National Estimates of Blood Lead Levels: United States, 1976–1980: Association with Selected Demographic and Socioeconomic Factors

Data from the second National Health and Nutrition Examination Survey showed that 22 per cent of persons six months through 74 years old had blood lead levels under 10 μg per deciliter; 1.9 per cent had elevated levels (≥30 μg per deciliter [≥1.45 μmol per liter]). Among children six months through five years old the prevalence of elevated levels was significantly higher (4 per cent) than previously predicted on the basis of fewer data. The prevalence of elevated lead levels was 12.2 per cent in black children and 2.0 per cent in white children. Mean levels of blood lead were higher in blacks than whites among children and adults, among young children living in urban and rural areas, and among members of low-income, moderate-income, and higher-income families. These racial contrasts may reflect different lead exposure or absorption (or both). Young children from families (both white and black) whose incomes were under $6,000 had a significantly higher prevalence of elevated lead levels than those from households with incomes of $6,000 or more. (N Engl J Med. 1982;307:573–9.) Undue exposure to lead and lead toxicity, particularly among young children, have remained public-health problems for decades. 1 , 2 During the 1970s several revisions were made in designating the level of blood lead deemed important in programs designed for the screening, diagnosis, treatment, and follow-up of children with undue lead absorption and lead poisoning. 3 4 5 These changes in diagnostic criteria reflected an increased awareness of the extent to which health can be affected by lead exposure. Previous estimates of the prevalence of undue lead absorption among high-risk pediatric age groups ranged from greater than 40 per cent in some cities 6 during the mid-1960s . . .