title: Drinking water treatment with ultraviolet light for travelers -- Evaluation of a mobile lightweight system.
abstract: BACKGROUND
  The SteriPEN(®) is a handheld device for disinfecting water with ultraviolet (UV) radiation. The manufacturer claims a reduction of at least 99.9% of bacteria, viruses, and protozoa. The present study intends to verify the general effectiveness of the device. Furthermore, the influence of bottle geometry and water movement is examined and the issue of user safety with regard to UV-C radiation is addressed.
  
  
  METHODS
  The device was applied on water containing a known number of microorganisms (Escherichia coli, Staphylococcus aureus, and the spore of Geobacillusstearothermophilus) and the survival rate was examined. Three different types of bottles commonly used among travelers served as test containers. All tests were conducted with and without agitating the water during irradiation. Furthermore, a spectral analysis was performed on the light of the device.
  
  
  RESULTS
  The SteriPEN(®) reached a mean reduction of more than 99.99% of bacteria and 99.57% of the spores when applied correctly. However, the results of the trials without agitating the water only yielded a 94.98% germ reduction. The device's maximal radiation intensity lies at 254 nm which is the wavelength most efficient in inactivating bacteria. The UV-C fraction is filtered out completely by common bottle materials. However, when applied in larger containers a portion of the UV-C rays exits the water surface.
  
  
  CONCLUSIONS
  If applied according to the instructions the device manages a satisfactory inactivation of bacteria. However, it bears the danger of user errors relevant to health. Therefore, education on the risks of incorrect application should be included in the travel medical consultation. Also there are still aspects that need to be subject to further independent research.
authors.affiliation: Institute of Occupational & Social Medicine, RWTH Aachen University, Aachen, Germany. Electronic address: Lisa.Timmermann@rwth-aachen.de.
authors.forename: Lisa F
authors.initials: LF
authors.lastname: Timmermann
authors.affiliation: Institute of Medical Microbiology, RWTH Aachen University, Aachen, Germany. Electronic address: kritter@ukaachen.de.
authors.forename: Klaus
authors.initials: K
authors.lastname: Ritter
authors.affiliation: Medical Commission of the Union Internationale des Associations d׳Alpinisme (UIAA MedCom), Bern, Switzerland. Electronic address: dh@hillebrandt.org.uk.
authors.forename: David
authors.initials: D
authors.lastname: Hillebrandt
authors.affiliation: Institute of Occupational & Social Medicine, RWTH Aachen University, Aachen, Germany; Medical Commission of the Union Internationale des Associations d׳Alpinisme (UIAA MedCom), Bern, Switzerland. Electronic address: tkuepper@ukaachen.de.
authors.forename: Thomas
authors.initials: T
authors.lastname: Küpper
mesh_terms: D003967:Diarrhea / Q000517:prevention & control; D004203:Disinfection / Q000295:instrumentation* / Q000379:methods*; D060766:Drinking Water / Q000382:microbiology / Q000469:parasitology / Q000821:virology; D004926:Escherichia coli / Q000528:radiation effects; D006801:Humans; D013170:Spores / Q000528:radiation effects; D013211:Staphylococcus aureus / Q000528:radiation effects; D014195:Travel; D014466:Ultraviolet Rays; D018508:Water Purification / Q000295:instrumentation* / Q000379:methods; D000069578:Waterborne Diseases / Q000517:prevention & control
chemical_list: D060766:Drinking Water
keywords: Disinfection; Steripen; Travelers׳ diarrhea; UV radiation; Waterborne pathogens