In the s and s, companies who set up mines did not widely implement ventilation systems. Despite the eventual realization of the hazards, radon-induced lung cancer in miners remained a significant hazard until the s.
Healthcare professionals now acknowledge that inhaling large quantities of radon causes lung cancer. According to the EPA, radon is the second most common cause of lung cancer, after smoking. Radon causes 21, lung cancer deaths per year in the U. About 2, of those deaths occur in people who have never smoked.
With the lack of available testing and noticeable symptoms, it is doubly important to minimize exposure to radon. More common rocks, such as limestone, also emanate radon, also this is a less common occurrence and levels are lower than other sources. Natural rock is not the only source of radon. Man-made structures can also be responsible for radon poisoning. Radon tends to enter buildings at their lowest point. It often makes its way in through splits in foundations, cracks in walls, gaps around pipes, cavities inside walls and the water supply.
The gas is likely to build up in poorly ventilated, airtight buildings. Levels vary a great deal between locations and, although the half-life of radon is less than 4 days, it can build up in high concentrations, especially in areas of low elevation, such as basements or mine shafts.
Two adjacent homes and even two adjacent rooms can vary significantly in their levels of radon. This helpful resource from the EPA shows the areas of the U. Iowa has the highest percentage of homes scoring above a safe radon level, with The high levels of radon in Iowa are the result of ancient glaciers that ground down granite rocks over time and deposited them in the form of soil. The exact risks of radon in the home are difficult to assess.
Most studies of the risks used data from miners, who will have had far more exposure to radon than is likely in any building. Carmona, issues a Health Advisory warning Americans about the health risk from exposure to radon in indoor air.
The Chief Physician urged Americans to test their homes to find out how much radon they might be breathing. In an effort to reduce the rate of lung cancer around the world, the World Health Organization WHO launched an international radon project to help countries increase awareness, collect data and encourage action to reduce radon-related risks.
The U. The following graphic compares EPA estimates of the annual radon-related lung cancer deaths to other selected cancers. View a larger version of this image. Skip to main content. Contact Us. Health Risk of Radon.
The excessive relative risk per WLM was 1. Miners exposed at a younger age and exposed to relatively low radon concentrations had a higher percentage increase in lung cancer death rate per WLM, compared to other miners. After these comprehensive studies, several updated or new cohort studies were published as shown in Table 1. In the near future, a new comprehensive report including these new studies is expected to be reported.
With the identification of an increased risk of lung cancer due to occupational radon exposure in miners, residential exposure in the general population is also be expected to yield an increased risk of lung cancer. However, it should be taken into account that there is a substantial uncertainty to directly extrapolate the results of the underground miners, since the special nature of the cohort of underground miners and the propensity of the cohort of the general population may differ in their smoking habits and exposure to other harmful substances, such as arsenic and quartz, which can also cause lung cancer.
Table 2 shows the case-control studies that have reported on residential radon exposure and lung cancer risk. The observation that many studies regarding residential exposure of the general population showed statistical insignificance, compared to occupational exposure among miners, could be explained by the smaller cohorts and the relatively lower levels of exposure to radon than among miners.
Accordingly, several reports that collected single cohort studies and carried out combined analyses were published, and representative combined studies are shown in Table 3. That study also concluded that the dose-response relation seemed to be linear, with no threshold dose, and there was a significant dose-response relation even at low doses. Considering the epidemiologic studies regarding the relationship between radon exposure and lung cancer risk so far, the majority of studies of underground miners and most combined studies of the general population have reported that the risk of lung cancer increases statistically significantly in proportion to radon exposure.
The World Health Organization considers that radon exposure is the second most common cause of lung cancer after cigarette smoking. There are many pieces of scientific evidence indicating that radon exposure can cause lung cancer; however, it is unclear whether radon can cause diseases other than lung cancer. Due to the unique biokinetics of radon inhalation in the body, the effective radiation doses reaching specific organs are much lower than that received by the lungs.
Therefore, when assessing a possible association between radon exposure and diseases other than lung cancer, the rationale for such a relationship is weak. Many studies regarding the relationship between radon exposure and hematological cancers have been reported, and these studies are shown in Table 4.
Some studies 39 , 44 even reported negative correlations; thus, the opinion that radon exposure may cause leukemia is generally not accepted as a scientific fact. However, it is thought that a combined report of all case-control studies will be needed. The relationship between radon exposure and central nervous system tumors is also inconclusive.
According to a systematic review performed by Ruano-Ravina et al. The relationship between radon exposure and thyroid cancer; 51 , 52 skin cancer; 53 , 54 , 55 head and neck cancer; 56 , 57 , 58 stomach cancer; 59 heart disease; 60 and reproductive, fetal, and hereditary effects 61 have also not been scientifically proven for the same reason.
It has been scientifically proven that exposure to radon can cause lung cancer. Diseases other than lung cancer, however, seem to be unrelated, and the relationship with some diseases, especially leukemia and COPD, remains controversial. Nevertheless, as interest among the public increases in the event of nuclear or radiation-related issues and causes excessive concern, passing on scientifically unproven information recklessly to the general public will lead to its acceptance as the truth, regardless of its authenticity.
