title: Risk of gastric cancer by water source: evidence from the Golestan case-control study.
abstract: BACKGROUND
  Gastric cancer (GC) is the world's fifth most common cancer, and the third leading cause of cancer-related death. Over 70% of incident cases and deaths occur in developing countries. We explored whether disparities in access to improved drinking water sources were associated with GC risk in the Golestan Gastric Cancer Case Control Study.
  
  
  RESULTS
  306 cases and 605 controls were matched on age, gender, and place of residence. We conducted unconditional logistic regression to calculate odds ratios (ORs) and 95% confidence intervals (CI), adjusted for age, gender, ethnicity, marital status, education, head of household education, place of birth and residence, homeownership, home size, wealth score, vegetable consumption, and H. pylori seropositivity. Fully-adjusted ORs were 0.23 (95% CI: 0.05-1.04) for chlorinated well water, 4.58 (95% CI: 2.07-10.16) for unchlorinated well water, 4.26 (95% CI: 1.81-10.04) for surface water, 1.11 (95% CI: 0.61-2.03) for water from cisterns, and 1.79 (95% CI: 1.20-2.69) for all unpiped sources, compared to in-home piped water. Comparing unchlorinated water to chlorinated water, we found over a two-fold increased GC risk (OR 2.37, 95% CI: 1.56-3.61).
  
  
  CONCLUSIONS
  Unpiped and unchlorinated drinking water sources, particularly wells and surface water, were significantly associated with the risk of GC.
authors.affiliation: Department of Anthropology, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX, 78249, United States of America; Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, 9609 Medical Center Dr., Bethesda, MD, 20892, United States of America.
authors.forename: Laura
authors.initials: L
authors.lastname: Eichelberger
authors.affiliation: Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, 9609 Medical Center Dr., Bethesda, MD, 20892, United States of America.
authors.forename: Gwen
authors.initials: G
authors.lastname: Murphy
authors.affiliation: Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, 9609 Medical Center Dr., Bethesda, MD, 20892, United States of America; Digestive Oncology Research Center, Digestive Disease Research Institute, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Arash
authors.initials: A
authors.lastname: Etemadi
authors.affiliation: Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, 9609 Medical Center Dr., Bethesda, MD, 20892, United States of America.
authors.forename: Christian C
authors.initials: CC
authors.lastname: Abnet
authors.affiliation: Digestive Oncology Research Center, Digestive Disease Research Institute, Tehran University of Medical Sciences, Tehran, Iran; Surveillance and Health Services Research, American Cancer Society, 250 Williams St., Atlanta, GA, 30303, United States of America.
authors.forename: Farhad
authors.initials: F
authors.lastname: Islami
authors.affiliation: Digestive Oncology Research Center, Digestive Disease Research Institute, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Ramin
authors.initials: R
authors.lastname: Shakeri
authors.affiliation: Digestive Oncology Research Center, Digestive Disease Research Institute, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Reza
authors.initials: R
authors.lastname: Malekzadeh
authors.affiliation: Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, 9609 Medical Center Dr., Bethesda, MD, 20892, United States of America.
authors.forename: Sanford M
authors.initials: SM
authors.lastname: Dawsey
mesh_terms: D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D060766:Drinking Water / Q000009:adverse effects* / Q000032:analysis; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D013274:Stomach Neoplasms / Q000139:chemically induced* / Q000453:epidemiology*; D014881:Water Supply
chemical_list: D060766:Drinking Water