WORKPLACE SAFETY AND INSURANCE APPEALS TRIBUNAL DECISION NO. 726/11I

Transcription

1 WORKPLACE SAFETY AND INSURANCE APPEALS TRIBUNAL DECISION NO. 726/11I BEFORE: R. McCutcheon : Vice-Chair B. Davis : Member Representative of Employers K. Hoskin : Member Representative of Workers HEARING: April 12, 2011, at Kitchener Oral hearing DATE OF DECISION: May 11, 2011 NEUTRAL CITATION: 2011 ONWSIAT 1120 DECISION(S) UNDER APPEAL: WSIB Appeals Resolution Officer (ARO) M. Evans dated January 15, 2010 APPEARANCES: For the worker: For the employer: J. Walsh, Office of the Worker Adviser K. Lawrence, Regional Human Resources Manager Workplace Safety and Insurance Appeals Tribunal Tribunal d appel de la sécurité professionnelle et de l assurance contre les accidents du travail 505 University Avenue 7 th Floor 505, avenue University, 7 e étage Toronto ON M5G 2P2 Toronto ON M5G 2P2

2 Decision No. 726/11I REASONS (i) Introduction to the appeal proceedings [1] The worker appeals a decision of the ARO, which concluded that he did not have initial entitlement for follicular non-hodgkin s lymphoma (NHL) as a condition arising out of and in the course of his employment. The ARO rendered a decision following an oral hearing. [2] The worker appeared and testified under oath. The employer of record was the worker s employer at the time that he was diagnosed with NHL in 2003, although the worker does not attribute his condition to exposure with this employer. The worker attributes his condition to exposures he sustained with prior employers. [3] For the reasons set out in this decision, the Panel finds it appropriate to obtain the opinion of an independent health professional (medical assessor) pursuant to section 134 of the Workplace Safety and Insurance Act, 1997 (the WSIA) before rendering a final decision in this appeal. (ii) Issues [4] The primary issue is whether the worker has entitlement for his condition of Non- Hodgkin s lymphoma (NHL) as a condition arising out of and in the course of his employment. In particular, the worker attributes his condition to solvent exposure in the printing industry from 1986 to [5] Should initial entitlement be granted, the worker also seeks entitlement to loss of earnings (LOE) benefits. At this stage of the adjudication, however, the Panel will focus upon the issue of initial entitlement. (iii) Background [6] This worker, born in 1965, held various odd jobs from the age of 11. After finishing high school, he worked for a fruit and vegetable company. He began employment with M.P., a package printing company, in The worker was employed with this company from 1986 to The worker testified that he was healthy when he started employment with M.P. in 1986, and there is no evidence to the contrary. [7] He attributes most of his exposure to this employment with M.P. The Panel will review the exposure evidence in more detail later in these reasons. [8] After M.P. closed, the worker was employed with another printing company from 1994 to 1995 ( L.M. ), and then another company from 1995 to 1996 ( S.P. ). He began employment with the employer of record, a community newspaper, in 1996.

3 Page: 2 Decision No. 726/11I [9] In March 2008, the worker filed a Worker s Report of Injury (Form 6) with the WSIB. He noted that he was diagnosed with NHL in October The worker provided the following details about his claim: I worked in the Printing Industry for 10 years. During that time I worked with, breathed in, and was dipping my hands in solvents (acetate, etc.) in drums labeled Cancer Causing ( ). [10] The worker also noted in the Form 6 that he did six months of chemotherapy treatment followed by a clinical study treatment. He stated that he has developed ongoing chronic pain, head pain, eye pains, chronic fatigue, sore back and legs, and frequent urination as a result of the condition and the treatments. [11] In a conversation with the WSIB Adjudicator in March 2008, the worker stated that he attributed his NHL to work in the printing industry from the mid 1980 s to the 1990 s. He noted that the first employer (M.P.) was no longer in business. From 1996, onward, he worked as a district representative for a community newspaper and had no exposure. [12] The WSIB undertook an investigation of the worker s claim. Derrick A. Chung, occupational hygienist, interviewed the worker as well as a former supervisor from M.P. and produced a report dated August 15, The hygienist concluded that the worker likely had routine high exposure to benzene as a laminator assistant from 1986 to 1988, but only occasional low exposure to trichloroethylene and tetrachloroethylene from 1988 to [13] The Adjudicator referred the issue to Dr. C. Smith, WSIB Occupational Medicine Consultant, for an opinion. Dr. Smith noted that there was limited evidence associating lymphomas with the occupation of printers and with benzene exposure. Since Dr. Smith believed that significant, heavy exposure had not been identified in this worker s case, it was considered unlikely that the employment was a significant factor in the development of the worker s disease. [14] In the decision under appeal, the ARO accepted that the worker had routine high exposure to benzene from 1986 to Based upon the worker s testimony, the ARO also accepted that the worker s exposure may have been somewhat higher than estimated by the occupational hygienist. The ARO accepted that the worker had elevated exposure from 1986 to Nonetheless, the ARO referred to two internal WSIB documents to find that the medical and scientific evidence shows an equivocal relationship between the suggested exposure level and the development of NHL. The worker s claim for entitlement was denied and the worker appeals to the Tribunal. (iv) Law and policy [15] Since the worker s condition was diagnosed in October 2002, the Workplace Safety and Insurance Act, 1997 (the WSIA ) is applicable to this appeal. All statutory references in this decision are to the WSIA, as amended, unless otherwise stated. [16] Section 13 of the Act provides that a worker is entitlement to benefits for personal injury by accident arising out of and in the course of employment. Section 15 of the Act applies to the adjudication of occupational disease claims and provides that if a worker suffers from an

