Occurrence, fate and ecological risks of phthalate esters and bisphenol A in coastal wastewater discharges

This study examines the occurrence and ecological risks of phthalate esters (PAEs) and bisphenol A (BPA) in raw urban wastewater from Bushehr, a coastal city in the northern Persian Gulf. PAEs, used as plasticizers, and BPA, found in various consumer products, are endocrine disruptors that pose environmental and health threats. The research evaluates the concentrations, distribution, and sources of these pollutants and assesses their ecological risks. Wastewater samples were collected from six discharge stations along the Bushehr coastline between February and April 2023. Using gas chromatography-mass spectrometry (GC-MS), seven PAE compounds, including dimethyl phthalate (DMP), diethyl phthalate (DEP), diisobutyl phthalate (DIBP), dibutyl phthalate (DBP), benzyl butyl phthalate (BBP), bis(2-ethylhexyl) phthalate (DEHP), and di-octyl phthalate (DOP), alongside BPA were analyzed. DEHP emerged as the dominant PAE, with concentrations ranging from 19.67 to 39.75 µg/L, while BPA levels ranged from 0.10 to 2.50 µg/L, peaking at Rishehr Park. Ecological risk assessment, conducted using the risk quotient (RQ) method, revealed that DEHP posed a high ecological risk (RQ > 1) to sensitive aquatic species. These findings highlight the urgent need for improved wastewater treatment and pollution control to safeguard marine ecosystems and public health. The study contributes valuable insights into the contamination levels and sources of PAEs and BPA in the northern Persian Gulf, advancing the understanding of regional marine pollution and its ecological impacts.