NOVA SCOTIA WORKERS COMPENSATION APPEALS TRIBUNAL. Participant entitled to Workers Compensation Board of Nova Scotia (Board)

Transcription

1 NOVA SCOTIA WORKERS COMPENSATION APPEALS TRIBUNAL Appellant: [X] (Worker) Participant entitled to respond to the appeal: Workers Compensation Board of Nova Scotia (Board) S.251 REFERRAL TO HEARING OFFICER Referral to: Representative: Form of Appeal: WCB Claim No.: Jane Corkum [X] Written submission [X] Date of Decision: August 24, 2010 Decision Summary: The appeal of the February 11, 2010 Board Hearing Officer decision is referred back to the Hearing Officer for reconsideration according to the reasons of Appeal Commissioner Gary H. Levine.

2 2 WCAT # RTH CLAIM HISTORY AND APPEAL PROCEEDINGS: The Worker* claims to have sustained occupational noise-induced hearing loss. If her hearing loss is shown to be due to occupational noise, she may be entitled to benefits from the Board under the Workers Compensation Act, S.N.S , c. 10, as amended, (the Act ). However, her claim was denied in a February 11, 2010 decision by a Board Hearing Officer. The history of proceedings is as follows: The Worker filed an Occupational Noise Hearing Loss claim form with the Board in July She indicated that she was exposed to excessive noise at her workplace in the dietary department from 1988 to The Worker had a diagnostic audiogram done on August 27, 2009 and was seen by Dr. M. Hafidh, an otolaryngologist, on December 18, 2008 and June 22, A Board Disease Benefits Administrator denied the claim in December On appeal, the Hearing Officer denied the claim. Board decision-makers principally relied upon expert evidence in a February 12, 2009 opinion from an audiology consultant, Mr. Michael Sharpe, as well as a September 29, 2009 Sound Level Survey report by ADI Limited. The Worker subsequently filed an appeal with the Tribunal. This matter proceeded by way of a review of the written record and submissions from the Worker s representative. The record includes the decision under appeal and the contents of the Worker s Board file. While all of the foregoing were considered, I will only refer to a portion of the relevant evidence and submissions below. ISSUE AND OUTCOME: Does the Worker have an acceptable claim for occupational noise-induced hearing loss? Although the Worker was probably exposed to excessive noise, the documented excessive exposure involved impulse or impact noise, not steady-state noise levels. The pattern of her hearing loss shown on a diagnostic audiogram makes it unlikely that her hearing loss was caused by steady-state noise. However, it isn t clear whether the pattern shown on the audiogram would exclude impulse or impact noise exposures. Under the circumstances, it is appropriate to direct the Board Hearing Officer to obtain further opinion evidence and reconsider her decision. *This decision contains personal inform ation and m ay be published. For this reason, I have not referred to the participants by nam e.

3 3 AUTHORITY FOR REFERRAL: Subsection 251(1) of the Act permits this Tribunal to refer appeals back to Board Hearing Officers. The Tribunal may refer an appeal back when the quantity or nature of new or additional evidence, or the disposition of the appeal, merits the referral. A Section 251 referral requires a Hearing Officer to reconsider some or all of the issues that have been appealed to the Tribunal. The referral does not decide the issue(s) on appeal. However, it brings the appeal before the Tribunal to an end. If the Hearing Officer's reconsidered decision is appealed, the appeal will receive priority over other appeals filed with the Tribunal. REASONS FOR REFERRAL: Compensable Injury, Causation and Burden of Proof: In order for the Worker to be entitled to benefits from the Board, she must have suffered a personal injury by accident arising out of and in the course of employment : Section 10(1) of the Act. A disablement, including an occupational noise-induced hearing loss, may be a compensable injury. Section 12 of the Act provides that where an occupational disease (such as occupational noise-induced hearing loss) is caused by the nature of any employment and the disease results in a loss of earnings, permanent impairment or death, the worker is entitled to compensation as if the occupational disease were a personal injury by accident. The Worker in this appeal asserts that she suffered a permanent impairment. Although a causal relationship linking an impairment to the workplace must be shown, the Worker is not required to prove causation to a scientific certainty. I may use common sense to infer causation: Nova Scotia (Workers Compensation Board) v. Nova Scotia (Workers Compensation Appeals Tribunal) and Johnstone (1999), 181 N.S.R. (2d) 247 (C.A.); Nurnber v. Nova Scotia (Workers Compensation Board) et al. (2004), 224 N.S.R. (2d) 276 (C.A.). Expert opinion evidence is often of great assistance in determining medical and other issues. However, I am mindful that expert evidence is not necessary to such a determination, nor is expert evidence necessarily conclusive. I must consider the evidence before me in light of s. 187 of the Act. The Worker is entitled to the benefit of the doubt on any issue involving compensation. Where there is doubt on an issue and the disputed possibilities are evenly balanced, the issue must be resolved in the Worker s favour. Any participant disputing an inference raised by the Worker is required to meet a greater burden of proof, the balance of probabilities standard generally required in civil matters. Whether an inference is reasonable depends upon the

