北运河粪源微生物分布特征及健康风险评价

河流微生物污染研究对流域水环境保护和公共卫生管理至关重要.本研究以海河流域北运河水系典型河流断面为研究对象,系统评估了北运河水系微生物污染特征及其健康风险.结果表明,北运河水系丰水期的粪源微生物污染严重,大部分断面菌群量超过105MPN·L~(-1),平水期和枯水期粪源微生物菌群量约为103～105MPN·L~(-1),变化不显著;流域内的农业河段粪源微生物最为严重,呈劣五类水体概率超60%,城市河段降雨前后粪源微生物含量变化更明显,部分河流断面的粪源微生物菌群量从103MPN·L~(-1)增长为106MPN·L~(-1); 2017年丰水期,北运河水系粪大肠菌群的单次暴露风险主要在0. 015～0. 035之间,莲花河、马草河、清河下、温榆河下为人体健康风险的关键敏感断面,需重点关注.

Pollution Characteristics and Health Risk Assessment of Microorganism Pollutions in the Beiyun River

Microorganism pollution in rivers is of great importance to the protection of watershed water quality and public health management. As a typical watershed of the Haihe River watershed, the Beiyun River was chosen as the study area, and the characteristics and health risk of microorganism pollution were assessed from a comprehensive perspective. The results showed that the microbial contamination of the fecal sources was serious during the wet season, and the microbial amount at most river sections was more than 10⁵ MPN·L^-1. During the normal season and dry season, the microbial amount was approximately 10³-10⁵ MPN·L^-1. Therefore, no obvious change could be observed. The fecal pollution in the agricultural river sections was the most severe, and the water quality of over 60% of these river sections was below the state Grade V level. The fecal microbial biomass of some urban river sections increased from 10³ MPN·L^-1 to 10⁶MPN·L^-1 after the rainfall event, indicating an obvious change of fecal microbial pollution during the rainfall process. For the Beiyun River, the exposure risk of the fecal microbial biomass was mainly between 0.015-0.035, while the Lianhua River, Macao River, lower reaches of Qinghe River, and lower reaches of Wenyu River were hotspots for contamination. Greater attention should be paid to these areas.