Schoolchildren may be having their emotional and intellectual growth stunted by low levels of lead in the environment, according to a report in the Archives of Disease in Childhood.
Researchers at Bristol University has found that blood-lead levels regarded as below the safe threshold are still having an effect.
They used samples from 488 children aged 30 months who were taking part in the Avon Longitudinal Study of Parents and Children (ALSPAC).
The current safety threshold is 10 micrograms per decilitre. The World Health Organisation estimates that half of urban children under five world-wide have blood lead above this level.
The Bristol team writes that ‘blood-lead levels show significant associations with reading, writing and spelling grades, on SATs and antisocial behaviour.
‘Children are more at risk following exposure to lead because it is more easily absorbed by their growing bodies, and because their tissues are especially sensitive to damage.
‘While adults absorb an average of 10-15% of an ingested quantity of lead, this amount can increase to 50% in infants and young children.’
They cite lead found in water pipes, soil, dust, pottery and toys, as well as herbal and traditional remedies, paint, ethnic make-up, children’s bead necklaces and Christmas lights.