Importance
The association between lead exposure and children’s IQ has been well studied, but few studies have examined the effects of blood lead on children’s behavior.
Objective
This study examined the association between blood lead concentrations and behavioral problems in a community sample of Chinese preschool children with a mean blood lead level <10 µg/dL.
Design
Prospective cohort study.
Setting
Four elementary schools in Jintan City, Jiangsu Province of China.
Participants
Participants were 1341 children at ages 3–5 years.
Main Outcome Measures
Blood lead concentration was measured at ages 3–5 years. Behavioral problems were assessed using Chinese versions of the Child Behavior Checklist and Teacher Report Form when children at age 6 years.
Results
Mean blood lead concentration was 6.4 µg/dL (SD=2.6), with 75th and 90th percentiles being 7.7 and 9.4 µg/dL respectively. General linear modeling showed significant associations between blood lead concentrations and increased scores for teacher reported behavioral problems. One µg/dL increase of blood lead concentration resulted in a 0.32, 0.25 and 0.30 increase of behavior scores on emotional reactivity, anxiety/depressed and pervasive developmental problems, respectively (p <0.05), while adjusting for parental and child variables,. Spline modeling showed that teacher-reported behavior scores increased with blood lead concentration, particular for older girls.
Conclusions and Relevance
Blood lead concentrations, even at mean levels of 6.4 µg/dL, were associated with increased risk of behavioral problems in Chinese preschool children, including internalizing and pervasive developmental problems. This association showed different patterns depending on age and gender.