Pharmaceutical active compounds in a heavily industrialized and urbanized bay, Eastern China

Bays are transition zones connecting freshwater ecosystems and marine ecosystems, and they are strongly influenced by intensive human activities. Pharmaceuticals are of concern in bay aquatic environments because of their potential threat to marine food web. We studied the occurrence, spatial distribution, and ecological risks of 34 pharmaceutical active compounds (PhACs) in Xiangshan Bay, a heavily industrialized and urbanized area in Zhejiang Province, Eastern China. PhACs were ubiquitously detected in the coastal waters of the study area. A total of twenty-nine compounds were detected in at least one sample. Carbamazepine, lincomycin, diltiazem, propranolol, venlafaxine, anhydro erythromycin, and ofloxacin had the highest detection rate (>= 93%). These compounds were detected with maximum concentrations of 31, 127, 0.52, 1.96, 2.98, 75, and 98 ng/L, respectively. Human pollution activities included marine aquacultural discharge and effluents from the local sewage treatment plants. These activities were the most influential sources in this study area based on principal component analysis. Lincomycin was an indicator of veterinary pollution of coastal aquatic environment, and the concentrations of lincomycin were positively related to the total phosphorus in this area (r = 0.28, p < 0.05). Typical PhACs such as venlafaxine, ofloxacin, norfloxacin, roxithromycin, and clarithromycin were significantly and positively correlated with nitrate and total nitrogen (r > 0.26, p < 0.05) based on Pearson's correlation analysis. Carbamazepine was negatively correlated with salinity (r < - 0.30, p < 0.01). Land use pattern was also correlated with the occurrence and distribution of PhACs in the Xiangshan Bay. Some PhACs, i.e., ofloxacin, ciprofloxacin, carbamazepine, and amitriptyline posed medium to high ecological risks to this coastal environment. The results of this study could be helpful to understand the levels of pharmaceuticals, potential sources, and ecological risks in marine aquacultural environment.

Automated summary

This study investigated the occurrence, spatial distribution, and ecological risks of 34 pharmaceutical active compounds (PhACs) in Xiangshan Bay, China. The study found that PhACs were widely detected in the coastal waters of the bay, with at least 29 compounds detected in one or more samples. Marine aquacultural discharge and effluents from sewage treatment plants were identified as the most influential sources of PhACs in the study area.