The temporal variabilities in the concentrations of airborne lead and its relationship to aerosol behavior

We have made routine measurements of the mass-particle size distributions of airborne particulate matter (PM) and the associated lead (Pb) concentrations from our sampling station at the Kyung Hee University-Suwon campus in Korea during November 1989 to September 1994. The monthly Pb concentration data for the entire campaign periods varied extensively, spanning from 34 (October 1990) to 526 (February 1991) ng m−3 with the mean ± 1SD of 244 ± 119 ng m−3 (N = 56). Examinations of temporal trends in Pb distribution behavior indicate several interesting features. Whereas its annual trends appear to be affected by the deteriorating conditions of the surrounding environment (e.g. relative Pb enhancement in odd-numbered years), its seasonal trends show a very systematic and cyclic pattern that can be characterized as: a gradual decrease in concentrations across winter, spring, and summer and a moderate change after summer. A statistical analysis of our Pb data indicates the existence of generally enhanced correlations between Pb and most of environmental variables investigated concurrently. The Pb data generally exhibited strong inverse correlations with such environmental variables as temperature, relative humidity, and the amount of precipitation on one hand but positive correlations with wind-related parameters like the frequency of calmness on the other hand. Through a comparative analysis of our Pb and PM concentration data as well as their individual relationships with various environmental variables, we were able to distinguish both similarities and differences between the geochemical distribution behavior of Pb and PM in the atmosphere.