[Distribution Characteristics and Health Risk Assessment of Thirteen Sulfonamides Antibiotics in a Drinking Water Source in East China].

Trace levels of residual antibiotics in drinking water sources may threaten public health and becomes a serious issue in modern society. Occurrence and distribution of 13 sulfonamides antibiotics in a drinking water source in East China were investigated using solid phase extraction-high performance liquid chromatography-tandem mass spectrometry. The results revealed that all 13 sulfonamides were detected with the total concentrations ranging from 10.5 ng·L-1 to 238.5 ng·L-1. Sulfamethoxazole (SMX) and sulfonamide (SAM) presented the 100% detected frequency, and the maximum concentrations reached 107.0 ng·L-1 and 43.1 ng·L-1, respectively. Sulfonamides contamination levels in the inlet were relatively higher than those in the outlet. The concentration of SMX was substantially unchanged in different positions of drinking water source. Seasonal variation of sulfonamide concentration showed that the concentrations were higher in winter and spring compared with those in summer and autumn. The range of total sulfonamides concentration detected in winter and spring was from 110.8 ng·L-1 to 117.9 ng·L-1, which was 3.6-3.8 times higher than those in summer and autumn. Human health risk characterization of residual sulfonamides in drinking water source was based on the assessment of risk quotients (RQs) for which different life stages were taken into account. The results showed that no sulfonamides had a RQs higher than 1. Trimethoprim (TMP) was the most risky antibiotic to the 0-3 months old infants with RQs reaching 0.001. Although the sulfonamides detected in the drinking water source do not pose any risk to the peoples' health, the implication of long-time exposure and comprehensive risk still deserve attention.