Online Program

Cancer incidence and use of geothermal hot water for heating and bathing

Tuesday, November 3, 2015 : 5:24 p.m. - 5:42 p.m.

Adalbjorg Kristbjornsdottir, PhD, Centre of Public Health Sciences, University of Iceland, Reykjavik, Iceland
Vilhjalmur Rafnsson, MD, Department of Preventive Medicine, University of Iceland, Reykjavik, Iceland
Background: Residents of geothermal areas have increased incidence and excess mortality of non-Hodgkin’s lymphoma, breast, prostate, and kidney cancers. These populations are exposed to chronic low level ground gas emissions and various pollutants from the geothermal hot water. The aim was to assess whether utilization of geothermal hot water is associated with risk of cancer according to length of residence.

Methods: Those 5-64 years of age were obtained from the census 1981, and followed through 1981-2013. Personal identifier was used in record linkage with nation-wide emigration, death and cancer registries. The exposed population was defined as inhabitants of communities with geothermal hot-water supply since 1972. Reference populations were defined according to different degree of volcanic/geothermal activity. Hazard ratio (HR), 95% confidence intervals (CI) and stratified by cumulative years of residence were estimated in Cox-model.

Results: Adjusted HR in the hot-water areas for all cancer was 1.21 (95%CI 1.12-1.30) as compared with the first reference area. The HR for pancreas cancer was 1.93 (1.22-3.07), breast cancer, 1.49 (1.23-1.80), prostate cancer 1.48 (1.23-1.78), kidney cancer 1.46 (1.03-2.05), lymphoid and haematopoietic tissue 1.55 (1.21-1.98), non-Hodgkin´s lymphoma 2.09 (1.38-3.17) and basal cell carcinoma of the skin 1.53 (1.27-1.84). Positive exposure-response relations were observed between incidence of cancers and length of residence.

Conclusion: The increased cancer incidence is consistent with previous findings in geothermal area. Positive exposure-response relations between incidence of cancers, length of residence, and gradient of geothermal/volcanic activity need urgent consideration. More information on water and air pollution is needed in further studies.

Learning Areas:


Learning Objectives:
Explain the procedure of record linkage based on personal identifier in register studies Identify important risk factors for cancer incidence in population based studies Discuss the possible risk factors for breast, prostate, and kidney cancer and non-Hodgkin's lymphoma Discuss how to design and conduct an ecological study with adjustment for several risk factors

Keyword(s): Cancer, Epidemiology

Presenting author's disclosure statement:

Qualified on the content I am responsible for because: I am a PhD student at the University of Iceland studying the possible environmental effect on cancer occurrence. I have MPH in Epidemiology and have been working in the field since 2010. I have published health data on this issue in peer reviewed journals. This abstract summaries a significant piece of work I have undertaken as part of my study to explore cancers in geothermal area.
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.