Abstract
This study investigated arsenic and lung cancer incidence in a community setting in the Montreal area. Job histories and sociodemographic factors were collected by interview from 857 lung cancer cases, 533 general population controls, and 1,360 controls with other cancers. Chemist-hygienists assessed each subject’s lifetime occupational exposure to 294 substances. Logistic regressions yielded arsenic/lung cancer odds ratios of 1.1 (95% confidence interval = 0.60, 1.7) based on cancer controls, and 0.82 (95% confidence interval = 0.41, 1.6) based on population controls. Risk did not rise with increasing level or probability of exposure.
Worksite studies consistently show lung carcinogenicity from arsenic. Since confounding from other chemicals was well controlled, the most likely explanation is substantially lower exposures than in previous studies. The lack of association in this study demonstrates the need for caution in interpreting negative findings from population-based case-control studies, particularly when exposures are low or rare, as well as the difficulty in generating hypotheses from such studies.
Résumé
Cette étude a évalué le rôle de l’arsenic sur l’incidence du cancer du poumon dans la population générale montréalaise. Au total, 857 cas de cancer du poumon, 533 témoins de la population générale et 1 360 témoins atteints d’autres cancers ont été interrogés afin d’obtenir leur histoire professionnelle et leurs caractéristiques socio-démographiques. Des chimisteshygiénistes ont évalué l’exposition à 294 substances au cours de leur vie professionnelle. Les régressions logistiques ont abouti à un rapport de cotes de 1,1 (intervalle de confiance à 95 % = 0,6–1,7) pour le cancer du poumon suite à l’exposition à l’arsenic en se basant sur les témoins avec cancer, et de 0,82 (intervalle de confiance à 95 % = 0,4–1,6) en se basant sur les témoins de la population. Le risque n’augmentait pas en fonction du niveau ou de la probabilité d’exposition.
Les études menées en milieu de travail indiquent de façon répétée que l’arsenic est un agent cancérogène pulmonaire. Puisqu’un bon ajustement était fait pour d’autres substances potentiellement confondantes, l’explication la plus plausible est que les expositions étaient plus faibles que dans les études précédentes. L’absence d’association dans cette étude démontre qu’il faut user de prudence en interprétant des résultats négatifs obtenus lors d’études castémoins menées dans la population, particulièrement lorsque les expositions sont faibles ou rares, et qu’il est difficile de générer des hypothèses à partir de telles études.
Footnotes
Support for this work was provided by NIEHS Grant #P42-ES05948.
References
- 1.Hill AB, Faning EL. Studies in the incidence of cancer in a factory handling inorganic compounds of arsenic. I. Mortality experience in the factory. Br J Ind Med. 1948;5:1–15. [PMC free article] [PubMed] [Google Scholar]
- 2.Axelson O. Arsenic exposure and mortality: A case-reference study from a Swedish copper smelter. Br J Ind Med. 1978;35:8–15. doi: 10.1136/oem.35.1.8. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 3.Tokudome S, Kuratsune M. A cohort study on mortality from cancer and other causes among workers at a metal refinery. Int J Cancer. 1976;17:310–17. doi: 10.1002/ijc.2910170306. [DOI] [PubMed] [Google Scholar]
- 4.Enterline PE, Marsh GM. Cancer among workers exposed to arsenic and other substances in a copper smelter. Am J Epidemiol. 1982;116:895–911. doi: 10.1093/oxfordjournals.aje.a113492. [DOI] [PubMed] [Google Scholar]
- 5.Lee-Feldstein A. Arsenic and respiratory cancer in humans: Follow-up of copper smelter employees in Montana. J Natl Cancer Inst. 1983;70:601–10. [PubMed] [Google Scholar]
- 6.Lee-Feldstein A. A comparison of several measures of exposure to arsenic: Matched casecontrol study of copper smelter employees. Am J Epidemiol. 1989;129:112–24. doi: 10.1093/oxfordjournals.aje.a115100. [DOI] [PubMed] [Google Scholar]
