View source for Radium and radon in the environment

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{{Short description|Significant contributors to environmental radioactivity}}
[[Image:US homes over recommended radon levels.gif|thumb|upright=1.65|Predicted fraction of U.S. homes have radon concentrations exceeding the EPA's recommended action level of 4 pCi/L]]
{{Pollution sidebar|Natural}}

[[Radium]] and [[radon]] are important contributors to [[environmental radioactivity]]. Radon occurs naturally as a result of decay of [[radioactive]] elements in soil and it can accumulate in houses built on areas where such decay occurs. Radon is a major cause of cancer; it is estimated to contribute to ~2% of all cancer related deaths in Europe.<ref>{{Cite journal|title = Radon in homes and risk of lung cancer: collaborative analysis of individual data from 13 European case-control studies|last = Darby|date = January 29, 2005|journal = British Medical Journal|volume = 330|issue = 7485|page = 223|doi = 10.1136/bmj.38308.477650.63|pmid = 15613366|pmc=546066|display-authors=etal}}</ref>

Radium, like radon, is radioactive and is found in small quantities in nature and is hazardous to life if radiation exceeds 20-50 [[sievert|mSv]]/year. Radium is a decay product of [[uranium]] and [[thorium]].<ref>Kirby et al. p. 3</ref> Radium may also be released into the environment by human activity: for example, in improperly discarded products painted with [[radioluminescent]] paint.

== Radium ==

===In the oil and gas industries ===

Residues from the [[Petroleum|oil]] and [[natural gas|gas]] industry often contain [[radium]] and its daughters. The sulfate scale from an oil well can be very radium rich. The water inside an oil field is often very rich in [[strontium]], [[barium]] and [[radium]], while seawater is very rich in [[sulfate]]: so if water from an oil well is discharged into the sea or mixed with seawater, the radium is likely to be brought out of solution by the barium/strontium sulfate which acts as a [[Catalyst|carrier]] precipitate.<ref name="profile">{{Cite book|title = Toxicological Profile for Radon|last = Keith|first =S|publisher = Agency for Toxic Substances and Disease Registry (US)|date=May 2012|location = Atlanta (GA) |display-authors=etal}}</ref>

=== Radioluminescent (glow in the dark) products ===

It is not unknown for local contamination to arise from improper disposal of radium-based [[Radioluminescence|radioluminescent]] paints.<ref>{{cite web |publisher=U.S. Radium Corp. |location=New Jersey |id=EPA ID#: NJD980654172 |title=EPA REGION 2, Congressional District(s): 10, Essex, City of Orange |date=February 5, 2010 |url=http://www.epa.gov/region02/superfund/npl/0200772c.pdf |archive-url=https://web.archive.org/web/20120714234109/http://www.epa.gov/region02/superfund/npl/0200772c.pdf |url-status=dead |archive-date=July 14, 2012 }}</ref>

=== In radioactive quackery ===

[[Eben Byers]] was a wealthy American socialite whose death in 1932 from using a [[radioactive quackery]] product called [[Radithor]] is a prominent example of a death caused by radium. Radithor contained ~1 μCi (40 kBq) of <sup>226</sup>Ra and 1 μCi of <sup>228</sup>Ra per bottle. Radithor was taken by mouth and radium, being a [[calcium]] mimic, has a very long [[biological halflife]] in [[bone]].<ref>{{Cite journal|title = Radiation Therapy Pursuit Leads to Unearthing of "Hot Bones"|last = Vanchieri|first = Cori|date = November 7, 1990|journal = Journal of the National Cancer Institute|doi = 10.1093/jnci/82.21.1667|volume=82|issue=21|page=1667}}</ref>

== Radon ==

[[File:Radon decay in a cloud chamber.jpg|thumb|[[Radon]] in air forms a part of the [[background radiation]], which can be observed in a [[cloud chamber]]]]
Most of the dose is due to the decay of the [[polonium]] (<sup>218</sup>Po) and [[lead]] (<sup>214</sup>Pb) daughters of <sup>222</sup>Rn.  By controlling exposure to the daughters the radioactive dose to the [[skin]] and [[lung]]s can be reduced by at least 90%. This can be done by wearing a dust mask, and wearing a suit to cover the entire body. Note that exposure to [[smoke]] at the same time as [[radon]] and radon daughters will increase the harmful effect of the radon. In [[uranium mining|uranium miner]]s radon has been found to be more [[carcinogenic]] in [[Tobacco smoking|smokers]] than in non-smokers.<ref name=profile />
[[Image:Decay chain(4n+2, Uranium series).svg|thumb|alt=Uranium series|The radium or uranium series.]]

