汛期连续降雨对中心城区河道微生物污染影响及健康风险研究

Influence of Continuous Rainfall on Microbial Pollution and Health Risk in Urban Rivers

研究以3条不同营养状态河段为例,调查分析了汛期连续降雨对河道微生物污染的影响,并以指示微生物-粪大肠菌群为例,进行了健康风险评价。研究表明,河段粪大肠菌群浓度在4.3×10^3-5.7×10^6MPN/L,河道营养程度越高,降雨对河道微生物污染的影响越大,河道良好的生态环境有利于水体粪大肠菌群快速恢复至较低水平。以日患肠道疾病的风险评价,汛期河道1和河道2健康风险低,河道3虽然直接接触的可能较小,但其潜在的健康风险不容忽视。

Rainfall runoff is a major source of microbial contamination of the river. In order to analyze the influence of continuous rainfall on river microbial pollution, three different trophic state rivers were selected for the study. The results showed that the concentration of fecal coliform(FC) in the central city was 4.3×10^3-5.7×10^6 MPN/L. During the continuous rainfall, there was no significant correlation between the concentration of FC and the amount of rainfall, which was significantly affected by rainfall intensity. The impact load of pumping station is high, which aggravates the pollution degree of microorganisms in receiving channel. Based on risk of intestinal diseases by daily exposure, there is no health risk for river 1 and river 2. Although the river 3 is black and smelly, there is little chance of direct contact. However, with the development of ecological restoration, the exposure of droplets and aerosols can not be ignored. It is suggested that hydrophilic activities should be avoided in flood season.