Assessment of radiation dose due to 210Po in water and food samples of Chamarajanagar district, Karnataka, India.

Groundwater is in direct contact with the soil and rocks that dissolve many compounds and minerals including uranium and its daughter products. 210Po is one of the decay products of 238U series that cause internal radiation dose in humans when consumed in the form of water and food, including sea food. Therefore, activities of 210Po have been studied in ground and surface water, and in food samples that are commonly used in Chamarajanagar region of Karnataka, India. The average 210Po concentration in bore well water samples and surface water samples are 3.21 and 1.85 mBq L-1, respectively. In raw rice and wheat, the average values of 210Po are 96 and 41 mBq kg-1, respectively. In millets and pulses, the average activity of 210Po is 157 and 79 mBq kg-1, respectively. Among food items, the highest activity of 1.3 kBq kg-1 is observed in marine crabs and the lowest activity of 2.6 mBq kg-1 is found in milk samples. The average ingestion dose due to 210Po in ground and surface water are 2.8 and 1.62 µSv y-1, respectively. The ingestion dose due to various food samples to the population is also calculated. Total ingestion dose due to 210Po to pure vegetarian population and general population are 38.09 and 590.80 µSv y-1, respectively. The concentration of 210Po in water samples and food samples of this region are in a comparable range with the world and Indian average values and lies well below the recommended guideline level.

Assessment of radiation dose due to 238U, 226Ra, 222Rn and 210Po in groundwater of Kodagu district, India.

Natural radionuclides are universally spread and can be found in varying levels in rock, soil and water depending on the geology. A potential health threat may be caused by them to humans on consumption of water, food and inhalation of air due to the presence of radionuclides. In the present study, an attempt has been made to study the distribution of 238U, 226Ra, 222Rn and 210Po in groundwater samples of Kodagu district, India. The activity concentrations of 238U, 226Ra, 222Rn and 210Po were found to vary from 0.44 to 8.81 µg L-1, 0.71 to 7.66 mBq L-1, 1.54 to 9.61 Bq L-1 and 0.47 to 4.35 mBq L-1, respectively. The associated dose due to radiation was assessed and was observed to be below the recommended standards. The total effective dose to the population was calculated and was found to be less than the recommended WHO standard of 100 mSv.

Characterization of natural radioactivity and relative dose due to consumption of edible bivalves inhabiting the Cochin Backwater Lagoon, Kerala, southwestern coast of India.

The study on natural radionuclides in edible bivalves from the Cochin backwater lagoon, Kerala, employing alpha spectrometry, revealed higher concentrations of 210Po and 210Pb compared to 238U and 232Th. The annual committed effective dose (ACED) for the adult coastal population was calculated at a range of 1494.9 to 5783.4 µSv y-1, with 210Po being the predominant contributor, responsible for about 85 % of the dose. This highlighted significant health risks, underscored by a calculated cumulative mortality and morbidity risk range between 5.23 × 10-3 and 2.02 × 10-2. These findings emphasized the need for further research and the development of regulatory measures to mitigate exposure risks.

Assessment of cancer risk and radiological effects from 210Po and 210Pb with consumption of wild medicinal herbal plants.

BACKGROUND: Plants' raw materials can accumulate chemical elements, including radioisotopes, to some extent and reflect the region they grow in. Due to their high environmental content and toxicity, natural radionuclides - polonium 210Po and lead 210Pb are the most dangerous radioisotopes for human health. METHODS: 70 raw medicinal herbal materials from 54 popular wild-growing medicinal plant species, most of them included in the European Pharmacopoeia, were collected across three regions. In 210 samples, the activity concentrations of 210Po and 210Pb were determined, and their radiotoxicity and cancer risk were calculated. RESULTS: The results of 210Po and 210Pb activities measured in herbal raw material were from 0.12 mBq g-1 dry weight in the fruits of the common chestnut (Aesculus hippocastanum) to 19.7 mBq g-1 dw in herb of ground elder (Aegopodium podagraria) for 210Po, while for 210Pb ranged from 0.16 mBq g-1 dw to 34.3 mBq g-1 dw in the same plants. There were statistically significant differences between 210Po and 210Pb content in leaves, herbs, flowers, and fruit. The studies indicated that the estimated annual effective radiation dose from Polish medicinal herbs consumption was low, ranging 0.03-105 µSv from 210Po and 0.02-98.2 µSv from 210Pb, while the risk of cancer morbidity and mortality ranged from 10-5 to 10-9. CONCLUSIONS: Consumption of the tested medicinal herbs is safe from the radiological point of view and, based on the predictions related to the calculated risk of cancer, should not increase the probability of its occurrence.

