Levels Of 210Po Research Articles

Evaluation of 210Po, 210Pb, and potentially toxic element concentrations in aquatic environments and polychaetes along the southeast coast of Chennai, Tamil Nadu: a baseline report

ABSTRACT The activity concentrations of radionuclides (210Po and 210Pb) and the concentrations of potentially toxic elements (PTEs) in water, sediment, and two polychaete species (Marphysa madrasi and Namalycastis jaya) collected from 12 stations, denoted as S1 to S12, along the coast of Tamil Nadu, Chennai, in southeast India has been investigated. The average activity concentrations of 210Po and 210Pb were 0.39 ± 0.01 mBq/L and 3.30 ± 0.06 mBq/L in water, and 0.80 ± 0.02 Bq/kg and 4.21 ± 0.19 Bq/kg in sediment, respectively. Marphysa madrasi exhibited higher 210Po and 210Pb activity concentrations (37.78 ± 0.43 Bq/kg and 17.25 ± 0.22 Bq/kg, respectively) compared to Namalycastis jaya (34.40 ± 0.42 Bq/kg and 15.91 ± 0.26 Bq/kg, respectively). Maximum activity concentrations for both radionuclides in water were observed at Kalpaakam (S11) and Nemmeli (S7), while maximum sediment activity concentrations were found at Nemmeli (S7). The elevated activity concentrations in polychaetes from Nemmeli (S7) likely reflect the significantly higher 210Po and 210Pb activity concentrations observed in sediments from this site when compared to other sites. Bioaccumulation values for 210Po and 210Pb averaged 6.89 × 101 and 4.20 for M. madrasi, and 6.17 × 101and 3.84 for N. jaya , respectively. Sediment PTE concentrations followed the order: Fe > Zn > Mn > Ni > Co > Cr > Pb > Cd > Cu. Risk assessment indicated alarming levels of PTE contamination in sediments, suggesting severe anthropogenic impacts. In contrast, average PTE concentrations in polychaetes followed the order: Fe > Cu > Zn > Mn> Cr > Ni > Co > Cd > Pb. Statistical analysis revealed strong and significant correlations (p < 0.05) between PTE concentrations in sediments and polychaetes. The present study offers baseline data for evaluatingthe levels of 210Po and 210Pb in water, sediment, and polychaetes in selected locations along Chennai, Tamil Nadu, India’s southeast coast. These findings lay the groundwork for further studies of polychaetes, specifically the ecological effects of PTEs and radionuclides on coastal creatures and biomagnification.

Tracing the Transport and Residence Times of Atmospheric Microplastics Using Natural Radionuclides.

While atmospheric microplastics are known to be transported over long distances, their residence times and transport processes lack clarity. This study utilized natural radionuclides 7Be, 210Pb, and 210Po to explore the transport of atmospheric microplastics in Tianjin, a coastal city in Northern China. Microplastic concentrations ranged from 0.03 to 0.13 particles m-3 over the course of a year. The proportion of microplastic fragments in winter was significantly higher than that in other seasons, with median microplastic sizes in autumn and winter being larger than those in spring and summer. The atmospheric microplastic surface was rough, exhibiting irregular pores and multiple depressions and cracks. Microplastics experienced vertical mixing with the upper atmosphere in April and August and were influenced by rainfall in July. The residence time of atmospheric particles ranged from 9.47 to 22.85 days throughout the year, with an average of 14.41 days. The peak residence time of atmospheric particulates in November may be correlated with increased 210Po levels from coal consumption. Their prolonged atmospheric presence and rough surface allow microplastics to act as carriers for various chemical pollutants, underscoring the complexity and potential risks associated with their presence in the atmosphere.

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 ± 2.3mBq/g and 18.5 ± 2.0mBq/g, with a total average of 17.8 ± 7.4mBq/g (15.5mBq/cigarette). Similarly, the average concentrations of 210Pb in these samples are 18.5 ± 2.6mBq/g and 20.3 ± 2.2mBq/g, with a total average of 19.6 ± 8.1mBq/g (17.0mBq/cigarette). In Jordan, the average concentrations of 210Po in cigarette samples and narghile tobacco are 20.1 ± 2.4mBq/g and 18.3 ± 4.1mBq/g, with a total average value of 19.6 ± 9.9mBq/g (18.0mBq/cigarette), while the average concentrations of 210Pb are 22.2 ± 2.6mBq/g and 20.2 ± 4.5mBq/g, with a total average value of 21.6 ± 10.8mBq/g (19.9mBq/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 34.7μSv/y to 186.5μSv/y with an average of 109.5μSv/y, while in Jordan 54.5μSv/y to 289.1μSv/y with an average of 130.9μSv/y.

