Characteristics of Heavy Metals in the Ambient Tsp on Mist and Clear Days

Abstract:

This study compared heavy metal characteristics in the ambient total suspended particulate (TSP) collected from a downtown area and an industrial area on clear and mist days. The TSP samples were collected from January to December of 2007. 5-day continuous samples, based on 24 hr sampling, each month were obtained using a high volume air sampler with glass fiber filters. Heavy metals in TSP samples were ultrasonically extracted using a mixed acid solution of HCl and HNO3 (1:1). The components of heavy metals were identified using inductively coupled plasma–optical emission spectrometer (ICP-OES). The concentrations of TSP on clear days were ranged from 25 to 119 μg/m3 with an average of 62 μg/m3 at the downtown area and from 41 to 131 μg/m3 with an average of 73 μg/m3 at the industrial area. The concentrations of TSP on mist days were ranged from 85 to 184 μg/m3 with an average of 130 μg/m3 at the downtown area and from 104 to 179 μg/m3 with an average of 141 μg/m3 at the industrial area. The concentrations of most heavy metals in TSP from both the downtown and the industrial areas on mist days were much higher (ranging from 1.5 to 2.5 times) those on clear days. In particular, Pb concentrations on the mist days were as high as 2.4 and 2.6 times at the downtown and the industrial areas, respectively, as compared those on the clear days. However, Cu concentrations on the mist days were almost similar to those on the clear days both at the downtown and the industrial areas. Cr concentrations on the mist days were slightly higher than those on the clear days; 1.3 and 1.1 times at the downtown and the industrial areas, respectively. In analysis of correlations among concentrations of TSP and heavy metals, the clear days showed higher correlations than the mist days at both the downtown and industrial areas.

Keywords: TSP, heavy metals, correlation, mist day, clear day