Estate of worker v. Employer, 2021 CanLII 140867

APPEALS RESOLUTION OFFICER DECISION

decision number:

20220007

OBJECTING PARTY:

ESTATE of worker

REPRESENTED by:

Estate representative

RESPONDENT:

EMPLOYER

REPRESENTED by:

SELF

HEARING:

HEARING IN WRITING

HEARD by:

L.CIRILLO, appeals resolution officer

DATED: DECEMBER 1, 2021

ISSUE

The estate objects to the Adjudicator’s decision dated June 5, 2020, which denied initial entitlement for Chronic Myelomonocytic Leukemia (CMML) as being related to the worker’s employment exposures as a Firefighter.

BACKGROUND

This claim was registered in November 2019 following receipt of a Form 6, Worker’s Report of Injury. The worker claimed that their workplace exposures, while employed as a Firefighter, were a significant contributing factor in the development of CMML.

The record reveals that the worker’s issues began in late 2018/early 2019 when their blood work demonstrated some abnormalities. The worker was assessed by Dr. Kuruvilla, Haematologist in January 2019 and they were investigated for thrombocytopenia and immature granulocytes. The thrombocytopenia was treated intermittently with prednisone and the diagnosis was considered to be immune thrombocytopenic purpura. A bone marrow biopsy conducted in April 2019 revealed the presence of CMML-0. In a report dated October 18, 2019, Dr. K. Yee (Princess Margaret Hospital) further confirmed the diagnosis. The date of injury was determined to be October 4, 2019. The worker was 76 years of age at the time of diagnosis and had worked as a Firefighter for the employer between October 1970 and 2002.

Stem cell transplantation was discussed; however, it was felt that the worker would not be a good candidate given their age and other underlying conditions. The medical opinions suggested that the worker continue with watchful waiting of their condition with no active treatment.

Entitlement was considered under the presumptive legislation, Bill 221 – s. 5(1) and based on merits and justice. Following review by an Occupational Medical Consultant (OMC), entitlement was denied as it was concluded that the diagnosis of CMML was not covered under the regulation and there was no scientific literature that causally linked cumulative firefighting exposure to the development of the condition. As such, initial entitlement was denied. The decision was communicated to the worker in correspondence dated June 5, 2020.

On the Intent to Object (ITO) form dated February 8, 2021, the worker’s representative objected to the denial of initial entitlement. In support of their position, they submitted a report from Dr. Michael Pysklywec from the Occupational Health Clinics for Ontario Workers (OHCOW) dated December 3, 2020.

As a result, the file was re-referred to the OMC in order to obtain an opinion on whether or not the new information provided sufficient evidence to support that the workplace exposures were a significant contributing factor in the development of the worker’s CMML.

Following review of the medical documentation, the OMC once again concluded that the diagnosis of CMML was not associated with the occupation or exposures of firefighters. The OMC did note however, that further review could take place if the worker had been involved in the clean-up of a radiation incident.

The Adjudicator spoke to the worker on April 27, 2021, and they did not confirm any exposure to radiation. As a result, it was once again concluded that the occupational exposures were not a significant contributing factor in the development of the worker’s CMML and therefore, initial entitlement remained denied. The reconsideration decision was communicated to the worker in correspondence dated April 27, 2021.

On the Appeal Readiness Form (ARF) dated May 10, 2021, the worker’s representative objected to the denial of initial entitlement. In support of their position, they submitted new information including an Asbestos Reassessment of Fire Station #109-FS09 by Pinchin Ltd dated September 30, 2019.

