Polonium in the Surficial Aquifer of West Central Florida

Analysis of water from shallow wells in west central Florida has revealed the existence of a number of wells with high concentrations of ²¹⁰Po, a radioactive daughter of ²²²Rn. Many concentrations are considerably higher than the Federal E.P.A. maximum contaminant levels for total alpha radioactivity (15 pCi I⁻¹). These high concentrations are surprising in view of the particle-active nature of polonium. Measured ²¹⁰Po activities range from less than 1 to over 500 pCi l⁻¹ in filtered samples and from less than 1 to over 2,500 pCi l⁻¹ in unfiltered samples. Measurements of ²²²Rn showed a range from less than 100 to over 40,000 pCi l⁻¹ and a range of less than 1 to 10 pCi l⁻¹ for the longest lived radon daughter, ²¹⁰Pb. The chemical characteristics of the waters high in polonium suggests a possible association between high ²¹⁰Po activity and acidic waters containing sulfide.