Lung cancer and arsenic concentrations in drinking water in Chile

Epidemiology. 2000 Nov;11(6):673-9. doi: 10.1097/00001648-200011000-00010.

Abstract

Cities in northern Chile had arsenic concentrations of 860 microg/liter in drinking water in the period 1958-1970. Concentrations have since been reduced to 40 microg/liter. We investigated the relation between lung cancer and arsenic in drinking water in northern Chile in a case-control study involving patients diagnosed with lung cancer between 1994 and 1996 and frequency-matched hospital controls. The study identified 152 lung cancer cases and 419 controls. Participants were interviewed regarding drinking water sources, cigarette smoking, and other variables. Logistic regression analysis revealed a clear trend in lung cancer odds ratios and 95% confidence intervals (CIs) with increasing concentration of arsenic in drinking water, as follows: 1, 1.6 (95% CI = 0.5-5.3), 3.9 (95% CI = 1.2-12.3), 5.2 (95% CI = 2.3-11.7), and 8.9 (95% CI = 4.0-19.6), for arsenic concentrations ranging from less than 10 microg/liter to a 65-year average concentration of 200-400 microg/liter. There was evidence of synergy between cigarette smoking and ingestion of arsenic in drinking water; the odds ratio for lung cancer was 32.0 (95% CI = 7.2-198.0) among smokers exposed to more than 200 microg/liter of arsenic in drinking water (lifetime average) compared with nonsmokers exposed to less than 50 microg/liter. This study provides strong evidence that ingestion of inorganic arsenic is associated with human lung cancer.

MeSH terms

  • Adult
  • Arsenic / adverse effects*
  • Arsenic / analysis*
  • Case-Control Studies
  • Chile / epidemiology
  • Copper
  • Female
  • Humans
  • Logistic Models
  • Lung Neoplasms / chemically induced*
  • Lung Neoplasms / epidemiology
  • Male
  • Middle Aged
  • Mining
  • Occupational Exposure
  • Smoking / adverse effects
  • Water Pollutants, Chemical / adverse effects*
  • Water Pollutants, Chemical / analysis*

Substances

  • Water Pollutants, Chemical
  • Copper
  • Arsenic