Analysis on Factors Influencing the Water Quality from Water Vending Machine and Control Strategies

Objectives To investigate the hygienic sanitary of water from water vending machines in Tianjin and to put forward countermeasures.

Methods A total of 151 sets of water vending machine were selected by simple random sampling method in 2014 and 2017 to analyze the usage of the machines and water-quality index.

Results Comparing the maintenance in 2014 and 2017, the maintenance cycle and the interval of changing filter material in 2017 were shorter than that in 2014 (the maintenance cycle:χ²=22.10, P < 0.05; the latest update:χ²=98.73, P < 0.05). Water-quality examinations, carried out in 86 water samples by random sampling in 2014 and 2017, and there was no signiticant difference (χ²=2.4, P=0.12). An unconditioned multi-logistic regression analysis showed that the risk of abnormal use of disinfection facilities was OR=46.499 (95% CI 6.02~359.48).

Conclusions Health inspection on water vending machines should be forced to carry out regularly, examination of water quality and replacing filter material should be on time to ensure water quality.