DECISION NUMBER:

20220107

OBJECTING PARTY:

THE ESTATE OF THE WORKER

REPRESENTED by:

SELF

RESPONDENT:

EMPLOYER (NOT PARTICIPATING)

REPRESENTED by:

HEARING:

HEARING IN WRITING

HEARD by:

L. MANSUETI, APPEALS RESOLUTION OFFICER

DATED: AUGUST 16, 2022

ISSUE

The worker’s Estate objects to the Occupational Disease & Survivor Benefits Program (OD&SBP) Adjudicator decision dated November 1, 2018 denying entitlement to benefits for multiple myeloma.

BACKGROUND

In 2015 the worker was diagnosed with multiple myeloma, and succumbed to the disease on July 17, 2017, at the age of 75. In March 2018, the worker’s Estate requested WSIB entitlement to benefits, claiming the worker’s exposures to ionizing radiation at work significantly contributed to the development of multiple myeloma. The worker was employed as a Draftsman with the employer from March 1969 until their retirement in April 1997.

The decision letter dated November 1, 2018 communicated there was no entitlement to benefits for multiple myeloma on the basis there was insufficient evidence to support a relationship between the condition and the workplace exposures, which was in keeping with an opinion provided by an Occupational Medical Consultant (OMC).

The worker’s Estate objected to the decision dated November 1, 2018. The worker’s Estate submitted additional information from the Occupational Health Clinics for Ontario Workers Inc. (OHCOW) for reconsideration. The operating area obtained a subsequent medical opinion from an OMC in light of the new information. The reconsideration letter dated January 14, 2022 communicated the November 1, 2018 remained upheld. The worker’s Estate continued to object to the November 1, 2018 decision, and this is now before the Appeals Services Division (ASD).

AUTHORITY

Section 2(1), 15 and 119(1) of the Workplace Safety and Insurance Act (WSIA), 1997, as amended

Operational Policy Manual

Published

11-01-03 Merits and Justice

Administrative Practice Document: Weighing of Medical Evidence (May 2017)

October 12, 2004

ANALYSIS

I have carefully considered all of the available information, legislation, relevant operational policy and support document in reaching this decision. For the reasons that follow, I find there is no entitlement to benefits for multiple myeloma.

Employment & Exposure History

The worker was employed as a Draftsman from March 1969 to April 1977 in the Design and Technical Service Branch (Plant Design Division) with the employer. As per memorandum xxx, the worker’s spouse indicated the worker’s occupation was a “desk job;” however, they were exposed to ionizing radiation at the workplace. While the worker never worked in active areas, there was only a wire fence that separated the worker from the area that was considered active. It is the position of the worker’s spouse there were opportunities for exposure on the jobsite at different times due to the proximity of the active location. It is also noted the worker’s spouse also worked at the same location, but did not experience any symptoms or issues. The worker’s spouse indicated the worker was not a drinker and did not smoke.

The record contains a Termination Health Assessment dated April 22, 1997 completed by the worker. The worker indicated they might have been exposed to radioactivity during their career. The worker stated, in part:

During my 28 years at (location) in the Design Office … I might have been exposed to radioactivity but I have never been contaminated to the best of my knowledge, always wearing any protection necessary for the particular task.

The Health Canada National Dose Registry Personal Dose History Summary dated September 18, 2018 listed gamma/beta (whole body) radiation dose for each year from 1968 to 1997. The annual dose is between 0.00 to 1.82. The lifetime effective dose is 16.40 millisievert (mSv). The annual skin case dose from 1968 to 1997 is between 0.00 and 1.82 with a total skin dose of 16.85. There was no indication of trillium oxide exposure.

