[Assessment of bus drivers' exposure to respirable particles [PM10] in Sari]

ABSTRACT

High concentrations of respirable particles may cause high incidence of respiratory diseases and mortality in public populations and in particular in public transportation workers. Epidemiological exposure studies showed that respirable particles that emitted from traffic sources have more potential effects on more incidence of hospitalization or mortality caused by cardiovascular diseases. In this study personal exposures of bus drivers to respirable particles [PM10] and factors that caused high personal exposure were studied in Sari city. In this study, a calibrated real time monitor [MicroDust Pro] with a personal sampling pump with 2 lit/min flow rate were used to measure Sari's bus drivers personal exposure to PM10 concentrations on 3 main routs. This study was carried out during a one calendar year and all possible effective factors on personal exposure were recorded in a questionnaire. The mean personal exposures to PM10 concentrations among bus drivers were varied in different months. Exposure to PM10 concentrations were higher in autumn and winter and increased to 300 micro gm[-3] in some days. Personal exposures to these particles were increased in the evening and on high traffic flow routs. Other factors such as rainy weather and temperature, number of passengers, bus' model year, picking up and dropping off the passengers were the most effectiveg factors on driver's personal exposures. Bus drivers' exposure to respirable particles PM10 in Sari was varied in different time. It was due to entrance of outdoor particulate air pollutants into the bus during the picking up and getting off the passengers and resuspension of settled fine particles