Geothermal areas and cancer

Background and aims: Previous studies in geothermal and volcanic areas have shown high risk of certain types of cancers. The aim was to study the association between residence in geothermal areas and the incidence and mortality of cancer in Iceland. Material and Methods: Studies I - IV are all population-based cohort studies. Records for individuals aged 5-64 years were obtained from the 1981 census, and they were followed through the years 1981-2013. A personal identifier was used in record linkage with nation-wide emigration, cause-of-death, and cancer registries. The exposed and reference populations were defined according to community codes, different ages of hot water supply systems, and age of bedrock. Hazard ratio, 95% confidence intervals stratified with and without cumulative years of residence were estimated in Cox-model, and different covariates were taken into account. Result: In these studies, with 33 years of follow-up, and nearly 1000 cancer cases, a high incidence was found in the population of the geothermal areas in comparison with the reference populations for all cancers combined, pancreatic cancer, breast cancer, prostate cancer, kidney cancer, combined cancers of the lymphoid and haematopoietic tissue, non-Hodgkin lymphoma and basal cell carcinoma of the skin. In the mortality study, high mortality for breast cancer, prostate cancer, kidney cancer, and non-Hodgkin lymphoma, in addition to high mortality for suicide and influenza were found in the populations of geothermal areas compared with the reference populations. The cumulative years of residence increased the risk, and dose response relation was found through the degree of volcanic/geothermal activity. Requiring five years latency yielded a higher hazard ratio. Conclusion: The result indicates high cancer risk in geothermal areas. The cause for this high incidence is not known from these ecological studies. Further studies are needed on the chemical and physical content of the geothermal water and the ambient air of the areas to detect recognized or new carcinogens.Inngangur: Erlendar rannsóknir hafa sýnt að búseta á jarðhita og eldfjalla svæðum tengist hærri tíðni ákveðinna tegunda krabbameina. Markmiðið var að rannsaka tengsl búsetu á jarðhitasvæðum og tíðni krabbameina á Íslandi. Efniviður og aðferðir: Í fjórum lýðgrunduðum hóprannsóknum var einstaklingum úr manntali 1981 fylgt eftir til loka árs 2013. Eftirfylgnin fór fram í Krabbameinsskrá og Dánarmeinaskrá. Viðbótarupplýsingar voru fengnar úr gagnagrunnum um reykinga venjur og barneignir. Útsettur hópur og samanburðar hópar voru skilgreindir samkvæmt sveitarfélagsnúmerum, eftir aldri hitaveitna og aldri berggrunns. Notuð var lifunargreining og áhættuhlutfall reiknað með 95% öryggismörkum með fjölþátta greiningu. Niðurstöður: Í rannsóknunum, með nærri 33 ára eftirfylgni og um 1000 krabbameins tilfellum á jarðhitasvæðum, fannst marktækt hærri tíðni vegna allra krabbameina saman, krabbameina í briskirtli, brjóstum, blöðruhálskirtli, nýrum, eitil- og blóðmyndandi vefjum, eitilæxlum öðrum en Hodgkins meinum og grunnfrumukrabbamein í húð, á jarðhitasvæðum heldur en á samanburðarsvæðum. Í dánarmeinarannsókn var aukin áhætta á að deyja vegna krabbameina í brjóstum, blöðruhálskirtli, nýrum og eitilæxlum öðrum en Hodgkins meinum, og vegna sjálfsvíga og inflúensu. Krabbameinstíðnin tengdist lengd búsetu, og einnig var krabbameinstíðnin hærri því meiri sem jarðhitavirkin var og hitaveiturnar voru eldri. Auk þessa var krabbameinstíðnin hærri þegar tekið var tillit til 5 ára hugsanlegs framleiðslutíma krabbameinanna. Ályktun: Ekki er vitað hver er orsökin fyrir hárri tíðni krabbameina á jarðhitasvæðunum á grunni þessara vistfræðilegu rannsókna. Frekari rannsókna er þörf á efna- og eðlisfræðilegum þáttum jarðhitavatns og umhverfisþátta á jarðhitasvæðum, til að athuga hvort finnast þekktir og/eða óþekktir krabbameinsvaldar sem gætu skýrt þessa háu krabbameinstíðni.This thesis was funded by grant from the University of Iceland Research Fund and the Icelandic Centre for Researc

Evolutionarily conserved and non-conserved retrovirus restriction activities of artiodactyl APOBEC3F proteins