4 Page: 3 Decision No. 726/11I occupational disease that occurs due to the nature of the worker s employment, the worker is entitled to benefits under the insurance plan as if the disease were a personal injury by accident. [17] In determining whether a worker has entitlement for an occupational disease, the Tribunal generally considers whether the employment exposure made a significant contribution to the development of the worker s condition. The standard of proof is the standard of probabilities. [18] The WSIA includes the following definition of occupational disease : occupational disease includes, (a) a disease resulting from exposure to a substance relating to a particular process, trade or occupation in an industry, (b) a disease peculiar to or characteristic of a particular industrial process, trade or occupation, (c) a medical condition that in the opinion of the Board requires a worker to be removed either temporarily or permanently from exposure to a substance because the condition may be a precursor to an occupational disease, (d) a disease mentioned in Schedule 3 or 4, or (e) a disease prescribed under clause 15.1 (8) (d); ( maladie professionnelle ) [19] Subsection 15(3) of the Act creates a rebuttable presumption of entitlement where a worker was employed in a process set out in Schedule 3 and if the worker contracts the disease specified in the Schedule. The worker's representative argued that the presumption of entitlement was applicable in this case under Schedule 3 of the Regulation. Schedule 3 provides that certain listed occupational diseases are presumed to be work-related if a worker was employed in a process set out in the Schedule. The worker's representative relies upon the following portion of Schedule 3: Column 1 Column 2 Description of Disease 7. Poisoning and its sequelae by ii. Benzol Process Any process involving the use of benzol [20] The worker in this case was not diagnosed with benzene poisoning and the worker's representative did not cite any case law in his submissions in support of the application of the presumption in these circumstances. Whether the presumption applies is primarily a legal issue. At this stage of the proceedings, the Panel will defer a finding on the legal issue, to focus on the issue of causation. The worker's representative will have an opportunity to make additional submissions after the assessor s report is received and the Panel will address the Schedule 3 presumption in the final decision in this appeal.

5 Page: 4 Decision No. 726/11I (v) WSIB Adjudication Documents [21] The WSIB does not have a formal policy addressing the adjudication of claims for NHL attributed to occupational exposure to benzene or solvents. The WSIB has, however, drafted two background documents that provide information and guidelines for adjudication. These documents are not binding on this Tribunal, but the Panel considers them useful for background information. a) The 2006 ODPR Paper [22] The file in this appeal includes a document entitled Adjudicative Support Material: Non-Hodgkin s Lymphoma, produced by the Occupational Disease Policy and Research Branch, December 2006 (the 2006 ODPR Paper ). The 2006 ODPR Paper is approximately 61 pages in length and includes a glossary and general information about NHL. The general information about NHL includes the following: NHL is the fifth most commonly diagnosed cancer in Canada, being diagnosed in 5516 people in 2001 (Cancer Surveillance Online 2002). Broken down by gender, it is the fifth most commonly diagnosed cancer in men and the sixth most commonly diagnosed cancer in women (Cancer Care Ontario 2002). NHL incidence is about 39% higher in men than women, and this gender difference is more pronounced in younger versus older groups (Cancer Care Ontario 2002). [23] The 2006 ODPR Paper includes a Summary Table, which provides the following explanation regarding occupational risk factors for NHL: The scientific review did not identify any occupational risks for which there is positive evidence of an increased risk for NHL. However, a complete review of all occupational risk factors for NHL was not undertaken. [24] The paper reviews a number of selected occupational exposures. Of particular relevance in this appeal are the following passages: Limited evidence of an increased risk of NHL was also found for the following occupations: [ ] Pulp and paper workers Welders and solderers Meat workers Hairdressers Textile workers Printers Firefighters There is limited evidence of an increased risk for the following classes of solvents: Chlorinated solvents: Trichloroethylene and tetrachloroethylene Benzene.