The presence of radiotoxic 210Po and 210Pb in Ukrainian wild medicinal plants and the assessment of related dose and cancer risk.

Herbal plants are considered natural pharmaceuticals but also accumulate chemical elements and compounds at high levels. 210Po and 210Pb are highly radiotoxic and may cause carcinogenesis due to ionizing radiation. Thirteen of the most popular wild-growing herbaceous plant species, mostly included in the European Pharmacopoeia, were collected across Ukraine. 210Po and 210Pb were determined in the medicinal plants, and their radiotoxicity and cancer risk were calculated. The results of 210Po activities measured in herbal raw material ranged from 2.28 Bq kg-1 dw (where dw is dry weight) in herb of common horsetail (Equisetum arvense L.) collected near Lviv to 37.7 Bq kg-1 dw in leaves of common birch (Betula pendula Roth.) from Rava Ruska. The activity concentrations of 210Pb varied from 0.44 Bq kg-1 dw in leaves of common birch from Starokostyantyniv to 28.4 Bq kg-1 dw in leaves of common birch from Mizhhirya. There were statistically significant differences between 210Po and 210Pb content in flowers, leaves, and aerial portions. The studies indicated that the estimated annual effective radiation dose from Ukrainian herbs consumption was low, ranging 5.00-82.6 µSv from 210Po and 0.56-35.8 µSv from 210Pb, while the cancer morbidity and mortality risk ranged from 10-4 to 10-6. The presented data indicated no radiological risk related to using herbal plant materials.

210Po and 210Pb radioactivity levels in local and imported tobacco used in Palestine and Jordan.

This study aimed to assess the concentrations of 210Po and 210Pb in various tobacco samples from Palestine and Jordan. Cigarette smoking is recognized as a significant contributor to the radiation dose received by individuals, primarily due to the elevated levels of 210Pb and 210Po found in tobacco. The analysis revealed that the average concentrations of 210Po in locally sourced tobacco and cigarette samples in Palestine are 16.8 ± 2.3 mBq/g and 18.5 ± 2.0 mBq/g, with a total average of 17.8 ± 7.4 mBq/g (15.5 mBq/cigarette). Similarly, the average concentrations of 210Pb in these samples are 18.5 ± 2.6 mBq/g and 20.3 ± 2.2 mBq/g, with a total average of 19.6 ± 8.1 mBq/g (17.0 mBq/cigarette). In Jordan, the average concentrations of 210Po in cigarette samples and narghile tobacco are 20.1 ± 2.4 mBq/g and 18.3 ± 4.1 mBq/g, with a total average value of 19.6 ± 9.9 mBq/g (18.0 mBq/cigarette), while the average concentrations of 210Pb are 22.2 ± 2.6 mBq/g and 20.2 ± 4.5 mBq/g, with a total average value of 21.6 ± 10.8 mBq/g (19.9 mBq/cigarette). The annual effective doses resulting from inhalation were calculated for smokers of these samples. The findings revealed that the levels of 210Po and 210Pb radioactivity in certain investigated samples exceeded the results of studies in many countries of the world. The associated effective doses per year from smoking for all brands products in Palestine range from 34.7 µSv/y to 186.5 µSv/y with an average of 109.5 µSv/y, while in Jordan 54.5 µSv/y to 289.1 µSv/y with an average of 130.9 µSv/y.

