ABSTRACT
Interest in the neurobehavioral toxicity of lead has stemmed from accumulating evidence suggesting neurological and psychological deficits in occupationally exposed workers with blood lead levels substantially below 70–80 μg/dl (e.g., Seppalainen, Hernberg, & Kock, 1979) and in school-aged children with levels of 35 μg/dl and less. In reference to the latter, Needleman, Gunnoe, Leviton, Reid, Peresii, Maker, & Barrett (1979) surveyed over 2,000 first- and second-grade children. Those with the highest dentine lead levels showed deficits on several psychometric tests, including IQ. Moreover, teachers' ratings of classroom behavior gave a surprisingly convincing relationship with tooth lead concentration. A subgroup of these children had previous blood lead measurements averaging 35.5 μg/dl. In the same range of blood lead values, decreased IQ scores of similar magnitude have been reported by Yule, Landsdown, Millar, & Urbanowicz (1981) and, more recently, by Winneke, Hrdina, and Brockhaus (1982) and Winneke, Kramer, Brockhaus, Ewers, Kujanek, Lechner, & Janke (1983).
