Occurrence and potential environmental risk assessment of alkylphenols and bisphenols in surface water collected in rivers flowing through Bac Ninh, Vietnam

ABSTRACT In recent decades, increasing attention has been directed toward the effects of alkylphenols and bisphenols due to their demonstrated endocrine-disruptive effects. This study investigated the occurrence and potential risk assessment of two alkylphenols and seven bisphenols in surface water collected from rivers (Cau River, Duong River, and Thai Binh River) flowing through Bac Ninh province, one of the pivotal economic regions in the North of Vietnam. The results demonstrated that these compounds were widely distributed in the rivers. The average concentrations were ranked as follows: 4-tert-octylphenol (4-t-OP) (91.2 ng/L) > 4-nonylphenol (4-NP) (78.9 ng/L) > bisphenol S (BPS) (72.4 ng/L) > bisphenol A (BPA) (5.6 ng/L) > bisphenol F (BPF) (below method detection limit) with detection frequencies of 100% (except for BPF of 23%). The presence of alkylphenols and bisphenols in aquatic environments closely correlates with anthropogenic activity. The environmental risk assessment was carried out based on the Risk Quotient (RQ) evaluation, indicating that 4-NP poses medium risk in all three rivers. In addition, 4-t-OP, which is more toxic than 4-NP, poses high risk to aquatic organisms in the Duong River (RQ = 1.1), while BPA and BPS show low risk to aquatic organisms in three rivers (RQ < 0).