The concentration of radioisotopes (Potassium-40, Polonium-210, Radium-226, and Thorium-230) in fillet tissue carp fishes: A systematic review and probabilistic exposure assessment.

Chemical contamination of seafood has become a global health concern. Carp fish is one of the most widely consumed globally, and several studies have been conducted on the contamination of carp fish with radioisotopes. In the current study, a meta-analysis and probabilistic exposure assessment regarding the Potassium-40 (40K), Polonium-210 (210Po), Radium-226 (226Ra), and Thorium-230 (230Th) in the fillet tissue of carp fish were performed. In this regard, Scopus and PubMed were screened to retrieve the associated citations with on the concentration of radioisotopes in the fillet tissue of carp fish until October 2021. The rank order of radioisotopes in fillet tissue carp fish was 40K (103.49 Bq kg-1) > 210Po (9.39 Bq kg-1) > 226Ra (0.62 Bq kg-1) > 230Th (0.39 Bq kg-1). The highest effective dose due to 210Po ingestion was observed in Spain (male; 4.44E-05 Sv y-1, female; 2.67E-06 Sv y-1); 40K (female, 5.07E-07 Sv y-1); 226Ra (male, 9.93E-09 Sv y-1). The mean of effective dose (ED) in the male and females in India due to ingestion of 230Th as result of carp fish consumption was (1.70E-06 Sv y-1) and (7.01E-08 Sv y-1), respectively. The probabilistic exposure assessment by the Monte Carlo simulation method revealed that consumers of fillet tissue carp fish content of radioisotopes are at a safe range (0.001 Sv y-1).

The activity of 210Pb in cigarette smoked in Kazakhstan.

The radon decay product 210Pb is a known component of tobacco. In this study, the activity concentration of 210Pb in the most popular cigarette brands (six samples) for Kazakhstan consumers was determined by beta spectrometry. The activity levels of 210Pb ranged between 2.69 ± 0.27 and 27.42 ± 2.74 mBq per cigarette. Higher activity concentrations for 210Pb were found in Sample No.4 and showed an excess of the world average by 1.8 times. The average activity concentrations of 210Pb in cigarette tobacco were 10.42 ± 1.04 mBq cig-1. The daily activities inhaled in the lungs of a smoker, and the resulting effective doses due to cigarette smoking were calculated. Effective doses per year due to cigarette smoking were calculated assuming that 42.13% of the 210Pb in tobacco were retained in the lungs of the smokers. It is concluded that for a smoker in Kazakhstan, the average effective dose ranges from 9.1 ± 0.9 µSv/year to 92.8 ± 9.3 µSv/year for a cigarette consumption of one pack of cigarettes per day. The results indicate that the annual effective doses from inhalation of 210Pb due to smoking one pack of cigarettes per day are from 7 to 58 times (for different types of cigarettes) greater than the annual effective doses from ingestion of radionuclides via the diet.

Review of natural radioactivity in tobacco cigarette brands.

Cigarettes smoking are leading causes of lung cancer in the world. In several countries, the radioactivity of tobaccos cigarette brands has been evaluated to estimate the effective dose from smoking inhalation. In this paper, we have reviewed 40 researched papers of radioactivity in tobacco cigarette brands by searching specified databases from various search engines such as Web of Science, Google Scholar, Scopus, Science Direct and PubMed for the studies published between the year 2000 and November, 2023 in English language. Results show that, the arithmetic mean and range of radioactivity concentration in mBq/g were 20.4 (0.4-128.6), 15.4 (2.0-78.8), 630.8 (1.2-1330.0), 8.1 (0.3-41.0), 15.2 (0.2-82.0) and 5.9 (2.0-16.0) from 210Po, 210Pb, 40K, 232Th and 232U and 226Ra, respectively. The annual effective doses were also estimated using the assumption that a smoker smokes 20 cigarettes per day. The mean annual effective doses in µSv/y from 210Po, 210Pb, 40K, 232Th and 232U and 226Ra were 295, 74.1, 5.80, 889.7, 192.6 and 90.1, respectively. The mean annual effective dose is lower than the reference level 1000 to 20000 µSv/y for existing situation in ICRP Publication 103. The average value of ELCR is 1.03 ×10-3, 0.26 ×10-3,0.02 ×10-3,3.11 ×10-3,0.67 ×10-3 and 0.32 ×10-3 for 210Po, 210Pb, 40K, 232Th and 232U and 226Ra, respectively. The ELCR values obtained in this study are well below the world average value of 1.45 ×10-3. The mean value of LCC in per million is 5.3, 1.3, 0.1, 16, 3.5 and 1.6 for 210Po, 210Pb, 40K, 232Th and 232U and 226Ra, respectively. The values of LCC obtained in this study are all below the limit range of 170-230 per million persons. The result shows 232Th contribute much larger for annual effective dose, annual equivalent dose, ELCR and LCC for smoking tobacco cigarette brands compared to other radionuclides. More studies in radioactivity in tobacco cigarette brands from different countries are required to have conclusive mean annual effective dose, annual equivalent dose, ELCR and LCC for each natural radionuclide.