=== Occurrence===

Radon concentration in open air varies between 1 and 100 Bq m<sup>−3</sup>.<ref>{{Cite journal|title = Daily variation of the radon concentration indoors and outdoors and the influence of meteorological parameters.|last = Porstendörfer|first =J.|date = September 1994|journal = Health Physics|doi = 10.1097/00004032-199409000-00011|pmid = 8056597|volume=67|issue=3|pages=283–287| bibcode=1994HeaPh..67..283P |display-authors=etal}}</ref> Radon can be found in some [[spring (water)|spring water]]s and [[hot spring]]s.<ref>{{Cite journal|title = Evaluation of the exposure levels to radioactivity in the hot-spring environment of the Island of Ischia during a year|last = Bartoli|first = G.|date = 1989|journal = Annali di Igiene: Medicina Preventiva e di Comunità|pmid = 2484503|volume=1|issue=6|pages=1781–1823|display-authors=etal}}</ref> The towns of [[Misasa, Tottori|Misasa]], [[Japan]], and [[Bad Kreuznach]], [[Germany]] boast radium-rich springs which emit radon, as does [[Radium Springs, New Mexico]].

Radon exhausts naturally from the ground, particularly in certain regions, especially but not only regions with [[granite|granitic]] soils. However, not all granitic regions are prone to high emissions of radon. For instance, while the rock which [[Aberdeen]] is on is very radium rich, the rock lacks the cracks required for the radon to migrate. In other nearby areas of Scotland (to the north of Aberdeen) and in [[Cornwall]]/[[Devon]] the radon is very much able to leave the rock.

Radon is a decay product of [[radium]] which in turn is a decay product of uranium. Maps of average radon levels in houses are available, to assist in planning mitigation measures.<ref>{{cite web |url=http://eetd.lbl.gov/IEP/high-radon/USgm.htm |title=Predicted median annual-average living-area concentration, by county |publisher=Lawrence Berkeley National Laboratory |access-date=2008-02-12 |url-status=dead |archive-url=https://web.archive.org/web/20071231195400/http://eetd.lbl.gov/IEP/high-radon/USgm.htm |archive-date=2007-12-31}}</ref>

While high uranium in the [[soil]]/[[Rock (geology)|rock]] under a house does not always lead to a high radon level in air, a positive correlation between the uranium content of the soil and the radon level in air can be seen.

===In air ===

Radon harms [[indoor air quality]] in many homes. (See "In houses" below.)

Radon (<sup>222</sup>Rn) released into the air decays to [[lead|<sup>210</sup>Pb]] and other radioisotopes and the levels of <sup>210</sup>Pb can be measured. It is important to note that the rate of deposition of this radioisotope is very dependent on the season. Here is a graph of the deposition rate observed in [[Japan]].<ref>{{Cite journal |title= Seasonal and spatial variation of atmospheric 210Pb and 7Be deposition: features of the Japan Sea side of Japan |last= Yamamoto |first= Masayoshi |date= September 21, 2005 |journal= Journal of Environmental Radioactivity |doi= 10.1016/j.jenvrad.2005.08.001 |pmid= 16181712 |issue=1 |pages=110–131 |volume=86 |display-authors=etal}}</ref>
{{wide image|Lead210inairatjapan.png|550px|align-cap=center|Lead-210 deposition rate as a function of time as observed in Japan}}

===In groundwater===

Well water can be very rich in radon; the use of this water inside a house is another route allowing radon to enter the house. The radon can enter the air and then be a source of exposure to the humans, or the water can be consumed by humans which is a different exposure route.<ref>{{Cite web |url= http://water.epa.gov/lawsregs/rulesregs/sdwa/radon/basicinformation.cfm |title= Basic Information about Radon in Drinking Water |date= June 30, 2014 |access-date= January 31, 2015 |publisher= United States Environmental Protection Agency |archive-url=https://web.archive.org/web/20150214054459/http://water.epa.gov/lawsregs/rulesregs/sdwa/radon/basicinformation.cfm |url-status=dead |archive-date=2015-02-14}}</ref>

