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.
References
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).
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.
Disclaimer
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