Distribution of U and 210PO in groundwater of Kodagu district, Karnataka, India.

Trace amounts of uranium along with its decay products are found in varying levels in natural soil, rocks, water and air. They are a matter of significant concern due to their carcinogenic nature. In the present work, the distribution of U and 210Po in groundwater of Kodagu District, Karnataka, India, was studied. The concentration of total U in groundwater samples was estimated using LASER and LED fluorimeter, and the activity of 210Po in groundwater was studied using electrochemical deposition followed by alpha counting method. The concentration of U and 210Po varied from 0.4 to 8.8 µgl-1 and 0.47 to 4.35 mBql-1, respectively. The ingestion dose due to U and 210Po in groundwater varied from 0.33 to 7.17 and 0.41 to 3.81 µSv y-1, respectively. The estimated U activity was found to be well below the standard safe limits of 30 µgl-1 in drinking water, as recommended by WHO and USEPA. The 210Po activity was low compared with the recommended 100 mBql-1 standard of WHO.

Detection of Polonium-210 in Environmental, Biological and Food Samples: A Review.

Ingestion of polonium-210 from environmental media and food can cause serious health hazards (e.g., gastrointestinal symptoms, tumours, etc.) and has been a public health concern worldwide since the 2006 poisoning of Agent Litvinenko 210Po in Russia. With the development of uranium mining and applications of nuclear technology in recent decades, the radioactive hazards posed by 210Po to living organisms and the environment have become increasingly prominent. In order to strengthen the monitoring of environmental 210Po and protect both the environment and human health, a series of explorations on the methods of 210Po determination have been ongoing by researchers across the globe. However, previous reviews have focused on individual sample types and have not provided a comprehensive account of environmental, food, and biological samples that are closely related to human health. In this work, the sources, health hazards, chemical purification, and detection methods of trace 210Po in different sample types are systematically reviewed. In particular, the advantages and disadvantages of various pretreatment methods are compared, and relevant domestic and international standards are integrated, which puts forward a new direction for the subsequent establishment of rapid, simple, and efficient measurement methods.

On 210Po and 210Pb in algae diet supplements - The assessed radiation hazard of aquatic superfoods.

Algae are believed to give health benefits. However, the studies showed they contain toxic elements, including radionuclides, and may affect human health. The study presents the values of activity concentrations of 210Po and 210Pb in the algae supplements available worldwide for adults. The activity concentrations (Bq/kg dw) ranged from 0.07 to 14.5 (210Po) and from 0.06 to 8.48 (210Pb). Also, the effective radiation doses and the cancer risk from 210Po and 210Pb decay ingested with analyzed algal supplements have been assessed. The highest values of annual effective doses have been estimated for 210Po in the recommended portion of Spirulina (Arthrospira platensis) from China (59.7 µSv/year) and Diatomaceous earth from the USA (50.4 µSv/year). The cancer morbidity and mortality risk ranged from 10-4 to 10-8. The study indicated the activity concentrations of 210Po and 210Pb were low, and algae supplements for human consumption could be considered safe food.