Therefore, mass media and related experts need to deliver accurate information continuously to the general public based on scientific evidence. When mass media or related experts communicate information to the public, there is a need for a balanced view supported by many studies, rather than focusing on one or two studies. There have been many commercial advertisements recently for air purifiers, foods, and drugs that can remove radon from the air or the body.
For now, scientific evidence regarding their health effects is insufficient, and these should be elucidated clearly. Based on the misunderstanding that anions can have a beneficial health effect, a monazite-containing substance that could release anions was added to bed mattresses, and this resulted in the radon bed mattress incident in Korea.
Thus, if products that are scientifically not validated are sold commercially through false or exaggerated advertisements, consumers could be deceived twice. Hence, attempts to further spread public fear of radon for commercial purposes and economic gains should be eradicated. It is difficult to accurately assess by how much the risk of lung cancer would increase among customers who used radon-releasing mattresses based only on the report regarding the concentration of radon in a specific mattress model announced by the Korean government.
Furthermore, because the occurrence of lung cancer due to radon exposure is a stochastic effect, this would need to be observed through long-term follow-up for several years to several decades. Some experts argue for epidemiological investigations regarding the radon mattress incident; however, in order to carry out an accurate epidemiological study, more precise individual data e.
In conclusion, it is scientifically proven that radon exposure can cause lung cancer, whereas its relation with diseases other than lung cancer remains controversial. Mass media and related experts need to communicate accurate information to the general public, and it is necessary to maintain a balanced view supported by many studies when providing information to the general public. The authors have no potential conflicts of interest to disclose.
National Center for Biotechnology Information , U. Journal List Yonsei Med J v. Yonsei Med J. Published online Jun Find articles by Jin-Kyu Kang. Find articles by Songwon Seo. Find articles by Young Woo Jin.
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This article has been cited by other articles in PMC. Abstract Radon is a naturally occurring radioactive material that is formed as the decay product of uranium and thorium, and is estimated to contribute to approximately half of the average annual natural background radiation.
Keywords: Radon, inhalation exposure, lung neoplasm. Lung cancer risk in underground miners Since the s, epidemiological studies of lung cancer risk in underground miners have been published. Open in a separate window. Lung cancer risk in the general population with residential exposure With the identification of an increased risk of lung cancer due to occupational radon exposure in miners, residential exposure in the general population is also be expected to yield an increased risk of lung cancer.
Author Year of publication No. Footnotes The authors have no potential conflicts of interest to disclose. Writing and review of manuscript: All authors. Environ Health Perspect. IARC monographs on the evaluation of carcinogenic risks to humans.
Radon permeability and radon exhalation of building materials. Indoor radon concentrations caused by construction materials in 23 workplaces. Residential radon and lung cancer among never-smokers in Sweden. Lung cancer risk from residential radon: Meta-analysis of eight epidemiologic studies. Case-control study of childhood acute lymphoblastic leukemia and residential radon exposure. National and regional distribution of airborne radon concentrations in US homes.
Health Phys. Morganstern H. Ecologic studies in epidemiology: Concepts, principles, and methods. Ann Rev Public Health. National Cancer Institute. Radon and Cancer. National Toxicology Program. Residential radon and risk of lung cancer in an Italian alpine area. Arch Environ Health. Radon exposure and mortality among white and American Indian uranium miners: An update of the Colorado Plateau cohort. A review of ecological studies of lung cancer and indoor radon.
American Cancer Society medical information is copyrighted material. For reprint requests, please see our Content Usage Policy. Download this topic [PDF]. Sun and Other Types of Radiation. Radon and Cancer What is radon? How are people exposed to radon? At home and in other buildings For both adults and children, most exposure to radon comes from being indoors in homes, offices, schools, and other buildings.
At certain jobs In the workplace, people working underground, such as some types of miners, are among the most likely to be exposed to high levels of radon. Does radon cause cancer? Studies in people Several types of studies in people have found that exposure to radon increases lung cancer risk: Studies of people working in underground mines with high levels of radon exposure Studies comparing radon levels in homes of people with lung cancer with the levels in homes of similar people without lung cancer Studies comparing lung cancer cases or deaths in areas with differing levels of radon exposure These studies also show that the overall risk of lung cancer from radon is even higher in people who smoke and people who used to smoke.
Studies done in the lab Studies in lab animals have also shown an increased risk of lung cancer with exposure to radon. What expert agencies say Several national and international agencies study different substances in the environment to determine if they can cause cancer.
Can I avoid being exposed to radon? In the home For most people, the largest potential source of radon exposure is in their home. There are no widely available medical tests to measure whether you have been exposed to radon.
Written by References. The American Cancer Society medical and editorial content team Our team is made up of doctors and oncology certified nurses with deep knowledge of cancer care as well as journalists, editors, and translators with extensive experience in medical writing.
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