===Radon in rainwater===
Rainwater can be highly radioactive due to high levels of radon and its decay progenies <sup>214</sup>Bi and <sup>214</sup>Pb; the concentrations of these [[radioisotope]]s can be high enough to seriously disrupt [[radiation monitoring]] at nuclear power plants.<ref name=Yamazawa>{{Cite conference
| doi = 10.1063/1.2991194
| conference = The Natural Radiation Environment
| volume = 1034
| pages = 149–152
| last = Yamazawa
| first = H.
|author2=M. Matsuda |author3=J. Moriizumi |author4=T. Iida
 | title = Wet Deposition of Radon Decay Products and its Relation with Long-Range Transported Radon
| date = 2008
| bibcode = 2008AIPC.1034..149Y
}}</ref> The highest levels of radon in rainwater occur during thunderstorms, and it is hypothesized that radon is concentrated in thunderstorms because it forms some positive ions during thunderstorms.<ref name=Greenfield-1>{{Cite conference
| conference = Bulletin of the American Physical Society
| last = Greenfield
| first = M.B.
|author2=A. Iwata |author3=N. Ito |author4=M. Ishigaki |author5=K. Kubo
 | title = Intense γ radiation from radon progeny accreted in/on rain during and following thunderstorms
| location = Nashville, Tennessee
| date = 2006
}}</ref> Estimates of the age of raindrops have been obtained from measuring the isotopic abundance of radon's short-lived decay progeny in rainwater.<ref name=Greenfield-2>{{Cite journal
 |doi        = 10.1063/1.2990773
 |issn       = 0021-8979
 |volume     = 104
 |issue      = 7
 |pages = 074912–074912–9
 |id         = 074912
 |last       = Greenfield
 |first      = M. B.
 |author2    = N. Ito
 |author3    = A. Iwata
 |author4    = K. Kubo
 |author5    = M. Ishigaki
 |author6    = K. Komura
 |title      = Determination of rain age via γ rays from accreted radon progeny
 |journal    = Journal of Applied Physics
 |access-date = 2011-08-23
 |year       = 2008
 |url        = http://link.aip.org/link/JAPIAU/v104/i7/p074912/s1&Agg=doi
 |archive-url = https://archive.today/20130223080358/http://link.aip.org/link/JAPIAU/v104/i7/p074912/s1&Agg=doi
 |url-status   = dead
 |archive-date = 2013-02-23
 |bibcode    = 2008JAP...104g4912G
|hdl= 2297/14438
 |s2cid = 122604767
 |hdl-access= free
 }}</ref>

===In the oil and gas industries ===

Water, oil and gas from a well often contain [[radon]]. The radon decays to form solid radioisotopes which form coatings on the inside of pipework. In an oil processing plant the area of the plant where [[propane]] is processed is often one of the more contaminated areas of the plant as radon has a similar boiling point to propane.<ref>{{cite web |title=Survey & Identification of NORM Contaminated Equipment |url=http://www.enprotec-inc.com/Presentations/NORM.pdf |publisher=Enprotec / Hibbs & Todd |date=October 2004 |access-date=2006-05-28 |archive-date=2006-02-20 |archive-url=https://web.archive.org/web/20060220195742/http://www.enprotec-inc.com/Presentations/NORM.pdf |url-status=dead }}</ref>

===In mines ===

Because uranium minerals emit [[radon]] gas, and their harmful and highly radioactive [[decay product]]s, uranium mining is considerably more dangerous than other (already dangerous) [[Underground mining (hard rock)|hard rock mining]], requiring adequate ventilation systems if the mines are not [[open-pit mining|open pit]]. In the 1950s, a significant number of American uranium miners were [[Navajo Nation|Navajo]], as many uranium deposits were discovered on Navajo [[Indian reservation|reservations]]. A statistically significant proportion of these miners later developed [[small-cell lung cancer]], a type of cancer usually not associated with smoking, after exposure to uranium ore and [[radon-222]], a natural decay product of uranium.<ref>{{Cite journal |last1=Gottlieb |first1=Leon S. |last2=Husen |first2=Luverne A. |title=Lung Cancer Among Navajo Uranium Miners |date=April 1982 |journal=Chest |volume=81 |issue=4 |pages=449–452 |doi=10.1378/chest.81.4.449 |pmid=6279361}}</ref> The cancer causing agent has been shown to be the radon which is produced by the uranium, and not the uranium itself.<ref>{{Cite web |last1=Harley |first1=Naomi |date=1999 |last2=Foulkes |first2=Ernest |last3=Hilborne |first3=Lee H. |last4=Hudson |first4=Arlene |last5=Anthony |first5=C. Ross |title=A Review of the Scientific Literature As It Pertains to Gulf War Illnesses: Volume 7: Depleted Uranium |url=https://www.rand.org/pubs/monograph_reports/MR1018z7.html |publisher=RAND Corp. |language=en |page=28}}</ref> Some survivors and their descendants received compensation under the [[Radiation Exposure Compensation Act]] in 1990.

