Objective To investigate the sanitary status and examine the risk factors of direct drinking water in middle and primary schools in Changning District, Shanghai, and to propose corresponding countermeasures.
Methods A total of 98 direct drinking water systems in 26 middle and primary schools in Changning District, Shanghai were investigated. In May 2014, related hygiene management was investigated by self-designed questionnaires according to the Basic Requirements for Construction and Maintenance of Direct Drinking Water Project in Middle and Primary Schools of Shanghai. In June 2014, water samples from each water system were collected and assessed following the Water Quality Standards for Fine Drinking Water (CJ94-2005). By means of interviews with 14 experts and non-conditional binary logistic regression analysis, risk factors associated with unqualified total number of colonies were identified.
Results In the health management of direct drinking water, existing problems were peripheral sanitation, equipment conditions, management regulation, water quality self-checks, maintenance records, and document management. In water quality detections, the total number of colonies exceeded relevant standard, with a qualified rate of 69.4%; turbidity, cadmium, and iron were graded as light pollution, with qualified rates of 95.9%, 98.0%, and 99.0%, respectively. The results of expert interviews suggested equipment design and maintenance might contribute to the exceeding total number of colonies. Logistic regression analysis showed that the presence of direct drinking water tanks (OR=11.880, 95%CI:3.567-39.570) and total chlorine <0.05 mg/L (OR=10.736, 95%CI:2.728-42.254) were the risk factors associated with the exceeding total number of colonies.
Conclusion Sanitary problems are identified in direct drinking water in the middle and primary schools in Changning District, Shanghai. We suggest revising the Basic Requirements for Construction and Maintenance of Direct Drinking Water Project in Middle and Primary Schools of Shanghai with focuses on the control against possible risk factors leading to the excessive concentrations of total number of colonies and some metal ions.
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