NOVA SCOTIA WORKERS COMPENSATION APPEALS TRIBUNAL

Transcription

1 NOVA SCOTIA WORKERS COMPENSATION APPEALS TRIBUNAL Appellant: [X] (Worker) Participants entitled to respond to this appeal: [X] (Employer) and The Workers Compensation Board of Nova Scotia (Board) APPEAL DECISION Representative: [X] Form of Appeal: Oral hearing at Sydney, NS, on April 20, 2011 WCB Claim Nos: [X] Date of Decision: May 18, 2011 Decision: The appeal of the March 5, 2009 and April 29, 2009 Board Hearing Officer decision are allowed in part, according to the reasons of Appeal Commissioner Sandy MacIntosh.

2 2 CLAIM HISTORY AND APPEAL PROCEEDINGS: On February 8, 2007, the Worker, a x ray darkroom technician, filed a chemical exposure claim with the Board. The Worker s claim was initially denied by the Board on March 19, There have been a number of appeal and reconsideration proceedings since that time. This eventually led to the following two hearing officer decisions which are under appeal: 1. On March 5, 2009, a Hearing Officer confirmed that there was insufficient evidence to conclude that the Worker had sustained a personal injury by accident arising out of and in the course of employment. She noted that the Worker had several complaints including pulmonary problems, GI problems, sleep apnea, sinus problems, food allergies, loss of balance, kidney pain, poor blood circulation, depression and joint pain. However, she was unable to link these to exposures in the workplace. She accepted the expert opinion of Dr. Janigan over other medical opinions in the Worker s file. 2. On April 29, 2009, a Hearing Officer found that additional evidence submitted on behalf of the Worker concerning darkroom disease was insufficient to find that the Worker has an acceptable claim. The Worker s appeals of the Hearing Officer decisions were filed with the Tribunal in mid Both the Worker and Board acquired additional specialist opinions after the appeals were filed. At the request of the Worker s representative, the Tribunal delayed hearing the appeals to give the Board the opportunity to review the additional evidence. The Worker s representative concedes that some of the symptoms complained of by the Worker may be unrelated to the occupational exposures. However, he argues that I do not need to accept all symptoms to accept the claim. Most important are the asthma and cognitive deficits. The environmental sensitivities are not as important. He argues that it may be appropriate for the Board to determine the full scope of which symptoms are related to the exposures. The representative relies heavily on the opinion of Dr. Liss and argues that it accords with common principles of causation. He argues that it should be given more weight than the opinions of Drs. Martin and Janigan. This decision contains personal information and may be published. For this reason, I have not referred to the participants by name.

3 3 ISSUE AND OUTCOME: Did the Worker sustain a personal injury by accident arising out of and in the course of his employment? Yes. However, there is only sufficient evidence to link the Worker s asthma to his employment. There is insufficient evidence to link his other symptoms to his employment. ANALYSIS: In order for the Worker to prove causation, it is not necessary for him to show that workplace exposures are the sole or most important cause of his symptoms. Instead, all that need be proven is that workplace exposures are a contributing cause in the sense that, but for the exposures, the symptoms would not have occurred when they did, or in exceptional cases where that legal test is unworkable, that workplace exposures contributed to the development of symptoms to a material degree. I do not need to rely solely on medical opinions when deciding whether there is a link between workplace exposures and symptoms. I can use common sense and logic to draw conclusions from proven facts (reasonable inferences). However, speculation, even if plausible, does not establish causation. I must decide disputed issues in the Worker s favour if the possibilities supporting his position are at least as strong as the possibilities against it. The Worker has the legal burden of proving his case on an as likely as not basis. Worker s testimony The Worker testified that he began employment in 1973 cleaning floors for the Employer. In 1979, he took the position of x ray darkroom technician. He testified that there was no formal training. He testified that the room contained two large chemical tanks and two smaller ones. He mixed the chemicals in an open vat and developed the x rays in a six foot by eight foot room. He testified that he spent about 6 ½ to 7 hours out of an eight hour shift in the room. There was no ventilation in the room, but the processors vented into the ceiling. The room had an acidic odour. He has been left with a permanent metallic taste in his mouth. The was no protective equipment and he wore his work clothes home. He testified that he