The Pinchin report outlined the following in part:

• Acoustic ceiling tiles containing chrysotile asbestos is present in 2nd floor stair, foyer, 1st floor office, bedroom, washroom, exercise room, and the dormitory;
• Drywall containing chrysotile asbestos is present as a wall and ceiling finish throughout the facility;
• Beige vinyl sheet flooring containing chrysotile asbestos in the paper backing layer (under pad) is present in the 1st floor lounge;
• Vinyl floor tiles containing chrysotile asbestos are present in storage

Summary of Recommendations:

• Perform a re-assessment of asbestos-containing materials on an annual basis;
• Prior to renovations or demolition, perform a pre-construction assessment to identify any hazardous materials that may be disturbed by the work;
• Follow appropriate safe work procedures when handling or disturbing asbestos

The representative argued the following in part:

• The worker was a firefighter from 1970 to 2002 – 32 years of service;
• Firefighters are routinely exposed to asbestos, benzene, diesel engine exhaust, formaldehyde, soot, dioxin, polychlorinated biphenyl, polycyclic aromatic hydrocarbons, ethylbenzene, and solar radiation;
• The American Cancer Society states with reference to Chronic Myelomonocytic Leukemia that “exposure to radiation or cancer-causing chemicals can cause mutations that lead to CMML”.
• The worker was exposed to cancer-causing chemicals while fighting a fire caused by a train derailment on November 10, 1979:
  • The fire burned for six days
  • The rail cars contained butane, propane, toluene, styrene, and chlorine
  • The chlorine tanker leaked for three days, causing a toxic pocket of chlorine gas
• The worker fought fires involving nursing homes, oil refineries, dumps, auto-wreckers and cars.
• They worked at Station #109 and other stations throughout their career, where they were unknowingly exposed to asbestos;
• The OHCOW report supported an association between the workplace exposures and the development of CMML;
• As per WSIA Section 119(2): If, in connection with a claim for benefits under the insurance plan, it is not practicable to decide an issue because the evidence for and against it is approximately equal in weight, the issue shall be resolved in favour of the person claiming benefits.

Based on the above, the adjudicator reconsidered entitlement once again. It was noted that an occupational hygienist did not review the file. However, the prior adjudicator did acknowledge that the scientific literature recognizes that firefighters have periodic short-term exposures including:

• a variety of fire combustion products and other airborne contaminants
• these include benzene, polycyclic aromatic hydrocarbons (PAHS), arsenic in wood preservatives, asbestos in building insulation, diesel engine exhaust, dioxins, vinyl chloride, chloroform, coal tar, asphalt, formaldehyde, metals (chromium, cadmium), aromatic amines and chlorinated hydrocarbons.

This acknowledgement was communicated to the OMC, who advised:

• Peer reviewed databases were searched for associations between CMML and occupations or occupational exposures and CMML is not recognized as an occupational cancer.
• CMML and firefighting was specifically researched and there was no association between CMML and firefighting.

In addition, the OMC also reviewed the OHCOW report and opined:

• In re-searching the peer-reviewed databases for an association between CMML and occupations, firefighting (specifically), and occupational exposures, this condition is not associated with the occupation or exposures of firefighting
• The worker’s cumulative exposures as a firefighter did not significantly contribute to the development of their Chronic Myelomonocytic Leukemia (CMML);
• Occupational Hygiene review could be helpful if the worker was involved in cleanup of a radiation incident.

Furthermore, the worker confirmed they had never been involved in the cleanup of a radiation incident and as a result, a referral for an occupational hygiene assessment was not in order.

With respect to asbestos exposures in the fire station, the adjudicator noted that hard asbestos products only release airborne fibres (which may be inhaled) during the installation or removal process of floor and ceiling tiles, drywall and textile products. The Pinchin Asbestos Reassessment Report did not indicate the need for any remediation work nor did it indicate any risk to firefighters working out of Fire Station #109.

Based on the above, initial entitlement for CMML remained denied. The reconsideration decision was communicated to the worker in correspondence dated May 31, 2021.

In September 2021, the WSIB was advised that the worker had passed away; however, the exact date is unknown.

As the estate continued to object to the denial of initial entitlement and the decision remained unchanged, the matter was referred to the Appeals Services Division (ASD) for further consideration.

