title: A noninvasive objective measure of sunscreen use and reapplication.
abstract: OBJECTIVE
  To study whether a noninvasive swabbing technique can detect sunscreen use for up to 6 hours, and whether the technique can detect reapplication of sunscreen.
  
  
  METHODS
  Thirty volunteer office workers were randomly assigned to have one of a variety of sunscreens applied using recommended application techniques, and half were randomly assigned to have sunscreen reapplied after 3 hours. Alcohol-based swabs were used to obtain a sample from participants' arm at 20 minutes, and hourly from 1 to 6 hours post-application. Absorption readings were analyzed using an UV-visible spectrophotometer.
  
  
  RESULTS
  The swabbing technique was consistently able to distinguish the sunscreen from control swabs for up to 6 hours. The absorption readings between 20 minutes and 6 hours were significantly higher than control swabs. There were no differences between the group that had sunscreen reapplied and the group that did not.
  
  
  CONCLUSIONS
  The sunscreen swabbing technique is an effective noninvasive method for detecting a variety of sunscreen products in adults over a 6-hour period. No differences in absorption readings were found with sunscreen reapplication. This procedure will be a useful adjunct to other objective measures of sun protection and UV radiation exposure, resulting in a more accurate picture of the sun protection habits of individuals.
authors.affiliation: Cancer Research Center of Hawaii, University of Hawaii, Honolulu, HI 96822, USA. doriordan@crch.hawaii.edu
authors.forename: David L
authors.initials: DL
authors.lastname: O'Riordan
authors.forename: Kevin B
authors.initials: KB
authors.lastname: Lunde
authors.forename: Johann
authors.initials: J
authors.lastname: Urschitz
authors.forename: Karen
authors.initials: K
authors.lastname: Glanz
mesh_terms: D000287:Administration, Topical; D000327:Adsorption; D000328:Adult; D003625:Data Collection; D004781:Environmental Exposure; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D013048:Specimen Handling; D013473:Sunscreening Agents / Q000008:administration & dosage* / Q000493:pharmacokinetics / Q000627:therapeutic use*; D014466:Ultraviolet Rays / Q000009:adverse effects
chemical_list: D013473:Sunscreening Agents