Pilot study on assessment of trace metals in PM10 at road sites in Bac Giang province, Vietnam

In this study, characterization of PM10 mass and its trace metals concentration at road sites in Bac Giang province located in the North of Vietnam during two different seasons has been performed. PM10 samples at 11 road sites using the high volume SIBATA HV-500R (Japan) at the flow rate of 400 L/min were collected during 10 hours (from 7:00 to 17:00) at flat low-lying plain, midland, mountain and highland areas. Data on PM10 mass and metals were used to estimate the pollution level of PM10 and trace elements bounded with PM10. The results showed that 10-hour mean PM10 concentrations at road sites in Bac Giang ranged from 103.4 µg/m3 to 577.9 µg/m3 with the average value of 292.6 µg/m3. Generally, the level of trace metals appeared to be higher in autumn than that in summer period. Additionally, concentrations of trace metals were higher at the sites with high traffic density than those with low traffic density. While the concentrations of Cd, Mn and Cr exceeded the guideline values of WHO, arsenic concentration was larger than the concentration limit of EU Directives. The degree of contamination values suggested that level of metal was high contamination at flat low-lying plain, while those values were from low to considerable contamination at the mountain and highland areas. The pollution load index values at most of sampling sites were larger than 1, which indicated the existence of dust pollution at road sides in Bac Giang province. Keywords: PM10; trace metals; degree of contamination; pollution load index, roadsides.