In September 2021, T. Irick, Occupational Hygienist (OH) at the Occupational Health Clinics for Ontario Workers Inc. (OHCOW), completed a Retrospective Exposure Assessment. T. Irick referenced cohort studies of nuclear industry workers at Atomic Energy Canada which showed there was an excessive relative risk (ERR) for all cancers of 0.36, meaning there was a 36 per cent increase for all cancers over what is expected in the unexposed population. A research study found the increased odds ratio (OR) for the development of multiple myeloma for radium OR is 0.6 to 5.3, and uranium OR is 0.8 to 4.5. In

addition, another research study indicated a significantly increased incidence of multiple myeloma with external dose was reported in the 3^rd National Registry for Radiation Workers in the UK (NRRW), although the authors cautioned that the reliability of the result was low, based on the few cases with relatively high doses. The OH opined:

Based on the exposure history of [the worker] and evidence linking ionizing radiation exposure and multiple myeloma, it is possible that ionizing radiation had a contribution to the development of the disease.

Medical Evidence

Dr. P. Donahue assessed the worker on January 14, 2015 for probable multiple myeloma. The consultation report indicated the worker had worked for decades in design engineering at the (location) Nuclear Power Station. It was noted the worker was seeing Dr. Scott for cognitive symptoms including slight confusion, uncharacteristic irritability, and missing connections in conversations, which had been present for one year. The worker’s medical history included basal cell carcinoma, “pre-diabetes,” prostate cancer treated surgically in 2012, and hypertension. Dr. Donahue did not observe any abnormal nodes in the node-bearing areas, there was evidence of mildly decreased air entry, and faint and inspiratory crackles in the far right base. The worker was noted to be asymptomatic at present. Reference was made to a skeletal survey, which showed evidence of a subtle compression fracture of T7 and a 0.6cm “subtle lucency” in the skull. Dr. Donahue indicated the assessment findings appeared to be highly suggestive of myeloma; however, this diagnosis needed to be confirmed by a haematologist.

S. Mithoowani, Resident for Dr. L. Minuk, Haematologist, assessed the worker on February 4, 2015 at the Myeloma Clinic. The report indicated the worker started having mild cognitive issues in October 2014, and further testing led to a diagnosis of possible multiple myeloma. The worker indicated they were feeling well and denied having any symptoms. The worker’s cognitive symptoms remained stable and there were no other neurological symptoms including headaches or sensory changes to report. The worker likely had a diagnosis of multiple myeloma given the blood test results. A bone marrow aspiration was completed to confirm the diagnosis. The worker returned to the Myeloma Clinic on February 11, 2015 wherein the worker was advised there was evidence of end organ damage with multiple myeloma. The worker was recommended to commence chemotherapy.

The worker received chemotherapy treatment from February to April 2015 at the Regional Cancer Program (RCP). The worker was admitted to hospital for pneumonia in November 2015 and in March 2016. The worker continued to be followed at the RCP throughout 2016 and 2017 for medication and symptom management. The worker passed away on July 17, 2017.

On October 26, 2018 Dr. S. Somerville, OMC, reviewed the record and provided a medical opinion with respect to this case. It must be noted Dr. Somerville did not assess or treat the worker at any time. Dr. Somerville noted the worker was diagnosed with multiple myeloma at about 73 years of age. The OMC indicated the incidence of this condition is highly age-dependent, rising with patient age, and more common in men than women. The cause for multiple myeloma is unclear. Risk factors for the condition include tobacco use, obesity, diet, alcohol ingestion, and a positive family history. The record indicated the worker was a non-smoker and rarely drank alcohol. Dr. Somerville pointed to the worker’s personal history of prostate cancer and basal cell carcinoma, citing prior cancer is a risk factor for cancer. The International Agency for Research on Cancer (IARC) lists x-radiation and gamma radiation as carcinogenic agents with sufficient evidence in humans with respect to leukemia and/or lymphoma.

