title: Measurement of low levels of arsenic exposure: a comparison of water and toenail concentrations.
abstract: A study was conducted to evaluate toenail arsenic concentrations as a biologic marker of drinking water arsenic exposure. Study subjects were controls in a US population-based case-control study of nonmelanoma skin cancer, randomly selected from drivers' license records (those < 65 years of age) and Medicare enrollment files (those > or = 65 years of age). Between 1994 and 1997, a total of 540 controls were interviewed and toenail samples of sufficient weight were collected from 506 (93.7%) of these. Beginning in 1995, a sample of tap water was taken from the participants' homes; a total of 217 (98.6%) water samples were obtained from the 220 subjects interviewed. Arsenic determinations were made from toenail samples using neutron activation analysis. Water samples were analyzed using hydride-generation magnet sector inductively coupled mass spectrometry. Among 208 subjects with both toenail and water measurements, the correlation (r) between water and nail arsenic was 0.65 (p < 0.001) among those with water arsenic concentrations of 1 microg/liter or higher and 0.08 (p = 0.31) among those with concentrations below 1 microg/liter (overall r = 0.46, p < 0.001). Our data suggest that toenail samples provide a useful biologic marker for quantifying low-level arsenic exposure.
authors.affiliation: Department of Community and Family Medicine, Dartmouth Medical School, Hanover, NH, USA. margaret.karagas@dartmouth.edu
authors.forename: M R
authors.initials: MR
authors.lastname: Karagas
authors.forename: T D
authors.initials: TD
authors.lastname: Tosteson
authors.forename: J
authors.initials: J
authors.lastname: Blum
authors.forename: B
authors.initials: B
authors.lastname: Klaue
authors.forename: J E
authors.initials: JE
authors.lastname: Weiss
authors.forename: V
authors.initials: V
authors.lastname: Stannard
authors.forename: V
authors.initials: V
authors.lastname: Spate
authors.forename: J S
authors.initials: JS
authors.lastname: Morris
mesh_terms: D000328:Adult; D000368:Aged; D001151:Arsenic / Q000032:analysis*; D016022:Case-Control Studies; D004781:Environmental Exposure / Q000032:analysis*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009262:Nails / Q000737:chemistry*; D014034:Toes; D014867:Water / Q000737:chemistry*; D014881:Water Supply
chemical_list: D014867:Water; D001151:Arsenic