What is radon?

Radon is a colourless and odourless gas and has been cited to be responsible for half of the natural radiation to which humans will be exposed to (Lorenzo-González et al., 2019). Specifically, Radon-222 stands as the most prevalent naturally-occurring isotope, as well as the most health significant to humans (Schwela & Kotzias, 2005). In general, these gaseous radon isotopes occur as a result of the natural radioactive decay of uranium-containing minerals found in bedrock, surficial materials, and groundwater (Missimer et al., 2019).

The prevalence of radon has proved to be problematic as the gas escapes easily from rocks and soils into the air, and subsequently tends to accumulate within enclosed indoor spaces such as houses and buildings (World Health Organisation [WHO], 2023).

Harmful effects of radon exposure

To date, radon is one of the 19 environmental carcinogens recognized by the WHO, and the International Agency for Research on Cancer has also similarly classified radon and its progeny as carcinogenic to humans (Li et al., 2020).

1. Lung cancer

Radon atoms can spontaneously decay or change into other atoms – resulting in a process known as radon progeny. These atoms can then attach themselves to dust particles present in indoor air, which can stick to the inner lining of the lung upon inhalation (National Research Council (US), 1999). The radiation emitted from the deposited radioactive particles can result in severe DNA damage (Riudavets et al., 2022), prompting cells to repair rapidly whilst introducing genetic errors in what has been termed as “genomic instability” (Stanley et al., 2019), thereby leading to lung cancer.

Radon currently stands as the overall second leading cause of lung cancer (US Environmental Protection Agency, 2023), and has been found to synergistic effects with cigarette smoke, leading to the increase of lung cancer risks in smokers (Kim & Ha, 2018). However, another alarming discovery is the fact that residential radon exposure has been found to be the leading cause of lung cancer in individuals who have never smoked before (Lorenzo-González et al., 2019).

2. Childhood leukemia

Ngoc et al. (2023) posit that children who grew up in homes with significant radon concentrations faced a much greater risk of developing childhood leukemia. Currently, researchers hypothesise that a small amount of radon is delivered to the bone marrow upon radon inhalation, which can then interfere with the development of leukocytes, thereby increasing the risk of leukemia (Tong et al., 2012).

Residential radon exposure

Fig. 1: Sources of radon gas within residential homes (Source: Centres for Disease Control and Prevention, 2022)

The concentration of residential radon depends on numerous factors:

Table 1: Factors that affect the concentration of residential radon (Source: Li et al., 2020)

While outdoor radon concentrations do not pose health risks to humans, human-made buildings have been found to artificially concentrate radon gas, amplifying radon exposure experienced by occupants. To elaborate, outdoor radon concentrations usually average around 5 Bq/m³-15 Bq/m³, which is significantly lower than the average of 142 Bq/m³ found in North American residential homes build after 1992 (Reddy et al., 2022).

These observations are further supported by a Canadian-based study, which discovered that newer residential buildings contain higher mean radon levels compared to older ones, along with higher occupancy rates within these newer buildings:

Fig. 2: Graph illustrating rising mean radon levels amongst newer residential buildings, along with increasing occupancy rates (Source: Simms et al., 2021)

It is crucial to note that high radon exposure concentrations are prevalent phenomenon across regions, with countries such as South Korea similarly higher residential radon concentrations in houses built between 2011 and 2014 than those built between 1989 and 2009 (Kim & Ha, 2018). Indoor radon levels have also been recorded to be significantly higher during colder seasons due to closed windows and doors, resulting in an increased accumulation of radon within enclosed areas (Baltrėnas et al., 2020). As such, this might suggest that regions which experience cold temperatures might have populations which are at a higher risk of increased radon exposure and its repercussions.