Radiological hazard assessment of 210Po in freshwater mussels (Sinanodonta jourdyi) and golden apple snail (Pomacea canaliculata) in Vietnam.

210Po is a significant source of ionizing radiation that people are exposed to through food globally. This paper presents the wide range of accumulation level of 210Po in the organs of two species of shellfish including freshwater mussel (Sinanodonta jourdyi) and golden apple snail (Pomacea canaliculata), common freshwater species in Vietnam. There was a significant correlation between 210Po activity in muscle to their mass and size of freshwater mussels. In contrast, there was no relation between other organs of both species with their mass and size. The annual effective dose due to consumption of freshwater mussels ranged from 68.7 to 291 μSv year-1 with a mean value of 138 μSv year-1 for muscle and from 321 to 4560 μSv year-1 with a mean value of 1422 μSv year-1 for the hepatopancreas. Meanwhile, the AED for golden apple snail was recorded to be higher with values ranging from 105 to 2189 μSv year-1 with mean value of 673 μSv year-1 for muscle and from 468 to 4155 μSv year-1 with a mean value of 2332 μSv year-1 for hepatopancreas. Thus, the consumption of these two types of shellfish is considered relatively safe, but the hepatopancreas gland must be removed before processing.

Characterizing 226Ra and its daughters in coastal zone groundwater of a typical human-activity affected bay: occurrence, safety, and source evaluation.

Due to their extremely toxic properties, 226Ra and it daughters (222Rn, 210Pb, and 210Po) in drinking groundwater require monitoring. Recent studies have reported exceptionally high levels of natural 210Po (up to 10,000Bq/m3), 226Ra, and 222Rn isotopes in groundwater. This study aims to provide background data on 226Ra and its daughter radionuclides in the typical agricultural-industrial Dongshan Bay (DSB) before the construction of Zhangzhou Nuclear Power Plant (Zhangzhou NPP). The measurement results indicate that no abnormally high activities of 210Po and 210Pb were detected in the investigated wells. Strong positive correlations between 210Pb and 210Po, as well as between 222Rn and 210Pb activities, suggest that the origins of 210Pb and 210Po in groundwater are strongly influenced by the decay of the parent radionuclides 222Rn and 210Pb, respectively. In the DSB coastal zone groundwater, significant deficiencies of 210Po relative to 210Pb and 210Pb relative to 222Rn were observed, providing further evidence that 210Po and 210Pb are also effectively scavenged due to their geochemical properties (specifically particle affinity) within the groundwater-aquifer system. A systematic comparison among all relevant water bodies in the DSB revealed that the activity concentrations of 210Pb and 210Po in groundwater were the highest, except for rainwater. Based on the evaluation of 210Pb sources, the results imply that submarine groundwater discharge (SGD) is an important pathway for transferring radionuclides (such as 210Pb) from land to the nearshore marine environment, even though the study area has a lower 210Pb background groundwater. By considering all the 210Pb's sources in the DSB, we found low 210Pb background groundwater discharge still needs to be taken into account for small-scale bays. This is because SGD was calculated to be one of the most important 210Pb sources in the bay during observation season. Regardless of whether the system is in a normal state or a nuclear accident emergency state, greater attention should be paid to the groundwater discharge of radionuclides into the ocean.

