Cancer Causes & Control

, Volume 7, Issue 6, pp 596–604 | Cite as

Case-control study of bladder cancer and chlorination by-products in treated water (Ontario, Canada)

  • Will D. King
  • Loraine D. Marrett
Research Papers

Chlorine is by far the most commonly used chemical for the disinfection of water supplies in North America. However, chlorine reacts with organic material in the raw water producing a number of halogenated hydrocarbon by-products. This population-based case-control study in Ontario, Canada examined the relationship between bladder cancer and exposure to chlorination by-products in public water supplies. Residence and water source histories and data from municipal water supplies were used to estimate individual exposure according to water source, chlorination status, and by-product levels (represented by trihalomethane [THM] concentration). Exposures were estimated for the 40-year period prior to the interview, using 696 cases diagnosed with bladder cancer between 1 September 1992 and 1 May 1994 and 1,545 controls with at least 30 years of exposure information. Odds ratios (OR) adjusted for potential confounders were used to estimate relative risk. Those exposed to chlorinated surface water for 35 or more years had an increased risk of bladder cancer compared with those exposed for less than 10 years (OR=1.41, 95 percent confidence interval [CI]=1.10–1.81). Those exposed to an estimated THM level≥50 μg/liter for 35 or more years had 1.63 times the risk of those exposed for less than 10 years (CI=1.08–2.46). These results indicate that the risk of bladder cancer increases with both duration and concentration of exposure to chlorination by-products, with population attributable risks of about 14 to 16 percent. Chlorination by-products represent a potentially important risk factor for bladder cancer.