References

About Radon. (n.d.). Retrieved February 23, 2023, from https://www.who.int/teams/environment-climate-change-and-health/radiation-and-health/environmental-exposure/radon/about

Baltrėnas, P., Grubliauskas, R., & Danila, V. (2020). Seasonal Variation of Indoor Radon Concentration Levels in Different Premises of a University Building. Sustainability, 12(15), Article 15. https://doi.org/10.3390/su12156174

CDC. (2022, December 22). Radon in the Home. Centers for Disease Control and Prevention. https://www.cdc.gov/radon/radon-facts.html

Kim, J.-H., & Ha, M. (2018). The Disease Burden of Lung Cancer Attributable to Residential Radon Exposure in Korean Homes. Journal of Korean Medical Science, 33(29), e223. https://doi.org/10.3346/jkms.2018.33.e223

Li, C., Wang, C., Yu, J., Fan, Y., Liu, D., Zhou, W., & Shi, T. (2020). Residential Radon and Histological Types of Lung Cancer: A Meta-Analysis of Case‒Control Studies. International Journal of Environmental Research and Public Health, 17(4), 1457. https://doi.org/10.3390/ijerph17041457

Lorenzo-González, M., Ruano-Ravina, A., Torres-Durán, M., Kelsey, K. T., Provencio, M., Parente-Lamelas, I., Leiro-Fernández, V., Vidal-García, I., Castro-Añón, O., Martínez, C., Golpe-Gómez, A., Zapata-Cachafeiro, M., Piñeiro-Lamas, M., Pérez-Ríos, M., Abal-Arca, J., Montero-Martínez, C., Fernández-Villar, A., & Barros-Dios, J. M. (2019). Lung cancer and residential radon in never-smokers: A pooling study in the Northwest of Spain. Environmental Research, 172, 713–718. https://doi.org/10.1016/j.envres.2019.03.011

Lorenzo-González, M., Torres-Durán, M., Barbosa-Lorenzo, R., Provencio-Pull, M., Barros-Dios, J. M., & Ruano-Ravina, A. (n.d.). Radon exposure: A major cause of lung cancer. Retrieved February 22, 2023, from https://www-tandfonline-com.libproxy1.nus.edu.sg/doi/epdf/10.1080/17476348.2019.1645599?needAccess=true&role=button

Missimer, T. M., Teaf, C., Maliva, R. G., Danley-Thomson, A., Covert, D., & Hegy, M. (2019). Natural Radiation in the Rocks, Soils, and Groundwater of Southern Florida with a Discussion on Potential Health Impacts. International Journal of Environmental Research and Public Health, 16(10), 1793. https://doi.org/10.3390/ijerph16101793

Ngoc, L. T. N., Park, D., & Lee, Y.-C. (2023). Human Health Impacts of Residential Radon Exposure: Updated Systematic Review and Meta-Analysis of Case–Control Studies. International Journal of Environmental Research and Public Health, 20(1), Article 1. https://doi.org/10.3390/ijerph20010097

Radon. (n.d.). Retrieved February 22, 2023, from https://www.who.int/news-room/fact-sheets/detail/radon-and-health

Reddy, A., Conde, C., Peterson, C., & Nugent, K. (2022). Residential radon exposure and cancer. Oncology Reviews, 16(1), 558. https://doi.org/10.4081/oncol.2022.558

Riudavets, M., Garcia de Herreros, M., Besse, B., & Mezquita, L. (2022). Radon and Lung Cancer: Current Trends and Future Perspectives. Cancers, 14(13), Article 13. https://doi.org/10.3390/cancers14133142

Schwela, D., & Kotzias, D. (2005). Pollution, Air Indoor. In Encyclopedia of Toxicology (pp. 475–489). Elsevier. https://doi.org/10.1016/B0-12-369400-0/00780-8

Stanley, F. K. T., Irvine, J. L., Jacques, W. R., Salgia, S. R., Innes, D. G., Winquist, B. D., Torr, D., Brenner, D. R., & Goodarzi, A. A. (2019). Radon exposure is rising steadily within the modern North American residential environment, and is increasingly uniform across seasons. Scientific Reports, 9(1), Article 1. https://doi.org/10.1038/s41598-019-54891-8

Tong, J., Qin, L., Cao, Y., Li, J., Zhang, J., Nie, J., & An, Y. (n.d.). Environmental Radon Exposure and Childhood Leukemia. Retrieved February 23, 2023, from https://www-tandfonline-com.libproxy1.nus.edu.sg/doi/epdf/10.1080/10937404.2012.689555?needAccess=true&role=button