Variation of 210-polonium in the cephalopod community from the Bay of Biscay, North-East Atlantic

Among natural radionuclides, 210Po is the major contributor to the radiation dose received by marine organisms. In cephalopods, 210Po is concentrated in the digestive gland, which contains over 90% of the whole-body burden of the nuclide. Although previous studies showed that 210Po was taken up independently of 210Pb, its parent nuclide, very little is known about the factors influencing its levels in cephalopods. To the best of our knowledge, no studies investigated 210Po levels in different species at the same time. In the present study, 210Po was analysed in the digestive gland of 62 individuals from 11 species representing a large range of feeding ecologies and habitats, including squids, cuttlefish and octopus species from coastal to deep-oceanic habitats. Among species, the highest activity was measured in Loligo vulgaris (5720 ± 3606 Bq/kg) and the lowest in T. megalops (188 Bq/kg). However, considering the habitats (benthic vs pelagic and neritic vs oceanic), no significant differences appeared. At the species level, no differences between sexes were found so both sexes were plotted together to test the size effect for species with at least 8 individuals (i.e., Eledone cirrhosa, L. vulgaris, L. forbesi and Sepia officinalis). In the first three species, 210Po levels decreased significantly with increasing size or weight but not in S. officinalis. In squid, this could be related to ontogenetic changes in diet from a high proportion of crustaceans (high Po content) in small individuals to fish (low Po content) in larger individuals, while the high dietary plasticity of S. officinalis at all stages of its life cycle could explain the lack of decrease in 210Po with size. In comparison to the few data from the literature, the levels of 210Po concentrations in the cephalopod community of the Bay of Biscay were overall in the same range than those reported in other cephalopods, varying across 4 orders of magnitude. Further studies are needed to understand the mechanism of retention in the cephalopod digestive gland.

Climate change - mediated atmospheric 210Po and 210Pb distribution: How significant can it be for the inhalation dose to humans?

The concentration of 210Po and 210Pb in vegetation, and their transfer from soil to vegetation and via aerosol deposited on foliage are well established. The available data show significantly higher levels of these radionuclides in ash from forest fires and aerosols downwind from industrial sites. The climate change-induced hot and dry conditions promote the spread of forest fires, which burn huge areas. On average, over 10 million hectares are reportedly lost annually. Large-scale forest fires and fossil-fuel and coal-operated Power and Desalination Plants are very likely to result in the dispersion of 210Pb and 210Po into the regional aerosol; such an effect has already been observed due to fires in Ukraine, Belarus, and Russia, which have led to the dispersion of 137Cs over large parts of Europe. We have measured elevated levels in Kuwait, and similar observations have been reported from Portugal. The higher levels of 210Po in PM2.5 raise a serious concern about an increased inhalation dose humans could receive. Our estimate shows that humans in areas affected by forest fires might receive a dose equivalent to 2 µSv d-1, which is significantly higher than 0.099 µSv d-1, the dose a person gets from smoking a packet of cigarettes daily. We propose that size-fractionated aerosol sampling should be taken up in regions affected by forest fires and industrial activities that add 210Po to the atmosphere in order to obtain a robust inhalation dose assessment and issue informed advisories to the public.

Radioactivity evaluation and radiation dosimetry assessment in Greek honey

Greek honey was examined for 238U, 234U, 210Pb, 210Po, 40K, and 137Cs levels. 238U was calculated from 0.013 ± 0.007 Bq kg−1 to 0.10 ± 0.02 Bq kg−1 while 234U ranged from 0.017 ± 0.009 Bq kg−1 to 0.11 ± 0.03 Bq kg−1. 210Pb measured from 0.04 ± 0.02 Bq kg−1 to 1.70 ± 0.26 Bq kg−1 whereas 210Po activity determined between 0.02 ± 0.01 Bq kg−1 and 2.31 ± 0.34 Bq kg−1. 40 K found at the range of 7.9 ± 1.6 Bq kg−1 to 102.2 ± 19.7 Bq kg−1 and 137Cs 0.3 ± 0.1 Bq kg−1 up to 0.8 ± 0.1 Bq kg−1. Uranium isotopes and 210Po were determined via alpha spectrometry. 210Pb was also indirectly determined by alpha spectrometry. 40 K and 137Cs were measured through γ-ray spectrometry. An annual dose calculation was performed for different age groups.