Estate’s Position:

The estate relies on their previous submission dated May 10, 2021.

Employer’s Position:

In correspondence dated August 20, 2021, the employer provides a claim background and argues the following in part:

• It is their position that the assessment, analysis and research of the OMC was thorough and the medical documentation on file was appropriately considered. In addition, there is no evidence that any fundamental error was made by the OMC in conducting the assessment and there is no evidence which refutes the validity of any of the OMC’s findings or conclusions;
• The employer submits that as outlined in the May 31, 2021 decision, based on scientific literature, it is recognized that firefighters have periodic exposures to a variety of fire combustion products and other airborne contaminants. However, as noted by the OMC in the assessment dated April 6, 2021, researching the peer-reviewed database showed no association between CMML and firefighting. As a result, there is no medical research to support that the cumulative exposures identified by the worker significantly contributed to the development of CMML. In fact, in the December 2020 OHCOW report, Dr. Pysklywec confirmed that there was “little in the way of epidemiology linking CMML with specific occupational exposures…CMML is a rare hematologic condition. The literature defines few risk factors for this condition”;
• Dr. Pysklywec relied on the “Bradford Hill Criteria” in concluding that the worker’s exposures may have contributed to the development of CMML. However, in Memo #A0014, the adjudicator cited information from the US National Library of Medicine National Institutes of Health (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4589117/):

In 1965, Sir Austin Bradford Hill published nine* “viewpoints” to help determine if observed epidemiologic associations are causal. Since then, the “Bradford Hill Criteria” have become the most frequently cited framework for causal inference in epidemiologic studies. However, when Hill published his causal guidelines—just 12 years after the double-helix model for DNA was first suggested and 25 years before the Human Genome Project began—disease causation was understood on a more elementary level than it is today. Advancements in genetics, molecular biology, toxicology, exposure science, and statistics have increased our analytical capabilities for exploring potential cause-and-effect relationships, and have resulted in a greater understanding of the complexity behind human disease onset and progression. These additional tools for causal inference necessitate a re-evaluation of how each Bradford Hill criterion should be interpreted when considering a variety of data types beyond classic epidemiology studies.

*strength of association, consistency, specificity, temporality, biological gradient, plausibility, coherence, experiment, analogy.

• It was concluded: Hill’s nine aspects of association were never intended to be viewed as rigid criteria or as a checklist for causation, yet have been popularized as such over the past 50 years. Instead, the so called “Bradford Hill Criteria” were written as flexible guidelines or considerations meant to guide epidemiologic investigations and aid in causal inference;
• With respect to the submissions attached to the Appeal Readiness Form, relating to the Pinchin report dated September 30, 2019, there is no indication in the report that the asbestos-containing materials (ACM) noted were disturbed or damaged in any way and resulted in the release of asbestos fibers. Rather, the recommendations are summarized in the report at Page ii and include: conducting a re-assessment of ACM on an annual basis; prior to renovations or demolition, performing a pre-construction assessment to identify any hazardous materials that may be disturbed by the work; and following appropriate safe work procedures when handling or disturbing asbestos. Clearly, no remediation work or safety risk was identified in the report;
• Contrary to the submissions set out in the Appeal Readiness Form, it is the employer’s position that based on the analysis and opinion of the OMC and the medical evidence in the claim file, there is no evidence supporting the worker’s entitlement to benefits. As a result, the worker’s objection should be denied;
• The employer submits that since the worker’s diagnosis does not fall under the Board’s presumptive policy (Policy #23-02-01, Cancers in Firefighters and Fire Investigators), it was appropriate for the Operations Division not to apply that policy. Conversely, conducting a review of the claim on its individual merit and concluding that there is no entitlement to benefits was appropriate.

