The pilot study obtained preliminary estimates of personal exposures to particulate matter (PM10) and carbon monoxide (CO) while traveling on four major roads in Hanoi, Vietnam. The effect of a few factors, such as mode of transport, route, rushhour, and air-conditioning on the exposure levels were investigated. Investigators carried lightweight portable realtime measurement devices while traveling on buses, cars, mobikes and while walking. They compared the exposures on three ‘hot-spot’ roads with that on a road with less traffic. In all, 96 samples were collected over four consecutive days. The mean value of all PM10 concentrations was found to be 455 ìg m-3 (the new World Health Organization guideline for PM10 is 50 ìg m-3 for 24-hour means, though this is not strictly comparable, because of the longer time duration), with 580 ìg m-3 measured on mobikes, 495 ìg m-3 while walking, 408 ìg m-3 in cars and 262 ìg m-3 in buses. The mean value of all CO concentrations was 15.7 ppm, with 18.6 ppm measured on mobikes, 18.5 ppm in cars, 11.5 ppm in buses and 8.5 ppm while walking (the World Health Organization guideline for CO is 100 ppm for 15-minute means and 50 ppm for 30-minute means). Rush-hour levels for PM10 and CO were found to be higher than during non-rush hour periods.
particulate matter, personal exposure, traffic |
