Effect Of Excessive Noise Exposure On Granite Factory Workers

BACKGROUNDMany workers are exposed to noise in their work places, where its level exceeds the permissible level of 90dB (A). Noise Induced Hearing Loss (NIHL) is an increase in threshold of hearing, which first appears in high frequencies, then expands to speech frequencies. Pure tone audiometry is done to assess for any auditory disorder. Factory workers are unaware that they are vulnerable to hearing loss, which has no obvious symptoms. It is necessary to provide information of the future risk to these workers. Hence this study is done to analyze the effect of noise exposure on granite factory workers in Kolar district.AIMS AND OBJECTIVES1. To assess the quality of hearing by a questionnaire in granite factory workers who are exposed to continuous noise.2. To determine the prevalence of hearing loss in these workers.MATERIALS AND METHODSEighty five granite factory workers in the exposed group and eighty five administrative workers in the unexposed group were selected considering the inclusion and exclusion criteria. Taking written informed consent, they were assessed by the questionnaire for the quality of hearing. The auditory thresholds of both ears were recorded using pure tone audiometer and plotted on an audiogram. The resulting data was statistically analyzed.RESULTSNoise levels in granite factories were higher than the accepted sound levels; 11% of the exposed group perceived their hearing to be significantly low; 44% had difficulty in hearing over phone and in a crowd; 35% had to keep their TV volume loud and conversed loudly; and 33% had history of tinnitus compared to none in the unexposed group. Exposure to continuous noise showed higher hearing thresholds in both the ears at 4000Hz and 6000Hz compared to the unexposed population.CONCLUSIONWe have found that the granite factory workers were exposed to sound levels as high as 105dB (A). The workers had an increase in auditory thresholds at 4000Hz and 6000Hz. Thus it is suggested to implement the use of personal protective equipments like ear plugs or ear muffs. Periodic health checkups and workshops should be carried out to motivate the subjects for regular usage and duty scheduling has to be done for exposure limitation.