AUTHORITY

Workplace Safety & Insurance Act (WSIA) Section 2 (1) & s. 15 Bill 221 – Regulation 253/07 s. 5 (1) Schedules 3 & 4

Operational Policies

Published

11-01-01 – Adjudicative Process 11-01-03 – Merits and Justice 23-02-01 – Cancers in Firefighters and Fire Investigators

November 3, 2008 October 12, 2004 July 4, 2018

ANALYSIS

I have reviewed the record and considered the information and relevant operational policies in reaching this decision. In considering all of the evidence, including the relevant legislation, operational policies, medical evidence on file, employment history, in addition to the OMC opinions on file and the arguments presented, I find there is no initial entitlement for CMML. The rationale for my decision is as follows.

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.

As is outlined above, the estate claims that the worker’s CMML was caused by their cumulative employment exposures while working as a Firefighter from 1970 to 2002.

On May 4, 2007, the Government of Ontario passed legislation amending the Workplace Safety and Insurance Act (the Act). Ontario Regulation 253/07 (the Regulation) specifies certain diseases that can be presumed to arise out of employment as a full-time firefighter and the conditions that are required for this presumption to apply. On November 5, 2009, the Regulation was amended (Ontario Regulation 423/09) to extend the same presumption to part-time and volunteer firefighters and fire investigators.

On May 1, 2014, a further amendment (Ontario Regulation 113/14) expanded the list of diseases that are presumed to be work-related.

Operational Policy 23-02-01 states in part:

If a firefighter or a fire investigator is diagnosed with a prescribed cancer on or after January 1, 1960, and meets the employment duration and additional criteria for the prescribed cancer, then the disease is presumed to be an occupational disease due to the nature of the worker’s employment, unless the contrary is shown.

This policy applies to:

• workers who are full-time or volunteer firefighters as defined in Section 1 of the Fire Protection and Prevention Act, 1997
• part-time firefighters, defined as a worker who is a firefighter and is not a volunteer or full-time firefighter
• workers who:
  • are employed by a band council and assigned to undertake fire protection services on a reserve [band council and reserve are defined in the Indian Act (Canada)], or
  • provide fire protection services on a reserve, either voluntarily or for a nominal consideration, honorarium, training or activity allowance
• fire investigators, defined as a worker,
  • to whom the Fire Marshal, appointed under subsection 8(1) of the Fire Protection and Prevention Act, 1997, has delegated the duty to investigate the cause, origin and circumstances of a fire
  • who was an inspector appointed under subsection 2(4) of the Fire Marshals Act before that Act was repealed by the Fire Protection and Prevention Act, 1997, or
  • who is employed by a band council and assigned to investigate the cause, origin and circumstances of a fire on a reserve.

For the purpose of this policy, the term "firefighter" refers to a full-time firefighter, a part-time firefighter or a volunteer firefighter.

Presumption

The presumption provides that the prescribed cancers are occupational diseases presumed to occur due to the nature of the worker’s employment as a firefighter or fire investigator, unless the contrary is shown.

To qualify for this presumption, workers must meet the inclusion criteria of this policy, and also must have been:

• diagnosed with a prescribed cancer
• diagnosed after the prescribed minimum employment duration, and
• diagnosed with that cancer on or after January 1, 1960.

Workers not meeting the inclusion criteria, and those excluded from this policy, will have their claims determined on their individual merits.

In considering the information on file, there is no issue with the worker’s accepted employment as a Firefighter from 1970 to 2002.

However, in my review, I note that the diagnosis of CMML does not appear in the list of prescribed cancers listed in operational policy. As this diagnosis does not fall under presumptive legislation for firefighters, and it is not listed in the schedules, entitlement cannot be accepted on this basis.

Operational policy 11-01-03 states in part:

The WSIB shall make its decision based upon the merits and justice of a case and is not bound by legal precedent.

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 CMML as a result of their workplace exposures while employed as a Firefighter.

In reviewing the medical evidence contained in the record, I note the file was reviewed on two separate occasions by a WSIB OMC, specifically on May 22, 2020 and April 6, 2021.

