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Current Trends Blood-Lead Levels in U.S. Population

One component of the Second National Health and Nutrition Examination Survey (NHANES II) (1), conducted between 1976-1980, was developed to measure degrees of exposure of the U.S. population to certain toxic substances, including lead. The primary measure of human exposure to this substance is the determination of lead levels in whole blood. The NHANES II sample design is a stratified, multistage, probability cluster sample of households throughout the United States, selected to represent the non-institutionalized U.S. civilian population between 6 months and 74 years of age.

Preliminary analysis suggests that in the 4-year period February 1976-February 1980 there was a 36.7% reduction in the overall mean blood-lead level from 15.8 ug/dL to 10.0 ug/dL. Decreases were found in all races, ages, and both sexes (Figure 6). Further analysis indicates that the reduction was not due to seasonal sampling, income sampling, geographic region sampling, urban vs. rural sampling, laboratory-measurement error, or chance.

The most discernible change in environmental lead sources was the reduced use of lead in gasoline as measured by 3 separate data sets (Figure 7). Figure 8 presents a comparison over the 4-year period of the amount of lead used in gasoline production and the NHANES II mean blood-lead concentrations. The decrease in mean blood-lead levels reflects the decrease in lead used in gasoline production. Reported by National Center for Health Statistics, and Center for Environmental Health (CDC).

Editorial Note

Editorial Note: Although the decrease in mean blood-lead levels was dramatic, the problem of pediatric lead poisoning in the United States has not been solved. In 1980, 502,900 children were reported to have been screened, and 26,500 were identified with lead toxicity (2). The reduction in mean blood-lead levels does mean that the high-risk young children living in environments with high-dose sources of lead (i.e., leaded paint, lead already deposited in dust and soil, etc.) will have a greater margin of safety. If the current downward trend in the amount of lead used in gasoline production continues, that margin of safety is expected to increase.


  1. Plan and Operation of Second National Health and Nutrition Examination Survey, 1976-1980. Washington, D.C.: National Center for Health Statistics, 1977. (Vital and Health Statistics. PHS Pub. No. 81-1317, Series 1-No. 15, Public Health Service, U.S. Govt. Printing Office).

  2. CDC. Annual summary 1980: reported morbidity and mortality in the United States. MMWR 1981:29(54). Note: Technical inquiries should be addressed to Division of

Health Examination and Statistics, National Center for Health Statistics, 3700 East West Highway, Hyattsville, Maryland 20782.

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