The APOBEC3 proteins are unique to mammals. Many inhibit retrovirus infection through a cDNA cytosine deamination mechanism. HIV-1 neutralizes this host defense through Vif, which triggers APOBEC3 ubiquitination and degradation. Here, we report an APOBEC3F-like, double deaminase domain protein from three artiodactyls: cattle, pigs and sheep. Like their human counterparts, APOBEC3F and APOBEC3G, the artiodactyl APOBEC3F proteins are DNA cytosine deaminases that locate predominantly to the cytosol and can inhibit the replication of HIV-1 and MLV. Retrovirus restriction is attributable to deaminase-dependent and -independent mechanisms, as deaminase-defective mutants retain significant anti-retroviral activity. However, unlike human APOBEC3F and APOBEC3G, the artiodactyl APOBEC3F proteins have an active N-terminal DNA cytosine deaminase domain, which elicits a broader dinucleotide deamination preference, and they are resistant to HIV-1 Vif. These data indicate that DNA cytosine deamination; sub-cellular localization and retrovirus restriction activities are conserved in mammals, whereas active site location, local mutational preferences and Vif susceptibility are not. Together, these studies indicate that some properties of the mammal-specific, APOBEC3-dependent retroelement restriction system are necessary and conserved, but others are simultaneously modular and highly adaptable

Dietary reference values for potassium

Scientific opinion on Dietary Reference Values for potassium

Dietary reference values for sodium

Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) derived dietary reference values (DRVs) for sodium. Evidence from balance studies on sodium and on the relationship between sodium intake and health outcomes, in particular cardiovascular disease (CVD)-related endpoints and bone health, was reviewed. The data were not sufficient to enable an average requirement (AR) or population reference intake (PRI) to be derived. However, by integrating the available evidence and associated uncertainties, the Panel considers that a sodium intake of 2.0 g/day represents a level of sodium for which there is sufficient confidence in a reduced risk of CVD in the general adult population. In addition, a sodium intake of 2.0 g/day is likely to allow most of the general adult population to maintain sodium balance. Therefore, the Panel considers that 2.0 g sodium/day is a safe and adequate intake for the general EU population of adults. The same value applies to pregnant and lactating women. Sodium intakes that are considered safe and adequate for children are extrapolated from the value for adults, adjusting for their respective energy requirement and including a growth factor, and are as follows: 1.1 g/day for children aged 1\u20133 years, 1.3 g/day for children aged 4\u20136 years, 1.7 g/day for children aged 7\u201310 years and 2.0 g/day for children aged 11\u201317 years, respectively. For infants aged 7\u201311 months, an Adequate Intake (AI) of 0.2 g/day is proposed based on upwards extrapolation of the estimated sodium intake in exclusively breast-fed infants aged 0\u20136 months

Incidence of cancer among residents of high temperature geothermal areas in Iceland: a census based study 1981 to 2010

Abstract Background Residents of geothermal areas are exposed to geothermal emissions and water containing hydrogen sulphide and radon. We aim to study the association of the residence in high temperature geothermal area with the risk of cancer. Methods This is an observational cohort study where the population of a high-temperature geothermal area (35,707 person years) was compared with the population of a cold, non-geothermal area (571,509 person years). The cohort originates from the 1981 National Census. The follow up from 1981 to 2010 was based on record linkage by personal identifier with nation-wide death and cancer registries. Through the registries it was possible to ascertain emigration and vital status and to identify the cancer cases, 95% of which had histological verification. The hazard ratio (HR) and 95% confidence intervals (CI) were estimated in Cox-model, adjusted for age, gender, education and housing. Results Adjusted HR in the high-temperature geothermal area for all cancers was 1.22 (95% CI 1.05 to 1.42) as compared with the cold area. The HR for pancreatic cancer was 2.85 (95% CI 1.39 to 5.86), breast cancer 1.59 (95% CI 1.10 to 2.31), lymphoid and hematopoietic cancer 1.64 (95% CI 1.00 to 2.66), and non-Hodgkins lymphoma 3.25 (95% CI 1.73 to 6.07). The HR for basal cell carcinoma of the skin was 1.61 (95% CI 1.10 to 2.35). The HRs were increased for cancers of the nasal cavities, larynx, lung, prostate, thyroid gland and for soft tissue sarcoma; however the 95% CIs included unity. Conclusions More precise information on chemical and physical exposures are needed to draw firm conclusions from the findings. The significant excess risk of breast cancer, and basal cell carcinoma of the skin, and the suggested excess risk of other radiation-sensitive cancers, calls for measurement of the content of the gas emissions and the hot water, which have been of concern in previous studies in volcanic areas. There are indications of an exposure-response relationship, as the risk was higher in comparison with the cold than with the warm reference area. Social status has been taken into account and data on reproductive factors and smoking habits show that these do not seem to explain the increased risk of cancers, however unknown confounding can not be excluded.</p

