Exposure to Fine Particles among Bangkok Mass Transit Authority Bus Drivers

Abstract

The exposure of 80 bus drivers to fine particles (PM_2.5), carbon dioxide (CO₂) and carbon monoxide (CO), were monitored for full shift in air - conditioned (A/C) and non-A/C buses on four routes in Bangkok, Thailand. The results revealed that the overall average of PM_2.5 exposure among the non-A/C bus drivers on the four routes (322.01 ± 157.97 mg/m³) was significantly higher than those of A/C bus drivers (208.42 ± 87.41 mg/m³). The average CO₂ concentrations on the four-route A/C and non-A/C buses were 1274.32 ± 245.47 and 463 ± 42.27 ppm, respectively. The CO concentrations in non-A/C buses (2.71 ± 0.93 ppm) were greater than those in A/C buses (1.92 ± 1.22 ppm); significant differences were found only in two of the four routes studied.