Workers in noisy coal washeries have been shown to suffer considerable hearing loss. According to one study, 20 per cent of washery workers had mildly handicapped hearing -- hearing loss becomes a handicap when the ability to hear conversational speech is impaired -- while the others developed slight hearing impairment. Among unexposed workers, only 30 per cent developed slight impairment, while the remaining had no significant hearing loss (Indian Journal of Environmental Protection, Vol 12 No 5).

Prolonged exposure to loud noise can cause heart ailments, hypertension, ulcers, insomnia, irritability and the inability to think and perform assigned tasks. The results of the study are not conclusive, but it does suggest noise levels in washeries should be reduced.