Non-orebody sources are significant contributors to blood lead of some children with low to moderate lead exposure in a major lead mining community.

High precision lead isotope ratios in blood from 58 children aged 1-11 years from the Broken Hill lead mining community have been measured to determine the source and pathways of lead in their blood. Sources of lead are from the Pb-Zn-Ag orebody (lead), from paint and from petrol. Thirty-five of the 58 children (60%) had blood leads (PbB) > or = 0.72 micromol/l (15 microg/dl), the current level of 'personal exposure and source remediation/abatement' compared with a 'background' level of approximately 0.29 micromol/l (6 microg/dl), estimated from adult females who were generally mothers of the children. Six of 17 children aged 7 years or older, had PbBs > or = 0.72 micromol/l (15 microg/dl). Even though the orebody lead is the major contributor to PbB in Broken Hill children, of the 35 children whose PbB is > or = 0.72 microm/l (15 microg/dl), 12 (34%) have approximately 50% or more of their PbB derived from sources such as paint and petrol or both by isotopic identification. The identification of elevated PbB in older children is a concern, especially for females, as there is potential for release of endogenous lead during pregnancy and lactation.