6 Page: 5 Decision No. 726/11I [25] The paper defines the following approach to Grading the Evidence : Positive evidence The scientific evidence is considered positive if it is consistent and strong enough to conclude that a causal association exists. Reasons for classifying evidence as positive may include (but is not limited to): Consistency across several cohort and/or case-control studies of high methodological quality The existence of studies with high statistical power and large population size; and Evidence of an exposure-response relationship. Limited evidence The evidence is considered limited if a preponderance of scientific evidence or suggestive evidence supports a causal association, but inconsistent results and methodological weaknesses preclude a definitive conclusion. Reasons for classifying evidence as limited may include (but are not restricted to): Limitations in study design or lack of statistical power Limitations in the type of studies that can be carried out on the working population of interest; and A limited number of studies due to a limited population with the exposure under study. Inconclusive evidence The scientific evidence is considered inconclusive if it is neither consistent nor strong. Both positive and negative findings may result from a variety of study weaknesses. A causal association can neither be identified nor ruled out. Evidence suggesting no association If the scientific evidence, including several large, good-quality studies, consistently shows no association between exposure and the disease, a causal association is unlikely. b) The 2008 ODPR Paper [26] Mike Lowther, scientist, prepared an ODPR memorandum dated September 11, 2008, entitled Non-Hodgkin s Lymphoma Risk and Benzene Exposure. That paper noted that the non-occupational risk factors for NHL with the most consistent evidence include age, gender, family history and congenital immune deficiencies, autoimmune diseases, e.g., rheumatoid arthritis, systemic lupus erythematosis, primary Sjögren syndrome, and infections. [27] The 2008 ODPR Paper provides the following summary of the review articles: Of the 11 narrative review articles, two found an increased risk of NHL with occupational benzene exposure, four concluded that the results were suggestive or equivocal at best, and five found no increased NHL risk with benzene exposure. One of the meta-analyses found an increased NHL risk with benzene exposures at a variety of workplaces and also, specifically with petroleum refinery work. Another found no increased risk of NHL with benzene exposures at a variety of workplaces, including petroleum industry exposures. The third meta-analysis reported that petroleum workers had no increased NHL risk from their benzene exposures. The pooled analysis did not

7 Page: 6 Decision No. 726/11I find an increased risk of NHL from occupational benzene exposures at a variety of workplaces that did not include any from the petroleum industry. [Footnotes omitted]. [28] The paper also refers to quality issues with the studies, including the varying definitions of NHL used, unclear study selection criteria, variable benzene exposure categories, and mixed exposures. Mr. Lowther notes that one meta-analysis and a related narrative review tried to correct study NHL risk estimates for the healthy worker effect, but many researchers question doing this for cancers. The 2008 Paper notes that only one cohort was generally regarded to have had long-term, high exposures to only benzene. The cohort has an extensively reviewed quantitative exposure assessment. The cohort s most recent follow-up showed no association between benzene exposure and NHL for males and females (all races combined), or for white males, with a minimum follow-up of 20 years (to as much as 56 years). [29] Mr. Lowther concludes: Overall Summary A review of the scientific data yields some studies that provide suggestive evidence that benzene exposure can result in an increased risk for non-hodgkin s lymphoma, but the totality of evidence for such an association is inconclusive. (vi) Documents submitted by the worker's representative [30] In preparation for this appeal, the worker's representative submitted an abstract of an article entitled Meta-analysis of benzene exposure and Non-Hodgkin lymphoma: biases could mask an important association. 1 The abstract provides the following conclusions: The finding of elevated relative risks in studies of both benzene exposure and refinery work provides further evidence that benzene exposure causes NHL. In addition, the finding of increased relative risks after removing studies that included unexposed or lesser exposed workers in exposed cohorts, and increased relative risk estimates after adjusting for the healthy worker effect, suggest that effects of benzene on NHL might be missed in occupational studies if these biases are not account for. [31] The 2008 ODPR Paper did refer to this article in noting that several researchers question adjusting for the healthy worker effect for cancers. [32] The worker's representative also submitted copies of two ARO decisions, dated November 30, 2010 and January 31, The 2011 ARO decision allowed a claim for NHL by a steel worker with 27 years of benzene exposure. The 2010 ARO decision allowed a claim for NHL by pipefitter/metalworker who was exposed to welding and soldering, varsol, chlorinated solvents, benzene, coke oven emissions, coke oven condensate, and light oil for many years without personal protective equipment. (vii) The Panel s findings regarding this worker s exposure [33] As noted above, the WSIB occupational hygienist prepared an exposure assessment in August M.P., the worker s employer from 1986 to 1994, had since closed. Therefore, the 1 Steinmaus C, Smith AH, Jones RM, Smith MT. Occup Environ Med 2008;65(6):371-8.

