title: Impact of patient visiting activities on indoor climate in a medical intensive care unit: a 1-year longitudinal study.
abstract: BACKGROUND
  Bioaerosols from numerous sources have been implicated in respiratory diseases. This study evaluated the characteristics and weekly variations in indoor air in a medical intensive care unit (ICU) in northern Taiwan for 1 year. It also investigated the impact of patient visiting activities on the indoor climate in the medical ICU.
  
  
  METHODS
  A 4-bed room with patients in the medical ICU was selected for long-term air monitoring. Air temperature, relative humidity, CO(2), particulate matter, bacteria, and fungi were measured.
  
  
  RESULTS
  Approximately 90% of the CO(2) samples exceeded 1000 ppm, and 20% of the fine particle samples exceeded 35 microg/m(3). The levels of bacteria and fungi varied during the survey period. The measured values for all indoor air characteristics except bacterial concentrations were higher after patient visitation than before patient visitation. A significant association was found between the coarse particle concentration and the number of patient visitors.
  
  
  CONCLUSIONS
  Patient visiting activity impacts the indoor air quality of the ICU environment, especially in terms of coarse particle concentrations. Periodic monitoring of ventilation system efficiency is needed to ensure optimal indoor air quality.
authors.affiliation: Department of Public Health, College of Medicine, Fu Jen Catholic University, Taipei, Taiwan.
authors.forename: Chin-Sheng
authors.initials: CS
authors.lastname: Tang
authors.forename: Feng-Fang
authors.initials: FF
authors.lastname: Chung
authors.forename: Meng-Chih
authors.initials: MC
authors.lastname: Lin
authors.forename: Gwo-Hwa
authors.initials: GH
authors.lastname: Wan
mesh_terms: D000391:Air Microbiology; D016902:Air Pollution, Indoor / Q000032:analysis*; D000818:Animals; D001419:Bacteria / Q000302:isolation & purification; D002245:Carbon Dioxide / Q000032:analysis; D002980:Climate; D005658:Fungi / Q000302:isolation & purification; D006801:Humans; D006813:Humidity; D007362:Intensive Care Units; D008137:Longitudinal Studies; D052638:Particulate Matter / Q000032:analysis; D013624:Taiwan; D014789:Visitors to Patients
chemical_list: D052638:Particulate Matter; D002245:Carbon Dioxide