Study on joint effect of welding fume and noise on hearing impairment

ObjectiveTo evaluate the joint effect of welding fume and noise exposure on hearing.MethodsThe audition test was conducted among three groups of workers,including 65 workers exposed to both weding fume and noise environment,59 workers only exposed to noise and 55 unexposed workers.ResultsThe incidence of hearing impairment in joint group was 61.54%.The high-frequency threshold,speech hearing threshold,hearing impairment level Ⅰ,Ⅱ,Ⅲ and above hearing loss rates were 60.00%,35.38%,16.92%,23.08% and 20.00%,respectively.All differences between the joint group and the control group were statistically significant(P<0.05).Comparing the mean of hearing threshold in each group at different frequency band,the threshold of audibility on 0.5,1,2,3,4,6kHz was 22.98±6.28dB(A),21.38±7.88dB(A),22.04±10.19dB(A),26.55±16.69dB(A),31.52±18.86dB(A)and 33.75±19.71dB(A),respectively.The threshold of audibility on 0.5,1,2,3,4,6kHz was significantly increased in the joint group than those in noise group and control group(P<0.05).ConclusionWelding fume and noise exposure might increase hearing impairment in workers.