Dear Ms. Kyriakides,
New research of Lasee et al.1 demonstrates the presence of fluorinated substances in pesticide formulations. After having previously found concentrations of a variety of PFAS substances in soil samples in the site studied (5 fields)2, the author now has been looking for the source of the contamination. In this study 24 members of the very large fluorinated family of PFAS (>4000 substances) were studied in 10 insecticide formulations that were previously used on the site. Perfluorooctane sulfonic acid (PFOS) was found in 6 of the 10 formulations with concentrations ranging from 3.92 to 19.2 mg/kg. PFOS (mg/kg) was found in Abamectin 3.92 ± 0.51, in Novaluron 9.18 ± 0.34, in Mineral Oil (Petroleum oil) 8.64 ± 0.67, in Imidacloprid 13.3 ± 1.4, in Spiromesifen 19.2 ± 1.2, and in Malathion 17.8 ± 0.7. Other members of the family were present at a lower level. PFOS (ng/kg dry soil) in soil was demonstrated in the 5 fields at 698 ± 120, 1150 ± 165, 1720 ± 299, 156 ± 26, 247 ± 14, while the blank value was 0.0. PFAS-contamination was also demonstrated in three samples of foodstuff crops (corn, beans, and peanuts) that were grown on site. Multiple PFAS species were found in soil and plant grab samples beyond what was observed in the insecticides tested (PFOS).