4 was paid overtime for cleaning the machines by hand after hours. WCAT # AD & AD He testified that he had good health before starting this employment. He started getting headaches, breathing difficulties and dizziness in the 1980s. He was never told they may be caused by chemical exposures. The headaches were so severe that he had to be hospitalized once. No one attributed these problems to work. The Worker testified that his breathing varied and he passed a pulmonary function test. He testified that he quit smoking about 35 years ago. He testified that he usually got the headaches around the end of the workday. Sometimes they occurred elsewhere. Back then, he did not react to perfume. He was transferred to another hospital in 1995 (for ease of reference I will refer to these as the old and the new hospital). The darkroom in the new hospital was also about six feet by eight feet in size. It did not have a ventilation system until about The chemicals were mechanically mixed twice a day in an open unit. This resulted in a stronger smell than at the former location. Complaints about the smell were common. He noticed his breathing becoming worse after he was transferred. His walking tolerance decreased due to shortness of breath. He also noticed that he was having memory problems around that time. He began to find it increasingly difficult to perform his employment. His mechanical skills decreased. He has difficulty recalling names, but remembers faces. The Worker testified that he developed a tumour in his left ear in 1997 resulting in deafness in that ear. His right ear is now failing as well. He had surgery, but it did not change his symptoms headaches, dizziness and a loss of balance. In 2000, the Worker had a CT scan to investigate the headaches. He was given a prescription at that time, but did not take it as its purpose was not explained to him. The Employer began providing masks with filters in 2005 after the Worker argued successfully for these. In 2006, he was sent to Dr. Fox by his doctor. His doctor sent him there after noticing the strong smell of chemicals on his clothing on a day he came directly from work. In 2007, Dr. Fox put the Worker off work and he remains on medical disability. He testified that he was put off work as he reacted to perfumes. They trigger headaches. He also experienced balance difficulties when he tried to return to work. His doctors believe his hearing loss might be related to workplace exposures as well, but they are not sure. 4

5 Since leaving work he has noticed that his skin colour has returned to pink. It had a gray hue when he stopped working. Otherwise, his symptoms have not improved. He develops headaches when exposed to strong smells. They can be so severe that he has to go to bed. It limits where he can go. He wears a hat as he has light sensitivity. Key documentary evidence I have reviewed the Worker s entire claim file. For purposes of this decision I will just set out the most important documentary evidence. I agree with the Worker s representative that the key opinion evidence is that of Drs. Janigan, Liss and Martin. Several of the Worker s former co workers and supervisors filed letters in support of the Worker s claim. These statements confirm the Worker s testimony that the darkrooms in the old hospital lacked ventilation. They are consistent with the Worker s description of his job. They indicate that no protective clothing was worn until about the time of the closing of the old hospital (with conflicting evidence as to whether masks were provided shortly before or after the closure of the old hospital). The statements also indicate that the volume of x rays being developed increased over time. Dr. Leckey, a neurologist, assessed the Worker for headaches in The Worker reported that the headaches began about 1999 and can occur at any time during the day and sometimes woke him up. They were short in duration, but intense. They occurred every five to six weeks. On January 9 and June 1, 2007, Dr. Fox, environmental health physician, noted that the Worker had significant solvent exposure while working in the darkroom over the years. He wrote that the Worker developed several symptoms over the years including chronic rhinitis, throat clearing, and decreased sense of smell and taste. He is short of breath with activity, and fatigued. He has mild chemical intolerance. His central nervous symptoms are impaired balance and a significant cognitive dysfunction. Dr. Fox expressed the view that the symptoms resulted from solvent exposure. He expressed the view that the Worker has dementia secondary to chemical exposure. Dr. Janigan, a pathologist, reviewed the Worker s claim file on several occasions at the request of the Board. He was unable to relate the Worker s symptoms to his darkroom exposures. He noted that documentary records provide conflicting evidence as to when the Worker s various symptoms first began. He noted that the neurological findings were intermittently present on testing. He noted that Dr. McKelvey, while concluding that there was some memory loss, did not diagnose dementia. He noted that Dr. McKelvey ultimately was unable to say what contribution chemicals may have made to the Worker s cognitive difficulties and stated that the pattern of symptoms was most consistent with a vascular cognitive impairment. 5