- 7.Taylor PR, Qiao Y-L, Schatzkin A, et al. Relation of arsenic exposure to lung cancer among tin miners in Yunnan Province, China. Br J Ind Med. 1989;46:881–86. doi: 10.1136/oem.46.12.881. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 8.Rencher AC, Carter MW, McKee DW. A retrospective epidemiological study of mortality at a large western copper smelter. J Occup Med. 1977;19:754–58. [PubMed] [Google Scholar]
- 9.Jarup L, Pershagen G, Wall S. Cumulative arsenic exposure and lung cancer in smelter workers: A dose-response study. Am J Ind Med. 1989;15:31–41. doi: 10.1002/ajim.4700150105. [DOI] [PubMed] [Google Scholar]
- 10.Jarup L, Pershagen G. Arsenic exposure, smoking and lung cancer in smelter workers–a casecontrol study. Am J Epidemiol. 1991;134:545–51. doi: 10.1093/oxfordjournals.aje.a116128. [DOI] [PubMed] [Google Scholar]
- 11.Hertz-Picciotto I, Smith AH, Holtzman D, et al. Synergism between occupational arsenic exposure and smoking in the induction of lung cancer. Epidemiol. 1992;3:23–31. doi: 10.1097/00001648-199201000-00006. [DOI] [PubMed] [Google Scholar]
- 12.Hertz-Picciotto I, Smith AH. Observations on the dose-response curve for arsenic exposure and lung cancer. Scand J Work Environ Health. 1993;19:217–26. doi: 10.5271/sjweh.1480. [DOI] [PubMed] [Google Scholar]
- 13.Siemiatycki J, Gérin M, Dewar R, Nadon L, Lakhani RZ, Richardson L. Association between occupational circumstances and cancer. In: Siemiatycki J, editor. Risk Factors for Cancer in the Workplace. Boca Raton, FL: CRC Press; 1991. [Google Scholar]
- 14.Siemiatycki J, Richardson L, Gérin M, et al. Associations between several sites of cancer and nine organic dusts: Results from a hypothesisgenerating case-control study in Montreal, 1979–1983. Am J Epidemiol. 1986;123:235–49. doi: 10.1093/oxfordjournals.aje.a114232. [DOI] [PubMed] [Google Scholar]
- 15.Siemiatycki J, Wacholder S, Richardson L, et al. Discovering carcinogens in the occupational environment: Methods of data collection and analysis of a large case-referent monitoring system. Scand J Work Environ Health. 1987;13:486–92. doi: 10.5271/sjweh.2009. [DOI] [PubMed] [Google Scholar]
- 16.Siemiatycki J, Dewar R, Nadon L, et al. Associations between several sites of cancer and twelve petroleum-derived liquids: Results from a case-referent study in Montreal. Scand J Work Environ Health. 1987;13:493–504. doi: 10.5271/sjweh.2008. [DOI] [PubMed] [Google Scholar]
- 17.Siemiatycki J, Dewar R, Stewart P, et al. Associations between several sites of cancer and ten types of exhaust and combustion products. Results from a case-referent study in Montreal. Scand J Work Environ Health. 1988;14:79–90. doi: 10.5271/sjweh.1949. [DOI] [PubMed] [Google Scholar]
- 18.Siemiatycki J, Nadon L, Lakhani R, et al. Exposure assessment. In: Siemiatycki J, et al., editors. Risk Factors for Cancer in the Workplace. Boca Raton, FL: CRC Press; 1991. [Google Scholar]
- 19.Fung KY, Howe GR. Methodological issues in case-control studies. III: The effect of joint misclassification of risk factors and confounding factors upon estimation and power. Int J Epidemiol. 1984;13:366–70. doi: 10.1093/ije/13.3.366. [DOI] [PubMed] [Google Scholar]
- 20.Tseng WP, Chu HM, How SW, et al. Prevalence of skin cancer in an endemic area of chronic arsenicism in Taiwan. J Natl Cancer Inst. 1968;40:453–63. [PubMed] [Google Scholar]
- 21.Smith AH, Hopenhayn-Rich C, Bates MN, et al. Cancer risks from arsenic in drinking water. Environ Health Perspect. 1992;97:259–67. doi: 10.1289/ehp.9297259. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 22.Dosemeci M, Stewart P. Recommendations for reducing the effects of exposure misclassification on relative risk estimates. Occup Hygiene. 1996;3:169–76. [Google Scholar]
- 23.Neal PA, Dreessen WC, Edwards TI, et al. A Study of the Effect of Lead Arsenate Exposure on Orchardists and Consumers of Sprayed Fruit. 1941. [Google Scholar]
- 24.Nelson WC, Lykins MH, Mackey J, et al. Mortality among orchard workers exposed to lead arsenate spray: A cohort study. J Chron Dis. 1973;26:105–18. doi: 10.1016/0021-9681(73)90009-X. [DOI] [PubMed] [Google Scholar]
- 25.Hertz-Picciotto I, Neutra RR. Resolving discrepancies among studies: The influence of dose on effect size. Epidemiol. 1994;5:156–63. doi: 10.1097/00001648-199403000-00005. [DOI] [PubMed] [Google Scholar]