Occurrence, fate and risk assessment of human and veterinary pharmaceuticals in Hong Kong sewage treatment plants, surface water and fish and in Chinese tap water ; Ren yong he shou yong yao pin zai Xianggang de wu shui chu li chang, di biao shui, yu lei ji Zhongguo zi lai shui de cun zai, su ming ji feng xian ping gu ; 人用和獸用藥品在香港的污水處理廠, 地表水, 魚類及中國自來水的存在, 宿命及風險評估

Pharmaceuticals, together with other personal care products, are collectively known as PPCPs and are regarded as a class of emerging environmental contaminants. In light of their global distribution in various matrices such as sediments and aqueous samples, and the potential threat they pose to non-target organisms, public and scientific awareness of the impacts of post-therapeutic pharmaceuticals has increased over recent decades in western countries. However, information gaps about pharmaceutical contamination and its possible consequences still exist in developing countries where less attention has been given to regulating the release of emerging chemicals. The principal objective of the present study is to investigate the occurrences and fate of pharmaceutical residues in sources (sewage treatment plants - STPs), surface waters, fish in Hong Kong and tap water in mainland China, and to carry out risk assessments on different aquatic organisms as well as human beings exposed to these contaminants. The first stage of this study involved a preliminary assessment of the occurrence, removal, consumption and environmental risks of 16 antibiotics by sampling several STPs in Hong Kong featuring different treatment levels, as well as surface waters in Victoria Harbour, the receiving water body for STP effluents. Antibiotic concentrations were quantified using solid phase extraction (SPE) coupled with high performance liquid chromatography-electrospray ionization-tandem mass spectrometry (HPLC-ESI-MS/MS). Among the 16 target compounds, twelve were found in sewage samples, of which cefalexin, ofloxacin and erythromycin-H2O were predominant, with concentrations of 1020-5640, 142-7900 and 243-4740 ng/L in influent, respectively, and their mass loads were comparable to levels reported in urban regions in China and were at the high end of the range reported for western countries. Antibiotic consumption in Hong Kong was estimated by back-calculation based on influent mass flows and consumption rates of almost all detected ...