A unique Institute of Railway Hygiene was created 70 years ago in Russia, one of the major railway countries in the world. Since then the Institute's staffers have carried out huge work on improvement of railway workers' health, prevention of their exposure to noise, unfavorable microclimate, vibration and other occupational hazards. Significant contribution into the world occupational hygiene was made by such Institute's professionals as S.F. Kazansky, P.I. Nikitin, A.M. Volkov and others.
It is suggested that, within the same energy level, an impulse noise is more hazardous to hearing than a permanent noise. To justify this hypothesis, a study was performed with groups of wood-cutters and shipyard workers to investigate different characteristics of noise load (noise levels, noise impulsivity from the outside and under the ear-flaps, noise emission levels with regard to the length of work and using ear-flaps), and hearing losses (both real and forecasted on the Robinson model). To avoid individual factors, a computerized assessment of 38 pairs of workers from both teams was performed (with regard to similar noise emission levels, diastolic pressures, smoking habits, their military service backgrounds as to the service in heavy artillery units, absence of otic diseases, low consumption of salicylates). The results showed that, within the same energy level, the noise in the shipyard was three times as impulsive and more otic disorders inducing than the noise in the wood-cutters' working conditions.
BACKGROUND: Stress, strain, and fatigue at the workplace have previously not been studied in relation to acoustic conditions. AIMS: To examine the influence of different acoustic conditions on the work environment and the staff in a coronary critical care unit (CCU). METHOD: Psychosocial work environment data from start and end of each individual shift were obtained from three shifts (morning, afternoon, and night) for a one-week baseline period and for two four-week periods during which either sound reflecting or sound absorbing tiles were installed. RESULTS: Reverberation times and speech intelligibility improved during the study period when the ceiling tiles were changed from sound reflecting tiles to sound absorbing ones of identical appearance. Improved acoustics positively affected the work environment; the afternoon shift staff experienced significantly lower work demands and reported less pressure and strain. CONCLUSIONS: Important gains in the psychosocial work environment of healthcare can be achieved by improving room acoustics. The study points to the importance of further research on possible effects of acoustics in healthcare on staff turnover, quality of patient care, and medical errors.
Occupational and residential noise exposure has been related to increased risk of cardiovascular disease. Alteration of serum lipid levels has been proposed as a possible causal pathway. The objective of this study was to investigate the relation between ambient and at-the-ear occupational noise exposure and serum levels of total cholesterol, low-density lipoprotein-cholesterol, high-density lipoprotein-cholesterol, and triglycerides when accounting for well-established predictors of lipid levels.
This cross-sectional study included 424 industrial workers and 84 financial workers to obtain contrast in noise exposure levels. They provided a serum sample and wore portable dosimeters that every 5-s recorded ambient noise exposure levels during a 24-h period. We extracted measurements obtained during work and calculated the full-shift mean ambient noise level. For 331 workers who kept a diary on the use of a hearing protection device (HPD), we subtracted 10 dB from every noise recording obtained during HPD use and estimated the mean full-shift noise exposure level at the ear.
Mean ambient noise level was 79.9 dB (A) [range 55.0-98.9] and the mean estimated level at the ear 77.8 dB (A) [range 55.0-94.2]. Ambient and at-the-ear noise levels were strongly associated with increasing levels of triglycerides, cholesterol-HDL ratio, and decreasing levels of HDL-cholesterol, but only in unadjusted analyses that did not account for HPD use and other risk factors.
No associations between ambient or at-the-ear occupational noise exposure and serum lipid levels were observed. This indicates that a causal pathway between occupational and residential noise exposure and cardiovascular disease does not include alteration of lipid levels.
The article covers changes in occupational cardiovascular risk for workers of nonferrous,metallurgy. Findings are that exposure to noise up to 94 dB with length of service increases possible atherosclerosis and metabolic syndrome. With 5 years of service, risk of the predicted conditions increases by 40.5%. When occupational exposure lasts over 5 years, risk of arterial hypertension increases. A group of workers without exposure to occupational factors appeared to have no connection between length of service and metabolic syndrome and arterial hypertension. Risk evolution modelling proved that risk of functional disorders in nonferrous metallurgy workers becomes unacceptable after 5 years of service (cardiovascular disorders are critical).
Many jobs at the Department of Fisheries and Oceans Canada (DFO) have several features in common: they are often performed in noisy environments and involve a number of auditory skills and abilities, such as speech communication, sound localization, and sound detection. If an individual lacks these skills and abilities, it may constitute a safety risk for this individual, as well as for fellow workers and the general public. A number of scientific models have been developed to predict performance on these auditory skills based on diagnostic measures of hearing such as pure-tone audiograms. While these models have significant scientific and research value, they are unable to provide accurate predictions of real life performance on auditory skills necessary to perform hearing-critical jobs. An alternative and more accurate approach has been developed in this research project. A direct measure of functional speech perception in noise (Hearing in Noise Test: HINT) has been identified and validated for use in screening applicants for hearing-critical jobs in DFO. This screening tool has adequate and well-defined psychometric properties (e.g. reliability, sensitivity, and validity) so that screening test results can be used to predict an individual's ability to perform critical auditory skills in noisy environments, with a known degree of prediction error. Important issues must be considered when setting screening criteria. First, the concept of hearing-critical tasks must be reviewed, since these tasks are often performed in high noise levels where normally-hearing people cannot hear adequately. Second, noise-induced hearing loss is frequent in these noisy environments, and workers who acquire a hearing loss might not continue to meet the minimal auditory screening criteria throughout their career. Other senses (e.g., vision, touch) also play an important role in these environments. Third, adaptation strategies have to be considered when recruits or incumbents fail the screening test.
An etiologic paradigm of hearing loss for industrial workers is introduced as having two major components, one being occupational and the other extra-occupational. The extra-occupational factors include age, noise exposure outside the work place, trauma, ear disease and ototoxic drugs. The work-related factors include occupational noise, whole body vibration, work-related diseases and toxic exposures. Within this framework, a review of the epidemiology of hearing loss examines the possible relationships between hearing loss and these factors.
Noise exposure in the sawmill industry is an area of concern. This study documents the level of noise exposure in nine sawmills in the province of Alberta, Canada.
Personal noise monitoring data were collected in nine Alberta sawmills, in winter and in summer (n = 213). Exposures were considered in light of an estimated "real world" noise reduction rating (NRR) calculation assuming use of conventional hearing protection. Limited comparisons were made with spot area monitoring data.
Only 10% of the personal monitoring measurements were below the Alberta 8-hr exposure limit of 85 dBA. Twenty-seven percent of the personal monitoring measurements were 95 dBA or higher. Worker enclosures played a large role in reducing noise exposure. There were no significant differences between seasons in noise category distributions (P = 0.61). The planermen and planer infeed operators had the highest percentage of personal monitoring measurements 95 dBA or higher (62% and 82%, respectively).
Based on a conservative formula, a risk of excess noise exposure could exist even when wearing required hearing protection due to very high noise levels found in planing operations in sawmills.