a family member’s DNA to the development of the worker’s prostate cancer (see memo A – family history);
The OMC indicated that the WSIB’s ODPR found inconclusive evidence of increased risk for prostate cancer from exposure to solvents, silica, asbestos, EMF’s and cadmium. Similarly, IARC has not found any carcinogenic agents with sufficient evidence in humans with respect to prostate cancer;
The employer notes that the WSIAT decision referred to by the estate’s representative is an interim decision with no final decision to date (is still pending). In addition, the employer submits that the facts of this case differ from those in this claim. The same holds true for the WSIAT decision dated 1507/11;
In this case, the OH concluded that the worker was not exposed to any of the carcinogens referenced to in the above WSIAT decision;
In conclusion, the employer submits that medical and science reviews conducted by the WSIB’s OMC and OH should be given more weight as their opinions are subjective and do not have a vested interest in either the employer or the union’s opinions/positions;
For these reasons, the employer requests that the decision to deny initial entitlement be upheld

Estate’s Rebuttal:

In correspondence dated December 18, 2023, the estate’s representative argues the following in part:

It remains the estate’s position that the information provided by the employer is biased and based predominantly, if not solely, on hearsay evidence as no company records exist prior to 1999. It is not disputed that the employer has acted in good faith; it remains, however, that the information provided to the WSIB is not historically accurate nor is it verifiable;
An understanding of a typical day is not at all demonstrative of the worker’s actual lived workday or workplace exposures. The pictures included add very little to our understanding as they are not time or date stamped. There is also no context as to when or for what reason the pictures were taken. Any reasonable person would expect that the picture taker would stage the most flattering pictures possible in support of their position;
As the information put forward by the employer with respect to the supposed work duties and potential exposures of the worker is not historically accurate or verifiable, she submits that the DeMatteo report ought to be deemed a more reliable source of information;
The employer’s position as it relates to genes and genetic predisposition is highly suggestive and factually untrue in the instant appeal. There is absolutely no objective evidence to support that any family member of the worker had a cancer with a “known” gene mutation. In fact, the worker themselves had no confirmed gene mutation that supports a predisposition for cancer;
While she recognizes that the worker’s paternal grandfather was determined to have prostate cancer, she disputes that this in and of itself is sufficient to disentitle the worker to benefits. The literature, as submitted by the employer, indicates that hereditary prostate cancer “is rare and accounts for about 5% of all cases. The low rate of hereditary incidence coupled with the standard of causation being a significant contributor, and not sole contributor, reinforces that this worker’s occupational exposure is more likely than not the cause of their occupational disease;
She submits that Dr. Somerville’s opinion is not at all demonstrative of the appropriate standard of causation. The significant contribution test does not require that the worker’s occupational exposures “play[ed] a major part in the development of their prostate cancer;
The representative once again argues that the objective evidence in the claim file along with the scientific literature and medical opinions contained therein of the DeMatteo report, the Demers report, and the OHCOW report all establish that it is more likely than not that the worker’s occupational exposures significantly contributed to their prostate cancer diagnosis;
While she recognizes that it is vital to have some medical and scientific evidence to support the link between the workplace exposures and the occupational disease, she states scientific certainty is not required (as per previous case law)

AUTHORITY

Workplace Safety & Insurance Act (WSIA), 1997

Sections 2 (1) & (15)

Schedules 3 & 4

Operational Policy Manual

Published

11-01-01 – Adjudicative Process

11-01-02 – Decision-Making

November 3, 2008

October 12, 2004

Support Material

Scientific Review Documents Prepared for the WSIB:

Occupational Disease and Survivor Benefits Program (OD&SBP) Adjudicative Support Material: Prostate Cancer, December 2006
Relationship between Prostate Cancer Risk and Cadmium Exposure, July 9, 2008

ANALYSIS

I have reviewed the record and considered the information and relevant legislation and operational policies in reaching this decision. In considering all of the evidencing including the OHCOW report, the opinions of the WSIB OH and OMC, the scientific review documents prepared for the WSIB related to prostate cancer, the information from the International Agency for Research on Cancer (IARC), as well as the reports and arguments made by the estate’s representative, I find there is no entitlement to prostate cancer. The rationale for my decision is as follows.

