Noise exposure and hearing loss among tractor drivers in India.

BACKGROUND

Tractors emit high intensity noise and prolonged exposure to high intensity noise causes hearing loss to the drivers.

OBJECTIVE

The aim of this study was to measure noise intensity at the tractor drivers' ear level and hearing loss among tractor drivers.

METHODS

Noise intensity was measured on 6 models of tractors which were operated with 5 different tillage implements. In order to assess hearing loss, audiometric test was performed at 7 frequencies, i.e. 250, 500, 1000, 2000, 4000, 6000, and 8000 Hz, among 30 tractor drivers and 30 control group subjects. All the selected tractor drivers and control group subjects were also interviewed to obtain personal information and noise exposure details.

RESULTS

The tractor drivers were exposed to noise intensity in the range of 91.7-97.5 dB(A). Audiogram analysis shows that the hearing threshold levels were significantly (p < 0.05) higher among the tractor drivers as compared with the control group subjects. The effect was significantly (p < 0.05) more on the left ear as compared with the right ear among the tractor drivers. Increase in age has significant (p < 0.05) effect on the hearing threshold levels on the left ear. Prevalence of high frequency hearing loss was 50% among tractor drivers as compared with 10% among control group subjects. Hearing loss was significantly (p < 0.05) more in the low frequency as compared with the high frequency among the tractor drivers.

CONCLUSION

Indian tractor operators are exposed to high noise levels which may result in hearing loss. It is recommended that hearing conservation programs should be initiated to prevent noise hazards and hearing loss among the tractor drivers.