Lead salts are an emission product from mobile (or automotive) emission sources due to the addition of tetraethyl lead to gasoline. Because of known toxic properties of lead salts, it has been proposed that alkyl manganese compounds be substituted as a fuel additive for tetraethyl lead. With the introduction of platinum and palladium in the catalytic converters of 1975-model year vehicles, it is of concern to determine the quantities of platinum and palladium metal and salts which will be in emission products and the biological effects of these compounds on mammalian tissues. Various parameters of toxicity have been studied for salts of manganese, lead, palladium, and platinum. Acute toxicities (LD-50 doses) are reported for both intraperitoneal injection and oral administration. Concentrations of metallic ions following dietary administration are reported, as are effects on weights of five organs (liver, kidney, spleen, heart, testes). Also following dietary administration, hepatic microsomes were isolated and the following parameters related to in vitro drug metabolism were measured, yield of microsomal protein/g liver, in vitro activities of aniline hydroxylase and aminopyrine demethylase, content of cytochromes P-450 and b5/mg microsomal protein. Development of a rapid and convenient method for the analysis of ribosomal RNA in studies of RNA synthesis is reported.

"January 1976." Contract No. 68-02-1205. Microfiche.