فهرست نشریات علمی دسترسی آزاد ایران

After a walk-through survey of existing units in Anzali Steel Ingot factory and the factory work schedule, 21 sampling points were selected in process, office and service units of the factory. Noise map of the factory revealed that in almost 68% of job groups in the factory, daily-averaged noise level is greater than the occupational exposure limit (OEL). Workers in furnace installation, electricity and facility units experienced the highest exposure with a daily exposure of more than 100 dB(A). The NIHL in process units increases between 1.25 and 7.5 dB, annually. The maximum increase has been observed at units whose workers' noise exposure is within 5 dB of the exposure limits, which is due to the lack of use of personal protective equipment (PPE). The daily exposure of the workers, who spend at least 25 % of daily working time in the furnace installation area, is above 100 dB(A), despite regular wearing of earplugs. Due to the ineffectiveness of the exposure time reduction, the best solution for these workers is to increase the noise reduction coefficient of the chamber's walls in the furnace installation unit, installing barriers in the furnace installation open area and increasing the number of chambers. In other process units, full inspection of the regular wearing of the PPE over a period of time is recommended. Thereafter the hearing loss of workers will be checked again and in case of inefficiency, changing the workplace of workers in different process units is recommended to reduce the exposure.