Prior to my analysis, I must note that while I have had regard for all of the previous case law, which has been referred to, the WSIB is not bound by these decisions and each case is adjudicated based on its own merits.

Further, while I note the estate’s representative referred to operational policy 23-02-01, this policy is specific to cancers in Firefighters and Fire Investigators and does not apply to this case. As there is no specific operational policy that applies to the worker’s prostate cancer, entitlement must be determined based upon the available evidence and the individual merits of the case, in accordance with Operational Policy 11-01-02.

The standard of proof required for entitlement to be granted in this claim is that it is more probable than not that the circumstances of the worker’s employment and exposure history significantly contributed to the development of their prostate cancer. I recognize that in determining the significant contributing factor, the work-related causes need not be the sole contributing factor, as long as they are a significant contributing factor.

The WSIB’s Operational Policy 11-01-01 Adjudicative Process states in part:

Five point check system

All decision-makers use the same criteria for ruling on initial entitlement to WSIB benefits. This system is known as the "five point check system.”

An allowable claim must have the following five points:

an employer
a worker
personal work-related injury
proof of accident, and
compatibility of diagnosis to accident or disablement history.

Diagnosis

If it is not clear that the (injury or disablement) diagnosis provided is the result of the accident or disablement history described, a decision-maker may consult with the WSIB's clinical staff to assist in making this determination.

Occupational disease cases are adjudicated under s. 2 (1) and s. 15 of the WSIA and by Regulation in Schedules 3 & 4 of the Act. If the disease is not listed in the Schedules, entitlement to benefits and services, is determined based on the merits and justice of the case. It must be established that it is more probable than not that the circumstances of the worker’s employment and exposure history significantly contributed to the development of the medical condition being claimed, in this case, the estate claims that the worker developed prostate cancer as a result of their workplace exposures to multiple agents of interest.

Diagnosis:

A review of the record confirms that the worker was diagnosed with adenocarcinoma of the prostate.

Employment and Employment Exposures

Pre-current Employer Employment History

The worker provided OHCOW with the following employment information:

While still in high school, was a butcher;
At the age of 17, they began two jobs: one in security and the second in building that involved dipping railway ties in order to coat them with a liquid protection. Believed that Creosol was one of the agents used;
In 1980, at the age of 18, began work at Company B for one year in material handling. This work required mixing drums of dyes and plastic pellets;
In 1981, began work at a local lumbar company where they worked for approximately nine months and are said to have been constantly exposed to sawdust. They also worked for 8 months with pressure treated wood;
From 1981 to 1989 worked as a butcher. During the 1981 to 1984 period, worked at Company C

With the Employer of Record (Day and Afternoon shifts)

September 1989 Roll Form
May 1990 RIM
June 1990 RIM
August 1990 Production Worker
June1991 R-RIM
November 1991 RIM
January 1992 R-RIM
January 1992 RIM
May1992 RIM
October 1992 R-RIM
November 1992 STD leave 01Nov to 18Dec1992
June1994 R-RIM Production to R-RIM Mids
August 1994 RIM Production
November 1994 RIM Clamp #6 – Trimming Fascia
November 1994 Injection Moulding
March 1996 RIM
June1998 RIM
Decembe1998 RIM to Paint
February 1999 Paint
March 2010 Paint Chemical Monitor
March 2014 Quality Auditor
March 2014 Driver Cleaner
April 2014 Quality Auditor
April 2014 Paint Chemical Monitor
August 2014 Quality Auditor
September 2014 Paint Chemical Monitor
January 2015 Quality Auditor
January 2015 Paint Chemical Monitor

The Occupational Disease and Survivor Benefits Program (OD&SBP) Adjudicative Support Material: Prostate Cancer, dated December 2006, found in part:

Based on the scope of the original scientific review of prostate cancer and occupation, there were no occupational risk factors identified for which there is positive evidence of an increased risk of prostate cancer;
Non-occupational risk factors for prostate cancer include age, family history, diet and smoking history

A review of the file reveals:

