Exposure of drivers and conductors to noise, heat, dust and volatile organic compounds in the state transport special buses of Kolkata city.

This paper studies work exposure of drivers and conductors of special state buses in Kolkata, India to noise, heat, respirable dust and volatile organic compounds (VOCs). Equivalent noise exposures of drivers at work and in-bus noise are evaluated using a precision noise level meter. Thermal conditions like wet bulb globe temperature, relative humidity, and dry-bulb temperature were measured while plying through different traffic routes. Personal sampling techniques are adopted for dust and VOC monitoring and gas chromatography with flame ionisation detector was used to estimate VOCs. Drivers' exposure to noise depended on the number of trips performed per day and exceeded the recommended American Conference of Governmental Industrial Hygienists' threshold limit value, mostly after a second trip. The WBGT index revealed strenuous conditions for the working group. Mean dust exposures for drivers and conductors were found to be much higher than the level proposed in the notice of intended changes of ACGIH TLV (1995-96) for diesel particulate matter. Exposure to benzene, toluene, and xylene exhibit higher results than reported elsewhere. (Author/publisher).