title: [Hygienic investigation of indoor environment in air-conditioned passenger trains].
abstract: OBJECTIVE
  Explore the hygienic status of indoor environment in railway air-conditioned passenger trains.
  
  
  METHODS
  We carried out a hygienic investigation of various air-conditioned passenger trains on total 10 railway lines in Shanghai, Chengtu, Kunming, Harbin, Urumchi and Guangzhou railway bureaus for two years between July, 1997 and Oct., 1999. The monitoring was conducted on difference train cars at different time, different railway status. The control groups were selected in the same condition.
  
  
  RESULTS
  The results of temperature and wind speed in air-conditioned trains both meet with the national standards GB 9673-1996 in summer and winter. The humidity in summer exceeded the national standards. Of different railways the status, the noise in four different cars except dining cars exceeded the national standards. The results of shock demonstrated that all measure up to the standards of ISO 2631/1-85. As to indoor air quality, the concentration of CO in air-conditioned trains in difference seasons(summer, autumn, winter) all met with the national standards, the ratio was 100%. In summer, the concentrations of CO2 in hard seat cars and soft berth car exceeded the national standard with a statistic significance(P < 0.01). In winter, the concentrations of CO2 in soft berth and hard berth cars both exceeded the same standard. The results of inhalable particulate matter(IP) and total count of bacteria all satisfied the standards, meanwhile the natural lighting and artificial illumination in air-conditioned train cars all were superior to that in ordinary trains.
  
  
  CONCLUSIONS
  Humidity in summer and noise in dining car exceeded the standards, the concentration of CO2 in different cars in summer and winter exceeded the standards in some degrees.
authors.affiliation: Center of Health Prevention of Shanghai Railway Bureau, Shanghai 200071, China.
authors.forename: Xiupei
authors.initials: X
authors.lastname: Zhang
authors.forename: Jianmin
authors.initials: J
authors.lastname: Ma
authors.forename: Weijing
authors.initials: W
authors.lastname: Zhou
authors.forename: Liyu
authors.initials: L
authors.lastname: Zhou
mesh_terms: D000389:Air Conditioning; D016902:Air Pollution, Indoor; D002245:Carbon Dioxide / Q000032:analysis; D004784:Environmental Monitoring; D006813:Humidity; D018986:Motor Vehicles / Q000592:standards*; D052638:Particulate Matter / Q000032:analysis; D012621:Seasons
chemical_list: D052638:Particulate Matter; D002245:Carbon Dioxide