Survey On Hygienic Status Of Centralized Air Ventilation System Of Twenty Hotels In Jilin Province

Background:With the progress of society, rapid economic development and continuous improvement of people's living standards, the number of large public places is increasing gradually in cities and the central air conditioning has been chosen to regulate indoor air for comfortable environment inside most public places. However, central air conditioning also bring hidden troubles to indoor air quality in public places when it creates a comfortable environment. According to some surveys, the indoor air pollution caused by long-term operation, non-standard management, improper cleaning and disinfection and unreasonable design of central air conditioning has become a major risk factor to health hazards of populations. WHO has been warning people to be concerned by health hazards and disease brought by central air conditioning. The outbreaks of infectious disease and chronic disease central air conditioning led to has covered most regions of the world, such as Asia, Europe, Oceania and America confirmed by domestic and foreign data. Therefore, it is very necessary for the health of population long-term living or working in air conditioned environment to make health survey and management to central air conditioning.Objective:To know the hygiene status of centralized air ventilation system in hotels in Jilin Province, find problems and make suggestions for improvement. To provide valuable information for efficient management of the relevant health authorities and departments using air conditioning. To provide the basis for improvement of air quality in public places, prevention of infectious disease and the protection of public health. Methods:From 2009 to 2010, collecting 20 hotels in Jilin Province with stratified and simple random sampling. According to the《Sanitary Standard for Centralized Air Ventilation System》,《Sanitary Evaluation Standard for Centralized Air Ventilation System》, collecting samples of centralized air ventilation system to detect the accumulated dust mass, bacteria such as Legionella pneumophila,β-hemolytic streptococcus, bacterial counts, epiphyte count, and other indicators, to make hygienic evaluation of central air conditionings, and to compare and analyze the data of 20 hotels divided into two groups according to stars level.Results:1. Passing rate of health indicators in collected centralized air ventilation system samples: in the test indicators of central air conditioning samples of 20 hotels, when the air was supplied, the passing rate of bacterial counts was 81%, the bacterial counts of individual samples is more than 10 times higher than the national standard limits; the passing rate of epiphyte count is 76%; the passing rate of inhalable particulate matter is 83%; the passing rate of accumulated dust mass on the surface of air duct is 68%; the passing rate of the fresh air of air conditioning system, the bacterial counts and epiphyte count on the surface of air duct is all 100%;β-hemolytic streptococcus was not detected. The detection rate of Legionella pneumophila in cooling water is 20%; the detection rate of Legionella pneumophila in condensing water is 10%.2. Place passing rate of individual health indicators of centralized air ventilation system: when the air was supplied, the place passing rate of bacterial counts was 85%; the place passing rate of epiphyte count is 80%; the place passing rate of inhalable particulate matter is 75%; the place passing rate of accumulated dust mass on the surface of air duct is 55%; the place passing rate ofβ-hemolytic streptococcus, the bacterial counts and epiphyte count on the surface of air duct, the fresh air of air conditioning system is all 100%; the place passing rate of Legionella pneumophila in cooling water and in condensing water is 80% and 90%.3. The hygienic evaluation of centralized air ventilation system in hotels: According to the《Sanitary Standard for Centralized Air Ventilation System of Public Place》, in 10 health indicators of centralized air ventilation system, there are 15 hotels with one or more indicators of failure in 20 hotels, there are only five hotels (one five-star hotel, four four-star hotels), the 10 indicators of which all meet the requirements. The passing rate of centralized air ventilation system in 20 hotels is 25%.Conclusion:The health status of centralized air ventilation system must be improved.The health status of centralized air ventilation system did not change significantly among three-star hotels, four-star hotels and five-star hotels.The poor health status of centralized air ventilation system is mainly concerned with the lack of cleaning and disinfection of the air conditioning system, non-standard method of operation or abnormal operation of central air conditioning system and other factors.