公共场所中央空调系统军团菌污染环节的研究

STUDIES ON THE LINKS OF LEGIONELLA CONTAMINATION IN CENTER AIR CONDITIONING SYSTEM IN PUBLIC PLACES.

目的:探索中央空调系统中各环节军团菌的污染情况和可能的污染环节。方法:对26户商场、宾馆、办公楼、医院等公共场所中央空调系统的冷却塔、冷凝器、膨胀水箱、蒸发器、冷凝水、空调送风末端等各环节点采集水样、涂抹样,检测军团菌。结果:135份中央空调系统各环节点,军团菌总检出率50.4%,分离到75株嗜肺军团菌,血清分型有Lp1和Lp10两种,水冷式、风冷式系统的阳性率分别为50.9%、47.8%,冷凝器水检出率高达93.8%,冷却塔水、膨胀水箱水在60%以上,低温运行的蒸发器水中检出率为40%,冷凝水为17.4%,97.1%的阳性水样中每ml水样中军团菌数小于100个。结论:各场所、各类型中央空调系统的各积、储水环节军团菌污染严重,军团菌有着顽强的低温生存能力,受军团菌污染的膨胀水箱水、冷冻水、冷却水、冷凝水都有可能对人体造成危害。

Objective： To describe and to explore the present status and approach of Legionella contamination in center air condition system. Methods： 135 samples were obtained from 26 public places such as markets, hotels, office buildings etc. Legionella was tested in water and painting samples of all components from cooling tower, condenser, swelling water box, evaporator, condensed water and blast terminal of center air condition in these pubilc places. Results： The total positive rate of Legionella was 50.4%, including two types of serogroup （Lp1 and Lp10） among these 75 strains of Pneumophila LegioneUa. The positive rates were 50.9%, 47.8% in water- cooling type systems and wind - cooling type systems respectively. The positive rate was 93.8% in condenser, and that was over 60% in cooling tower and in swelling water box. The positive rate was 40% in evaporator during lower temperature and 17.4% in condensed water. The amounts of Legionella were less than 100 per milliliter in 97.1% of the positive water samples. Conclusion： This study suggested that the Legionella contamination in the collection and storage components of center air conditioning system in public places is a very critical problem in our country. Legionella could survive in lower temperature, so it was possible that the population will be infected by Legionella from water of swelling water box, freezing water, cooling water and condenser water.