However, the risk of cancer from radiation exposure increases as the dose of radiation increases. According to the Biological Effects of Ionizing Radiation (BEIR) VII Report of the US National Academy of

Sciences defined low dose as doses up to approximately 100 mSv. The Health Canada National Dose Registry Personal Dose History for the worker lists the whole body radiation dose for each year from 1968 to 1997 as between 0.00 and 1.82, and the lifetime effective dose as 16.40 mSv. Dr. Somerville indicated the current occupational hygiene information does not show evidence of moderate or high levels of exposure, but instead describes low exposure. The OMC stated, in part, “I cannot conclude that it is more likely than not [the worker’s] workplace exposures materially contributed to the development of his multiple myeloma.”

Dr. R. Bourgault from OHCOW, reviewed the record on September 6, 2021, and provided an opinion with respect to this case. It must be noted Dr. Bourgault did not assess or treat the worker at any time. The report indicated the worker was diagnosed with multiple myeloma in approximately 2015, and passed away on July 17, 2017. The worker’s Estate is of the view the diagnosis is related to workplace exposures to ionizing radiation. The report indicated the worker suffered from arthritis, diabetes, and high cholesterol. The worker was a life-long non-smoker and did not consume alcohol or any recreational drugs. Dr. Bourgault indicated that while the etiology of multiple myeloma remains unclear, it has been suggested it may be associated with certain workplace exposures and that the increased prevalence of the disease among men may be a reflection of occupational exposure in male-dominated industries. Dr. Bourgault further indicated it has been reported in many studies that there is evidence of a link between exposure to ionizing radiation and the development of multiple myeloma. As per the Retrospective Exposure Report, Dr. Bourgault indicated the worker’s radiation exposure was at a level that is associated with an ERR of cancer. Dr. Bourgault stated, in part:

In conclusion based on the evidence linking Ionizing Radiation Exposure to the development of multiple myeloma there is evidence to suggest [the worker’s] workplace exposures likely played a role in the development of his disease.

On January 13, 2022, Dr. J. Razavi, OMC, reviewed the record and provided a medical opinion with respect to this case. It must be noted Dr. Razavi did not assess or treat the worker at any time. Dr. Razavi advised they concurred with the medical opinion provided by Dr. Somerville, in that there is a relationship between moderate-high dose ionizing radiation and multiple myeloma, but not with a low dose. Dr. Razavi indicated the worker’s radiation exposure history and Retrospective Exposure Assessment did not describe moderate-high level exposure to radiation. The worker’s exposures did not support a significant positive association to the development of multiple myeloma. Furthermore, the latency period between exposure and diagnosis is expected to be 5 or 10 years. However, in this case the worker retired in 1997 and was not diagnosed with multiple myeloma until 2015, which does not support a causative association. Lastly, the worker’s non-modifiable risk profile which includes previous history of cancers, age, and gender, supports the presence of risk factors associated with the development of the condition in the general population. Dr. Razavi indicated the new information from OHCOW did not support a change in the previous decision.

Assessment of the Evidence

The WSIB does not have specific policies for multiple myeloma and ionizing radiation exposure. When the condition or disease claimed is not listed in the Schedules and there is no specific WSIB policy, the decision is rendered based on the merits and justice of the individual case in accordance with the general provisions of the Act, as indicated in Operational Policy 11-01-03, which states, in part:

Decisions related to occupational disease

When determining entitlement to a disease claim, a decision-maker considers the worker’s clinical condition and exposure at work, the up-to-date clinical and scientific information, any pertinent non-occupational factors, and all of the relevant policies.

Entitlement to WSIB benefits and services is determined based on the merits and justice of the individual claim. It must be established that it is more probable than not the worker’s employment and/or exposure history caused or significantly contributed to the development of the medical condition for which benefits are being claimed. As such, the question to be determined is whether the workplace exposure ionizing radiation caused or significantly contributed to the development of the worker’s multiple myeloma.

