270924 Cancer incidence and residency in geothermal area: A census based cohort study

Monday, October 29, 2012 : 11:00 AM - 11:15 AM

Vilhjalmur Rafnsson, MD , Department of Preventive Medicine, University of Iceland, Reykjavik, Iceland
Adalbjorg Kristbjornsdottir, MPH , Centre of Public Health Sciences, University of Iceland, Reykjavik, Iceland
Purpose: To assess whether exposure to geothermal gases such as hydrogen sulphide and radon among residents of a geothermal area are associated with risk of cancer. Methods: The source of data was the census in 1981. Using personal identifier those 5 to 65 years of age were record linked with nation-wide death and cancer registries. Thus, vital and emigration status was ascertained for all and cancers cases found. The total population was 183 047, total number of person years was 4 533 812, and total number of first cancers was 23 360. Population in high temperature geothermal area, defined by community code, was compared with population in non-geothermal area in Cox-model, adjusted for age, gender, education, and lodgings. Results: The hazard ratio (HR) in the high temperature geothermal area for all cancer was 1.22 (95% confidence interval (CI) 1.05-1.42) as compared with non-geothermal area. The HR for pancreas cancer was 2.85 (95%CI 1.39-5.87), bone cancer 5.80 (95%CI 1.11-30.32) breast cancer 1.59 (95%CI 1.10-2.31), lymph-hematopoietic cancer 1.64 (95%CI 1.00-2.66), and non-Hodgkin lymphoma 3.25 (95%CI 1.73-6.07). The HR for selected cancer sites were in no case significantly lower than unity. Conclusion: There is an excess risk of cancer sites sensitive to radiation; indicating that radon exposure may contribute to the risk of cancer among the population in the geothermal area. Adjustment are made for social variables and data on reproductive factors and smoking habits shows that these do not seem to explain the increased risk of cancers. Limitations of the study are inadequate information on exposure.

Learning Areas:
Environmental health sciences
Epidemiology

Learning Objectives:
Explain the strength of record linkage based on personal identifier in register studies. Identify a cancer pattern that is in agreement with exposure to ionizing radiation. Discuss whether an association is possible a causal association.

Keywords: Cancer, Epidemiology

Presenting author's disclosure statement:

Qualified on the content I am responsible for because: I am currently professor in Preventive Medicine at the University of Iceland, Iceland, and have several international publication in the field.
Any relevant financial relationships? No

I agree to comply with the American Public Health Association Conflict of Interest and Commercial Support Guidelines, and to disclose to the participants any off-label or experimental uses of a commercial product or service discussed in my presentation.

Back to: 3127.0: Environmental Epidemiology