You can’t see it; you can’t smell it; and you can’t taste it. Still, radon in the food you eat, the water you drink and the air you breathe is toxic and in the long run it can cause serious health problems leading to death, including lung cancer. Radon is an inert and radioactive gas in the decay chain of uranium (Pundir et. al. 2012).Radon is an interesting subject. Despite its toxic qualities, many also believe that radon is positive for health in low doses as it increases homeostasis effects, and radon therapy is popular in Russia and Central European countries (EPA 2013). For a long time it was believed that radon was an effective therapy for lung cancer (for example, Kernan 1933). This is called the radiation homeostasis theory, and recent research has been exploring its validity with some success. A study using dogs showed that they had fewer cancers of the lung when exposed to low doses of radon (Fisher & Weller 2010).
Radon is a gas, and it is released from the soil and natural materials where it is found naturally and this can include materials used in the construction of buildings (Health Canada 2014). A further problem with radon gas is the breakdown productions which are radioactive and referred to as radon daughters (Ibid.). These radon daughters can cause considerable harm to living tissue (Ibid.).
Radon is constantly present in rocks and natural land products and the water and air. It is the greatest source of natural radiation (Pundir et. al. 2012). Radon gas can go through small spaces and be released from the other or natural building materials. If it cannot escape, then it continues to build and concentrate, posing a potential health danger (EPA 2013). Radon gas escapes from soil and rock and dissolves in water and into the air. In geographic areas with higher levels, this will likely be found in soil, water and atmosphere (Ibid.)
Radon levels in the environment are measured in Becquerel (Bq) by most nations, or picocuries per litre (pCi/L) in the United States. Both of these measurements indicate concentration of radioactivity (Health Canada 2014). A high measurement therefore indicates high amounts of radon gas (Ibid.). One pCi/L equals 37 Bq/m³ (Ibid). Because radon occurs naturally, it builds up to different levels depending on climate, buildings, soil conditions and other variables, there can be diverse levels even in close proximity. Conditions of high radon levels can be found in underground mining situations, inside buildings and in geographic areas of high natural radon levels. The WHO’s recommends that 100 Bq/m³ is the reference level, and 300 Bq/ m³ is the highest level that should be considered safe (Ibid.). The EPA recommendation is more stringent, and it recommends radon levels in homes be no higher than 4 pCi/L (EPA 2013).
Radon and decay products can enter the body through good, water or inhalation (EPA 2013). Radon clings to particulate in the air, and this allows it to be inhaled where it can stay in the lungs or cause damage in the time that it is there (Ibid.). When radon gas breaks down it releases alpha particles, and these release damaging radioactive energy which enters lung tissue, causing damage which can result in cancer (Health Canada 2014).
Smokers have increased vulnerability to the effects of radon due to their exposure from their habit. Smokers exposed to other sources of radon have increased risks (Health Canada 2014). Natural radon daughters produced during the decay of radon becomes attached to tobacco leaves. After the leaves are dried and manufactured as tobacco the radon decay products remain and an inhaled into the lungs when the tobacco is smoked. Because radon clings to particles in the air second hand smoke is also a problem as radon and its by-products cling to it in the air. These particles with radon decay products attached are inhaled and enter the lungs.
When radon gas is inhaled, most is also exhaled, but radon decay products attached to air particulate are likely to remain in the lungs (EPA 2013). It is in the lungs that radon’s toxins appear to have the most impact on cells. Radon decays quickly, and when it is inside the body it the tiny radioactive particles are in the body long for the radiation released to damage the cells of the lung tissues (Ibid.). While there is some risk that water that has high amounts of radon can damage cells of the stomach lining, for the most part the alpha particles which are given off by radon and progeny which cause the damage are typically absorbed by other compounds in water and expelled in urine (EPA 2013).
Radon impacts the cells of the body, causing changes to the cells ability to function due to radioactive damage. As inhalation is the typical route, the result is cancer. Damaged lung cells are the cause of this cancer. For this reason radon one of the leading causes of lung cancer (Health Canada 2014). The evidence regarding harm from radon other than lung cancer is not proven (Health Canada 2014).
These negative effects lead to the symptoms seen in the patient as the damage to the lung tissue disrupts homeostasis. Homeostasis refers to the actions taken by the body on several levels to keep its environment within a certain range. When homeostatic disruption is caused by toxins, it is because those exposed cells have been poisoned, their mechanisms have malfunctioned and they are now sending improper messages. These messages, such as the creation of more mutant cells, are implicated in cancerous tumour and spread.
There is no way to know that one has been exposed to toxic radon until symptoms present themselves. There is no test that can determine radon exposure or impacts, although some radon decay products can be found in urine, lung and bone tissues (ATRDR 2012). The symptoms are similar to lung cancer, including persistent cough and respiratory infections (EPA 2013). In order to treat exposure to radon, the medical community works to return the body to homeostasis by treating the damaged cells. The greatest symptom of radon exposure is respiratory disease, in particular lung cancer. Returning the body to homeostasis therefore consists of treatments for the cancer to reduce the spread of damaged cancerous cells.
It is impossible to detect radon using the senses; therefore it can be difficult to avoid radon gas. Some techniques are avoiding geographic regions with high levels of radon, never smoking, and using preventing the building up of radon inside buildings (Health Canada 2014). Given that radon decay products attach to dust, aerosol and particulate in the air, ensuring minimal dust and open windows can prevent the buildup and inhalation of radon inside buildings. In Active Soil Depressurisation (ASD), radon gas is captured from buildings through a hole, pipe and fan which are put into the floor of the building at the lowest level, releasing the gas into the outside air (Ibid.).
You will not see, smell or taste it yet it could be damaging to your health- or beneficial. There is considerable research still to do to better understand radon gas and its effects on human health, both how it causes damage to the human body, how to avoid it, and how it radon may have potential uses in health. There is so much that is not understood but research in this area is increasing.
- Agency for Toxic Substances and Disease Registry (ATSDR). (May 2012). Public Health Statement: Radon. Retrieved from http://www.atsdr.cdc.gov/ToxProfiles/tp145-c1-b.pdf
- Environmental Protection Agency (EPA). (2013). “Radon”. EPA website. Retrieved from http://www.epa.gov/radiation/radionuclides/radon.html
- Fisher, D.R., & Weller, R.E.. (2010). Carcinogenesis from Inhaled 239PuO2 in Beagles: Evidence for Radiation Homeostasis at Low Doses?. Health physics. 99(3), 357-362.
- Health Canada. (2014). Radon Frequently Asked Questions. Health Canada website. Retrieved from: http://www.hc-sc.gc.ca/ewh-semt/radiation/radon/faq_fq-eng.php#indoor
- Kernan, J. D. (1933). Carcinoma of the lung and bronchus: Treatment with radon implantations and diathermy. Archives of Otolaryngology, 17(4), 457-475.
- Pundir, A., Kamboj, S., Bansal, V., Chauhan, R. P., & Rana, R. S. (2012). Radon concentration and exhalation rates in building material samples from crushing zone in Shivalik Foot Hills. In Proceedings of the international conference on emerging frontiers and challenges in radiation biology: abstracts.
- World Health Organization (WHO). (2014). Radon and health. WHO website. Retrieved from: http://www.who.int/mediacentre/factsheets/fs291/en/