US EPA, O. (2014, August 14). Health Risk of Radon [Overviews and Factsheets]. https://www.epa.gov/radon/health-risk-radon

Vi), N. R. C. (US) C. on H. R. of E. to R. (BEIR. (1999). Public Summary: The Health Effects of Exposure to Indoor Radon. In Health Effects of Exposure to Radon: BEIR VI. National Academies Press (US). https://www.ncbi.nlm.nih.gov/books/NBK233259/

Vogeltanz-Holm, N., & Schwartz, G. G. (2018). Radon and lung cancer: What does the public really know? Journal of Environmental Radioactivity, 192, 26–31. https://doi.org/10.1016/j.jenvrad.2018.05.017

Figure 1: “Small Boy” nuclear test in Nevada 1962 (Source: Science, 2020)

What is nuclear fallout?

Nuclear fallout refers to the condensation of radioactive material produced from the detonation of nuclear weapons (Centres for Disease Control and Prevention, 2018). The dominant lethal effects lasting up to weeks, and the subsequent fallout contamination lasting up to decades (MIT Press Reader, 2022). As fallout consists of particles, nuclear fallout is often carried over long distances through wind, extending to areas beyond the explosion site. These charged particles can then mix with atmospheric water droplets, soot, or dust (Science, 2020).

Dangers of nuclear fallout

1. Human impacts

The impacts of radioactive fallout are wide, with people become irradiated through several ways following a nuclear fallout event. These include inhaling fallout particles or absorbing radiation through physical contact with fallout particles, as well as through consuming contaminated food (Black et al., 2017). One of the more widely studied incidents include the radioactive contamination of milk – in which cows consuming contaminated grass, resulting in the excretion of iodine 131 in their milk. The ingestion of radioactive iodine 131 then resulted in high concentrations of radioactivity in the thyroid gland (Yamamoto, 2013), increasing the chances of thyroid cancer in humans. More recent studies include Markabayeva et al.’s (2018) study on the effects of fallout exposure due to nuclear weapons testing in Kazakhstan, which found that populations living near these test sites had a higher incidence of cardiovascular diseases due to fallout exposure. To date, radioactive fallout in Kazakhstan mostly stems from uranium extraction activities, with fallout effects remaining a public health concern in populations living near nuclear test sites (Markabayeva et al., 2018). For populations who received significant amounts of radioactive fallout directly on their skin, this resulted in skin “burns”, as seen in Marshallese populations following the Bravo nuclear test on the Marshall Islands (Simon et al., 2014).

2. Environmental impacts

According to the International Committee of the Red Cross ([ICRC], 2020), modern environmental modelling techniques have shown that the emission of nuclear fallout particles from the use of nuclear weapons can lead to atmospheric cooling and shorter growing seasons, resulting in food shortages. The release of soot would block out sunlight, resulting in not just a decrease in global temperatures, but also less rainfall due to reduced evaporation rates due to lower temperatures (Van Hoesen, 2019). This phenomenon has come to be known as a “nuclear winter” (Carter, 2023), which could result global starvation along with the contamination of soil and water near nuclear weapons detonation sites.

References

Black, S., Bütikofer, A., Devereux, P., & Salvanes, K. (2013). This Is Only a Test? Long-Run Impacts of Prenatal Exposure to Radioactive Fallout (No. w18987; p. w18987). National Bureau of Economic Research. https://doi.org/10.3386/w18987

Carter, J. (n.d.). No Sunny Days For A Decade, Extreme Cold And Starvation: ‘Nuclear Winter’ And The Urgent Need For Public Education. Forbes. Retrieved February 15, 2023, from https://www.forbes.com/sites/jamiecartereurope/2023/02/13/no-sunny-days-for-a-decade-extreme-cold-and-starvation-nuclear-winter-and-the-urgent-need-for-public-education/

