Low Lead Levels and Behavior Problems in Children

Abstract

Children who survive lead poisoning are at risk for severe behavioral disorders resulting from damage to the central nervous system. Recent resarch has suggested that among children with lead levels below those associated with overt lead poisoning, behavioral disorders may also occur. The present study was undertaken to investigate possible relationships between lead levels and behavioral problems in children. Lead levels taken from hair samples in a group of children (N = 26) having behavioral problems as defined by teacher judgment were compared with lead levels taken from hair samples in a control group (N = 29) not having behavioral problems by teacher judgment. Subjects were drawn from the Upper Cumberland Region of Tennessee. There were no significant differences between the groups in socioeconomic status, sex, or ethnic group distributions. Mean age in the behavior problem group was 10.73 and in the controls, 8.68. Hair samples taken from the participants were analyzed for mineral content by induction-coupled plasma spectroscopy. Each child was also rated by his classroom teacher on the Walker Problem Behavior Identification Checklist (WPBIC). The group of behavior problem children had significantly higher hair lead levels (t = 3.37, 53, p < .001). Correlations were run between lead levels and WPBIC ratings for the 55 children. Lead levels correlated significantly and positively with the WPBIC scales measuring distractibility, aggression, disturbed peer relations, and immaturity. It was concluded that a continuing reexamination of lead poisoning levels is needed because lead levels previously thought harmless may be associated with neurobehavioral impairments.