Online Program

Incidence of skin cancers among population exposed to geothermal hot water while bathing and washing

Monday, November 4, 2013 : 1:35 p.m. - 1:55 p.m.

Vilhjalmur Rafnsson, MD, Department of Preventive Medicine, University of Iceland, Reykjavik, Iceland
Adalbjorg Kristbjornsdottir, PhD, Centre of Public Health Sciences, University of Iceland, Reykjavik, Iceland
Background/Purpose: Studies on populations in volcanic/geothermal areas in Iceland showed increased incidence of all cancers, breast, prostate cancer, and basal cell carcinoma of skin (BCC). The aim was to study the risk of skin cancers according to morphology and point of origin in the combined populations of previous studies. Methods: Cohort from census included information on personal identifier, age, gender, residency, education, and housing. The follow-up from 1981 to 2010 was based on record linkage of 74,806 individuals, initially 5-64 years of age, with nation-wide death and cancer registries. The exposed population was from communities located on volcanic soil with geothermal hot-water supply generated from geothermal wells since 1972. Two reference populations were from communities located on soil with different degree of volcanic/geothermal activity, without old geothermal hot-water supply. Adjusted hazard ratio (aHR) and 95% confidence intervals (CI) were estimated in Cox-model. Results: The aHR for all skin cancer was 1.13 (95% CI 0.79-1.63) compared with reference area. The aHR for cutaneous malignant melanoma (CMM) was 1.29 (0.77-2.16), squamous cell carcinoma (SCC) 1.03 (0.62-1.72), and BCC 1.49 (1.21-1.82). The aHR for BCC of trunk was 2.57 (1.73-3.82), and of multiple/unspecified sites 4.50 (1.57-12.94). Positive exposure-response relation was observed between the risk of BCC and the degree of volcanic/geothermal activity. Conclusion: The increase of BCC was without parallel increase of CMM or SCC indicating that exposure to ultraviolet radiation is not a confounding factor and explanation should be sought in gas emission and hot-water content previously of concern in volcanic areas.

Learning Areas:

Environmental health sciences
Public health or related research

Learning Objectives:
Explain the procedure of record linkage based on personal identifier in a register study Identify the strength of nation wide cancer registry for studying morphology and point of origin in population based study Discuss the possible risk factors for skin cancers

Keyword(s): Cancer, Environment

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, and my research and publications include assessment of environmental factors and cancer risk
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: 3235.0: Cancer Epidemiology