CDC Radiation Emergencies | Frequently Asked Questions About a Nuclear Blast. (2022, April 8). https://www.cdc.gov/nceh/radiation/emergencies/nuclearfaq.htm

Perkins, S. (n.d.). Can nuclear fallout make it rain? Retrieved February 15, 2023, from https://www.science.org/content/article/can-nuclear-fallout-make-it-rain

Reader, T. M. P. (2022, March 2). The Devastating Effects of Nuclear Weapons. The MIT Press Reader. https://thereader.mitpress.mit.edu/devastating-effects-of-nuclear-weapons-war/

Simon, S. L., Bouville, A., Land, C. E., & Beck, H. L. (2010). RADIATION DOSES AND CANCER RISKS IN THE MARSHALL ISLANDS ASSOCIATED WITH EXPOSURE TO RADIOACTIVE FALLOUT FROM BIKINI AND ENEWETAK NUCLEAR WEAPONS TESTS: SUMMARY. Health Physics, 99(2), 105–123. https://doi.org/10.1097/HP.0b013e3181dc523c

Van Hoesen, S. (2023). Science of Environmental Effects of Nuclear War // Artifacts Journal. https://artifactsjournal.missouri.edu/2019/06/science-of-environmental-effects-of-nuclear-war/

Yamamoto, L. G. (2013). Risks and Management of Radiation Exposure. Pediatric Emergency Care, 29(9), 1016. https://doi.org/10.1097/PEC.0b013e3182a380b8

(Image source: PBS News Hour)

Radioactive waste products are generally classified into two broad categories – low-level waste (LLW) and high-level waste (HLW) , such as uranium till minings and spent nuclear reactor fuel respectively (Energy Information Administration, 2022). While the disposal of LLW is often deemed to be “straightforward and can be undertaken safely almost anywhere” (World Nuclear Association, 2023), HLW is usually first stored away for a certain period of time to allow the decay of radioactivity and heat before disposal (World Nuclear Association, 2023). As the management of HLW is significantly more challenging, this blog article will focus on the current measures used to store and dispose HLW, and the risks of pollution arising from the (mis)management of HLW.

Storage and disposal of high-level nuclear waste

High-level radioactive waste, such as spent nuclear fuel, is first stored temporarily in underground or surface storage tanks, large concrete bays, or water pools. For such radioactive waste materials to be permanently stored away, HLW must be completely isolated from the environment for at least 10 half-lives, which can range from centuries to hundreds of thousands of years (Saeb & Patchet, 2003).

The final disposal of HLW through storing it in a Deep Geological Repository (DGR) has been deemed as an internationally accepted method for managing high-level nuclear waste (Lopez-Fernandez et al., 2015). Additionally, DGR is also among the preferred options when handling the high-energy contents of HLW such as spent nuclear fuel. This first involves storing the HLW in special dry storage casks which consist of several barriers, each with a specific purpose (Kurniawan et al., 2022):

These containers are then stored deep within a stable geologic environment, usually around an average of 500m underground. The surrounding bedrock, or host rock—which acts as the fifth barrier—has to be of low permeability to ensure that the nuclear fuel remains isolated for prolonged periods (Nuclear Waste Management Organisation [NWMO], n.d.).

Figure 1: Storage of spent nuclear fuel in a deep geological repository (Source: Bruno et al., 2020)

So… what’s the problem with nuclear waste disposal?

The amount of nuclear waste stemming from spent nuclear fuel is predicted to increase exponentially within the next 50 years, as shown in this graph below:

Figure 2: Growing quantities of spent nuclear fuel over the next 50 years (Source: Yano et al., 2018)

This then brings forth the issue of not just space constraints to store large quantities of spent nuclear fuel, but also the need to assess if current waste disposal methods are sufficient. While nuclear waste disposal is relatively well-established for LLW, Ojovan and Steinmetz (2022) argue that HLW disposal, even with the utilisation of DGRs, still remains challenging. These challenges often pertain to three main reasons: the need for constant safety monitoring, that the operation of DGRs is still relatively understudied, and that these repository sites require prolonged periods of geological stability:

Figure 3: Limitations of several HLW disposal methods (Source: Ojovan & Steinmetz, 2022)

Furthermore, while dry storage casks and DGRs appear to have multiple safeguards to ensure that HLW is properly stored away, trace amounts of more mobile radionuclides can still end up dispersed in rock-groundwater systems (Chapman & McCombie, 2003). This is due to the fact that as HLW containers are not completely resistant to corrosion (Kurniawan et al., 2022), radioactive waste leakages can still occur.

