An epidemiological survey was conducted in Houston, Texas on five trace metals in policemen, parking garage attendants, women living near freeways and three control groups of subjects. The controls were mnatched with the exposed groups for covariate information such as age, sex, smoking habits, ethnic background, socioeconomic status, hair color, and education. Each subject was sampled four times for blood, urine, hair, and feces, and these samples were analyzed for lead, cadmium, zinc, manganese, and copper. Lead and cadmium were correlated with airborne exposures but zinc, manganese and copper were not.The second part of this paper deals with a market study of platinum and palladium markets and a design of an epidemiology survey of individuals occupationally and nonoccupationally exposed to these two metals. The market survey shows that although the catalytic muffler will have a major impact on the market, it is predicted that producers can meet these demands. Measurement of Human Exposure to Fuel AdditivesThe most commonly used fuel additive in gasoline powered engines in the United States is tetraethyl lead. There are, however, a number of other fuel additives which may be used in gteater quantities in the future that contain a variety of trace metals such as manganese, copper, and zinc. Other trace elements such as cadmium are present as impurities. It has been shown that trace metals such as these may accumulate in various tissuse and possibly contribute to the incidence of carcinogenic, mutagenic or teratogenic processes.