Early asymptomatic lead exposure and development at school age.

Sixty-seven 7-year-old children, who had asymptomatic lead exposure between 1 and 3 years of age, were compared in their performance on a series of psychologic tests to 70 children of the same age and socioeconomic background who presumably did not have significant exposure to lead. Exposed children had deficits in global IQ and associative abilities, in visual and fine motor coordination, and in behavior. School failure due to learning and behavior problems was more frequent in the lead exposed than in the control group.