| 1. |
- Hansen, Violeta, 1979, et al.
(författare)
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Indoor radon survey in Greenland and Whitehorse, Canada, and dose assessment
- 2023
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Ingår i: XIX conference of the Nordic Society for Radiation Protection, held at Malmö Live, Malmö, Sweden, June 5-9, 2023. - https://nsfs.org/?lang=en : Yukon Lung Association.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Indoor radon and its decay products are the primary sources of the population's exposure to background ionizing radiation and one of the leading causes of lung cancer, with a higher risk for smokers due to the synergistic effects of radon decay products and cigarette smoking. In the Arctic and sub-Arctic, winters are longer than at lower latitudes, and people spend more time indoors than in more temperate climate regions. The permafrost acts as an effective radon barrier, reducing indoor radon exposure, but permafrost is now thawing due to climate change, and its effect on indoor radon exposure is unknown. A total of 459 year-long radon measurements in 257 detached and semi-detached residential homes in southwest and south Greenland were carried out and a dose assessment was performed. A community-driven long-term radon survey was completed in 232 residential homes in different subdivisions of sub-Arctic Whitehorse, Canada, during the heating season from November to April in 2016 – 2017 and 2017 – 2018. The annual arithmetic and geometric means of indoor radon concentrations were 10.5 ± 0.2 Bq m-3 and 8.0 ± 2.3 Bq m-3 in Nuuk, 139.0 ± 1.0 Bq m-3 and 97.3 ± 2.1 Bq m-3 in Narsaq, and 42.1 ± 0.7 Bq m-3 and 22.0 ± 3.1 Bq m-3 in Qaqortoq. The arithmetic and geometric means of indoor radon activity concentrations in different subdivisions of Whitehorse ranged from 52 ± 0.6 Bq m-3 and 37 ± 2.3 Bq m-3 in Downtown to 993.0 ± 55.0 Bq m-3 and 726.2 ± 2.4 Bq m-3 in Wolf Creek. Underlying geology and the glacial surfaces may partly explain these variations in indoor radon concentrations. The estimated annual average dose to adults in Greenland and Whitehorse is higher than the world's average annual effective dose of 1.3 mSv due to inhalation of indoor radon.
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| 2. |
- Hansen, Violeta, 1979, et al.
(författare)
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Naturally occurring radionuclides assessment in the Arctic
- 2023
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Ingår i: The XIX conference of the Nordic Society for Radiation Protection, held at Malmö Live, Malmö, Sweden, June 5-9, 2023. - https://nsfs.org/?lang=en : The Nordic Society for Radiation Protection (NSFS).
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Naturally occurring radionuclides (NORs), primarily 210Po, accumulates in seafood, marine, and terrestrial mammals, which are an important part of the traditional Arctic diet. Arctic seafood plays an important role in the worldwide seafood industry. NORs were measured in glaciers from Svalbard, the Arctic Ocean, surface seawater and sediments from Norwegian marine areas, seabirds from Greenland, seafood and marine mammals from the Nordic region, Faroe Islands, Greenland, and Canada, terrestrial mammals from Greenland, and lake sediments in northernmost Finland. Outdoor 222Rn was measured in Finland, Canada, and Norway and atmospheric 210Pb, 212Pb, and 7Be were measured in Norway, Sweden, Finland, Iceland, and Canada. Deposited 210Pb and 7Be were measured in Sweden and Finland. Glaciers and marine sediment results show oil and gas, coal combustion, and ore mining as anthropogenic sources. NORs are long-range transported via atmospheric and oceanic currents in the Arctic. 210Pb has a long atmospheric residence time, especially in winter. 228Ra activities in the Transpolar Drift approximately doubled between 2007 and 2015, indicating that climate-driven changes may be increasing the release of shelf-derived elements to the open Arctic Ocean. Results showed no effect of climate change on 210Pb deposition in sediments in Lake Kevojarvi in northernmost Finland. 210Po is the major contributor to the annual effective dose via seafood and marine and terrestrial mammal consumption in the Arctic population, far exceeding dose contributions from 137Cs, 226Ra, 228Ra, and 210Pb. 210Po absorbed dose rates to studied biota are several orders of magnitude lower than the recommended dose rate screening value of 10 µGy h-1. NORs atmospheric results follow an annual cycle, which is mainly driven by seasonal weather and climate changes. Understanding the sources and associated doses from NORs is necessary to assess risks and public perception of risks, support science-based decision-making, and policy development engaging public and Indigenous peoples.
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| 3. |
- Jeremiassen, Ninni, et al.
(författare)
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Leaching dynamics of Pb, Zn, and F: Long-term leaching of waste rock from mine site of Ivittuut, South Greenland
- 2024
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Ingår i: 15th International Mine Water Association Congress (IMWA), April 21–26, 2024, West Virginia, USA.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Mining pollution legacies can have significant environmental and health impacts on nearby communities. Therefore, it is important to understand the weathering processes of mining waste to explore proper methods for remediation. Ivittuut, situated in Arsuk Fjord, South Greenland, is among the few mining pollution legacies in Greenland, where cryolite has been mined for approximately 130 years. The generated waste rock was disposed of along the coastline in Ivittuut, which contains sulphides, including pyrite (FeS2), galena (PbS), sphalerite (ZnS), and chalcopyrite (CuFeS2), and minor amounts of arsenopyrite (FeAsS) and molybdenite (MoS2). Moreover, there are siderite (FeCO3) and cryolite (Na3AlF6) exposed. Heavy metals, primarily Pb and Zn, are leached from the waste rock. A monitoring project over the past four decades has estimated the annual release of dissolved Pb into the fjord to be 133-333 kg. The current study focuses on leaching experiments, using seawater and natural precipitation as leachants. The Humidity Cell Test (HCT) method was used over 40 weeks with a weekly water saturation cycle. The HCTs were performed at room temperature, in a 5-degree cooling room, and outdoors, exposed to natural precipitation and temperature. While the first two conditions adhered to the standard HCT procedure, the third aimed to replicate natural weathering processes. The physicochemical parameters of the leachates were measured weekly, and the chemical composition of selected samples was analysed. Indoor leaching began at low concentrations in the first weeks, increased to maximum levels after 17 weeks, and gradually decreased toward the end of the experiment. Additionally, significant differences were observed between leaching experiments conducted at different temperature settings. Higher temperatures resulted in higher concentrations of Pb and Zn, and vice versa. The outdoor leaching with natural precipitation, showed more fluctuating concentrations of Pb and Zn compared to the controlled indoor conditions. The variability was likely due to the fluctuating amount of leachant entering the system as well as environmental temperature changes. Our results showed that Arctic climatic conditions delayed the leaching initiation and the release of Pb and Zn from the waste rock. Furthermore, the concentrations of Pb and Zn appear to corelate to precipitation levels. During winter, generation of leachate stopped due to freezing conditions. The precipitation levels in spring and late summer were high, resulting in leachates with higher concentrations of Pb and Zn, while mid-summer had low precipitation that resulted in lower concentrations.
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