Blood lead levels and behaviour of 400 preschool children

A study of 400 Sydney children of preschool age has found a range of blood lead levels from 0.1 mumol/L to 1.4 mumol/L (2 micrograms/100 mL to 29 micrograms/100 mL), with no children having readings above the currently accepted "level of concern". Within the Sydney metropolitan area, a significant inverse relationship was found between blood lead level and distance of the home from the city centre. Within the range of blood lead levels, no relationship appeared between blood lead levels and performance in verbal intelligence test, three of the tests of motor ability, and a parent rating. In one of the tests of fine motor coordination, there was a tendency for the children with lower lead levels to perform better than those with moderate blood lead levels. In one of the tests of gross motor skill, the results for the two age groups were conflicting. Further studies of a prospective nature covering the period of maximum vulnerability (0 to three years) are essential before any conclusion can be drawn about the effects of subclinical blood levels of lead.