9321274 Hites The objective of this award is to obtain more comprehensive knowledge than is now available regarding the major sources of chlorinated dibenzo-p-dioxin contaminants of air, water and soil. The global deposition of these compounds that has been estimated to date from analyses of air, sediment and soil is significantly higher than has been determined to be possible by summation of discharges from known sources. The investigator plans on resolving the disparity in this respect by global collection of samples of soil and sediment, analysis of these samples and determination of their significance in establishing a better mass balance than is now known regarding the disparity between deposition from known sources and the presence of these compounds in soil and sediments. Considerable effort is now being made to displace the use of many useful chlorinated chemical compounds from use as a step toward removing or reducing the presence of polychlorinated dibenzo-p- dioxins and dibenzofurans from lakes, soils and vegetation. The expected result of this project is better knowledge regarding the presence, dispersion and flux of these compounds as a step toward determining the extent to which additional control over their sources is necessary. This in turn is expected to provide the basis for any improvements in processes for reducing or eliminating the emission of these compounds into the atmosphere. ***
