The present research studies noise of two different occupational areas in electro-production instruments factories participated in this cross-sectional study, where 54 workers were exposed to this noise. The study was divided into 2 parts with different noise exposure as follows: 1- Factory No. 1 (Metal factory), 2-Factory No. 2 (Metal factory). Measurements of major parameters were carried out in each factory, which included noise measurements such as: maximum and maximum peak sound pressure level (L_(Amax), L_(Apmax)), minimum sound pressure levels (L_(Amin)) and mean equivalent sound pressure levels for 8 h working day (L_(Aeq,8h)), and threshold of hearing. On other hands, minor parameters of age, working years can be estimated. The following effects of the noise exposure levels were observed in different factories: The overall noise level and exposure to noise in factories No.1, No.2 was about 93.9, 90.4. Hearing threshold levels at test frequencies 0.5,1, 2, 3, 4, 6 and 8 kHz were obtained for both ears at different age years and different working years of workers at each factory. According to the World Health Organization (WHO, 1986) shows mild and moderate hearing loss at most of frequencies with different age group. The rate of hearing loss was particularly higher in among workers who reported longer years of working in most of factories. aWorkers showed significantly poorer hearing in the left ear in some factories. Workers did not use hearing protection devices (HPDs) at both factories. It concluded that noise pollution is emerging as an industrial problem, it is clear from the results of this investigation that the hazards of noise exposure in industries in many factories that cause hearing loss as in this study.
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