The OHCOW report dated March 16, 2016, completed by Dr. Noel Kerin provides a list of possible prostate carcinogenic agents. Dr. Kerin stated that these agents have been found in the areas where the worker worked in at the employer. The list includes asbestos, aromatic amines (n-Nitrosamines, benzene, cadmium, cigarette smoking, endocrine disruptor, Bisphenol A – Epoxy constituent (BPA), formaldehyde, metal working fluids, polycyclic aromatic hydrocarbons (PAHs), polyvinyl chloride (PVC), shift work, quartz silica, trichloroethylene (TCE), diesel exhaust fumes and chromium VI. A review of some relevant literature is also provided. He states that the worker would have been at significant and increased risk for the development of a malignancy and specifically prostate cancer as a result of their workplace exposures;
Appendix C of the DeMatteo report lists the chemical products used by the employer between 1986 and 1996 including the hazardous ingredients, decomposition and health effects. The report also lists the chemicals used in the departments the worker worked in (page 38). Nitrosamines and PAHs were part of some of the chemicals the worker was exposed to;
The December 14, 2016, Occupational Hygiene Review report completed by Lawrence Kurtz, OH, noted that the worker’s work history (~27 years with the employer of record) was documented on file. He reviewed the worker’s previous WSIB claims along with various submissions from the employer, the worker and OHCOW. In relation to the worker’s claim for prostate cancer, and based upon a review of peer-reviewed literature, suggested that the primary agent of interest for this type of cancer is ionizing radiation. Secondary agents of interest included exposure to arsenic compounds and cadmium compounds.
In conclusion he found the following:
The worker was employed with the employer of record from 1989-present during which time they worked in R-Rim, paint department, assembly and production where they would have been exposed to solvents, dust isocyanates, paints, chlorinated solvents, and thermoplastic fume emissions and possible traces of agents such as Bisphenol A or other adhesive compounds;
The worker did not have any known or confirmed exposures to ionizing radiation from their employment;
The worker did not have any known or confirmed exposures to cadmium compounds from their employment;
The worker possibly handled or used arsenic containing pressure treated lumber or creosote oils from their early, pre-employer work reportedly for 1-2 years; however, this is not confirmed. It is unlikely that the worker was exposed to notable arsenic compounds from work with the employer of record
Interviews from BD, Manufacturing Supervisor (undated) and HL (undated) provide information related to possible exposures at the employer, the layout of the plant floor and the ventilation system, the worker’s adherence to safety protocols and their smoking history; however, these statements provided no quantitative information.

Based on my assessment of the available evidence, I accept the worker was exposed to several agents at work including nitrosamines and PAHs, and that some of these are considered carcinogenic. I also accept the worker’s chemical exposure was through inhalation and dermal exposure.

That being said, while I acknowledge the arguments presented by the estate’s representative, I place more weight on and accept the WSIB OH Assessment report dated December 14, 2016 as providing an accurate and detailed review of the worker’s employment and potential exposure to substances of importance in the development of their cancer. In making this determination, I note the OH is a trained professional who specializes in recognizing health hazards in the working environment and his review of the information in the worker’s claim as it was available and created at that time. In addition, they are well versed in WSIB operational policy and legislation. More importantly, the report was created based on the hygienist’s training, experience and expertise in considering the appropriate aspects of the work and exposures pertinent to the nature of the claim and medical condition.

I must also note that I have had regard for the arguments presented by the worker’s representative with respect to Dr. P.A. Demers’ January 9, 2020 report titled “Using Scientific Evidence and Principles to Help Determine the Work-Relatedness of Cancer”.

The WSIB addresses Dr. Demers’ report on its website at www.wsib.ca/en/wsib-occupational-disease-moving-forward, which states the following:

When we look at occupational disease claims, we rely on the best scientific evidence available, in addition to information about the person’s illness, workplace exposures and other relevant factors. As the scientific research related to occupational disease evolves, we continue to look for new information that may help with our evidence-based decision-making.

Our Occupational Disease Strategy will help us achieve a more responsive and sustainable approach to occupational disease policy and decision-making. It draws on recommendations from the Demers report - Using scientific evidence and principles to help determine the work-relatedness of cancer - released in July 2020, the KPMG, "Value for Money Audit Report: Occupational Disease and Survivor Benefit Program", released in 2019.

The Occupational Disease Strategy includes short-term, medium-term, and long-term activities.

We have completed the short term, foundational activities focused on three main areas:

Establishing a Scientific Advisory Table on Occupational Disease to provide expert scientific advice to the WSIB to support policy development and scheduling
Developing an overarching Occupational Disease Policy Framework, in consultation with our stakeholders, to guide future policy development and scheduling
Leveraging our Research and Grants Program to ensure the collection of up-to-date scientific evidence to support evidence-based decision-making – see occupational disease research currently underway.

