The Yugoslavia Prospective Lead Study: contributions of prenatal and postnatal lead exposure to early intelligence

To investigate associations between the timing of lead (Pb) exposure on ear ly intelligence, we examined the results of psychometric evaluations at age s 3, 4, 5, and 7 years, from 442 children whose mothers were recruited duri ng pregnancy from a smelter town and a non-lead-exposed town in Yugoslavia. We compared the relative contribution of prenatal blood lead (BPb) with th at of relative increases in BPb in either the early (0-2 years) or the late r (from 2 years on) postnatal period to child intelligence measured longitu dinally at ages 3 and 4 (McCarthy GCI), 5 (Wechsler Preschool and Primary S cale of Intelligence-Revised, WPPSI-R IQ), and 7 (Wechsler Intelligence Sca le for Children-version ITT, WISC-III IQ), controlling for: Home Observatio n for Measurement of the Environment (HOME) quality; maternal age, intellig ence, education, and ethnicity; and birthweight and gender. Elevations in b oth prenatal and postnatal BPb were associated with small decrements in you ng children's intelligence. (C) 2000 Elsevier Science Inc. All rights reser ved.