广州市地铁站集中空调通风系统微生物污染状况

Microbial contamination status of centralized air conditioning ventilation systems in metros in Guangzhou City

目的了解广州市地铁站集中空调通风系统微生物污染状况,为制定相应的防制对策提供依据。方法参照卫生部《公共场所集中空调通风系统卫生规范》WS394-2012的要求,2013-2015年于每年的4月(春季)和8月(夏季)分别对广州市5条地铁线10个地铁站的集中空调通风系统进行微生物指标检测。结果地铁站集中空调送风中细菌总数、真菌总数的合格率在不同季节差异有统计学意义(P<0.05),其中夏季空调送风中细菌总数合格率为41.11%、真菌总数合格率为72.22%,细菌总数、真菌总数的最高浓度分别超出《卫生规范》中所规定限值的11倍、5倍以上;空调送风中细菌总数合格率为58.33%、真菌总数合格率为79.44%,分别低于风管内表面细菌总数和真菌总数的合格率,差异有统计学意义(P<0.05),β-溶血性链球菌未检出;冷却水嗜肺军团菌的检出率为48.33%,夏季冷却水阳性检出率明显高于春季,差异有统计学意义(P<0.05)。结论广州市地铁站集中空调通风系统存在微生物污染,对其危险性应引起高度重视,并进行有效控制,避免大规模公共卫生突发事件的发生。

Objective To investigate the microbial contamination status of centralized air conditioning ventilation systems in metros in Guangzhou City so as to provide evidence for formulating the related prevention and control measures. Methods Ac- cording to the requirements of Hygienic Standard for Centralized Air Conditioning Ventilation System in Public Places （ WS394- 2012） , the microbiological indices of centralized air conditioning ventilation systems in 10 stations of 5 different lines of metros were tested in April and August during 2013-2015. Results There were statistically significant differences in the qualified rates of the total bacterial count and the total fungal count in the wind supply system between summer and winter （ P〈0.05）. The qualified rates of the total bacterial count and the total fungal count in summer were 41.11% and 72.22% respectively. The detected maximum concentrations of the total bacterial count and the total fungal count were 11 times and 5 times higher than the standard respectively. The qualified rates of the total bacterial count and the total fungal count in the wind from the wind supply system were 58.33% and 79.44% respectively, which were all lower than the qualified rates detected in the duct＇ s internal surface, with statis-tically significant differences （P〈0.05）. No β-Streptococcus haemolyticus was detected. The detection rate of LegioneUa pneumophila in cooling water was 48.33%, and the positive detection rate was significantly higher in summer than in winter, with a statis- tically significant difference （P〈0.05）. Conclusions There exists microbial contamination in centralized air conditioning ven- tilation systems of metros in Guangzhou City ; and hence, we should pay special attention to the risk of the contamination and effec- tively control it so as to avoid the occurrence of large-scale public health emergencies.