The Concentration of Radionuclides (Lead-210, Polonium-210, and Cesium-137) in the Muscle of Sardine Fish: a Global Systematic Review, Meta-analysis, and Exposure Assessment.

With the increasing use of nuclear technology, concerns about the contamination of water resources with radionuclides and the contamination of seafood are increasing. In the current investigation, a meta-analysis and exposure assessment regarding the concentration of radionuclides, including lead-210 (Pb-210), polonium -210 (Po-210), and cesium-137 (Cs-137) in the muscle of Sardin fish were conducted. In this regard, some databases including Scopus and PubMed were selected to retrieve papers on the concentration of radionuclides in the muscle of Sardin fish from January 2000 to 25 June 2021. The used keywords were polonium-210, natural radioactivity, lead-210, radiocesium, cesium-137, radionuclides, radium-226, seafood, marine foods, fish, sardine fish, sardinella longiceps, and Clupeidae. Also, effective dose (ED) was calculated to estimate carcinogenic risk in Sardine fish consumers. The rank order of radionuclides in the muscle of sardine fish was Po-210 (31.50 Bq/kg) > Pb-210 (3.34 Bq/kg) > Cs-137 (0.48 Bq/kg). Based on level of Pb-210 rank of countries was France (12.00 Bq/kg) > India (4.06 Bq/kg) > Turkey (3.29 Bq/kg) > Spain (1.00 Bq/kg) > Slovenia (0.55 Bq/kg); Po-210 was Turkey (74.96 Bq/kg) > Spain (48.00 Bq/kg) > France (31.500 Bq/kg > India (30.25 Bq/kg) > Slovenia (25.00 Bq/kg) > Kuwait (7.28 Bq/kg) and also, Cs-137 was Japan (1.22 Bq/kg) > Croatia (0.18 Bq/kg) > India (0.23 Bq/kg). The lowest and highest ED of 210Po was observed in Kuwait (5.10E-04 msv/y, female) and France (3.14E-01, male); Pb-210, Slovenia (7.24E-05 msv/y, male) and France (1.48E-02 msv/y, female), and Cs-137, Croatia (8.47E-08 msv/y, male) and Japan (2.54E-05 msv/y, female), respectively. The risk assessment shows that the exposed population are at an acceptable range of risk (H < 1 mSv/y).

Radiological dose and associated risk due to 210Po in commercial inter-tidal bivalves of southwest (Arabian Sea) coast of India.

The activity concentration of 210Po was determined in edible tissues of commercial bivalves on the southwest coast of India. The 210Po activity ranged from 38.3 ± 6.9 Bq kg-1 to 91.2 ± 18.6 Bq kg-1. The annual committed effective dose (ACED) and lifetime carcinogenic risk (LCR) were calculated for different age groups to determine the potential health risk associated with bivalve consumption. The average ACED ranged from 81.5 to 194.1 µSv y-1, with the 10th and 95th percentiles being 68 and 261 µSv y-1, respectively. Lifelong mortality risk (LMTR) values ranged from 1.2 × 10-3 to 2.9 × 10-3, while lifetime morbidity risk (LMBR) values ranged from 1.9 × 10-6 to 4.9 × 10-6. The effective dose was found to be within the UNSCEAR limits.

Determining baseline radiation levels in marine biota - A comparison of SE Queensland commercial species.