In addition to completing the short-term activities, we have worked with the Ministry of Labour, Immigration, Training and Skills Development (MLITSD) to make a regulatory change under the Workplace Safety and Insurance Act (WSIA) to add a new presumption for Parkinson’s disease in McIntyre Powder-exposed miners. This means that if anyone was exposed to McIntyre Powder through work in the mining industry and develops Parkinson’s disease, the disease is presumed to be work-related, unless the contrary is shown.

Work on medium and long-term activities has now begun, including:

Ongoing review and updating of the existing policies and schedule entries
Identifying opportunities for new policies and schedule entries
Posting new grant opportunities
Working with our Scientific Advisory table on Occupational Disease to support the activities above

As the WSIB continues to work with its system partners in relation to the development and implementation of the recommendations in Dr. Demers’ report at this time, I make no finding of fact regarding the report in this decision. I come to this conclusion on the basis that the information in the report, which pertain to the facts in this case, does not at this time, form part of the WSIB’s legislative, policy, and/or best practices frameworks.

The estate’s representative argues that the worker was exposed to multiple carcinogenic agents that acted synergistically and were additive and this was a significant contributing factor in the development of the worker’s prostate cancer. The representative refers to the OHCOW report, where Dr. Kerin outlined that the agents of interest, did not occur singularly, but in combination, either sequentially or together in some fashion and that this mixture appeared to be a significant risk factor for accelerated toxic cellular effects, including cancer.

The WSIB OMC reviewed the file in his memo dated March 9, 2017 and opined the following in part:

Prostate cancer is the second most common cancer in men in North America;
Age is an important factor in the development of prostate cancer, especially after the age of 50. The worker was 52 years of age when they were diagnosed with adenocarcinoma of the prostate which is the most prevalent type;
Family History is an important factor for prostate cancer. The risk of prostate cancer is increased approximately twofold in men with one or more affected first-degree relatives (brother, father). The worker did not have a first-degree family history of prostate cancer, but their paternal grandfather had prostate cancer according to Dr. Li’s consultation report of October 30, 2014;
Smoking appears to be associated with a moderately increased relative risk of prostate cancer, with a dose-response relationship noted between number of pack-years smoked and prostate cancer in one population-based case-control study. The worker had a 25 pack-year smoking history, quitting about one year prior to their prostate cancer diagnosis;
There appears to be a statistically significant increase in prostate cancer with increasing BMI. The worker’s height and weight data on file indicates obesity;
Most cases of prostate cancer have an unknown cause;
Shift work and prostate risk has been the subject of recent research. Disruption of the circadian system has been considered to increase cancer risk. A review of epidemiological studies evaluating the effects of light at night, sleep patterns and night shift work on prostate risk concluded that, although the circadian rhythm disruption hypothesis is plausible, more studies with individual level, prospectively collected, stringent exposure measurements were needed to draw definite conclusions. There is not enough evidence at this stage to determine whether shiftwork is an important risk factor;
Occupational risk factors have been investigated with inconsistent findings. The WSIB’s Occupational Disease and Policy Research Branch (ODPR) found there to be inconclusive evidence of increased risk for prostate cancer from exposure to solvents, silica, asbestos, electromagnetic fields and cadmium;
The WSIB occupational hygiene review suggests that the worker’s potential workplace exposures based on the production areas where they worked included isocyanates, organic solvents, chlorinated solvents, paint coagulates, thermos-plastic fume emissions and dust. In relation to the claim for prostate cancer, the primary agent of interest is exposure to ionizing radiation. Secondary agents of interest include exposure to arsenic compounds and cadmium compounds. There is no evidence in the work history to suggest that they had radiation exposure or exposure to cadmium or cadmium compounds. The worker possibly handled or used arsenic-containing pressure-treated lumber or creosote oils from your earlier pre-employer work reportedly for one to two years. However, this employment has not been confirmed and it is unlikely they were exposed to notable arsenic compounds with the employer;
The International Agency for Research on Cancer (IARC) does not report any carcinogenic agents with sufficient evidence in humans with respect to prostate cancer. Prostate cancer, like many cancers, also occurs in those with no evident risk factors;
The OMC concluded that given the prevalence of prostate cancer in North America, the multifactorial nature of prostate cancer causation, the lack of well-established workplace risk factors, and the absence of occupational hygiene information demonstrating elevated exposure to prostate carcinogens, there is insufficient evidence, that the workplace exposures played a role in the development of the worker’s prostate cancer.