A notable example of a HLW leakage is the radioactive contamination at the Hanford Nuclear Reservation – the result of 67 out of 149 single shell tanks leaking a total of 1.9 million litres of radioactive waste. HLW at this site has been argued to have already migrated through the vadose zone, resulting in groundwater contamination (Ma et al., 2018). This is especially concerning given the many potential repercussions, such as the contamination of drinking water sources and the bioaccumulation of radionuclides within crops planted in contaminated soils. Furthermore, this leakage has also been projected to eventually reach the Columbia River (Washington State Department, n.d.), which would then magnify the extent of contamination significantly.

References

Bruno, J., Duro, L., & Diaz-Maurin, F. (2020). 13—Spent nuclear fuel and disposal. In M. H. A. Piro (Ed.), Advances in Nuclear Fuel Chemistry (pp. 527–553). Woodhead Publishing. https://doi.org/10.1016/B978-0-08-102571-0.00014-8

Chapman, N., & McCombie, C. (2003). Chapter 2 Safety and security issues in deep geological disposal. In Waste Management Series (Vol. 3, pp. 21–44). Elsevier. https://doi.org/10.1016/S0713-2743(03)80004-1

Department for Business, Energy & Industrial Strategy. (2014, July 24). Geological disposal of radioactive waste: A guide for communities. GOV.UK. https://www.gov.uk/guidance/managing-radioactive-waste-safely-a-guide-for-communities

Kurniawan, T. A., Othman, M. H. D., Singh, D., Avtar, R., Hwang, G. H., Setiadi, T., & Lo, W. (2022). Technological solutions for long-term storage of partially used nuclear waste: A critical review. Annals of Nuclear Energy, 166, 108736. https://doi.org/10.1016/j.anucene.2021.108736

Leaking tanks—Washington State Department of Ecology. (n.d.). Retrieved February 7, 2023, from https://ecology.wa.gov/Waste-Toxics/Nuclear-waste/Hanford-cleanup/Leaking-tanks

Lopez-Fernandez, M., Cherkouk, A., Vilchez-Vargas, R., Jauregui, R., Pieper, D., Boon, N., Sanchez-Castro, I., & Merroun, M. L. (2015). Bacterial Diversity in Bentonites, Engineered Barrier for Deep Geological Disposal of Radioactive Wastes. Microbial Ecology, 70(4), 922–935. https://doi.org/10.1007/s00248-015-0630-7

Ma, R., Zheng, C., & Liu, C. (2018). Groundwater Impacts of Radioactive Wastes and Associated Environmental Modeling Assessment. In R. A. Meyers (Ed.), Encyclopedia of Sustainability Science and Technology (pp. 1–12). Springer. https://doi.org/10.1007/978-1-4939-2493-6_203-3

Multiple-Barrier System. (n.d.). Retrieved February 6, 2023, from https://www.nwmo.ca/en/A-Safe-Approach/Facilities/Deep-Geological-Repository/Multiple-Barrier-System

Nuclear power and the environment—U.S. Energy Information Administration (EIA). (n.d.). Retrieved February 6, 2023, from https://www.eia.gov/energyexplained/nuclear/nuclear-power-and-the-environment.php

Ojovan, M. I., & Steinmetz, H. J. (2022). Approaches to Disposal of Nuclear Waste. Energies, 15(20), Article 20. https://doi.org/10.3390/en15207804

Powell, T. (2021, April 30). An underground tank in Washington is leaking gallons of radioactive chemical waste. https://www.cbsnews.com/news/hanford-nuclear-site-leaking-radioactive-chemical-waste/