4 4 circumstances of each case. PMI, Board Guidelines and Minimum Hearing Loss Required: Section 34 of the Act directs the Board to determine the existence and degree of a worker s permanent medical impairment (PMI). An impairment is basically the loss of, loss of use of, or derangement of any body part, system or function (after maximum recovery). Generally speaking, a permanent impairment is determined by considering information contained in a worker s claim file, the results of an examination and applicable guidelines. The degree of such impairment must be quantified as a percent of the whole body. For a noise-induced hearing loss claim occurring on or after January 1, 2000, as claimed in this case, Policy 1.2.5AR directs the Board to use the American Medical Association s th Guides to the Evaluation of Permanent Impairment 4 Edition (AMA Guides). According to the AMA Guides, the total hearing loss, measured in decibels, for four speech frequencies (500, 1000, 2000, and 3000 Hz) is used to determine whether a PMI exists. The hearing loss must be 100 db or more in at least one ear. Policy 1.2.5AR further requires that, in order for the Board to accept a claim, a diagnostic audiogram should show a pattern consistent with noise-induced hearing loss. In addition, according to Policy 1.2.6R, hearing loss claims will be considered when daily exposures to either steady noise or impulse noise exceed levels adopted by the Nova Scotia Department of Labour and Workforce Development. For example, exposures to steady-state noise in excess of 85 db over 8 hours, or any impulse/impact noise over 140 db, satisfy the criteria for consideration. Evidence and Findings: The Worker s duties required her to work in the Employer s kitchen area approximately 8 hours per day. She apparently worked near a loud exhaust fan. In recent years, she noticed difficulties with her hearing. The Worker underwent a hearing test on August 27, An audiogram from the test, a so-called diagnostic audiogram, was considered acceptable evidence of hearing loss by the Board. By my rough estimate, it showed hearing loss of approximately 145 db over the four speech frequencies for the right ear and approximately 160 db over the same frequencies for the left ear. Thus, the hearing loss in either ear would be sufficient to constitute an impairment if her hearing loss was due to exposure to occupational noise. According to Dr. Hafidh s September 29, 2009 report, the Worker s hearing test basically showed moderate sensor neural [sic] hearing loss in both ears. An MRI scan showed normal internal auditory canals and inner ears. Given a lack of signs of infection and no

5 5 abnormality in her inner ears disclosed by an MRI, Dr. Hafidh felt that the most probable cause for the Worker s hearing loss was noise exposure. He wrote, [t]he picture of hearing loss looks like as if she has noise induced hearing loss. The Worker s representative argued that the ADI Sound Level Survey report provides sufficient evidence of excessive noise levels. The representative submitted as follows: On file is a copy of the ADI Limited, Sound Level Survey report conducted at [the Worker s] place of employment. This study confirms that the Threshold Limit Values for the bakers were measured at 79.2 db (TWA) and the kitchen staff member at 83.8 db (TWA). These levels are below the Guidelines set by the province for noise exposure during an 8 hour word day, ACGIH TLV Guidelines.... The report also notes that instantaneous sound level reading for maximum peak reading at anytime during the 8 hours were above the maximum pressure level of 140 db, ACGIH TLV Guidelines. The noise dosimeter woren [sic] by the kitchen employee measured a peak maximum pressure level of db.... [original in bold] It seems reasonable that, if a kitchen co-worker s dosimeter showed impulse or impact noise in excess of that permitted according to Board Policy, the Worker was also exposed to the same level of noise. I therefore accept that the Worker was exposed to excessive impact or impulse noise in her workplace. However, the evidence appears to be in conflict as to what may have caused the pattern of hearing loss shown on the Worker s audiogram. Dr. Hafidh felt that the loss was due to noise, but he did not discuss the specific findings in the diagnostic audiogram which may have led him to this conclusion. On the other hand Mr. Sharpe discussed the audiogram results in some detail. He described the pattern as a U shaped or cookie bite audiogram. He was of the opinion that the pattern was not consistent with noise induced hearing loss because the Worker s greatest degree of damage was at 2000Hz on the right and 1500 Hz and 2000 Hz on the left. Mr. Sharpe explained the basis for his opinion as follows: The thresholds at 4000Hz and 6000Hz are within normal limits on the right and although mildly damaged on the left the thresholds are significantly better that [sic] at 1500Hz and 2000Hz. It is not possible that the noise would have damaged 1500Hz and 2000Hz to a greater degree than 2 of the most susceptible frequencies. Noise will not skip a higher frequency and

6 6 damage a lower frequency first. According to Mr. Sharpe, research supports the notion that damage to the inner ear is first detected in the 3000Hz to 6000Hz range with the greatest degree of damage most commonly occurring at 4000Hz. Although damage could occur at 2000Hz, it would apparently require an abnormally long ear canal (which was not indicated from an MRI or from Dr. Hafidh s reports). Mr. Sharpe concluded his opinion with the following recommendation: I would recommend against accepting this claim for a work related noise induced hears [sic] loss as the pattern of the hearing loss is not consistent with a noise induced hearing loss as well as the limited time the client would have been exposed to 85dBA for 8 hours. [emphasis added] Mr. Sharpe s evidence is more specific than Dr. Hafidh s evidence with respect to the process and progress of hearing loss due to noise exposure. He relied upon medical science which tends to exclude noise induced hearing loss as the cause of the Worker s impairment. Nonetheless, it is not clear whether Mr. Sharpe s discussion pertains solely to hearing loss attributable to steady-state noise. This raises the concern that a different audiogram pattern might be present for impulse or impact noise than for steady-state noise. Under the circumstances, it is appropriate to direct the Board Hearing Officer to obtain further evidence and reconsider her decision. The evidence should, at a minimum, assist the Board to determine whether the pattern of hearing loss sustained by the Worker, as shown on her diagnostic audiogram, is consistent with excessive impulse or impact noise. CONCLUSION: The disposition of the appeal merits a referral of the appeal back to the Hearing Officer for reconsideration. The Board is to obtain further evidence to assist it in determining whether the pattern of hearing loss sustained by the Worker, as shown on her diagnostic audiogram, is consistent with excessive impulse or impact noise. th DATED AT HALIFAX, NOVA SCOTIA, this 24 day of August, Gary H. Levine Appeal Commissioner