Variability of Unit Risk Estimates under Different Statistical Models and between Different Epidemiological Data Sets

  • Heiko Becher
  • Jürgen Wahrendorf


The unit risk has been proposed as a conceptually simple parameter which allows to describe the effect of a carcinogenic substance in low concentration in ambient air to the general population. It is in freqpent use by agencies like the WHO or the EPA. In this paper we describe some models for dose-response analysis and methods for estimating the unit risk and investigate the variability of unit risk estimates as it emerges from using different dose-response analyses and various dataseis. Three substances are investigated, two of which were found to provide a sufficient basis for quantitative risk estimation (arsenic, benzene). The systematic variation of the unit risk estimates was found to be relatively small for both substances.


Cumulative Exposure Nickel Compound Quantitative Risk Assessment Unit Risk Respiratory Cancer 
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  1. 1.
    Austin, H., Delzell, E., Cole, P. (1988) Benzene and Leukemia: A review of the literature and a risk assessment. Am.J.Epidemiol., 127, 419–439.Google Scholar
  2. 2.
    Becker, N., Frentzel-Beyme, R., Wagner, G. (1984) Atlas of Cancer Mortality in the Federal Republic of Germany. Springer, Heidelberg.CrossRefGoogle Scholar
  3. 3.
    Berry, G. (1980) Dose-response in case-control studies. J.Epidemiol.Community Health, 34, 217–222.CrossRefGoogle Scholar
  4. 4.
    Bond, G.G., McLaren, E.A., Baldwin, C.L., Cook, R.R. (1986) An update of mortality among chemical workers exposed to benzene. Br.J.Ind.Med., 43, 685–91.Google Scholar
  5. 5.
    Breslow, N.E. & Day, N.E. (1980) Statistical methods in cancer research Vol. I — The analysis of case-control studies. IARC Scientific Publications No. 32. Google Scholar
  6. 6.
    Breslow, N.E. & Day, N.E. (1987) Statistical methods in cancer research Vol. II — The design and analysis of cohort studies. IARC Scientific Publications No. 82. Google Scholar
  7. 7.
    Breslow, N.E., Lubin, J.H., Marek, P., Langholz, B. (1983) Multiplicative models and cohort analysis. J.Am.Stat.Assoc., 78, 1–12.Google Scholar
  8. 8.
    Cox, D.R. (1972) Regression models and life tables (with discussion). J.R.Stat.Soc. B, 34, 187–220.Google Scholar
  9. 9.
    Enterline, P.E., Henderson, V.L. & Marsh, G.M. (1987) Exposure to arsenic and respiratory cancer. A Reanalysis. Am.J. Epidemiol., 125, 929–938.Google Scholar
  10. 10.
    Enterline, P.E., Marsh, G.M., Esmen, N.A., Henderson, V.L., Callahan, CM., Paik, M. (1987) Some effects of cigarette smoking, arsenic, and SO2 on mortality among US copper smelter workers. J.Occup.Med., 29, 831–838.Google Scholar
  11. 11.
    Environmental Protection Agency (1984) The carcinogen assessment group’s final risk assessment on arsenic. EPA-600/8–83–02IF.Google Scholar
  12. 12.
    Environmental Protection Agency (1985) Carcinogen Assessment Group. Interim quantitative cancer Unit Risk estimates due to inhalation of benzene. EPA-600/X-85–022.Google Scholar
  13. 13.
    Gart, J.J., Krewski, D., Lee, P.N., Tarone, R.E., Wahrendorf, J. (1986) Statistical methods in cancer research Vol. III — The design and analysis of long-term animal experiments. IARC Scientific Publications No. 79. Google Scholar
  14. 14.
    Guerrero, V.M., Johnson, R.A. (1982) Use of the Box-Cox transformation with binary response models. Biometrika, 69, 309–314.CrossRefGoogle Scholar
  15. 15.
    International Agency for Research on Cancer (1982) Evaluation of the carcinogenic risk of chemicals to humans. IARC Monograph, 29.Google Scholar
  16. 16.
    International Agency for Research on Cancer (1987) Overall Evaluations of Carcinogenicity: An Updating of IARC Monographs Volumes 1 to 42. IARC Monograph, Suppl. 7.Google Scholar
  17. 17.
    Lee-Feldstein, A. (1986) Cumulative exposure to arsenic and its relationship to respiratory cancer among copper smelter employees. J.Occup.Med., 28, 296–302.Google Scholar
  18. 18.
    Lubin, J.H., Pottern, L.M., Blot, W.J., Tokudome, S., Stone, B.J., Fraumeni, J.F. (1981) Respiratory cancer among copper smelter workers: recent mortality statistics. J.Occup.Med., 23, 779–784.CrossRefGoogle Scholar
  19. 19.
    Ott, M.G., Holder, B.B. & Gordon, M.D. (1974) Respiratory cancer and occupational exposure to arsenicals. Arch. Environ.Health, 29, 250–255.Google Scholar
  20. 20.
    Pott, F., Rippe, R.M., Roller, M., Csicsaky, M., Rosenbruch, M., Huth, F. (1988) Carcinogenicity of nickel compounds and nickel alloys in rats by LP. Injection. Proceed. of the 4th Intern. Conference on Nickel Metabol. and Toxicol., Finland.Google Scholar
  21. 21.
    Pott, F., Ziem, U., Reiffer, F.J., Huth, F., Ernst, H., Mohr, U. (1987) Carcinogenicity studies on fibres, metal compounds, and some other dusts in rats. Exp.Pathol, 32, 129–152.CrossRefGoogle Scholar
  22. 22.
    Rinsky, R.A, Smith, A.B., Hornung, R., Filloon, T.G., Young, R.J., Okun, AH., Landrigan, P.J. (1987) Benzene and leukemia — an epidemiologic risk assessment. N.Engl.J.Med., 316, 1044–1050.CrossRefGoogle Scholar
  23. 23.
    WHO (1987) Air quality guidelines for Europe. WHO regional publications. European series No. 23.Google Scholar
  24. 24.
    Welch, K., Higgins, I., Oh, M., Burchfiel, C. (1982) Arsenic exposure, smoking, and respiratory cancer in copper smelter workers. Arch.Environ.Health, 37, 325–335.Google Scholar
  25. 25.
    Wong, O. (1987) An industry wide mortality study of chemical workers occupationally exposed to benzene. II. Dose response analyses. Br.J.Jnd.Med., 44, 382–95.Google Scholar
  26. 26.
    Yin, S.N., Li, G.L., Tain, F.D., Fu, Z.I., Jin, C., Chen, Y.J., Luo, S.J., Ye, P.Z., Zhang, J.Z., Wang, G.C. (1987) Leukemia in benzene workers: A retrospective cohort study. Br.J.Ind.Med., 44, 124–8.Google Scholar

Copyright information

© Birkhäuser Boston 1990

Authors and Affiliations

  • Heiko Becher
    • 1
  • Jürgen Wahrendorf
    • 1
  1. 1.Institute of Epidemiology and BiometryGerman Cancer Research CenterHeidelbergFederal Republic of Germany

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