While I acknowledge the literature, which has been referred to by the estate’s representative, I am more persuaded by the findings of the International Agency for Research on Cancer (IARC). I come to this conclusion on the basis that the IARC is an intergovernmental agency forming part of the World Health Organization. Their role is to conduct and coordinate research into the causes of cancer, the mechanisms of carcinogenesis and the development of scientific strategies for cancer control.

IARC has published a List of Classifications (updated December 1, 2023) by cancer sites with sufficient or limited evidence in humans, Volumes 1 to 135a.

IARC has not identified any carcinogenic agents with sufficient evidence in humans for prostate cancer.

Agents with limited evidence in humans include:

Androgenic (anabolic) steroids

Arsenic and inorganic arsenic compounds

Cadmium and cadmium compounds

Firefighter (occupational exposure as a)

Malathion

Night shift work

Red meat (consumption of)

Rubber manufacturing industry

Thorium-232 and its decay products

X- and Gamma-radiation

Of the agents with limited evidence in humans, the worker was exposed to nitrosamines and PAHs (i.e. Rubber Manufacturing industry) and possibly handled or used arsenic containing pressure treated lumber. That being said, the standard of proof required for entitlement to be granted is that it is more probable than not that the circumstances of the worker’s employment and exposure history significantly contributed to the development of their prostate cancer.

While I recognize the IARC has identified agents with limited evidence in humans, this suggests that while a causal relationship was credible, chance, bias, or confounding could not be ruled out with reasonable confidence.

In my review of the available evidence, I am satisfied that there is no reliable evidence and/or studies demonstrating satisfactory evidence of a causal connection between any of the worker’s workplace exposures and the development of their prostate cancer. In my assessment of the evidence, I place significant weight on the worker not being exposed to any agents with sufficient evidence in humans for prostate cancer, while at work.

While, I recognize that there is some epidemiological literature suggesting a positive relationship between some agents and prostate cancer, I am satisfied that the evidence as a whole suggests that at best, it is possible that a relationship exists. However, “possible” does not rise to the level of probability (it is more probable than not), as is required in occupational disease cases, and the standard upon which I must rely on making my decision.

As outlined by the OMC, prostate cancer is the second most commonly diagnosed cancer in males and the current lifetime risk of prostate cancer for men in the United States is estimated to be approximately 1 in 6. Further, the risk of developing increases with age (the worker was in their early 50s when diagnosed). Other factors include genetic factors, dietary factors, diabetes mellitus, alcohol consumption, obesity and physical activity levels. Smoking also appears to be associated with a moderately increased relative risk. Based on all of the above, I find the weight of the evidence does not establish the worker’s prostate cancer was causally related to their employment exposures.

I acknowledge the arguments presented by the estate’s representative; however, in my review of the IARC monograph and in the absence of any other strong scientific literature indicating otherwise, I am in agreement with the OMC and find that there is a weak epidemiological link between the workplace exposures and the development of prostate cancer. Therefore, they were not a significant contributing factor in the development of the disease.

In considering all of the evidence, I do not consider that the overall evidence in this case establishes probable work-relatedness or that the evidence for and against entitlement is equal in weight. Based on the evidence in this case, I find the while the worker did have exposure to some agents of interest, as noted in the OD&SBP Material on Prostate Cancer, the evidence is inconclusive on an increased risk of prostate cancer after occupational exposures. Further, IARC did not identify any agents with sufficient evidence of carcinogenicity in humans.

For these reasons, on the balance of probabilities, I conclude that the workplace exposures were not a significant contributing factor in the development of the worker’s prostate cancer and as a result, initial entitlement is denied.

CONCLUSION

Based on the available evidence, I conclude that the balance of evidence does not support that the workplace exposure were a significant contributing factor in the development of prostate cancer.

The estate’s objection is therefore, denied.

DATED January 30, 2024

L. Cirillo

Appeals Resolution Officer

Appeals Services Division