DEVELOPING AND DEPLOYING A FIELD TEST KIT FOR BIOACCESSIBLE LEAD IN SOILS
The first batch of 63 soil samples analyzed by the field test kit ranged from 40 to 50,000 mg/kg total Pb and 10 to 7400 mg/kg leachable Pb. All 25 samples with the color ranking “low” had leachate levels below the EPA standard of 400 mg/kg Pb for safe soil, and 15 of all 18 samples with the color ranking “high” had Pb levels over the EPA standard of 1,200 mg/kg for contaminated soil, though all were above 750 mg/kg. Soil samples measured by XRF in the four Peruvian communities ranged from 20 to 10,000 mg/kg, and identified two hot spots of contamination above 1,200 mg/kg; two towns had no hot spot. Mean soil Pb concentrations ranged from 400-700 mg/kg. Local parents used the field kit to collect approximately 90 samples. Local sampling identified an area of high contamination that was missed by the gridded XRF survey. The test kit results from the field were consistent with those from the laboratory. With further improvements and simplification, we hope the kit can be deployed by individual households on a much larger scale in areas where children are likely to be exposed to Pb through contaminated soil.