旅客列车空调系统卫生学调查

Hygienic Survey on Air-conditioning System in Passenger Train

目的了解旅客列车空调系统的卫生状况。方法于2009年1—10月,采用分层整群随机抽样的方法抽取合肥车辆段空调列车车厢108节,其中,硬座车厢30节、硬卧车厢28节、餐车车厢24节(燃煤燃电各12节)、软卧车厢26节。测定回风管道中的积尘量、细菌总数、真菌总数、β-溶血性链球菌;送风口PM10、细菌总数、真菌总数、β-溶血性链球菌;冷凝水嗜肺军团菌。结果回风管和送风口细菌总数合格率均较低,分别为15.6%和59.2%。β-溶血性链球菌均合格。不同类型车厢空调送风口的PM10合格率间比较,差异有统计学意义(χ2=22.49,P<0.05);其合格率依次为餐车(54.2%)<硬座(76.7%)<硬卧(96.4%)<软卧(100.0%)。不同运行年限车厢空调回风管的积尘量、细菌总数间比较,差异均有统计学意义(积尘量:χ2=24.71,P<0.05;细菌总数:χ2=19.75,P<0.05),且空调回风管积尘量随着车厢运行年限的延长有增加的趋势。采集冷凝水水样34件,嗜肺军团菌的检出率为2.9%。结论列车空调系统积尘量和细菌总数超标严重。建议在段修(即运行列车空调运行2～3年时)对空调通风管道进行彻底的清洗和消毒。

Objective To explore the hygienic status of the air-conditioning system in the train. Methods From Jan to Oct in 2009,Total 108 air-conditioning trains in Hefei vehicles section were collected randomly by stratified cluster sampling, including 30 hard-seat compartments,28 hard-berth compartments,24 dining cars with 12 coal-fired trains and 12 electric trains respectively, and 26 soft-herth compartments. The dirt amount, total bacteria count, total fungal plate count and beta-haemolytie s treptococcus in return-air pipelines were determined. The PM10, total bacteria count, total fungal plate count and beta-haemolytie streptococcus in supply-air outlets were also determined. The legionella pneumophila in condensed water were assayed. Results The qualified rate of total bacteria count was 15.6% in return-air pipeline,and that in supply-air outlet is 59.2%. The beta-haemolytie streptococcus count was qualified. The qualified rate of PM10 was 54.2%, 76.7%, 96.4% and 100% in dining cars, hard-seat compartments ,hard-berth compartments and soft-berth compartments,respectively. The difference was significant （χ^2=22.49 ,P〈0.05）. The dirt amount in return-air pipeline was different significantly between different running time of subway train （χ^2=24.71 ,P〈0.05） and increased with running time. The total bacteria count was different significantly between different running time of subway train （χ^2=19.75,P〈0.05）. Total 34 condensed water samples were collected,and detection rate of legionella pneumophila was 2.9%. Conclusion The dirt amount and total bacteria count in the air-conditioning system of the train are over standard severely. It is suggested that measures should be taken to clean and disinfect thoroughly for ventilation air-conditioning piping when air-conditioning system has run for 2 to 3 years.