Icelanders have long benefitted from inhabiting a relatively young landmass, using the abundance of geothermal energy to heat homes and swimming pools and even converting it to electricity. However, new research indicates that living with the luxury of geothermal energy may come at a price: research shows that certain types of cancer are more frequent amongst residents of high temperature geothermal areas than cooler areas in Iceland.
Behind this research is Aðalbjörg Kristbjörnsdóttir, who graduated from the University of Iceland last year with a Master’s degree in public health science. For her thesis, she conducted an observational study of cancer cases among residents of the Mývatnssveit region in the north and Hveragerði in the south, from 1981 to 2010.
Geologically speaking, those are the youngest areas of Iceland. In some places the bedrock is still hot and provides the warm water in hot springs, geysers and natural baths for which Iceland is famous. The comparison areas in the study were the Eastfjords and the Westfjords, areas with some of the island’s oldest bedrock, which has long since cooled down.
“Without a doubt, there were far more incidents of cancer, especially breast cancer and a certain type of skin cancer, amongst those who live in the two areas we studied,” Aðalbjörg says of her results, which confirmed a suspicion that arose when living in her hometown, Húsavík. “I looked around me and felt there were way too many people getting sick with cancer, in my social circle alone,” she says. “I thought there must be some reason behind it which hadn’t been discovered yet, something we were not paying enough attention to.”
Thus, she took a thorough look at her immediate environment where the common denominator was geothermal energy. “I’ve always been passionate about environmental issues and I had sometimes wondered whether the geothermal water might be affecting us more than we realised,” she explains, “and it’s never been fully investigated since we started utilising it decades ago.”
Specifically, Aðalbjörg found a 22% increased chance of getting cancer of every type for people living in high temperature geothermal areas, with the most significant results being a 59% increase in breast cancer in women, a 61% increase in skin cancer (basal cell carcinoma of the skin) and a 64% increase in lymphatic and haematopoietic tissue cancers.
When she and her supervisor Vilhjálmur, a doctor in epidemiology, presented the results of the study to authorities in both Mývatnssveit and Hveragerði, Aðalbjörg says people there were quite shaken and are keen on further research.
TOO EARLY TO SAY
Being the ever so careful scientist, Aðalbjörg emphasises that it’s still too early to say exactly whether the geothermal areas have negative long-term effects on people’s health. “We’re not drawing detailed conclusions as we’ve only found a correlation. For all we know, further studies might show that the actual cause for the increase is something completely different. In any case, I think it’s necessary to continue this research.”
To that end, Aðalbjörg and Vilhjálmur have recently finished another study, which was recently published on the website of International Journal of Cancer. In short, it supports their initial findings. This study focuses on the areas that have utilised a hot water supply generated from geothermal wells since before 1972, comparing cancer incidents there with areas that don’t have geothermal hot water supplies in the cold areas in the east and west of Iceland.
“There were clues in the first study that caught our attention,” Aðalbjörg explains. “The skin cancer dispersed differently within the geothermal areas than the other cancers. So it occurred to us to look at what those particular areas had in common, which turned out to be the geothermal hot water supply, and the results show that there’s every reason to investigate this further.”
The second study shows a 15% increased chance of getting cancer for those living in areas benefitting from a geothermal hot water supply compared to areas that don’t. The increased rate in breast cancer in women is 40%; in lymphatic and haematopoietic tissue cancers it is 45% and in basal cell carcinoma of the skin it is slightly more at 46%. But the most significant increase is in prostate cancer, at 61%, and kidney cancer, at 64%.
It became clear in this second study that gas emissions in geothermal areas are not causing an increase in lung cancer among the residents, as there’s no difference between the frequency of lung cancer cases in the hot and cold areas. So Aðalbjörg wants to focus on the hot water and is planning a more specific study, which will be the founding part of her doctoral thesis in public health science.
“These first two studies were just a starting point. We now need to analyse the water and also get access to information about how long these individuals lived in the geothermal areas before they were diagnosed. Hopefully we’ll get permission to do that so we can continue the investigation,” Aðalbjörg says, stressing that these initial results should not be over interpreted.
Similar research has been carried out abroad like in New Zealand where a correlation between geothermal areas and increase in cancer cases was also found. “But there they focused more on linking specific types of cancer to the geothermal areas, like breast cancer, whereas we took into account all cancer incidents registered,” Aðalbjörg says. Aðalbjörg and Vilhjálmur’s studies therefore indicate that the supplied geothermal water might be having a broader effect on the users’ health than the foreign research has shown.
After decades of utilising geothermally heated water, it is perhaps high time to find out whether it really is safe in the long run. Still, Aðalbjörg doesn’t believe that the outcome of future research could mean the end of the joys of hot water, and says there’s no need to panic. “I only aim to make our environment safer. The more we know about the hot water, the more likely it is we can make the necessary changes to ensure we can continue using it without having to worry about our safety.”