title: ATP bioluminescence values are significantly different depending upon material surface properties of the sampling location in hospitals.
abstract: BACKGROUND
  Our previous study into assessing hospital cleanliness in Japan by two common methods, ATP bioluminescence and the stamp agar method, revealed considerable variability in the data of both methods (BMC Research Notes, 7: 121, 2014). To investigate the reason(s) for the variability, we reanalyzed the data (n = 752) from the point of view of the material surface properties of sampling sites.
  
  
  METHODS
  Data obtained from surfaces with unknown properties and different purposes such as floor were omitted, and the remaining data (n = 488) were used for this study. The material surface properties on sampling sites were divided into six categories: melamine coated (n = 216), vinyl chloride (n = 16), stainless steel (n = 144), wood (n = 63), and acrylonitrile-butadiene styrene resin coated (n = 48). The data between individual material properties were compared.
  
  
  RESULTS
  The ATP values of high-touch places were significantly different depending on the type of surface, but no significant difference in stamp values between material properties was seen, indicating that in contrast to stamp values, ATP-accumulation more depends on the physical properties of the material surface such as electronic charges or roughness. To confirm this, we assessed a degree of roughness on vinyl chloride material surface (disutilized floor samples actually used for each of the hospitals) by observation with scanning electron microscope (SEM). As a result, SEM observation similarly revealed considerable roughness on the materials, which may allow microbes to contaminate the materials without noticing it.
  
  
  CONCLUSIONS
  Material properties must be considered when evaluating hospital cleanliness with ATP values, and provide a strong warning into evaluating hospital cleanliness.
authors.affiliation: Department of Fundamental Nursing, Faculty of Health Sciences, Hokkaido University, Sapporo, Japan. tshimoda@hs.hokudai.ac.jp.
authors.forename: Tomoko
authors.initials: T
authors.lastname: Shimoda
authors.affiliation: Department of Fundamental Nursing, Faculty of Health Sciences, Hokkaido University, Sapporo, Japan. r-yano@med.hokudai.ac.jp.
authors.forename: Rika
authors.initials: R
authors.lastname: Yano
authors.affiliation: Laboratory of Morphology and Image Analysis, Biomedical Research Center, Juntendo University Graduate School of Medicine, Tokyo, Japan. shinji-n@juntendo.ac.jp.
authors.forename: Shinji
authors.initials: S
authors.lastname: Nakamura
authors.affiliation: Laboratory of Morphology and Image Analysis, Biomedical Research Center, Juntendo University Graduate School of Medicine, Tokyo, Japan. myoshida@juntendo.ac.jp.
authors.forename: Mitsutaka
authors.initials: M
authors.lastname: Yoshida
authors.affiliation: Department of Medical Laboratory Science, Faculty of Health Sciences, Hokkaido University, Nishi-5 Kita-12 Jo, Kita-ku, Sapporo, Hokkaido, 060-0812, Japan. matsuo@hs.hokudai.ac.jp.
authors.forename: Junji
authors.initials: J
authors.lastname: Matsuo
authors.affiliation: Department of Fundamental Nursing, Faculty of Health Sciences, Hokkaido University, Sapporo, Japan. sadako@med.hokudai.ac.jp.
authors.forename: Sadako
authors.initials: S
authors.lastname: Yoshimura
authors.affiliation: Department of Medical Laboratory Science, Faculty of Health Sciences, Hokkaido University, Nishi-5 Kita-12 Jo, Kita-ku, Sapporo, Hokkaido, 060-0812, Japan. hiroyuki@med.hokudai.ac.jp.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Yamaguchi
mesh_terms: D000255:Adenosine Triphosphate; D004866:Equipment Contamination / Q000706:statistics & numerical data; D006761:Hospitals / Q000592:standards* / Q000706:statistics & numerical data; D006801:Humans; D007564:Japan; D008163:Luminescent Measurements / Q000592:standards* / Q000706:statistics & numerical data; D008855:Microscopy, Electron, Scanning / Q000592:standards* / Q000706:statistics & numerical data; D013499:Surface Properties
chemical_list: D000255:Adenosine Triphosphate