Phenolic endocrine-disrupting compounds in the Xiangjiang River: occurrence and risk assessment

The levels of three phenolic endocrine-disrupting compounds (EDCs), NP, BPA and 4-t-OP were determined in water and sediment collected from sites along the Xiangjiang River, Zunyi, China. The NP, BPA and 4-t-OP concentrations ranged from 18.02 to 311.79 ng/L in the surface water, 16.04-408.12 ng/L in the submerged water, and 21.13-892.37 μg/kg dw in the sediment. NP contamination was most severe in both the river water and sediment. The ranges of the three phenolic EDCs were slightly greater in the submerged water than in the surface water (p > 0.05). The concentrations in the middle reaches were greater than those in the upstream and downstream reaches in both the water and sediment, and significant differences in content were detected in some reaches. The levels of three phenolic EDCs in the water and sediment had a positive correlation. In addition, the distribution coefficient (K_d) indicated that NP was more likely to adsorb to the sediment, and BPA and 4-t-OP were more likely to adsorb to river water. Moreover, the risk quotient (RQ) and hazard quotients (HQ) were used to reveal the environmental and health risks caused by coexposure to the three phenolic pollutants. The results showed that the current pollution is a threat to the environment of the study area and not a threat to the health of the local population.