title: [Bacterial contamination after use and assessment of countermeasures a dust mask facepiece].
abstract: OBJECTIVE
  Bacteria on the facepiece of a dust respirator were measured just after use and after 24-hours storage at a room temperature after being worn, and bacteria disinfection methods other than ethanol were examined.
  
  
  METHODS
  The existence of bacteria on a facepiece of a mask that had been worn for about one hour in a laboratory was investigated. In order to eliminate bacteria before use on the next day, five methods of bacteria disinfection were investigated: wiping with a facial tissue impregnated with ethanol as a control; wiping with a facial tissue wetted with tap water; wiping with a dry facial tissue after wiping with one wetted with tap water; wiping with a dry facial tissue after wiping with one wetted with distilled water; and wiping with a dry facial tissue two times. The tests were carried out using silicone rubber sheets plated with bacteria collected from human skin. The disinfection methods that were as effective as facial paper wetted with ethanol, were then assayed on the facepiece of the dust respirator.
  
  
  RESULTS
  Bacteria were detected on the facepiece immediately after it had been worn. Bacteria were also detected on the facepiece after it had been stored at 25°C for 24-hours after being worn. The methods of wiping with a dry facial tissue after wiping with either tap water or distilled water were almost as statistically effective as wiping with ethanol wetted facial paper. Bacteria on the facepiece were decreased by wiping with a dry facial tissue after wiping with one wetted with tap water.
  
  
  CONCLUSIONS
  Colonies of bacteria were detected on a facepiece that had been stored 24 hours after being worn, which suggests that bacteria disinfection just after a respirator has been worn should be recommended. It is very important that the water on the facepiece should be removed after wiping with a wet facial tissue.
authors.affiliation: Department of Environmental Management, School of Health Sciences,University of Occupational and Environmental Health, Japan, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyushu, Fukuoka 807-8555, Japan.
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Hinoue
authors.forename: Yuka
authors.initials: Y
authors.lastname: Simada
authors.forename: Sumiyo
authors.initials: S
authors.lastname: Ishimatsu
authors.forename: Toru
authors.initials: T
authors.lastname: Ishidao
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Fueta
authors.forename: Hajime
authors.initials: H
authors.lastname: Hori
mesh_terms: D001419:Bacteria / Q000302:isolation & purification*; D015169:Colony Count, Microbial; D004203:Disinfection / Q000379:methods*; D004391:Dust; D000431:Ethanol; D006801:Humans; D008297:Male; D008397:Masks / Q000382:microbiology*; D012134:Respiratory Protective Devices / Q000382:microbiology*; D012867:Skin / Q000382:microbiology; D013696:Temperature; D013997:Time Factors; D014867:Water
chemical_list: D004391:Dust; D014867:Water; D000431:Ethanol