ABSTRACT
The best method of assessing occurrence and distribution on a national scale is through national and multistate monitoring studies, but only five have been done in the United States since the 1960’s and none of these covered the entire nation. Occurrence and geographic distribution of pesticides in air and rain, and the relation between the measured air concentrations, detection frequencies, and national use can best be examined by comparing results from individual national and multistate occurrence studies to national pesticide use patterns. The greatest intensity of studies that focused on organochlorine compounds in the atmosphere has taken place in the Great Lakes region since the 1960’s. Many types of herbicides other than the triazines and acetanilides are used in agriculture. Many of them have been detected in air and rain throughout the United States and elsewhere. Data are adequate for assessing long-term trends only for organochlorine compounds, and most data are for the Great Lakes region, Canada, and the Arctic.
