Application of arsenical pesticides to orchard fruit trees has led to widespread contamination of soil above regulatory health standards. As former orchard properties are developed for residential use, residual arsenic contamination poses a significant threat to human health. This study demonstrates the use of a portable X-ray spectrometer (PXRF) to analyze soil rapidly at a former orchard in southeastern Pennsylvania. Elevated concentrations of arsenic were detected within the orchard and nearby where pesticides were mixed or dumped. The maximum As concentration recorded was 91 mg/kg, well above the Pennsylvania residential and industrial health standards of 12 and 53 mg/kg, respectively. Statistical analyses revealed that the geometric mean As concentration of 45.5 mg/kg within the orchard was significantly greater than background. Soil profile analysis demonstrated that the greatest As concentrations were present in the top 30 cm of soil, indicating that the metal is relatively immobile at this site. The PXRF is a valuable research tool that could be used to screen former orchard properties before they are considered for future development or to assist during remediation efforts.
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