Blood lead levels in the US population. Phase 1 of the Third National Health and Nutrition Examination Survey (NHANES III, 1988 to 1991).

Objective: To determine mean blood lead levels and their sociodemographic correlates in the US population.

Design: Nationally representative cross-sectional health examination survey that included measurements of venous blood lead.

Participants: A total of 13,201 persons aged 1 year and older examined during phase 1 of the third National Health and Nutrition Examination Survey (1988 to 1991).

Results: The overall mean blood lead level for the US population was 0.14 mumol/L (2.8 micrograms/dL). Blood lead levels were consistently higher for younger children than for older children, for older adults than for younger adults, for males than for females, for blacks than for whites, and for central-city residents than for non-central-city residents. Other correlates of higher blood lead levels included low income, low educational attainment, and residence in the Northeast region of the United States. National estimates for children 1 to 5 years of age indicate that 8.9%, or approximately 1.7 million children, have blood lead levels 0.48 mumol/L (10 micrograms/dL) or greater. These levels are high enough to be of health concern under 1991 Centers for Disease Control and Prevention guidelines.

Conclusions: The low overall mean blood lead levels demonstrate a major public health success in primary prevention efforts. However, exposure to lead at levels that may adversely affect the health of children remains a problem especially for those who are minority, urban, and from low-income families. Strategies to identify the most vulnerable risk groups are necessary to further reduce lead exposure in the United States.