If established, the above will generally be considered persuasive evidence that the worker’s employment made a significant contribution to the worker’s illness. A significant or material contributing factor is one of considerable effect or importance. The record contains contrasting medical opinions. The Administrative Practice Document, Weighing Medical Evidence, states, “Where there is a conflict in the medical information or opinions between the health care professionals, the decision-maker is expected to assess and weigh each report in order to reach a decision.”

Dr. Somerville indicated the occupational hygiene information in the record did not show evidence of moderate or high levels of exposure, instead, described the worker as having low exposure to ionizing radiation. The OMC indicated the worker’s previous prostate cancer was a risk factor for the subsequent cancer, as well as age and gender. It was the opinion of Dr. Somerville that the worker’s workplace exposures did not materially contribute to the development of multiple myeloma.

In contrast, Dr. Bourgault indicated the worker’s diagnosis of multiple myeloma was likely related to workplace exposures to ionizing radiation. Dr. Bourgault placed significant weight on the Retrospective Exposure Assessment completed by T. Irick, wherein the worker’s radiation exposure was at a level that has been associated with an ERR for cancer. As such, Dr. Bourgault indicated the worker’s exposure to ionizing radiation exposure was linked to the development of multiple myeloma.

Finally, Dr. Razavi indicated they were in agreement with Dr. Somerville’s opinion in that there was in fact a relationship between moderate-high dose ionizing radiation and multiple myeloma, but not with a low dose. Dr. Razavi reviewed the worker’s radiation exposure history and retroactive OH assessment, and noted they did not describe moderate to high level exposures to radiation. Therefore, the worker’s exposures did not support a significant positive association to the development of multiple myeloma. The OMC also indicated the delayed latency, previous history of cancer, age, and gender were factors associated with the development in the condition.

In review of these medical opinions in the record, I have placed less weight on the medical opinion provided by Dr. Bourgault and assigned more significant weight to the opinions provided by Dr.

Somerville and Dr. Razavi. Dr. Bourgault indicated the worker’s radiation exposure was at a level that has been associated with an excess relative risk of cancer based on the Retrospective Exposure Assessment; which indicated cohort studies of nuclear industry workers had a 0.36 ERR, in other words, there is a 36 per cent increase for all cancers over what is expected in the unexposed population. It must be noted this finding is general as it is for all cancers, and not specific to multiple myeloma, which I find is an important distinction. Furthermore, Dr. Bourgault surmised there was sufficient evidence to support the worker’s exposures to ionizing radiation likely played a role in the development of the multiple myeloma on the basis there are “many studies that there is evidence of a link between exposure to Ionizing Radiation and the development of multiple myeloma.” While I appreciate this medical opinion, it must be noted there is a lack of rationale to support it, as it does not appear to be specific to the worker’s case.

I acknowledge and accept there are many studies that provide evidence showing a strong association between multiple myeloma and exposure to ionizing radiation. The question to be determined is whether the worker’s workplace exposures caused or significantly contributed to the development of multiple myeloma, which does not appear to be the case. Dr. Bourgault provides several research examples which illustrate the association between multiple myeloma and exposure to ionizing radiation. It is noted Dr. Somerville and Dr. Razavi are also in agreement with this association; however, in the worker’s case, the evidence supports they had a low exposure to ionizing radiation. The worker’s low-dose exposure is confirmed by the findings gleaned from the Health Canada National Dose Registry Personal Dose

In review of the evidence before me, I accept the medical opinions provided by Dr. Somerville and Dr. Razavi. The evidence of the worker’s low-dose exposure to ionizing radiation and long latency period coupled with their own non-modifiable risk profile, which includes previous history of cancer, age, and gender, leads me to find the worker’s exposure to ionizing radiation in the workplace was likely not a significant contributing factor in the development of multiple myeloma. As such, I am unable to grant entitlement to benefits in this claim.

CONCLUSION

I conclude there is no entitlement to benefits for multiple myeloma. The worker’s Estate objection is denied.

DATED August 16, 2022

L. Mansueti

Appeals Resolution Officer Appeals Services Division