再生水补给型景观水体微生物健康风险评价——以圆明园为例

再生水作为景观水体的非常规补给水源被全球各个国家广泛使用，而其内病原微生物的存在可能会通过不同传输途径对人体健康产生一定的威胁.因此，本文以粪大肠菌群（Fecal Coliform，FC）、大肠杆菌（Escherichia coli，EC）、肠球菌（Enterococcus，ENT）为研究对象，系统调查了圆明园景观水体中这3种指示微生物的污染特征，并运用定量微生物风险评价模型（Quantitative Microbial Risk Assessment，QMRA）量化了其对人体健康造成的潜在风险.研究结果显示，沿着园区内水体的流动方向，3种指示菌的浓度与入水时相比均出现了明显的增长，其中ENT和FC浓度最高值分别达到了入水时的14.3倍和17.6倍，增长情况最为明显.采用不同剂量-A反应方程表征的FC、EC、ENT单次暴露的健康风险值皆低于1.7×10^-2，处于风险可接受的范围；在年健康风险方面，职业人群的年健康风险远高于非职业人群；经过人工湿地工程的生态修复区域能够显著削减指示微生物浓度，同时在一定程度上降低病原微生物带来的健康风险，因此扩大生态修复范围可以进一步降低风险.

Microorganism health risk assessment of landscape water supplied with reclaimed water: A case from the Old Summer Palace

Reclaimed water is widely used as an unconventional supply of landscape water but the presence of pathogenic microorganisms in it may pose a threat to human health through different transport routes. Therefore, this study systematically investigated the pollution characteristics of three indicator microorganisms, Fecal Coliform (FC), Escherichia coli (EC) and Enterococcus (ENT), in the landscape water of the Old Summer Palace and quantified the potential risks to human health by Quantitative Microbial Risk Assessment (QMRA). The results showed that the concentrations of the three indicator bacteria all increased significantly along the direction of flow in the park. The growths of ENT and FC are especially remarkable with concentrations increasing 14.3 and 17.6 folds, respectively. The health risks of FC, EC and ENT for single exposure characterized by different dose-response equations were all lower than 1.7×10^-2, which was within the acceptable range of risk. In terms of annual health risk, the annual health risk of professional is much higher than that of a non-professional. The ecological restoration area constructed by a wetland project can significantly reduce the concentration of indicator microorganisms and reduce the health risks brought by pathogenic microorganisms. Expanding the scope of ecological restoration can further reduce the risks.