Saeb, S., & Patchet, S. J. (2003). Radioactive Waste Disposal (Geology). In R. A. Meyers (Ed.), Encyclopedia of Physical Science and Technology (Third Edition) (pp. 633–641). Academic Press. https://doi.org/10.1016/B0-12-227410-5/00641-4

Yano, K. H., Mao, K. S., Wharry, J. P., & Porterfield, D. M. (2018). Investing in a permanent and sustainable nuclear waste disposal solution. Progress in Nuclear Energy, 108, 474–479. https://doi.org/10.1016/j.pnucene.2018.07.003

Fig. 1: Chernobyl Power Plant (Source: Chemical & Engineering News, n.d.)

What Happened:

The Chernobyl disaster of April 1986 was the result of a flawed nuclear reactor design, coupled with inadequately trained personnel operating the reactors (World Nuclear Association, 2022). The Number Four RBMK reactor, which was designed without a precautionary containment structure, received a sudden power surge during a reactor systems test and was destroyed (United States Nuclear Regulatory Commission, 2022). This incident then caused a steam explosion and resultant fire that­ ultimately released large amounts of radioactive elements over large parts of the Soviet Union (International Atomic Energy Agency [IAEA], n.d.). 134 workers who were present onsite suffered acute radiation sickness immediately following the explosion, in which 28 of them died within the following months (Canadian Nuclear Safety Commission, 2022).

This incident led to 31 immediate deaths and exposed more than 600,000 liquidators—firefighters and clean-up workers—to dangerously high levels of radiation (United Nations, n.d.). Reports also indicated that 155,000km² of territory across Belarus, Russia, and Ukraine, along with 52,000km² were contaminated with long-lived radionuclides (United Nations, n.d.).

Fig. 2: Dispersal of radioactive elements following the Chernobyl accident (Source: Saenko et al., 2011)

The population of Pripyat—a town with a population of more than 49,000—was evacuated 36 hours after the explosion, with an estimation of 200,000 people relocated as a result of the Chernobyl disaster (IAEA, n.d.). Till today, Pripyat remains an abandoned town, preserving Soviet elements in its architecture and environment.

After-effects of Chernobyl: Radiation-associated diseases

Decades after the Chernobyl disaster, many studies have established strong links between exposure to radiation and the development of cancer (Cardis & Hatch, 2011). To elaborate, exposure to iodine isotopes has been found to increase the likelihood of developing radiation-associated thyroid cancer (Saenko et al., 2011), especially . This observation has been supported by the huge onset of thyroid cancer in children and adults four years following the Chernobyl disaster, with around 13,000 children having been exposed to dangerously high levels of radiation (Petryna, 2004).

To date, radiation-associated thyroid cancer among children and adolescents still remains as the only direct adverse health consequence of the Chernobyl disaster (Abbott et al., 2007). However, the record of diseases of Chernobyl liquidators extends much further than just thyroid cancer:

Fig. 3: Disease-related death causes of Chernobyl workers (Source: Viel et al., 1996)

Aside from the list of suspected radiation-associated diseases and illnesses, the exposure to ionizing radiation has been alleged to cause damage to hereditary structures. To elaborate, the frequency of irradiated parents having children with abnormal chromosomes is higher compared to children born in less contaminated areas across Russia, Ukraine, and Belarus (Yablokov, 2009). As such, this illustrates how the impacts of irradiation extend far beyond those who were located within the contaminated zones – children born to irradiated parents years after the Chernobyl catastrophe still continue to bear the harmful health impacts of radiation exposure.

In recent years, however, more researchers have begun disputing the effects of children born to highly irradiated parents, citing that “even when people were exposed to relatively high doses of radiation – when compared to background radiation – it had no effect on their future children” (Gill, 2021).

What about Chernobyl today?

Fig. 4: Sarcophagus built over Chernobyl’s Unit 4 reactor (Source: British Broadcasting System, 2017)

The Chernobyl Exclusion Zone (CEZ) has grown to become a popular tourist site, with highly regulated tours issuing Geiger counters to tourists and letting them wander through abandoned towns, and interacting with the dead zone residents (Stone, 2013). This has often been cited as part of the wider phenomenon of exploring disaster cites, where tourist activity continues to contribute to “difficult heritage” of the CEZ (Banaszkiewicz et al., 2017).