Concentration of radionuclides in Swedish market basket and its radiological implications

The entrance of radionuclides to the human food chain together with the ingestion favour tissues deposition of radionuclides throughout the human body, which may have long-term implications for radiation doses. That affects world population, since it represents approximately 12% of the annual effective dose received for the public. This contribution will be quite variable depending on the food habits, food origin and the background levels of the place of residence. It is therefore necessary to monitor the food to be able to control and quantify the risk of exposure of the public. A wide range of food products (vegetables, fruits, meat, fish etc.) have been collected and analysed by different radiometric techniques in order to measure the activity concentration of naturally occurring and anthropogenic radionuclides (40K, 137Cs, 210Po, 226Ra, 228Ra, 234U and 238U). The results of the investigation highlighted that the average committed effective dose from one year's food consumption in Sweden ranged from 82 to 142 μSv for children and it was around 134 μSv for adults. Additionally, considering the consumption percentile 95 (P95), the total ingestion exposure could raise up to 560 μSv/y for children and 340 μSv/y for adults. In all population groups analysed, the internal exposure was mainly controlled by the intake of 210Po (∼ 94–98%), in particular via seafood consumption for example, as a result of the high levels of 210Po in shellfish such as shrimp (30 ± 2 Bq/kg) or blue mussel (55 ± 7 Bq/kg).

The JUNO OSIRIS Detector

The Online Scintillator Internal Radioactivity Investigation System (OSIRIS) is a 20-ton liquid scintillator detector currently under construction at the Jiangmen Underground Neutrino Observatory (JUNO) in Kaiping, China. OSIRIS features 76 newly developed, “intelligent PMTs” (iPMTs) surrounding a cylindrical acrylic vessel enclosed in a Cherenkov muon veto. Two calibration systems, an Automated Calibration Unit (ACU) and a laser calibration system are available. The detector will be integrated into the Liquid Handling System (LHS) of JUNO. The main purpose of OSIRIS is the monitoring of the radiopurity of the liquid scintillator during the filling phase of JUNO, measuring contamination levels of 238U, 232Th, 85Kr, 210Po and 14C. A consecutive physics phase addressing solar neutrinos and 0νββ decay is foreseen.

Assessment of intake of 210Po and 210Pb isotopes from cow’s milk in Poland

ABSTRACT Milk has been known for its nutritional properties for centuries and is often the staple of the diet in many countries. Therefore, monitoring of milk composition seems to be a relevant task as it was the purpose of this study to compare levels of 210Po and 210Pb in several Polish voivodeships. The methodology was based on mineralization, loss on an inorganic matrix and concentration measurement on an alpha spectrometer. The concentrations of 210Po and 210Pb in collected milk samples were measured using alpha spectrometry and calculations, respectively. The results showed that the lowest concentration of 210Po is 2.8 ± 0.2 mBq l−1 and the highest is 56.3 ± 0.7 mBq l−1 while the 210Pb concentrations are in the range from 2.8 ± 0.2 to 44.0 ± 1.7 mBq l−1. The associated annual effective doses for adults jmrange from 3.5 ± 0.1 to 11.0 ± 0.2 µSv a−1 for 210Po and from 2.0 ± 0.1 to 5.0 ± 0.1 µSv a−1 for 210Pb. The lowest doses were noticed in Kuyavian-Pomeranian Voivodeship and the highest values were found in Lesser Poland Voivodeship. The results show that the annual effective dose in individual provinces is not dangerous to health. However, there are significant differences between highly and lowly industrialized voivodeships.

Natural radionuclides (NORM) in a Moroccan river affected by former conventional metal mining activities

The main aim of this work was to determine the levels of multiple natural radionuclides in an aquatic system (Moulouya river, Morocco) impacted by multiple abandoned Zinc and Lead mines. 238U, 234U, 232Th, 230Th and 210Po were determined by alpha-particle spectrometry in water and sediment samples collected along the river and in samples from three pit lakes of abandoned mines, located in the Upper Moulouya catchment area. The results enabled the analysis of the different levels of impact of former mining activities, depending on the natural radionuclides. While the activity concentration of U-isotopes in Moulouya river water was slightly elevated in the vicinity of abandoned mine wastes, other natural radionuclides (Th-isotopes and 210Po) levels were typical of a natural environment. This fact is clearly reflected in the magnitude and range observed in the distribution coefficients for the different radionuclides analyzed.

