Bone lead levels and language processing performance

The relation between bone lead absorption and language processing abilities in 156 randomly selected 11- to 14-year-old boys who were asymptomatic for lead toxicity is examined. Tibial lead concentrations were measured by X-r ay fluorescence spectroscopy. The language processing outcome variables con sisted of the least and most difficult subtests from the Nonword Repetition Task, Competing Language Processing Task, and the Revised Token Test. Part icipants were classified by quartiles according to bone lead concentrations , and analysis of variance and analysis of covariance measured the impact o n language processing scores. Results showed that children in the highest b one lead quartile displayed decreased language processing performance on th e most difficult language processing tasks but not on the easier tasks.