Key words

Bladder neoplasms Canada chlorine environmental exposures 

References

  1. 1.
    White, GC. Handbook of Chlorination. New York, NY (USA): Van Nostrand Reinhold, 1986: 256.Google Scholar
  2. 2.
    Federation of Associations on the Canadian Environment. National inventory of municipal waterworks and waste-water systems in Canada 1986. Ottawa, Ontario (Canada): Minister of Supply and Services Canada 1987.Google Scholar
  3. 3.
    Steven, AA, Moore, LA, Slocum, CJ, Smith, BL, Seeger, DR, Ireland, JC. By-products of water chlorination at ten operating utilities. In: Jolley, R, Condie, L, Johnson, JD, et al, eds. Water Chlorination: Chemistry, Environmental Impact and Health Effects. Chelsea, Michigan (USA): Lewis Publishers, Inc, 1990: 6:579–604.Google Scholar
  4. 4.
    International Agency for Research on Cancer. Chlorinated drinking-water; chlorination by-products; some other halogenated compounds; cobalt and cobalt compounds. Lyon, France: IARC, 1991; IARC Monogr Eval Carcinog Risk Hum, Vol. 52.Google Scholar
  5. 5.
    Cantor, KP. Epidemiologic studies and risk assessment of volatile organic compounds in drinking water. In: Ram, NM, Christman, RF, Cantor, KP, eds. Significance and Treatment of Volatile Organic Compounds in Water Supplies. Chelsea, MI (USA): Lewis Publishers, 1990: 465–84.Google Scholar
  6. 6.
    Bull, RJ, Robinson, M, Meier, JR, Stober, J. Use of biological assay systems to assess the relative carcinogenic hazards of disinfection by-products. Environ Health Perspect 1982; 46: 215–27.Google Scholar
  7. 7.
    McGeehin, MA, Reif, JS, Becher, JC, Mangione, EJ.Case-control study of bladder cancer and water disinfection methods in Colorado. Am J Epidemiol 1993; 138: 492–501.Google Scholar
  8. 8.
    Zierler, S, Feingold, L, Damley, RA, Craun, G. Bladder cancer in Massachusetts related to chlorinated and chloraminated drinking water: A case-control study. Arch Environ Health 1988; 43: 195–200.Google Scholar
  9. 9.
    Cantor, KP, Hoover, R, Hartge, P, et al. Bladder cancer, drinking water source and tap water consumption: a case-control study. JNCI 1987; 79: 1269–79.Google Scholar
  10. 10.
    Wilkins, JR, Comstock, GW. Source of drinking water at home and site specific cancer incidence in Washington County, Maryland. Am J Epidemiol 1981; 114: 178–90.Google Scholar
  11. 11.
    Gottlieb, MS, Carr, JK, Clarkson, JR. Drinking water and cancer incidence in Louisiana. Am J Epidemiol 1982; 116: 652–67.Google Scholar
  12. 12.
    Young, TB, Kanarek, MS, Tsiatis, AA. Epidemiologic study of drinking water chlorination and Wisconsin female cancer mortality. JNCI 1981; 67: 1991–98.Google Scholar
  13. 13.
    Brenniman, GR, Lagos, J, Amsel, J. Case-control study of cancer deaths in Illinois communities served by chlorinated and non-chlorinated water. In: Jolley, RL, Brings, W, Coamings, RB, eds. Water Chlorination Environmental Impact and Health Effects. Ann Arbor, MI (USA): Ann Arbor Science Publishers, 1980: 3: 1043–57.Google Scholar
  14. 14.
    Alavanja, M, Goldstein, I, Susser, M. A case-control study of gastrointestinal and urinary tract cancer mortality and drinking water chlorination. In: Jolley, RL, Brings, W, Coamings, RB, eds. Water Chlorination Environmental Impact and Health Effects. Ann Arbor, MI (USA): Ann Arbor Science Publishers, 1980: 3: 395–409.Google Scholar
  15. 15.
    Morris, RD, Audet, AM, Angelillo, IF, Chalmers, TC, Mosteller, F. Chlorination, chlorination by-products, and cancer: A meta-analysis. Am J Public Health 1992; 82: 955–63.Google Scholar
  16. 16.
    Lynch, CF, Woolson, RF, O'Gorman, T, Cantor, KP. Chlorinated drinking water and bladder cancer: effect of misclassification on risk estimates. Arch Environ Health 1989; 44: 252–9.Google Scholar
  17. 17.
    World Health Organization. International Classification of Diseases, Ninth Revision. Geneva, Switzerland: WHO, 1977.Google Scholar
  18. 18.
    Robles, SC, Marrett, LD, Clarke, EA, Risch, HA. An application of capture-recapture methods to the estimation of completeness of cancer registration. J Clin Epidemiol 1988; 41: 495–501.Google Scholar
  19. 19.
    Breslow, NE, Day, NE, eds. Statistical Methods in Cancer Research, Vol 1. The Analysis of Case-control Studies. Lyon, France: International Agency for Research on Cancer, 1980; IARC Sci. Pub. No. 32.Google Scholar
  20. 20.
    Bull, RJ, Meier, JR, Robinson, M, et al. Evaluation of mutagenic and carcinogenic properties of brominated and chlorinated acetonitriles, by-products of chlorination. Fundam Appl Toxicol 1985; 5: 1065–74.Google Scholar
  21. 21.
    Marrett, LD, Kreiger, N, Dodds, L, Hilditch, S. The effect on response rates of offering a small incentive with a mailed questionnaire. Ann Epidemiol 1992; 2: 745–53.Google Scholar
  22. 22.
    Siemiatycki, J, Dewar, R, Nadon, L, Gérin, M. Occupational risk factors for bladder cancer: Results from a case-control study in Montreal, Quebec, Canada. Am J Epidemiol 1994; 140: 1061–80.Google Scholar
  23. 23.
    Bruzzi, P, Green, SB, Byar, DP, et al. Estimating the population attributable risk for multiple risk factors using case-control data. Am J Epidemiol 1985; 122: 904–14.Google Scholar

Copyright information

© Rapid Science Publishers 1996

Authors and Affiliations

  • Will D. King
  • Loraine D. Marrett

There are no affiliations available

Personalised recommendations