Cancer Mortality in a Chinese Population Exposed to Hexavalent Chromium in Drinking Water

• Published in: Epidemiology (Cambridge, Mass.) Mass.), 2008-01, Vol.19 (1), p.12-23
• Main Authors: Beaumont, James J., Sedman, Richard M., Reynolds, Stephen D., Sherman, Claire D., Li, Ling-Hong, Howd, Robert A., Sandy, Martha S., Zeise, Lauren, Alexeeff, George V.
• Format: Article
• Language: English
• Subjects: China - epidemiology; Chromium; Chromium - analysis; Chromium - toxicity; Groundwater; Humans; Lung neoplasms; Lung Neoplasms - mortality; Mortality; Odds Ratio; Population estimates; Potable water; Retrospective Studies; River water; Stomach; Stomach cancer; Stomach Neoplasms - mortality; Toxic Metals; Water Pollutants, Chemical - analysis; Water Pollutants, Chemical - toxicity; Water pollution; Water Supply - analysis
• ISSN: 1044-3983; 1531-5487
• DOI: 10.1097/EDE.0b013e31815cea4c

Background: In 1987, investigators in Liaoning Province, China, reported that mortality rates for all cancer, stomach cancer, and lung cancer in 1970-1978 were higher in villages with hexavalent chromium (Cr⁺⁶)-contaminated drinking water than in the general population. The investigators reported rates, but did not report statistical measures of association or precision. Methods: Using reports and other communications from investigators at the local Jinzhou Health and Anti-Epidemic Station, we obtained data on Cr⁺⁶ contamination of groundwater and cancer mortality in 9 study regions near a ferrochromium factory. We estimated: (1) person-years at risk in the study regions, based on census and population growth rate data, (2) mortality counts, based on estimated person-years at risk and previously reported mortality rates, and (3) rate ratios and 95% confidence intervals. Results: The all-cancer mortality rate in the combined 5 study regions with Cr⁺⁶-contaminated water was negligibly elevated in comparison with the rate in the 4 combined study regions without contaminated water (rate ratio = 1.13; 95% confidence interval = 0.86-1.46), but was somewhat more elevated in comparison with the whole province (1.23; 0.97-1.53). Stomach cancer mortality in the regions with contaminated water was more substantially elevated in comparison with the regions without contaminated water (1.82; 1.11-2.91) and the whole province (1.69; 1.12-2.44). Lung cancer mortality was slightly elevated in comparison with the unexposed study regions (1.15; 0.62-2.07), and more strongly elevated in comparison with the whole province (1.78; 1.03-2.87). Mortality from other cancers combined was not elevated in comparison with either the unexposed study regions (0.86; 0.53-1.36) or the whole province (0.92; 0.58-1.38). Conclusions: While these data are limited, they are consistent with increased stomach cancer risk in a population exposed to Cr⁺⁶ in drinking water.