Lead Poisoning: From Screening to Primary Prevention

Knowledge of the extent and seriousness of childhood lead poisoning has vastly expanded since the last statement regarding lead poisoning by the American Academy of Pediatrics in 1987.1 Blood lead levels once thought to be safe have been shown to be associated with IQ deficits, behavior disorders, slowed growth, and impaired hearing.2 In fact, lead poisoning is, according to the Department of Health and Human Services, "the most important environmental health problem for young children."3 The rapid development of the scientific database requires recognition by physicians of the significance of effects at lower levels and a change in clinical practice. During the last 30 years the Centers for Disease Control and Prevention (CDC) has revised downward the definition of the blood level at which lead poisoning occurs from 60 µg/dL whole blood in the early 1960s, to 30 µg/dL in 1975, and 25 µg/dL in 1985. The 1991 CDC statement "Preventing Lead Poisoning in Young Children" recommended lowering the community intervention level to 10 µg/dL and setting several action levels (Table 1).2 In 1987 the American Academy of Pediatrics stated that lead levels greater than 25 µg/dL were unacceptable for children.1 The Academy now recognizes that impairment of cognitive function begins to occur at levels greater than 10 µg/dL, even though clinical symptoms are not seen. In the late 1970s, the average blood lead level for US children was 16 µg/dL.4 The mean blood lead level for US children has declined since 1976 due to the phaseout of lead in gasoline5 and the reduction of lead in food, and it is now between 4 and 6 µg/dL.6