Identification of the sources of metal (lead) contamination in drinking waters in north-eastern Tasmania using lead isotopic compositions

This study utilises a range of scientific approaches, including lead isotopic compositions, to differentiate unknown sources of ongoing lead contamination of a drinking water supply in north-eastern Tasmania, Australia. Drinking water lead concentrations are elevated above the Australian Drinking Water Guideline (10 μg/L), reaching 540 μg/L in the supply network. Water lead isotopic compositions from the town of Pioneer (²⁰⁸Pb/²⁰⁷Pb 2.406, ²⁰⁶Pb/²⁰⁷Pb 1.144 to ²⁰⁸Pb/²⁰⁷Pb 2.360, ²⁰⁶Pb/²⁰⁷Pb 1.094) and Ringarooma (²⁰⁸Pb/²⁰⁷Pb 2.398, ²⁰⁶Pb/²⁰⁷Pb 1.117) are markedly different from the local bedrock (²⁰⁸Pb/²⁰⁷Pb 2.496, ²⁰⁶Pb/²⁰⁷Pb 1.237). The data show that the lead in the local waters is sourced from a combination of dilapidated drinking water infrastructure, including lead jointed pipelines, end-of-life polyvinyl chloride pipes and household plumbing. Drinking water is being inadvertently contaminated by aging infrastructure, and it is an issue that warrants investigation to limit the burden of disease from lead exposure.