Chemistry of United States precipitation. Final report on the national precipitation sampling network

Abstract

Atmospheric precipitation washes large quantities of particulate and gaseous materials from air, and thus provides a means of studying contamination of the atmosphere. The relationships between the concentration of constituents in air and their concentrations in precipitation are not known with quantitative certainty. However, it is believed that the concentration patterns of contaminants in precipitation reflect their patterns in air. Moreover, though analysis of precipitation water does not reveal absolute values for air contamination, it does provide a means of monitoring changes in contamination with time. The purposes of the project are: (1) to determine mean benchmark values of contaminants throughout the country; (2) to detect possible trends in these values over long periods of time; (3) to observe seasonal fluctuations and geographical distributions which may reveal the sources of these atmospheric contaminants. 48 references, 27 figures, 5 tables.