Abstract
A study of blood lead levels and intelligence, reading, and behaviour problems was carried out using a sample of 579 Dunedin 11-yr-old children. The results suggested that when account was taken of social, environmental, and background factors, raised blood lead is associated with a small but statistically significant increase in children's general behaviour problems as reported by both parents and teachers. These results applied especially to the more specific problems of inattention and hyperactivity.