Limited data exists on the contribution to radiological dose to members of the public from ingestion of radioactivity in seafood in the Australian diet. There is also a lack of data available to assess the radiological dose to marine fauna in Australian waters. Natural and anthropogenic radionuclides and trace metals were measured in the edible flesh of prawns to determine the radiological dose to humans. The remaining tissues were combined and analysed to enable uptake and environmental radiological doses to be assessed. Although in international studies, the edible flesh is generally measured to determine radiation dose or ingestion of trace metals, the effects of preparation and cooking techniques are rarely assessed. In this study, cooking and preparation techniques that may influence the radiological dose to humans were assessed. Eggs were also removed from a selected number of samples to assess the potential dose in sensitive developmental tissues and possible implications for environmental effects. Order of magnitude differences in 210Po activity concentrations and Cd concentrations were observed between whole animals and the edible flesh of Australian caught King (Melicertus spp.) and Tiger (Penaeus spp.) prawns, with the hepatopancreas primarily responsible for this difference. Most 210Po was unsupported by 210Pb and activity concentrations of all other radionuclides measured (137Cs, 210Pb, 226Ra, 232Th, and 238U) were very low. The major contribution to radiation dose via the ingestion pathway and to the organism itself was from 210Po. Cooking techniques that may lead to leaching of 210Po from the hepatopancreas could substantially increase the radiological dose from ingestion of this isotope. Organism dose estimates using different input assumptions in the radiological assessment tool "ERICA", including site-specific tissue activity concentrations with site- or region-specific media concentrations, were compared with ERICA default distribution coefficients (Kd) and concentration ratios.

S-values for radium-223 and absorbed doses estimates for 223RACL2 using three computational phantoms.

Radium-223 dichloride (223RaCl2), approved by FDA (Food and Drug Administration) in 2013 and in Brazil by ANVISA (Agência Nacional de Vigilância Sanitária) in 2016, offers a new therapeutic option for bone metastases from castration-resistant prostate cancer (CRPC). The advantages of radionuclide therapy for bone metastases include the simultaneous treatment of multiple lesions at the same time. The activity prescription is based on the patient's body weight, disregarding the absorbed dose limit of 2 Gy in the organ at risk: bone marrow. This study focuses on Internal Dosimetry for 223RaCl2 therapy aiming to apply biokinetic models described in the literature to estimate absorbed doses in the organs of interests, especially for the bone marrow. For this purpose, the present paper compares and validates the GATE Monte Carlo simulation with the Radioactive Decay Module (RDM) and calculates a set of S-values for Radium-223 radionuclide using male and female XCAT computational models. Moreover, a comparison of S-values for Radium-223 for three male computational models with different anatomies is also evaluated, Male (standard), Pat1 (lower body weight) and Pat2 (highest body weight). A comprehensive set of S-values was calculated for the Male model, 30 source-regions and 47 target-regions, and for Female model, 30 source-regions and 42 target-regions for Radium-223 and its decay scheme: Radon-219, Polonium-215, Lead-211, Bismuth- 211, Polonium-211 and Thallium-207. The new set of S-values will facilitate absorbed dose calculations for Radium-223 therapy. In addition, Absorbed Dose Evaluation for 223RaCl2 therapy was estimated for three different biodistributions described in the literature within three male computational models. For all biodistributions, the Pat2 phantom has a greatest absorbed dose within the red marrow, when compared with Male and Pat1.

Evaluation of the radiological dose due to 210Po in commercial clupeid fish collected in the near-shore environment of the high background natural radiation area (HBNRA) on the southwest coast of India.

In this study, we quantified the tissue concentration of 210Po in a variety of commercial sardine fish species of the family Clupeidae from an area of high background natural radiation area on the southwest coast of India. The smooth belly sardine Amblygaster leiogaster had the lowest 210Po concentration in its muscle (45.6 ± 7.9 Bq kg-1 fresh), while the goldstripe sardine Sardinella gibbosa had the highest (103.4 ± 10.1 Bq kg-1 fresh). The Annual Committed Effective Dose (ACED) of fried sardine and sardine curry were 134.3-304.3 µSv y-1 and 226.6-513.5 µSv y-1, respectively. Of the 210Po loss, 20 % was due to frying and 10 % to preparing sardine curry. The effective dose was found to be globally comparable and well below the world limit. Consumption of sardines containing 210Po would not pose a health hazard to the residents of Manavalakurchi.

OPTIMIZING THE INTERNAL CELL STRUCTURE OF THE RADON MONITOR BASED ON ELECTROSTATIC COLLECTION METHOD.