Cancer mortality and other causes of death in users of geothermal hot water

<div><p></p><p><b>Background.</b> Residents of geothermal areas have increased incidence of non-Hodgkin's lymphoma, breast, prostate, and kidney cancers. The aim was to study whether this is also reflected in cancer mortality among the population using geothermal hot water for space heating, washing, and showering.</p><p><b>Methods.</b> The follow-up was from 1981 to 2009. Personal identifier of those 5–64 years of age was used in record linkage with nationwide death registry. Thus, vital and emigration status was ascertained. The exposed population was defined as inhabitants of communities with district heating generated from geothermal wells since 1972. Reference populations were inhabitants of other areas with different degrees of volcanic/geothermal activity. Hazard ratio (HR) and 95% confidence intervals (CI) were adjusted for age, gender, education, housing, reproductive factors and smoking habits.</p><p><b>Results.</b> Among those using geothermal water, the HR for all causes of death was 0.98 (95% CI 0.91–1.05) as compared with cold reference area. The HR for breast cancer was 1.53 (1.04–2.24), prostate cancer 1.74 (1.21–2.52), kidney cancer 1.78 (1.03–3.07), and for non-Hodgkin's lymphoma 2.01 (1.05–3.38). HR for influenza was 3.36 (1.32–8.58) and for suicide 1.49 (1.03–2.17).</p><p><b>Conclusion.</b> The significant excess mortality risk of breast and prostate cancers, and non-Hodgkin's lymphoma confirmed the results of similarly designed studies in Iceland on cancer incidence among populations from high-temperature geothermal areas and users of geothermal hot water. The risk is not confined to cancers with good prognosis, but also concerns fatal cancers. Further studies are needed on the chemical and physical content of the water and the environment emissions in geothermal areas.</p></div

Kaplan-Meier estimates of event free proportion for all cancers since the census 1981, dashed line indicate population in geothermal heating area, and black line population in the cold reference area.

<p>Kaplan-Meier estimates of event free proportion for all cancers since the census 1981, dashed line indicate population in geothermal heating area, and black line population in the cold reference area.</p

Association of Cancer Incidence and Duration of Residence in Geothermal Heating Area in Iceland: An Extended Follow-Up

<div><p>Background</p><p>Residents of geothermal areas have higher incidence of non-Hodgkin’s lymphoma, breast cancer, prostate cancer, and kidney cancers than others. These populations are exposed to chronic low-level ground gas emissions and various pollutants from geothermal water. The aim was to assess whether habitation in geothermal areas and utilisation of geothermal water is associated with risk of cancer according to duration of residence.</p><p>Methods</p><p>The cohort obtained from the census 1981 was followed to the end of 2013. Personal identifier was used in record linkage with nation-wide emigration, death, and cancer registries. The exposed population, defined by community codes, was located on young bedrock and had utilised geothermal water supply systems since 1972. Two reference populations were located by community codes on older bedrock or had not utilised geothermal water supply systems for as long a period as had the exposed population. Adjusted hazard ratio (HR), 95% confidence intervals (CI) non-stratified and stratified on cumulative years of residence were estimated in Cox-model.</p><p>Results</p><p>The HR for all cancer was 1.21 (95% CI 1.12–1.30) as compared with the first reference area. The HR for pancreatic cancer was 1.93 (1.22–3.06), breast cancer, 1.48 (1.23–1.80), prostate cancer 1.47 (1.22–1.77), kidney cancer 1.46 (1.03–2.05), lymphoid and haematopoietic tissue 1.54 (1.21–1.97), non-Hodgkin´s lymphoma 2.08 (1.38–3.15) and basal cell carcinoma of the skin 1.62 (1.35–1.94). Positive dose-response relationship was observed between incidence of cancers and duration of residence, and between incidence of cancer and degree of geothermal/volcanic activity in the comparison areas.</p><p>Conclusions</p><p>The higher cancer incidence in geothermal areas than in reference areas is consistent with previous findings. As the dose-response relationships were positive between incidence of cancers and duration of residence, it is now more urgent than before to investigate the chemical and physical content of the geothermal water and of the ambient air of the areas to detect recognized or new carcinogens.</p></div