Lung cancer and arsenic concentrations in drinking water in Chile.
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.
Ferreccio
C
C
Facultad de Matemáticas, Pontificia Universidad Católica de Chile, Santiago.
González
C
C
Milosavjlevic
V
V
Marshall
G
G
Sancha
A M
AM
Smith
A H
AH
D000328:Adult; D001151:Arsenic / Q000009:adverse effects* / Q000032:analysis*; D016022:Case-Control Studies; D002677:Chile / Q000453:epidemiology; D003300:Copper; D005260:Female; D006801:Humans; D016015:Logistic Models; D008175:Lung Neoplasms / Q000139:chemically induced* / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D008906:Mining; D016273:Occupational Exposure; D012907:Smoking / Q000009:adverse effects; D014874:Water Pollutants, Chemical / Q000009:adverse effects* / Q000032:analysis*
D014874:Water Pollutants, Chemical; D003300:Copper; D001151:Arsenic