Dissolved and particulate phase phthalic acid esters in urban, suburban, and rural riverine catchments along the southeast coast of India after the COVID-19 pandemic.

Dumped waste plastics have been evidenced as a potential source for harmful chemicals along the riverine regions of India. Furthermore, Corona Virus Disease - 19 (COVID-19) pandemic resulted in a subsequent surge in the use of personal protective equipment (PPE) related single-use plastics and Tamil Nadu was India's second major waste generator. Given the newer challenges from dumped waste plastics along the four major rivers of Tamil Nadu emptying into the Bay of Bengal, we investigated thirteen phthalic acid esters (PAEs), in both dissolved and particulate phases of river water and drinking water samples. ƩPAEs in both phases followed the urban > suburban > rural catchment trend. Di (2-ethyl hexyl) phthalate (DEHP) was ubiquitous in both phases and the sites having a prevalence of open burning activities in the urban catchment showed elevated levels. The suburban and rural catchments of the Kaveri River (KR) and Thamirabharani River (TR) were predominated by DEP and DEHP. It is noteworthy that in the urban catchment, Ln (DiBP) and dissolved organic carbon (Ln DOC), were strongly correlated (R = 0.894, p < 0.05). Furthermore, a significant increase of DiBP (p < 0.05) in the urban catchment after the second phase of the pandemic most likely resulted from the wide use of DiBP in PPE plastics. Community-stored water from urban catchment was found to have a maximum of ∑PAEs up to 3769.38 ng/L in the dissolved phase with elevated DMP concentrations leading to higher estrogenic equivalent. The average daily intake for dissolved phase PAEs was below the USEPA-recommended limit for drinking water. However, prolonged exposure to heavier PAEs in particulate matter cannot be ignored. Estimated ecotoxicological risk assessment showed the highest risk for fish species due to DEHP.