Locally produced chicken eggs-a source of dietary lead for an Australian community living with an active lead...

The South Australian regional city of Port Pirie has a long history of environmental lead contamination caused by smelting operations that have resulted in elevated blood lead levels in local children. This study examines the potential exposure of children to lead as a result of consuming eggs produced by domestic chickens kept in a lead-contaminated environment. Lead concentrations were measured in eggs, chicken enclosure soil, chicken feed and forage vegetation collected from a domestic site in Port Pirie. Eggs produced in the vicinity of the operating smelter had higher whole-egg lead concentrations (median: 0.09 mg/kg; range: 0.03-0.19 mg/kg) than control eggs (median: 0.002 mg/kg; range: 0.002-0.005 mg/kg). Soil and forage vegetation were identified as potential lead sources for the chickens in this study. The impact of remediating potential lead sources accessed by the chickens was examined and remedial actions were found to be only partly effective with a three-fold reduction in lead concentrations in eggs. Estimated lead intake for a 2-year-old child consuming these eggs indicated that a diet rich in eggs could more than double the child's daily lead exposure from dietary sources. Eggs produced by chickens housed in residential backyards are a readily avoidable additional source of lead exposure for children living in this industrial community, where all environmental lead sources contribute to an unacceptable daily intake.