Hg and 210Po in consumed fish of the Tadjoura Gulf (Djibouti): Levels and human health risk assessment

Hg and 210Po were measured in the muscle tissue of commercially important fish species collected in the main coastal cities of the Djiboutian coast (Tadjoura Gulf) to evaluate the potential risk associated with their consumption. The levels of Hg among the different species ranged from 0.02 to 1.69 mg/kg w.w and exceeded tolerable limits as reported by the national regulation (2000-0727/PR/MAEM) and the Codex Alimentarius. The probabilistic distributions of health hazard were evaluated through Monte-Carlo simulation, which confirmed the carcinogenic risk from Hg. The levels of 210Po ranged from 4.1 to 134.5 Bq/kg w.w among muscle tissues of the eight commercially important species. The carcinogenic risk was in an unacceptable range and simulation revealed that children were the most vulnerable population. The results obtained confirms that the health impact is reduced when consuming two servings per week.

Novel Application of 210Po-210Pb Disequilibria to Date Snow, Melt Pond, Ice Core, and Ice-Rafted Sediments in the Arctic Ocean

We collected surface ocean water, snow, grab ice, ice core, melt pond and ice-rafted sediment (IRS) from 5 ice stations during the Western Arctic US GEOTRACES cruise (USGCG Healy; August 10 – October 7, 2015) and analyzed for 210Po (T1/2 = 138.4 days) and 210Pb (T1/2 = 22.3 years) in dissolved and particulate phases (snow, grab ice, ice core, surface seawater) to investigate the 210Po:210Pb disequilibria in these matrices. Thirteen aerosol samples, using a large-volume aerosol sampler (PM10), from Dutch Harbor, AK to North Pole, were also collected and analyzed for 210Po/210Pb to quantify the atmospheric depositional input to the snow and surface waters. Falling snowfall is tagged with 210Po/210Pb ratio (AR) similar to that in the air column from the cloud condensation height to air-sea interface. From the measured AR in aerosol and snow, modeling the sources of 210Po and 210Pb input to the melt pond, and measured disequilibrium in ice core and ice-rafted sediment, we show 210Po/210Pb AR is a novel chronometer to date snow, ice core, melt pond, and IRS. The calculated mean ages of aerosol, snow, melt pond and IRS are 12 ± 7 (n = 13), 13 ± 11 (n = 6), 60 ± 14 (n = 4), and 87 ± 23 (n = 6) days, respectively. The average IRS age corresponds to an average drift velocity of sediment-laden ice of 0.18 ± 0.06 (n = 6) m s–1. We report highly elevated levels of 210Po and 210Pb in snow and melt pond compared to those in Arctic surface seawater and enrichment of 210Po compared to 210Pb onto particles extracted from snow, ice and melt ponds. The observed disequilibrium between 210Po and 210Pb in ice could serve as a quantitative tool in delineating multiple-year ice from seasonal ice as well as a metric in quantifying the speed of ice/snow melting and delay in autumn freeze.

A study on 210Pb and 210Po levels in different tobacco types produced in Turkey and the estimation of the committed effective dose

A study on 210Pb and 210Po levels in different tobacco types produced in Turkey and the estimation of the committed effective dose

Natural radionuclides (NORM) in a Moroccan river affected by former conventional metal mining activities

The main aim of this work was to determine the levels of multiple natural radionuclides in an aquatic system (Moulouya river, Morocco) impacted by multiple abandoned Zinc and Lead mines. 238U, 234U, 232Th, 230Th and 210Po were determined by alpha-particle spectrometry in water and sediment samples collected along the river and in samples from three pit lakes of abandoned mines, located in the Upper Moulouya catchment area. The results enabled the analysis of the different levels of impact of former mining activities, depending on the natural radionuclides. While the activity concentration of U-isotopes in Moulouya river water was slightly elevated in the vicinity of abandoned mine wastes, other natural radionuclides (Th-isotopes and 210Po) levels were typical of a natural environment. This fact is clearly reflected in the magnitude and range observed in the distribution coefficients for the different radionuclides analyzed.

Levels and Distributions of 210Pb and 210Po in Selected Seafood Samples in China and Assessment of Related Dose to Population.

