Assessment of the environmental sound level and the noise exposure in a steel Industry

In the steel industry, a wide range of machinery and equipment is used in the manufacturing process, are considered as sources of annoying noise. This study aimed to assess the environmental sound level and the noise exposure in the steel industry. After identifying the sources and characteristics of sound equipment in the production process Measurement of noise level and dosimetry was performed using sound level meter model of Cell.450 and dosimeter model TES-1345. Distribution of noise level in the investigated workshop in form of noise map was provided using AutoCAD software. The rate of hearing loss workers was extracted during three consecutive years. Hearing loss workers were analyzed to the equivalent sound level of exposure and the dose received. 18.5% of measurement stations were in the danger zone. The sound pressure level in the furnace, energy, costing and material workroom was 97.6, 95, 89.7 and 83 dB(A) respectively. Sound pressure level was more than 90dB (A) in the blast furnace, blower and cooling tower units. The average of noise dose in blast furnace, costing, blower, bag filter and cooling tower was 282.8%, 295.1%, 239.9%, 234% and 180.5% respectively. Average NIHL workers in three consecutive years were 12.4, 14.5 and 15.4 dBA, respectively. Noise pollution in blast furnace, costing and blower units is high So that the mean hearing loss of workers has increased to 1.5dB per year. Therefore, appropriate control measures should be taken in these units.