The proposed research is designed to elucidate the routes of environmental and bodily transport of chlorinated hydrocarbons, with emphasis on the molecular aspects of these transport processes. As a result of their low water solubilities chlorinated hydrocarbons are frequently associated with suspended particulate matter. We will investigate the rates of cell membrane uptake of CH off particulates with emphasis on: 1. The effects of chemical composition of the particles on the rates of cellular uptake of the CH and 2. Those factors which govern and limit membrane uptake of CH off particles. After uptake by organisms, the transport of CH is likely to be mediated by blood components. Hence, we will examine: 1. The role of erythrocytes, albumin, and the serum lipoproteins in binding of transporting chlorinated hydrocarbons in the blood and 2. The role of these blood components in delivering the CH to cell membranes. The CH investigated will include representative examples from those commonly used in industry and agriculture: 2,4-D 2,4,5-T dioxin, polyhalogenated biphenyls, aldrin, dieldrin, lindane, DDT, DDE, and/or other closely related molecules. Some aspects of methylmercury transport will also be studied. The particulates investigated will include silicates and clays, such as kaolinite and montmorillonite, asbestos particles, such as chrysotile and anthrophyllite, organic particles like carbon black, and natrural particles, such as lignand and algal cells. For these investigations, we will rely primarily on a newly developed fluorescence quenching methodology. In this laboratory we have already demonstrated this method to be applicable to most commonly used chlorinated hydrocarbons and most types of particulate matter. We also intend to extend the range and usefulness of our quenching method by synthesis of labeled phospholipids which contain a superior fluorophore.