DEVELOPING HEARING CONSERVATION PROGRAM FOR ROLLING STOCK PLANT WORKERS

Sliwinska-Kowalska M (1,2), Zamojska M (1), Dudarewicz A (1), Kotylo P (1), Pawelczyk M (1), Pawlaczyk-Luszczynska M (1).

(1) Nofer Institute of Occupational Medicine, Lodz, Poland; (2) Medical University of Lodz, Poland.

Background: The use of exposure limits and the integration of workers in health surveillance program are nowadays the most efficient international tools in controlling and assessing workplace exposures and preventing their consequences. According to the EC Noise Directive, hearing conservation programs must involve estimation of individual risk for hearing threshold shift as an outcome of complex interaction of external and intrinsic factors.

Aims: The aim of the study was to estimate the individual risk of hearing loss in rolling stock plant workers and to evaluate the need for implementing hearing conservation programs in this industry.

Methods: Noise measurements, questionnaire inquiries, pure-tone audiometry and distortion product otoacoustic emissions were carried out in 123 employees of a rolling stock plant. A questionnaire was aimed at self-assessment of hearing status and identification of occupational and non-occupational risk factors for the noise-induced hearing loss (NIHL).

Results: Based on the results from noise measurements and questionnaire data, the assessment of risk of hearing impairment was performed according to the ISO 1999:1990 standard. Workers under study were exposed to noise at equivalent-continuous A-weighted sound pressure levels from 78 to 97 dB during the period of 1-40 years. Such exposures were associated with increased risk of NIHL. Most respondents (82 %) were aware of exposure to excessive noise and declared usage of hearing protectors (89 %). However, nearly every third worker noticed hearing impairment. Predicted hearing threshold shifts based on the ISO standard were compared to actually measured ones.

Conclusions: Obtained results confirmed the need to implement the hearing conservation program in the rolling stock industry. The details of the program will be presented.

E-mail: marsliw@imp.lodz.pl