8 Page: 7 Decision No. 726/11I occupational hygienist relied upon interviews with the worker and a former supervisor and undertook a review of published research to estimate the worker s exposure. [34] The occupational hygiene report defines the following categories of exposure, which the Panel will rely upon in making its findings: Pattern of Exposure: The exposure pattern is defined as: routine if the task was conducted on daily basis or if the worker spent more than 50% of the work shift potentially exposed to the agent; occasional if the task occurred on a weekly or monthly basis or if the worker spent 50% to 25% of the work shift potentially exposure, and rare if the task was not planned or schedule or if the worker was potentially exposed for less than 25% of the shift. Exposure Category: The category of exposure is defined as high if it was likely that exposure levels exceed 100% of the occupational exposure limit (OEL). An elevated category is defined as levels between % of the OEL. A moderate category is between 10-50% and a low category is defined as levels below 10% of the OEL. The 2006 TLV-TWA for benzene is 0.5 ppm; the basis for this TLV was leukemia. The TLV-TWA for trichloroethylene is 10 ppm with critical health effects noted as CNS [central nervous system] impairment, cognitive decrements and renal toxicity. The TLV- TWA for perchloroethylene (tetrachloroethylene) is 25 ppm with critical health effects noted as CNS impairment. [references omitted] [35] In summary, the Panel finds that the worker had routine high exposure to benzene from 1986 to 1988 and routine elevated exposure from We explain our findings below. [36] The Panel accepts the occupational hygienist s characterization of the worker s exposure from 1986 to 1988 as a laminator assistant. The occupational hygienist described the worker s job duties as follows: Laminator Assistant: This job involved 3 main tasks: 40% of a typical shift might be spent loading and unloading substrate and printed material from the laminator; at least 40% of a shift involved the mixing of blue. This task involved the manual transfer of organic solvent from bulk storage and addition to blue pails to ensure proper blue viscosity. The remaining 20% of the worker s time would have been spent manually wiping the rollers of the laminator with solvent soaked rags. [37] The occupational hygienist concluded that the worker likely had high routine exposure to benzene as a laminator assistant from 1986 to The conclusions were explained as follows: Benzene: The worker s most likely exposure to organic solvents occurred during his approximately 2-year tenure as a Laminator Assistant. During this period the worker spent more than 50% of a typical shift handling organic solvents. These solvents were used to reduce the viscosity of lamination adhesives and for cleaning the laminator. No information was available to accurately identify the composition of these solvents. In a Japanese study Inoue (1984) noted toluene was a common solvent in adhesives. Based on this information and comments from the worker s former supervisor, it was assumed the adhesive and cleaners used at the laminator might have contained toluene and the toluene might have been contaminated with benzene. Promulgation of WHMIS legislation and the establishment of benzene as an Ontario designated substance during the mid-1980s suggests the level of contamination was likely less than 1% by volume.

