title: Arsenic in drinking water and prostate cancer in Illinois counties: An ecologic study.
abstract: Inorganic arsenic is a lung, bladder, and skin carcinogen. One of the major sources of exposure to arsenic is through naturally contaminated drinking water. While positive associations have been observed between arsenic in drinking water and prostate cancer, few studies have explored this association in the United States.
  
  
  
  To evaluate the association between inorganic arsenic concentrations in community water systems and prostate cancer incidence in Illinois using an ecologic study design.
  
  
  
  Illinois Environmental Protection Agency data on arsenic concentrations in drinking water from community water systems throughout the state were linked with county-level prostate cancer incidence data from 2007 to 2011 from the Illinois State Cancer Registry. Incidence rates were indirectly standardized by age to calculate standardized incidence ratios (SIRs) for each county. A Poisson regression model was used to model the association between county-level SIRs and mean arsenic tertile (0.33-0.72, 0.73-1.60, and 1.61-16.23ppb), adjusting for potential confounders.
  
  
  
  For counties with mean arsenic levels in the second tertile, the SIR was 1.05 (95% CI: 0.96-1.16). For counties with mean arsenic levels in the third tertile, the SIR was 1.10 (95% CI: 1.03-1.19). There was a significant linear dose-response relationship observed between mean arsenic levels and prostate cancer incidence (p for trend=0.003).
  
  
  
  In this ecologic study, counties with higher mean arsenic levels in community water systems had significantly higher prostate cancer incidence. Individual-level studies of prostate cancer incidence and low-level arsenic exposure are needed.
authors.affiliation: University of Illinois at Chicago, School of Public Health, Epidemiology and Biostatistics Division, 1603 W. Taylor Street, Chicago, IL 60612, United States. Electronic address: cbulka2@uic.edu.
authors.forename: Catherine M
authors.initials: CM
authors.lastname: Bulka
authors.affiliation: University of Illinois at Chicago, School of Public Health, Environmental and Occupational Health Sciences Division, 2121W. Taylor Street, Chicago, IL 60612, United States. Electronic address: rjones25@uic.edu.
authors.forename: Rachael M
authors.initials: RM
authors.lastname: Jones
authors.affiliation: University of Illinois at Chicago, School of Public Health, Epidemiology and Biostatistics Division, 1603 W. Taylor Street, Chicago, IL 60612, United States. Electronic address: mturyk1@uic.edu.
authors.forename: Mary E
authors.initials: ME
authors.lastname: Turyk
authors.affiliation: University of Illinois at Chicago, School of Public Health, Epidemiology and Biostatistics Division, 1603 W. Taylor Street, Chicago, IL 60612, United States. Electronic address: lstayner@uic.edu.
authors.forename: Leslie T
authors.initials: LT
authors.lastname: Stayner
authors.affiliation: University of Illinois at Chicago, School of Public Health, Epidemiology and Biostatistics Division, 1603 W. Taylor Street, Chicago, IL 60612, United States. Electronic address: argos@uic.edu.
authors.forename: Maria
authors.initials: M
authors.lastname: Argos
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001151:Arsenic / Q000032:analysis*; D002273:Carcinogens / Q000032:analysis*; D006801:Humans; D007087:Illinois / Q000453:epidemiology; D015994:Incidence; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D011471:Prostatic Neoplasms / Q000453:epidemiology*; D012044:Regression Analysis; D014874:Water Pollutants, Chemical / Q000032:analysis*; D055815:Young Adult
chemical_list: D002273:Carcinogens; D014874:Water Pollutants, Chemical; D001151:Arsenic
keywords: Arsenic; Poisson; Prostate cancer; Spatial autocorrelation; Water