Intellectual and behavioural consequences of low level lead exposure: a review of recent studies.

Recent studies investigating the association between low levels of lead and children's IQ, behaviour and educational attainment are reviewed. The main emphasis is on the methodological issues and problems which face researchers carrying out these cross-sectional epidemiological studies, and in particular the problem of confounding social factors. It is concluded that body lead levels in children do to some extent act as a marker for socially disadvantageous factors, and that when these are controlled adequately, if there are any functional effects due to lead, then these are so small that they cannot be detected with any certainty, and they may not exist at all.