6 Dr. Janigan notes Dr. Fox related the symptoms to solvent exposure without identifying any particular solvent. Dr. Janigan noted that the Worker s blood work and liver cell testing revealed normal results which is inconsistent with chronic solvent exposure. He noted that neoplasm, the cause of the Worker s left hearing loss, is unrelated to chemical exposures. He noted that glutaraldehyde and hydroquinone are not solvents. However, glutaraldehyde is a potent immunological sensitizer which can impact the respiratory tract and result in rhinitis, asthma or asthma like conditions. Dr. Janigan noted that while skin contact was the most significant method of exposure, the Worker had no significant history of skin rash. He noted some history of respiratory tract symptoms. However, these are not well documented. He indicated that his review of literature revealed the papers supporting the existence of darkroom disease were often published by organisations with a bias and that studies from more objective organisations generally did not support there being a significant correlation. Dr. Liss and Dr. Martin are the most recent specialists who reviewed the Worker s claim. Both are university professors and experts in the fields of occupational and environmental health. Both acknowledge that the other is respected in his field. Both had the opportunity to review the Worker s entire file, including all specialist reports on file. Both opinions are supported by multiple scientific studies. Both agree that the Worker has adult onset asthma and a cognitive impairment. Dr. Liss noted that work in a darkroom would have exposed the Worker to glutaraldehyde, hydroquinone, acetic acid and sulphites/sulphates (as well to sulphur dioxide). He noted that these chemicals can impact lung function, and are known sensitizers. He noted that the MSDS information included possible central nervous system effects, and respiratory tract effects. He expressed the view that of particular concern was the combined effect of the mixtures of the chemicals. The means that combined concentrations have to be considered when assessing whether the Worker was exposed to an unsafe level of chemicals. He argued that Dr. Janigan s opinion (against accepting the claim) was largely based on not having specific measurements of exposures in the workplace. He rejected this approach stating that there was no reason to believe that the workplace would have been materially better than other darkrooms (in other words, generic evidence could be considered regarding exposures). Dr. Liss also noted that the Worker had 15 years in the old hospital with poor ventilation, no protective gear and that he cleaned the machines daily. The Worker s representative provided Dr. Liss with a list of symptoms. Dr. Liss only commented on the ones he believed could be linked to occupational exposures. 6

7 Dr. Liss expressed the view that the Worker s adult onset asthma is linked to his employment. He felt that this was the easiest of the conditions to relate to employment. He noted that the Worker first complained to his doctor of shortness of breath, and tightness of the chest, when walking up stairs in He noted that several studies reveal increased asthma and respiratory symptoms amongst those exposed to darkroom chemicals. He noted that the difference was statistically significant compared to the general population. Studies also revealed males were significantly more likely to develop such symptoms. It was noted that males were more likely to be involved in cleaning and maintaining the equipment, giving them more significant hands on exposure. Dr. Liss expressed the view that the Worker s neurological complaints headaches, cognitive dysfunction, impaired balance and mood change were linked to his employment. He noted that headaches were documented in When assessed in 2007, the Worker had evidence of balance disorder and the Worker reported that he had noticed significant memory problems, particularly in the past 2 3 years. In 2008, the Worker reported that he first noticed minor memory difficulties in the 1980s. He noted that a study he conducted revealed that central nervous/cognitive symptoms were more common in darkroom workers than in physiotherapists. Dr. Liss expressed the view that the rhinitis/sinusitis, metallic taste in the mouth and chemical intolerances were related to his occupational exposures. He noted that these were documented in The Worker reported that the intolerances began around Dr. Liss noted that darkroom syndrome is a term used to describe several somatic symptoms that may be experienced by darkroom workers. These include sore eyes, itchy nose, sore throat, headache and abnormal fatigue. He discussed research papers, including a study where he was an author. He expressed a view that there was a strong association between darkroom work and these symptoms and explained possible mechanisms. One symptom that is strongly, statistically associated with darkroom work is a metallic taste. He noted that he was not aware of any surveys addressing darkroom work and environmental intolerances. His own statistical information does not reveal a significant difference between physiotherapists and darkroom workers. He argued that court and adjudicative decisions regarding others who claimed chemical intolerances should be considered. Dr. Martin s report largely focussed on assessing Dr. Liss s report. He agrees that the Worker has adult onset asthma. However, he does not believe it to be work related. He noted that it was unclear when this condition developed. While the Worker complained of shortness of breath, it was not always present. For example, the Worker s physician 7

8 noted on January 6, 2006 that the Worker had no shortness of breath. It appears that the use of puffers was a more recent development. If the asthma developed in the mid 1990s, he would expect it to progressively worsen if workplace exposures were the cause. However, there is no documentation of this occurring. Alternatively, given the occupational exposures were less intensive at the new hospital, a later development of asthma would be less likely to be work related. While Dr. Martin agreed that Dr. Liss performed a thorough review of literature, he felt that some significant studies were not discussed, including findings that occupational asthma in radiographers is rare. He noted that respiratory symptoms in radiographers have alternatively been linked to workplace stress. Dr. Martin agrees that the Worker has a cognitive impairment which appears to be worsening. However, he feels that the evidence is strongly against a work related cause. On reviewing the MSDSs on file, he could not identify any neuro toxic agents other than di ethylene glycol (used in the developer). However, this chemical would not cause the type of cognitive symptoms experienced by the Worker and its neurological impacts would occur at the same time as symptoms such as renal failure. A literature search did not reveal any case reports of chronic solvent encephalopathy in radiographers. Further, if the Worker s cognitive dysfunction were linked to occupational exposures, he would expect it to stop progressing after exposure ended. He felt the Worker s condition to be suspicious for dementia. He felt that it should be further investigated. Dr. Martin felt that the darkroom syndrome and environmental intolerances were unrelated to work. He noted that the studies discussed by Dr. Liss only concerned current employees they did not address those whose symptoms continued after leaving the workplace. Dr. Liss responded to Dr. Martin s report. He expressed the view that many cases of occupational asthma continue after occupational exposures end. He explained that the asthma could have been caused by either the exposure to sensitizers or by chronic irritant exposures. He noted that his study looked at those who were diagnosed by a doctor with asthma only after starting employment. That radiographic workers might have workplace stress does not mean that they also do not having workplace related asthma. He argues that, properly interpreted, the contrary studies mentioned by Dr. Martin actually support a relationship between darkroom work and asthma, particularly when increased respiratory symptoms in general are considered. He agreed that the neurocognitive dysfunction should be further investigated, however he reiterated the findings of his epidemiologic study concerning nervous system symptoms. He argued that just because the darkroom syndrome and environmental intolerances are 8

