Noise-induced Hearing Loss in Construction Workers Being Assessed for Hand-arm Vibration Syndrome

Abstract

Many workers are exposed to high noise levels and may develop noise-induced hearing loss (NIHL). 1,2 Tak et al. 3 estimated that, after the manufacturing sector, the construction sector had the greatest number of workers occupationally exposed to noise in the US. Construction workers in Canada are similarly exposed to high noise levels 4 and at risk of NIHL. 5,6 In construction work, the use of hand-held vibrating tools is an important source of noise exposure. 4 Exposure to hand-arm vibration may result in Hand-Arm Vibration Syndrome (HAVS) which is comprised of vascular, neurological and musculoskeletal components. 7,8 The main vascular component consists of cold-induced blanching of the fingers, a form of secondary Raynaud's phenomenon which is often referred to as Vibration White Finger (VWF). 9 Several studies have found that in workers exposed to both noise and hand-arm vibration, those workers with VWF have greater hearing loss than workers without VWF, after controlling for noise exposure. [10][11][12][13][14][15] However a well-designed study by Pyykko et al. 16 found that the permanent hearing loss in workers exposed to noise and vibration did not exceed the permanent hearing loss from exposure to noise only. Therefore it appears that VWF might be a marker for increased individual susceptibility to noise-induced hearing loss without the vibration conferring increased risk of hearing loss from noise exposure. 17,18 The Occupational Health Clinic at St. Michael's Hospital in Toronto, Ontario has a comprehensive program to assess workers for HAVS. Most of the construction workers assessed for HAVS have not had audiometry at work and therefore the clinic offers audiometry to these workers as a means of case finding for NIHL. This study was carried out to assess the extent of NIHL in these construction workers and to examine possible predictors, in particular the duration of work in construction and the severity of VWF. METHODSA total of 191 construction workers were assessed for HAVS between January 1, 2006 and December 31, 2007. All had been exposed to noise from their vibrating tools such as grinders, drills and impact tools. Twenty-two workers decided not to have the audiometric test that was offered and therefore the study group with new audiometric data comprised 169 subjects.The data abstracted from these workers' medical charts in 2008-9 included the age at assessment, years worked in construction, job title, audiometric test results and the HAVS Stockholm vascular

Noise and hand-arm vibration exposure in relation to the risk of hearing loss

“…[32] Earlier longitudinal and case-control studies have found an increased risk of hearing loss for workers with VWF. [6][7][8] The present study did not include VWF in the analysis.…”

“…[2][3][4][5] Another factor that could confound and also increase the risk of hearing loss is vibrations. [3,[6][7][8][9] A study by Pyykko et al [7] suggested a common mechanism behind the association between exposure to noise and HAV and their combined effect on hearing. They suggest that vibration exposure from hand-held tools reduces the blood flow in the cochlea by activating the sympathetic nervous system, leading to increased risk of hearing loss.…”

“…[3,9] However, longitudinal and case-control studies on subjects who have contracted vibration-related disorders found that subjects with vibration white fingers (VWF) have an increased risk of developing hearing loss. [6][7][8] To gain further knowledge, a new longitudinal study is presented.…”

Raynaud′s phenomenon among men and women with noise-induced hearing loss in relation to vibration exposure

“…Earlier longitudinal and cross-sectional studies have found an increased risk of hearing loss among workers with VWF compared to workers without VWF who have similar noise exposure and are of similar age. [1,[5][6][7][8][9] Therefore, WF from exposure to HAV might be a factor that increases the risk of noise-induced hearing loss.…”

“…Workers using vibrating hand-held tools who have VWF have an increased risk for noise-induced hearing loss compared with workers without VWF but of similar age and with similar noise exposures. [1,[5][6][7][8][9] Episodes of "WF" among those with WF or Raynaud's phenomenon are primarily triggered by cold or emotional stress. [10] Primary Raynaud's phenomenon has no related disease of external identified cause but could have a genetic component.…”