Investigation on association of occupational noise exposure,duration of work and cumulative noise exposure with hearing loss in textile mill workers

Objective To understand the relationship between hearing loss and occupational noise exposure,duration of work and cumulative noise exposure of workers who exposed to occupational noise in a textile mill.Methods A cross-sectional study was conducted in 60 employees exposed to occupational noise for more than one year from February 2010 to January 2011.Noise level was measured at workplace,their age,gender,duration of work,time for exposure to noise per day,and the number of work day each week were inquired.Cumulative noise exposure was calculated,and worker's hearing ability was assessed.Results The noise levels of 14 positions at workplace were higher than national criteria.28.33% of the workers exposed to occupational noise was diagnosed as hearing loss,and the hearing loss increased with the duration of work(P = 0.043).Both the hearing loss and the severity of hearing loss were significantly and positively associated with cumulative noise exposure,and their P values were 0.021 and 0.013 respectively.Conclusion Long term exposure to occupational noise might induce hearing loss,which implicated that some control measures should be strengthened for improving workers' hearing health.