Determinations of blood lead levels among adult workers in the United States were recently analyzed by the National Institute for Occupational Safety and Health (NIOSH) and the National Center for Health Statistics (NCHS); data were collected during the Second National Health and Nutrition Evaluation Survey (NHANES-II). Blood lead levels were significantly higher among adults working in occupations with potential exposure to lead than in occupations without such potential exposures. Cigarette smokers had consistently higher blood lead determinations than nonsmokers, and men had higher levels than women. NHANES II, conducted by NCHS from 1976 to 1980, was a cross-sectional survey of a probability sample of 27,801 persons, aged 6 months to 74 years, who were selected as representative of the total non-institutionalized civilian population of the United States. The survey used medical histories, physicians' examinations, and laboratory tests to collect a broad range of information on health status, including measurements of lead concentrations in whole blood (1). The NHANES-II blood lead determinations were compared with data previously collected during the National Occupational Hazard Survey (NOHS) (2), conducted by NIOSH from 1972 to 1974. NOHS collected information on potential exposures of workers to chemical and physical agents in a probability sample survey of approximately 5,000 workplaces across the United States. These data identified occupations with potential occupational exposure* to lead in the workplace. The results of blood lead determinations among workers, aged 18-74 years, surveyed by NHANES II were divided into two groups: those for persons working in settings previously identified by NOHS as affording potential exposures to lead and those for persons working in settings without such potential exposures. Preliminary results of this comparison indicate that the mean of blood lead determinations for men in the United States with potential occupational exposures to lead (17.9 ug/dL) was significantly greater than that for men without potential occupational exposure to lead (15.5 ug/dL) (p 0.001) (Table 2). Of the male workers with potential occupational exposure to lead, 5.8% had blood lead levels greater than 30 ug/dL. Of male workers without potential occupational exposure to lead, 1.2% had blood lead levels over 30 ug/dL. Hence, 92% of adult men in the United States found in 1976-1980 with blood lead levels over 30 ug/dL worked in occupations that were judged in 1972 to be associated with potential occupational exposure to lead. Because NHANES-II also recorded information on the smoking status of examinees, it was possible to demonstrate that smokers have significantly higher blood lead levels than nonsmokers. This was true for adults of both sexes and for workers with and without potential occupational exposures to lead. Smoking appeared to have an additive effect to the potential occupational exposure to lead in producing elevated blood lead levels. Reported by Surveillance Br, Div of Surveillance, Hazard Evaluations, and Field Studies, National Institute for Occupational Safety and Health, CDC.