During the first review, Dr. Razavi outlined the following in part:

• CMML is a malignant hematopoietic stem cell disorder with clinical and pathological features of both a myeloproliferative neoplasm (MPN) and myelodysplastic syndrome (MDS). CMML is characterized by a peripheral blood monocytosis accompanied by bone marrow dysplasia; cytopenias and hepatosplenomegaly are common. There is a propensity for progression to acute myeloid leukemia (AML) which is defined by >20 percent marrow blast cells;
• CMML is a clinically and genetically distinct entity with unique clinical presentation and natural history;
• It is one of the most aggressive chronic leukemias;
• CMML has a distinct “genetic fingerprint” – arises by serial acquisition of somatic genetic events that create multiple, distinct neoplastic cell clones;
• In the absence of genetic abnormalities, a diagnosis of CMML is established only after the patient has been followed for weeks to months with repeated laboratory testing rather than applying the diagnosis based upon the first abnormal peripheral blood count;
• Based on a review of peer-reviewed databases, CMML is not recognized as an occupational cancer. In addition, the condition is not currently associated with the occupation or exposures of firefighters.

In his report dated December 3, 2020, Dr. Pysklywec noted the following in part:

• The worker spent 33 years as a firefighter and had extensive exposures to carcinogens from fighting various fires including benzene and PAHs. In particular, they worked at a time when personal protective equipment was substandard;
• CMML is a rare hematologic condition. The medical literature defines few risk factors;
• Myelodysplastic conditions, notably AML, are clearly associated with firefighting. There is no detail in the epidemiology describing the leukemia subtypes, particularly rare conditions ( such as CMML)
• Consideration of Bradford-Hill criteria would suggest that exposures might play a role in contributing to CMML. The worker worked around extensive carcinogens, including PAHs and benzene. By consideration of the Bradford-Hill criteria, it is quite plausible that such exposures may have contributed to the development of CMML;
• Whether the diagnosis of lupus was contributory or a consequent of his CMML is difficult to establish. Besides this, the worker generally enjoyed a healthy life with no obvious risk factors such as personal exposures or family history;
• The occupational exposures would have been impressive from decades of firefighting. The potential for firefighting to induce hematological malignancies would by extension quite reasonably contribute to the development of a myelodysplastic condition such as CMML;
• In considering all of the above, the OHCOW physician opined that it was their feeling that the worker’s work likely contributed to the development of CMML; however, they noted that it was difficult to establish risk factors for such rare cancers. Nevertheless, they stated that the worker’s occupational exposures would have been impressive from decades of firefighting. The potential for firefighting to induce hematological malignancies would by extension, quite reasonably contribute to the development of a myelodysplastic condition such as CMML.

It is my understanding that epidemiological studies analyse statistical associations between “populations” rather than cause of disease in an individual case. Thus, they do not prove causality in the individual case. Nonetheless, they can be given weight and they can be used in helping to judge whether an individual worker’s disability is likely work-related.

In his well-known paper entitled “The Environment and Disease: Association or Causation?” Sir Austin Bradford Hill described the following aspects of the statistical association that should be considered before deciding that the most likely interpretation of the association is causation:

1. Strength of the association (the less strong the association, the more likely it is that factors other than the studied variable account for the association);
2. Consistency of the observed association (has the observed association been repeatedly observed by different persons in different circumstances?);
3. Specificity of the association (is the association limited to specific workers and particular sites and types of disease?);
4. Temporal relationship of the association (which is the cart and which is the horse – does the association exist because the environment promotes disease or because a population with the disease is more likely to be in that environment?);
5. Biological gradient (is there a dose-response curve?);
6. Plausibility (is causation biologically plausible?);
7. Coherence (would causation be coherent with the generally known facts of the natural history and biology of the disease?);
8. Experiment (is there experimental evidence that supports the causation hypothesis - such as a reduction in incidence when an exposure is reduced?);
9. Analogy (is the association similar to that found for other known diseases that may be analogous?).