As Rn-222 decays, an alpha particle is emitted and the residual polonium nucleus recoils in the opposite direction. At the end of the recoil path, 88% of the polonium atoms have a positive charge and 12% are neutral. The electric potential distribution in the 60 ml hemispherical internal cell of the radon monitor based on electrostatic collection is studied for reducing the combined probability of the positively charged Po-218 and the OH- produced by the ionization of water vapour in the air. The COMSOL software is used to simulate the electric potential distribution in the internal cell of the radon monitor based on the electrostatic collection method at 27°C, a pressure of 0.1 Mpa. For improving the collection efficiency of Po-218 ions, the average collection time along vertical and oblique lines is calculated when the upper surface of the internal cell is plastic, uncharged metal and charged metal, respectively. Assuming that the gas in the internal cell is uniformly distributed, the results show that if the upper surface of the hemispherical internal cell is plastic or uncharged metal, the electric potential formed in the internal cell is more uniform, and it is beneficial to reduce the total collection time of the positively charged Po-218 ions, thereby improving collection efficiency. The simulation results can be used as an effective reference for optimizing the design of the internal cell structure of the radon monitor based on electrostatic collection method.

Environmental evaluation of radioactivity levels and associated radiation hazards in groundwater around the WIPP site.

Groundwater may contain radioactive substances which can be dangerous to human health. Concentrations of natural radionuclides polonium (Po), thorium (Th), uranium (U), and radium (Ra) isotopes were measured in groundwater samples collected from different locations in the vicinity of the Waste Isolation Pilot Plant (WIPP) site in Carlsbad, New Mexico. The average values of gross activity concentrations of 210Po, 228Th, 238U, 234U, 226Ra and 228 Ra isotopes were determined to be 1.62 Bq L-1 in shallow groundwater and 5.88 Bq L-1 in deep groundwater, respectively. The total radioactivity in deep groundwater was higher than that in shallow groundwater, and most of the radioactivity in the water is from 226Ra. Furthermore, the effective doses for ingestion of natural radionuclides were about 0.333 mSv y-1 for shallow groundwater and about 1.338 mSv y-1 for deep groundwater samples, which are higher than the World Health Organization (WHO, 2017) guideline level (0.1 mSv y-1) for drinking water. Ra dominated the total ingestion dose, contributing 93.06 % and 75.40 % of the total effective doses to the deep and shallow groundwater, respectively. The ingrowth and decay of natural radionuclides suggested that 228Ra/226Ra ratio can be a useful indicator of the source of radioactive contamination. The radioactivity data obtained from the investigated groundwater samples can be used to establish a baseline for radioactivity levels in groundwater around the WIPP site.

210Po and 210Pb content in the smoke of Heated Tobacco Products versus Conventional Cigarette smoking.

210Po is a radioactive component of conventional cigarette tobacco smoke and is a recognized carcinogen. Despite the expanding market of heated tobacco products, no data are available on the activity of 210Po in the smoke of IQOS Heets cigarette. We determined the 210Po activity in the mainstream smoke of thirteen cigarette brands available on the Swiss market using a smoking machine and compared the results to the 210Po activity measured in the mainstream smoke of the IQOS system. In addition, we measured the 210Po and 210Pb loss on heating after uniform heating from 50 to 600 °C for several cigarette brands and the Heets cigarettes. 13.6 ± 4.1% of 210Po activity was found in the mainstream smoke in conventional cigarette smoking (7% for 210Pb). This dropped to 1.8 ± 0.3% in the mainstream smoke of IQOS Heets. Conversely, when the tobacco was heated uniformly at 330 °C, a loss of 210Po of more than 80% was observed for all type of cigarettes. Apparently, IQOS significantly reduced the 210Po and 210Pb activities in the mainstream smoke. However, our results show that only 15% of the Heets tobacco reaches 330 °C with IQOS. While IQOS reduces the 210Po and 210Pb activities in the mainstream smoke compared to conventional cigarettes, it only heats a marginal fraction of the tobacco present in the Heets cigarette. Because smoking is an addiction (mostly due to nicotine), IQOS could possibly deliver an unsatisfactory dose of nicotine to a Heets cigarette smoker, as most of the tobacco is left unaltered.