Abstract

Aims: Tractors are one of the most important sources of noise exposure in agriculture. This study aimed to investigate noise exposure in Romanian tractor drivers and bystanders' when it's operating at different engine speeds and gears. Methods: This cross-sectional study was carried out on Romanian tractor (M-650) available in agriculture college field of Bahonar University of Kerman in 2011. According to international standards a 20m×3m field was chosen and then the noise levels for two positions, the driver's ear and bystanders, were measured in two conditions, static (neutral) and moving (at different gears and engine speeds). To define the characteristics of the tractor's noise, frequency analysis was also performed. Data analysis was done by descriptive statistical methods using Excel software. Results: While working in place, bystanders near the exhaust had the highest noise exposure and an increase in motor speed from 850 to 1700 rounds per minute led to an increase in noise for the driver's ear from an average of 5.8 to 9.3db and for the bystanders from an average of 2.3 to 10.3 db. The mean sound level at lower frequencies was higher than middle and high frequencies. Conclusion: When the tractor is moving, at 850 rounds per minute the driver's exposure to noise in all gears is less than standard, but at 1700 rounds per minute the noise level is higher than the Iranian and ACGIH standard and controlling measures seems to be necessary.