An Investigation on Occupational Noise Exposure in Kerman Metropolitan Bus Drivers

Abstract

Noise is one of the major hazardous occupational exposures and one of the occupations at risk is the transportation industry. However, few studies have measured and reported the amount of noise exposure in drivers. In this study, we evaluated noise exposure among the public transportation bus drivers of one major Iranian city, Kerman, southeast Iran. Eighty public transportation buses in the streets of Kerman, Iran in 2010 were randomly sampled during week day business hours and in each driver noise exposure was measured for 10 minutes according to the standard methods. The noise exposure was measured in 4 different models of buses. All of the buses were 7 or fewer years old. There was no significant difference in the noise produced by the 4 models. The measurements were similar ranging from 65.9 dBA to 79 dBA. The noise pressure, measured in a range from 31.5 Hz to 8000 Hz, decreased from about 90 dBA to 50 dBA as frequency increased but was below 85 dBA in the speech frequencies. The noise levels measured in these buses for the drivers were under the 85 dBA threshold for speech frequencies, and by sure less than 85 dBA for the passengers; it will probably not cause hearing or other health related problems. However, more studies in this field are suggested.