In his report, Dr. Pysklywec outlined that with a lack of helpful epidemiology, it is often useful to consider the Bradford Hill criteria for causation. He opined that these criteria define points in which to consider causation in a general context. In their view, it was quite plausible and consistent that firefighting exposure could contribute to CMML risk noting there have been known carcinogens in this industry. In particular, hematologic malignancies and specifically Acute Myeloid Leukemia (AML).

While I acknowledge Dr. Pysklywec’s suggestion that the Bradford Hill criteria be considered for the purpose of causation, I also note that when this document was created, disease causation was understood on a more elementary level than it is today. Advancements in genetics, molecular biology, toxicology, exposure science, and statistics have increased analytical capabilities for exploring potential cause-and-effect relationships, and have resulted in a greater understanding of the complexity behind human disease, onset and progression. These additional tools for causal inference necessitate a re-evaluation of how each Bradford Hill criterion should be interpreted when considering a variety of data types beyond classic epidemiology studies.

In my review of the OHCOW report, with all due respect, I note that Dr. Pysklywec’s Bradford Hill assessment was neither a complete nor a comprehensive assessment as outlined above. Further, the strength of association was not clearly supported by any epidemiological evidence. This is supported by the fact that Dr. Pysklywec could not identify any specific studies looking at the diagnosis of CMML and firefighting nor is there any evidence that the worker suffered from AML, for which they states there is ample evidence of causation between the diagnosis and firefighting duties. Therefore, in this case, I place little weight on their opinion on causation given they acknowledge there is essentially no epidemiology to support a causal connection.

I also note that following receipt of the OHCOW report, the file was once again reviewed by Dr. Razavi on April 6, 2021. At that time, they noted the following in part:

• The OHCOW report does not alter their previous decision;
• CMML occurs most commonly in older adults, with a median age at diagnosis of 65-75 years and a male: female ratio of 1.5 to 3.1;
• In some cases CMML occurs in patients after treatment with chemotherapy or ionizing radiation;
• A re-review of peer-reviewed databases confirmed that CMML is currently not recognized as an occupational cancer. While there has been some suggestion that exposure to benzene may lead to this condition, more studies are required to study the association;
• A further re-review of peer-reviewed databases confirmed the condition is not associated with the occupation or exposure of firefighters and as a result, they opined that the cumulative workplace exposures were not a significant contributing factor in the development of CMML.

In considering the above, I find Dr. Pysklywec's opinion on causation to be speculative. This is supported by the overwhelming balance of Dr. Razavi’s review of the relevant medical literature.

While I also acknowledge the Pinchin Asbestos Reassessment report at Fire Station #109-, FS09 dated September 30, 2019, the report did not indicate the need for any remediation work, nor did it identify any risk to firefighters at this fire station. In the absence of processes, which would release airborne asbestos fibres, which could be potentially inhaled (such as installation or removal process of floor and ceiling tiles, drywall and textile products), I am not persuaded that work at this location produced any additional risk.

In considering all of the above, I am more persuaded by the opinion of Razavi and I find it is clear that the worker suffered from CMML, which:

• Is not considered to be occupational or caused by occupational exposures;
• Is not a condition that is associated/caused by exposure to occupationally related agents;
• Is currently not associated with the occupation or exposures of firefighters;
• Is a clinically and genetically distinct entity with unique clinical presentation; and,
• Has a large “genetic fingerprint.”

As a result, I find there is no persuasive evidence that establishes that the worker’s CMML was causally related to their employment or employment exposures as a firefighter.

In addition, 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. For these reasons, on the balance of probabilities, I find that the worker’s cumulative exposures as a Firefighter were not a significant contributing factor in the development of CMML, and for these reasons, initial entitlement is denied.

CONCLUSION

I conclude there is no initial entitlement for CMML.

The estate’s objection is therefore, denied.

DATED December 1, 2021

L. Cirillo Appeals Resolution Officer Appeals Services Division