Monitoring of ambient particles and heavy metals in a residential area of Seoul, Korea.

In this study, ambient TSP, PM10, and PM2.5 in a residential area located in the northern part of Seoul were monitored every other month for 1 year from April 2005 to February 2006. The monthly average levels of TSP, PM10, and PM2.5 had ranges of 71 approximately 158, 40 approximately 106, and 28 approximately 43 microg/m(3), respectively. TSP and PM10 showed highest concentration in April; this seems to be due to Asian dust from China and/or Mongolia. However, the fine particle of PM2.5 showed a relatively constant level during the monitoring period. Heavy metals in PM 10 and PM2.5, such as Cr, As, Cd, Mn, Zn and Pb, were also analysed during the same period. The monthly average concentrations of heavy metal in PM2.5 were Cr:1.9 approximately 22.7 ng/m(3); As:0.9 approximately 2.5 ng/m(3); Cd: 0.6 approximately 7 ng/m(3); Mn:6.1 approximately 22.6 ng/m(3); Zn: 38.9 approximately 204.8 ng/m(3), and Pb: 21.6 approximately 201.1 ng/m(3). For the health risk assessment of heavy metals in ambient particles, excess cancer risks were calculated using IRIS unit risk. As a result, the excess cancer risks of chromium, cadmium, and arsenic were shown to be more than one per million based on the annual concentration of heavy metals, and chromium showed the highest excess cancer risk in ambient particles in Seoul.