Early detection of emerging persistent perfluorinated alkyl substances (PFAS) along the east coast of India

Abstract

Perfluorooctanoic acid (PFOA) and Perfluorooctane sulfonate (PFOS) are resistant to breakdown and are now considered global contaminants. However, interest in these recalcitrant compounds among scientists and legislators has grown significantly in recent years. In the present study, we analyzed the level of PFOA and PFOS contamination in surface water from the coastal regions of Tamil Nadu and West Bengal. After solid phase extraction, 49 samples were analyzed by liquid chromatography coupled with mass spectrometry (LOD ≤ 1.5 ng L⁻¹). The PFOA and PFOS present in all samples at the highest concentration were found in the Ennore coastal region (reaching a maximum of 24.8 ng L⁻¹ and 13.9 ng L⁻¹ in CH-6 and CH-14 respectively). Similarly, on the West Bengal coast, concentrations of PFOA ranged from <1.5 to 14.0 ng L⁻¹ and <1.3 to 8.2 ng g⁻¹ in water and sediment respectively. PFOS concentrations in water and sediment ranged from <1.2 to 9.0 ng L⁻¹ and <1.2 to 7.9 ng g⁻¹, respectively. According to the principal component analysis, the majority of the variances (65.04 %) show a positive association, which points to industrial and domestic discharges as significant point sources of these compounds. The results from this study could be used to determine and understand the levels of PFOA and PFOS contamination along the Indian Coast as well as provide baseline information for imminent monitoring investigations. The environmental occurrences of PFOA and PFOS reported in the current study would allow policymakers to take appropriate measures to safeguard coastal ecosystems or reduce the likelihood of contamination, creating a sustainable and healthy environment.