Nationwide distribution and potential risk of bisphenol analogues in Indian waters

Bisphenol A (BPA) has been frequently found in surface waters worldwide, and its estrogenic effects in humans are well documented. Nevertheless, less is known about other bisphenol analogues (BPs), such as bisphenol S (BPS) and bisphenol F (BPF) which are alternative to BPA. There have been few environmental investigations on BPs in developing countries, especially India. In the present study, eight BPs were analyzed, among which BPA, BPS, and BPF were found prevalent in surface water and wastewater from drains collected from 12 states and Delhi-National Capital Territory in India. The detection frequencies of BPA, BPS, and BPF were 67.6%, 41.9%, and 29.7%, respectively in all samples (n = 74). BPA was the predominant species among the three analogues. The highest BPA concentration was observed in the Yamuna River (14,800 ng/L), followed by the Cooum River (1,420 ng/L). The highest concentrations of BPS and BPF were 438 ng/L and 333 ng/L, respectively, both found in wastewater samples. The occurrence of BPS and BPF in nationwide surface water and wastewater samples from India for the first time suggests that new BPs as BPA replacements are being used and released in India. Ecological risk assessment of BPA, BPS and BPF exposure was performed using hazard quotient (HQ) for three aquatic taxonomic groups: algae, crustaceans, and fish, with the last group exhibiting the highest HQs (0.89-148) for BPA exposure. The human exposure risk of BPA through drinking river water was observed negligible in the present study. Our findings indicate the urgent need for, (1) regulations on the use and release of BPs in India, (2) effective processes to remove BPs in wastewater treatment plants, (3) more investigations on the distribution and toxicity of BPs in India, in particular BPA, BPS and BPF, as these analogues were detected at substantial concentration in Indian waters.