Bone lead levels and delinquent behavior

Lead exposure may predispose young children to antisocial behavior and delinquency. Researchers asked the parents and teachers of 301 grade-school boys to rate the child's behavior at the age of 7 and 11 using questionnaires that measure antisocial tendencies. The boys were also asked to rate themselves. X-ray fluorescence was used to measure the lead concentration in the boy's bones at the age of 11. Compared to boys with low lead levels, boys with high lead levels were rated by their parents and teachers as more aggressive and as having other problems such as health complaints, attention problems and delinquent behavior. The boys with high lead levels rated themselves as having more behavioral problems. Parents and teachers reported that behavioural problems in boys with high lead levels had gotten worse between the ages of 7 and 11. The association between high lead levels and antisocial behavior remained when the data were adjusted for other social and family factors.