广西城乡部分中小学寄宿学校饮用水污染状况及其影响因素分析

Investigation on drinking water polluting status and its influence factors of middle boarding schools and primary boarding schools in urban and rural region of Guangxi

目的掌握广西城乡中小学寄宿学校生活饮用水污染状况,探讨学校内水型传播肠道传染病疫情暴发频繁的环境危险因素。方法选择南宁、柳州、桂林3个地级市,按随机整群抽样方法抽9县1市,统一收集、分析其所属范围内寄宿中小学校饮用水水源类型、供水方式以及饮用人口数等基本情况;随机抽取100所学校开展生活饮用水卫生学调查和以水型传播的肠道传染病疫情流行特征分析,采集饮用水水样进行细菌学指标以及氨氮、亚硝酸盐指标检验和评价。结果9县1市有寄宿学校321所,师生人数349730人,饮用地下水源为主(占65.73%);市政供水占26.79%,自备水源占55.76%,乡镇供水占17.45%,后两者主要分布在农村地区。100所学校近6年来共发生肠道传染病疫情29起,其中24起为水型传播。本次调查水质抽检总合格率为27.00%,其中市政供水为100.00%,有简易消毒设施的自备水为47.37%,无消毒设施的自备水和乡镇供水分别为16.95%和17.65%;不合格指标为总大肠菌群、粪大肠菌群、细菌总数,超标率依次为65.00%、58.00%、28.00%。结论广西以自备水源、乡镇供水为主的农村寄宿学校,周边环境卫生条件恶劣,对水源防护、饮水消毒等基础卫生设施建设严重滞后,导致水源遭受人畜粪便和生活污水等污染,是多年来广西伤寒副伤寒等肠道传染病疫情在学校频繁发生的环境危险因素,需加大对农村寄宿学校饮水安全工程建设和饮水卫生监测力度。

Objective to master the drinking water polluting status and explore the environment risk factors of water-borne disease outbreak, in middle boarding schools and primary boarding schools in urban and rural regions of Guangxi. Methods 10 counties in Nanning, Liuzhou and Guilin cities by using tile random stratified cluster sampiing method were selected; the riverhead＇s type, the modes of water supply and the population of drinking water and so on,in middle boarding schools and primary boarding schools of the 10 counties were annlysed;the drinking water was sampled from 100 boarding schools to investigate the sanitary status, the epidemic characters of waterborne disease, to verify and assess the bacteriological indicators and pollution of NH3 - N, nitrite. Results there were 321 boarding schools in the 10 counties, there were 349730 school teacbers and students. The rate of underground riverhead was 65.73 %, the rate of municipal water supply was 26.79%, the rate of self water supply was 55.76%, the rate of township water supply was 17,45%, self water supply and township water supply mostly occurred in rural area. In the past six years there were 29 cases of infectious endemic diseases in the schools, including 24 cases of water-borne disease. The qualified rate of drinking water quality in all schools was 27.00%, the qualified rate of municipal water supply was 100.00%, the qualified rate of self water supply with disinfection facility was 47.37%, the qualified rate of self water supply and township water supply without disinfection facility were 16.95% and 17.65%. the rates of coliform, dejecta intestinal bacterium and total bacterium were incom- petent, they were 65.00%, 58.00% and 28,00% respctively. Conclusions Around the boarding schools in rural area with self water supply and township water supply, the environment is very foul, and the sanitary measures such as riverhead protection, drinking water disinfection are very laggard, so the polluting factors such as dejecta, life sewage are the risk factors that induce typhoid and paratyphoid to outbreak. It is urgent to construct school water supply safety system and drinking water disinfection, and strengthen the sanitary management.