Fig. 5: Tourists in the Chernobyl Exclusion Zone (Source: The Guardian, 2020)

References

Abbott, P., Wallace, C., & Beck, M. (n.d.). Chernobyl: Living with risk and uncertainty. https://doi.org/10.1080/13698570600677167

Backgrounder on Chernobyl Nuclear Power Plant Accident. (n.d.). NRC Web. Retrieved January 30, 2023, from https://www.nrc.gov/reading-rm/doc-collections/fact-sheets/chernobyl-bg.html

Banaszkiewicz, M., Kruczek, Z., & Duda, A. (2017). The Chernobyl Exclusion Zone as a Tourist Attraction: Reflections on the Turistification of the Zone. Folia Turistica / Akademia Wychowania Fizycznego Im. B. Czecha w Krakowie, nr 44, 145–169. https://doi.org/10.5604/01.3001.0010.8736

Biological Citizenship: The Science and Politics of Chernobyl-Exposed Populations. (n.d.). https://doi.org/10.1086/649405

Borys, C. (2017, January 30). A vast new tomb for the most dangerous waste in the world. Retrieved February 2, 2023, from https://www.bbc.com/future/article/20170101-a-new-tomb-for-the-most-dangerous-disaster-site-in-the-world

Chernobyl | Chernobyl Accident | Chernobyl Disaster—World Nuclear Association. (n.d.). Retrieved January 30, 2023, from https://world-nuclear.org/information-library/safety-and-security/safety-of-plants/chernobyl-accident.aspx

Dolzhenko, S. (2020, February 4). Tourists flock to Chernobyl – in pictures. The Guardian. http://www.theguardian.com/environment/gallery/2020/feb/04/tourists-flock-to-chernobyl-in-pictures

Frequently Asked Chernobyl Questions. (2016, November 7). [Text]. IAEA. https://www.iaea.org/newscenter/focus/chernobyl/faqs

Full article: Chernobyl: Living with risk and uncertainty. (n.d.). Retrieved February 1, 2023, from https://www-tandfonline-com.libproxy1.nus.edu.sg/doi/full/10.1080/13698570600677167

Gill, V. (2021, April 22). Chernobyl radiation damage “not passed to children.” BBC News. https://www.bbc.com/news/science-environment-56846728

Hussain, C. M., & Keçili, R. (2020). Chapter 1—Environmental pollution and environmental analysis. In C. M. Hussain & R. Keçili (Eds.), Modern Environmental Analysis Techniques for Pollutants (pp. 1–36). Elsevier. https://doi.org/10.1016/B978-0-12-816934-6.00001-1

Savage, N. (2022, February 25). Russia took control of the Chernobyl nuclear site in Ukraine. What does that mean? Retrieved February 1, 2023, from https://cen.acs.org/safety/Russia-took-control-Chernobyl-nuclear-site-in-Ukraine-What-does-that-mean/100/web/2022/02

Saenko, V., Ivanov, V., Tsyb, A., Bogdanova, T., Tronko, M., Demuidchik, Y., & Yamashita, S. (2011). The Chernobyl Accident and its Consequences. Clinical Oncology, 23(4), 234–243. https://doi.org/10.1016/j.clon.2011.01.502

Viel, J. F., Curbakova, E., Dzerve, B., Eglite, M., Zvagule, T., & Vincent, C. (1997). Risk factors for long-term mental and psychosomatic distress in Latvian Chernobyl liquidators. Environmental Health Perspectives, 105 Suppl 6(Suppl 6), 1539–1544. https://doi.org/10.1289/ehp.97105s61539

Yablokov, A. V. (2009). 5. Nonmalignant diseases after the Chernobyl catastrophe. Annals of the New York Academy of Sciences, 1181, 58–160. https://doi.org/10.1111/j.1749-6632.2009.04826.x