9 Page: 8 Decision No. 726/11I As a Laminator Assistant it was likely the worker was potentially exposed to organic solvents via dermal and airborne routes. Site-specific sampling data to describe these potential routes of exposure was not available. A 2001 paper by Purvis et al. described solvent exposures for workers in paint manufacturing facilities. The authors described exposures to various organic solvents, such as benzene and toluene, during a variety of tasks, e.g., manual mixing, filling and cleaning, similar to those described by the worker. The exposure data suggested that workers performing these tasks were typically over exposed to VOCs. Air sampling conducted by NIOSH in 1988 examined press operator exposure to benzene at a small printing shop. Limited results from this study indicated that operator exposure to benzene ranged from 1.1 to 0.98 ppm. It was assumed the worker was similarly exposed to organic solvents as described in the citations above. The airborne levels suggest that the worker was potentially exposed to high levels of airborne benzene during his 2-year tenure as a Laminator Assistant. It is possible that the worker was additionally exposed to benzene via dermal contact. [38] For the period from 1988 and to 1994, the worker was employed as a plate maker and plate mounter. The occupational hygienist noted that the worker was potentially exposed to a variety of organic solvents that were components of printing inks and cleaners. The hygienist noted that the process involved rubber printing plates and information from the EPA indicated that aromatic solvents were not compatible with rubber plates. Based upon this assumption, the hygienist concluded that it was unlikely that the worker handled aromatic solvents, such as toluene. [39] Based upon the worker s testimony, however, we are persuaded that the worker continued to have routine exposure to the same solvents after The worker testified regarding his job duties as a plate maker and a plate mounter. He continued to handle the same solvents as he did prior to As a plate maker, the worker wiped the cylinders as they came off the press. He soaked a rag and wiped the cylinders by hand. He did not use gloves or other personal protective equipment (PPE). He performed this process approximately every 30 minutes and used half of a five-gallon can of solvent per shift. He also cleaned the rubber printing plates, since the ink department would send the plates with the ink still on them. The solvents would be retrieved from the ink room in the same manner as when he was a laminator assistant. Sometimes he would retrieve the solvent, and at other times a co-worker would do so. Regarding the hygienist s comment that aromatic solvents were not compatible with rubber plates, the worker testified that the rubber plates naturally deteriorated over time and were replaced as needed. The solvents were also mixed into the inks, so the worker did not see that it would make a difference that the aromatic solvents would be considered incompatible with rubber plates. As a plate maker/plate mounter, the worker testified that a so-called garbage solvent was used most often. He was told that this solvent was made up of a mix of leftover solvents. This was presumably cheaper. [40] Accepting the worker s straightforward testimony, the Panel finds that the worker continued to handle solvents on a regular basis from 1988 to The primary difference was that he worked in an open area during this time, whereas he worked in an enclosed room with no ventilation from 1986 to The worker testified that he requested a job change because he found the work environment difficult in the ink room from 1986 to His eyes were constantly watering and his skin was breaking out and flaking. As a plate maker/plate mounter, there was more open air. He felt better in that environment, but he could not avoid the solvents. He confirmed that he did not use any personal protective equipment. Gloves were impractical to

10 Page: 9 Decision No. 726/11I use. Even if he used gloves, the solvent dripped on his arms, because he had to reach overhead to clean the cylinders. The worker testified that he often worked overtime, up to ten to twelve hours per shift. The Panel accepts that the worker worked approximately ten hours per shift, on average. [41] The employer, M.P., closed in 1994, and the worker found other employment in the printing industry because it was well paid. He spent a year at L.D. performing plate mounting and plate making. He described his employer from 1995 to 1996 ( S.P. ) as a particularly bad environment for fumes. The ventilation was very poor. By 1996, he could not handle the solvent fumes any more and found employment with a community newspaper. [42] In summary, the Panel does not have precise exposure data regarding the worker s exposures, but based upon the occupational hygiene report and the worker s testimony, we estimate the worker s exposure follows: The worker had routine, high exposure to benzene from 1986 to 1988; The worker had routine, elevated exposure to benzene from 1988 to The worker had occasional, low exposure to TCE and Perc from 1988 to (viii) Referral to an independent health professional [43] The Panel finds it is appropriate to refer this matter to an assessor for an opinion, as it appears that there are different interpretations of the current evidence on whether there is a causal link between benzene exposure and the development of NHL. In addition, if there is a causal link, clarification is required as to the duration and intensity of exposure that would be associated with the development of NHL. [44] Accordingly, we ask that the Medical Liaison Office refer this to an assessor in the appropriate specialty to respond to the following questions based upon a review of the file and the Panel s findings of fact (as set out in this decision): 1. Based upon a review of the current epidemiological literature, has an association between benzene exposure and NHL been noted? Please explain. 2. Please comment upon any potential relationship between NHL in this worker and the exposures in the workplace, as described by the Panel s findings of fact in this decision. Please explain. 3. Would the latency period be appropriate? Please comment. 4. Are there any other factors that may have contributed to the development of NHL? 5. Can you provide any other information or observations which you feel would be helpful to the Panel and the parties to this appeal?

11 Page: 10 Decision No. 726/11I INTERIM DISPOSITION [45] The Panel defers a decision in this appeal, pending further investigation. This matter is to be referred to an independent health professional, as outlined in this interim decision. The Panel is seized of the appeal. DATED: May 11, 2011 SIGNED: R. McCutcheon, B. Davis, K. Hoskin