THE TEMPORAL VARIABILITIES IN THE CONCENTRATIONS OF AIRBORNE LEAD ANDITS RELATIONSHIP TO AEROSOL BEHAVIOR

We have made routine measurements of the mass-particle size distributi ons of airborne particulate matter (PM) and the associated lead (Pb) c oncentrations from our sampling station at the Kyung Hee University-Su won campus in Korea during November 1989 to September 1994. The monthl y Pb concentration data for the entire campaign periods varied extensi vely, 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 o f temporal trends in Pb distribution behavior indicate several interes ting 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 ver y systematic and cyclic pattern that can be characterized as: a gradua l decrease in concentrations across winter, spring, and summer and a m oderate change after summer. A statistical analysis of our Pb data ind icates the existence of generally enhanced correlations between Pb and most of environmental variables investigated concurrently. The Pb dat a generally exhibited strong inverse correlations with such environmen tal variables as temperature, relative humidity, and the amount of pre cipitation on one hand but positive correlations with wind-related par ameters like the frequency of calmness on the other hand. Through a co mparative analysis of our Pb and PM concentration data as well as thei r individual relationships with various environmental variables, we we re able to distinguish both similarities and differences between the g eochemical distribution behavior of Pb and PM in the atmosphere. (C) 1 997 Elsevier Science Ltd.