9 not medically explained does not mean that they are unrelated to workplace exposures. He noted that the Bradford Hill criteria for a causal connection are met when certain studies are considered. Scientific proof is not necessary for the Worker to establish his claim. However, speculation, even if plausible, is not evidence. This, in my view, is the difficulty with Dr. Fox s opinion evidence. Dr. Fox appears to have inferred that exposures to unknown solvents somehow initiated a broad spectrum of symptoms, some progressive and some waxing and waning. The basis for the opinion beyond that is unclear. With respect to the Worker s asthma (or asthma like condition), I accept the opinion of Dr. Liss that it is work related. I accept that the Worker had significant exposure to workplace chemicals which can cause asthma or asthma like conditions. The Worker, in addition to working with these chemicals in developing x rays, was exposed to the chemicals while cleaning the machines by hand for many years. Dr. Janigan stated that these chemicals can cause asthma (however, he noted that the symptoms were not well documented while the Worker had testing around 1994). Dr. Martin doubted the work relatedness on the basis of a lack of documentation concerning a progression. While not medically documented, it appears that the asthma did become worse with time and now is measurable on pulmonary function testing. Overall, I find that the evidence meets the as likely as not basis. On the symptoms other than asthma, I accept the opinions of Drs. Janigan and Dr. Martin over that of Dr. Liss. I accept that the evidence supports that the Worker has an apparently progressing, cognitive dysfunction and experiences various symptoms (some of which wax and wane) which, for sake of convenience, can be labelled as darkroom syndrome and environmental intolerances. There is evidence supporting a link between the workplace and the Worker s cognitive dysfunction, darkroom disease and environmental intolerances. These all developed after the Worker began his employment, so there is a temporal relationship. The Worker testified that his head aches and dizziness began in the 1980s and that the headaches tended to develop around the end of the workday. The Worker testified that he found the chemical odours stronger after his move to the new hospital. The Worker had significant exposure to chemicals, particularly in the first fifteen years of his employment, when no protection was worn. Dr. Liss expressed the view that there was a relationship citing various studies concerning darkroom employees (including his own). However, the evidence against the Worker s position is stronger than the evidence in his favour. It was only after the Worker began wearing better protection that most of his symptoms 9

10 10 WCAT # AD & AD began to be documented. When Dr. Leckey documented the Worker s headaches, they were said to occur anytime. If, historically, they mostly came on around the end of the workday, I would think this significant fact would have been documented by Dr. Leckey. Dr. McKelvie s investigations appear to point more towards a vascular cause for the cognitive dysfunctions than a chemical cause. Dr. Liss, in responding to Dr. Martin s opinion, did not dispute that the studies he referred to dealt with symptoms that occur at the time of exposure, as opposed to ongoing symptoms. Dr. Liss does not refute Dr. Martin s evidence that the Worker s specific exposures are not linked to his type of cognitive dysfunction, nor does he explain the lack of organ failure discussed by Dr. Martin. Dr. Liss s opinion carries an advocacy tone when he argues for the use of findings of courts or tribunals in unrelated proceedings to bolster his opinion. Finally, I note that there was no significant change in the Worker s symptoms after he left the workforce (ending his exposures). Therefore, considering the evidence in its entirety, I conclude that there is only sufficient evidence to link the Worker s asthma to workplace occupational exposures. CONCLUSION: The appeal is allowed in part. The Worker did sustain a personal injury by accident arising out and in course of employment being his asthma or asthma like condition. However, there is insufficient evidence to link his other ongoing symptoms to his former employment. DATED AT HALIFAX, NOVA SCOTIA, THIS 18 th DAY OF MAY, Sandy MacIntosh Appeal Commissioner

11 11 WCAT # AD & AD