Objective To investigate the usage and hygienic condition of cooling towers in public places in Dongcheng District of Beijing, China, and to evaluate the health risk of legionellosis from cooling towers in public places.
Methods From May to September in 2018, the cooling water of cooling towers was collected from 26 public places of three categories in Dongcheng District, and a questionnaire survey was conducted at the same time. The health risk of each public place was calculated based on the model of the health risk index of legionellosis.
Results In this study, Legionella pneumophila was negative in all samples of cooling water, with a qualified rate of 100%. The mean level of free residual chlorine was 0.15 mg/L. There were significant differences in scale, dosing mode and frequency among the cooling towers in hotels and those in the other places. The mean health risk value of 26 public places was 61.49, among which the risk of Legionella proliferation, the risk of bacterial aerosol transmission, and the risk of susceptibility among exposed people were 16.13, 22.66, and 22.70, respectively. There were different health risk of legionellosis in different cooling towers, and the health risk index of hospitals was significantly higher than that of hotels and stores (F=3.78, P < 0.05).
Conclusion The health risk of legionellosis from cooling tower is mainly determined by the susceptible people around the public places. The health administrative departments of those areas should strengthen the protection of the susceptible people and formulate, improve, and implement relevant policies and regulations for public places.
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