Human exposure to metals in groundwater affected by acid sulfate soil disturbance.

The disturbance and oxidation of sulfidic soils can cause an increase in acidity resulting in the mobilization of high concentrations of metals in groundwater or connected surface water. This is an increasing problem in urban areas of Australia and internationally. We hypothesized that the risks of exposure to contaminated water would be increased by this phenomenon. We undertook a preliminary investigation of human exposure to metals recruiting 27 residents in an acid sulfate soil-affected area, 21 residents using a bore (groundwater) for home-grown produce irrigation, and 6 residents who did not. Participants completed a questionnaire and provided a sample of urine (first morning void), toenails (from all 10 toes), hair, and borewater. Only hair metal concentrations were higher in those using bore water and ranged from below detection (<DL) to 38 mg/kg Al; <DL = 0.07 mg/kg As, 0.02-0.57 mg/kg Cd, 0.19-4.3 mg/kg Pb, 11-160 mg/kg Cu, and 99-280 mg/kg Zn. The data indicate exposure to metals in bore-water users might be occurring and further investigation is warranted even though the concentrations recorded in this study are considered low.