In this study, the activity concentrations levels of 210Pb and 210Po in the edible portions of eight seafood samples collected from the Fujian coast of China were determined. The activity concentrations ranged from 0.74 ± 0.08 to 12.6 ± 1.0 Bq/kg for 210Po and from the minimum detectable limit (MDL, 0.80 Bq/kg) to 11. 7 ± 1.1 Bq/kg for 210Pb. The 210Po activity concentration in all the fish organs ranged from 0.68 to 204 Bq/kg (w.w.), and the 210Po activity was mainly concentrated in the stomach, spleen, heart, liver, gonad, and intestine samples. The 210Pb activity concentration in all the fish organs ranged from the MDL to 15.2 Bq/kg (w.w.), and the 210Pb activity was concentrated in the head, fish scale, and gill samples. The annual effective ingestion doses ranged from 82.8 to 255 μSv/a for all age groups, and the lifetime risk of cancers were estimated. Both the effective ingestion doses and cancer risk to humans were within the acceptable ranges.

210Po in Paddy Soils and Rice Grains in Chau Doc, An Giang, Vietnam: Activity Concentration, Soil-to-Rice Transfer, and Health Hazard

Introduction: Soil-to-rice transfer factors (TF) are widely used to predict radionuclides' activity concentrations in rice plants. Since rice (Oryza sativa L.) is one of the most popular crops in Vietnam, the radiological risks due to 210Po contaminating rice grains and the TF must be concerned. Methods: Alpha spectrometry measured the activity concentration of 210Po in rice and soil samples collected in Chau Doc, An Giang province. TF for the uptake of 210Po from soil to rice plant has been calculated the ratio of the dry weight concentration in the plants to the dry weight concentration in the specified soil layer. Assessment of radiological risks due to ingestion of rice grains was based on estimation of the effective dose. Results: The activity concentrations of 210Po were in the ranges of 63.77 – 117.75 Bq kgdry weight-1 and 7.38 – 14.16 Bq kgdry weight-1 in soils and rice grains, respectively. Based on the radiation dose assessment, the accumulation of 210Po in rice grains was not considered for public health. The average TF values of 210Po were 0.12, 0.11, and 0.37 for grains, straws, and roots, respectively. Our TF values for rice were higher than the corresponding values found by other studies and the IAEA TRS-472 report. Conclusion: The analytical method for 210Po determination using alpha spectrometry can be applied for further studies in the field of environmental radioactivity. The measured TF values can be used to predict the radioactivity level of 210Po in rice plants cultivated in other fields in the Mekong Delta region.

STUDY OF POLONIUM-210 IN PERSIAN CIGARETTE AND TOBACCO CROPS.

Alpha radiation from Polonium-210 (210Po) is considered to be an important agent of bronchial cancer in smokers. Besides reexamination of the radionuclide in domestic and imported cigarette brands separately, the radioactive contamination was also followed during the cigarette-producing procedure in Gilan as one of the major regions of tobacco cultivation in Iran. The activity level of 210Po in Iranian domestic and imported cigarettes averaged 38.4±6% and 20.0±7% mBq g-1, respectively. Drying in direct contact with fumes of fossil fuel seems like one of the main excessive sources of 210Po in Persian cigarettes.

Levels of Polonium-210 in brain and pulmonary tissues: Preliminary study in autopsies conducted in the city of Sao Paulo, Brazil

The accumulation of detectable amounts of radon progeny in human tissues may be a risk factor for development and progression of chronic diseases. In this study, we analyzed the levels of alpha-emitting radon progeny 210-Polonium (210Po) in the olfactory epithelium, olfactory bulb, frontal lobe, and lung tissues in cadavers from the city of Sao Paulo, SP, Brazil. We investigated the association between 210Po levels with the traffic-related pleural anthracosis index, smoking habits and socioeconomic index. Our findings show that olfactory bulb presented higher concentrations of 210Po in comparison with other tissues among all ages and gender. Women, smokers and elderly presented higher 210Po levels in some tissues, especially in lungs. We found statistically significant association between 210Po levels and anthracosis in lungs of non-smokers and lower socioeconomic index. The presence of high concentrations of 210Po in olfactory bulb may indicate the main pathway for transfer of radon progeny from nasal tissues to the central nervous system. Our findings suggest that radon progeny in human tissues may contribute to the development of chronic diseases in urban areas, including neurodegenerative diseases.