Pharmaceuticals and personal care products in a mesoscale subtropical watershed and their application as sewage markers.

This study comprehensively analyzed 23 classes of 51 pharmaceuticals and personal care products (PPCPs) in the two major prongs of Jiulong River and its estuary in southeast China, where the levels of the targeted PPCPs were mostly unknown. For both Jiulong River and its estuary, nine PPCPs were detected with 100% detection frequencies including two anti-inflammatory and analgesic drugs (ketoprofen and diclofenac acid), a stimulant (caffeine), a plasticizer (bisphenol A), two preservatives (methyl paraben and propyl paraben), two antimicrobials (triclosan and triclocarban) and a β-blocks (metoprolol), among which bisphenol A and caffeine accounted for more than 60% in concentrations. PPCPs generally had higher concentrations in dry season than normal season and wet season, while certain PPCPs, such as UV filters, showed higher concentrations in wet season, which were presumed to be related to their usage patterns. The concentrations of PPCPs were significantly correlated to several quality parameters of the surface water. The selected sewage markers were also used to track sewage in the studied river and the ratios of easily removed markers and conservative markers were used to identify the contribution of raw or treated sewage input. From our result, Jiulong River and its estuary were likely polluted by potential discharge of raw sewage.