Salāmat-i kār-i Īrān (Apr 2006)
Assessment Of Noise Pollution And Its Effects On Stone Cut IndustryWorkers Of MalayerDistrict
Abstract
Background and Aims: Noise is one of the important injurious agents causing hearing loss orvarious incidents. High levels of noise pollution affect workers in stone industries. Iran has theworld second rank in production of 9 million tone stone. There are 1806 stone cutting and 230stone processing units with 6 million tones processing in the country, of them 22 stone cutting and3.2 percent of stone processing units are located in Hamedan province.Method: In this survey 10 stone cutting units of Malayer district were chosen. Noise pollutionwas measured by sound level meter (model 2230 B&K). General noise using grinding method andworker posture was measured. One octave band frequency analyzing was measured in 21 stations(more than 85 dBA). Equivalent levels (leq) and Noise Induced Hearing Loss (NIHL) werecalculated for 40 workers in the units.Results:Average leq was 91.1 dBA (SD: 5.5) and mean work experience was 10.9 (SD: 5.5)years). Regression analysis showed a significant correlation between NIHL and Leq (8hr)(p<0.05). NIHL and work experience was also correlated (P< 0.05). Granite stone industriesoctave band noise analysis had a major SPL in high frequency while other industries had lowfrequency.Conclusion:NIHLresults in this study revealed minimal loss; however, the workers did not havelong experience. Asevere hearing loss in subsequent years is expected. Selection of acousticabsorbers for stone cutting units should be considered.