The level of radon in the air of mines is now normally controlled by law. In a working mine, the radon level can be controlled by [[Ventilation (architecture)|ventilation]], sealing off old workings and controlling the water in the mine. The level in a mine can go up when a mine is abandoned; it can reach a level which can cause the skin to become red (a mild [[radiation burn]]). The radon levels in some of the mines can reach 400 to 700 kBq m<sup>−3</sup>.<ref>{{Cite journal|title = Assessment of health risks to skin and lung of elevated radon levels in abandoned mines.|last1 = Denman|first1 = A.R.|date = December 2003|journal = Health Physics|doi = 10.1097/00004032-200312000-00018|pmid = 14626324|last2 = Eatough|first2 = J.P.|first3 = G.|first4 = P.S.|last3 = Gillmore|last4 = Phillips|issue = 6|pages = 733–739|volume=85| bibcode=2003HeaPh..85..733D | s2cid=12197510 }}</ref>

A common unit of exposure of lung tissue to [[alpha emitter]]s is the [[working level]] month ('''WLM'''), this is where the human [[lung]]s have been exposed for 170 hours (a typical month worth of work for a miner) to air which has 3.7 kBq of <sup>222</sup>Rn (in equilibrium with its decay products). This is air which has the alpha dose rate of 1 [[working level]] ('''WL'''). It is estimated that the average person ([[general public]]) is subject to 0.2 WLM per year, which works out at about 15 to 20 WLM in a lifetime. According to the NRC, 1 WLM is a 5 to 10 mSv lung dose (0.5 to 1.0 [[Röntgen equivalent man|rem]]), while the [[Organisation for Economic Co-operation and Development]] (OECD) consider that 1 WLM is equal to a lung dose of 5.5 mSv, and the [[International Commission on Radiological Protection]] (ICRP) consider 1 WLM to be a 5 mSv lung dose for professional workers (and a 4 mSv lung dose for the general public). Lastly the [[United Nations Scientific Committee on the Effects of Atomic Radiation]] (UNSCEAR) consider that the exposure of the lungs to 1 Bq of <sup>222</sup>Rn (in equilibrium with its decay products) for one year will cause a dose of 61 μSv.<ref>{{Cite book|title = Radioactivity, Ionizing Radiation, and Nuclear Energy|last1 = Hala|first1 = Jiri|publisher = Konvoj|year = 2003|isbn = 9788073020538|last2 = Navratil|first2 = James}}</ref>

{{Citation needed span|text=In humans a relationship between [[lung cancer]] and radon has been shown to exist (beyond all reasonable doubt) for exposures of 100 WLM and above. By using the data from several studies it has been possible to show that an increased risk can be caused by a dose as low as 15 to 20 WLM. Sadly these studies have been difficult as the random errors in the data are very large. It is likely that the miners are also subject to other effects which can harm their lungs while at work (for example dust and [[Diesel exhaust|diesel]] fumes).|date=January 2022}}

===In houses ===

It has been known since at least the 1950s that radon is present in indoor air, and research into its effects on human health started in the early 1970s.<ref>{{Cite journal|url = http://monographs.iarc.fr/ENG/Monographs/vol43/|title = Man-made Mineral Fibres and Radon|date = 1988|journal = IARC Monographs on the Evaluation of Carcinogenic Risks to Humans|access-date = January 31, 2015|issue = 43| isbn=9789283212430 }}</ref> The danger of radon exposure in [[dwellings]] received more widespread public awareness after 1984, as a result of the case of [[Health effects of radon#Stanley Watras|Stanley Watras]], an employee at the [[Limerick nuclear power plant]] in [[Pennsylvania]].<ref>{{Cite journal|title = Indoor radon and lung cancer. Estimating the risks.|last = Samet|first = J. M.|date = January 1992|journal = Western Journal of Medicine|pmid = 1734594|pmc=1003141|volume=156|issue=1|pages=25–29}}</ref> Mr. Watras set off the [[radiation]] alarms (see [[Geiger counter]]) on his way ''into'' work for two weeks straight while authorities searched for the source of the [[contamination]]. They were shocked to find that the source was astonishingly high levels of radon in his [[basement]] and it was not related to the nuclear plant. The risks associated with living in his house were estimated to be equivalent to [[Tobacco smoking|smoking]] 135 packs of [[cigarette]]s every day.<ref>{{Cite web|url = http://oldweb.northampton.ac.uk/aps/env/wastes/radon_hotline/radonstory.htm|title = The Radon Story|date = 2001|access-date = January 1, 2015|publisher = The Radon Council|url-status = dead|archive-url = https://archive.today/20150201024505/http://oldweb.northampton.ac.uk/aps/env/wastes/radon_hotline/radonstory.htm|archive-date = February 1, 2015}}</ref>

Depending how houses are built and ventilated, radon may accumulate in basements and dwellings. The [[European Union]] recommends that [[Radon mitigation|mitigation]] should be taken starting from concentrations of 400&nbsp;[[Becquerel|Bq]]/m<sup>3</sup> for old houses, and 200&nbsp;Bq/m<sup>3</sup> for new ones.<ref name=":0">{{Cite journal|url = http://www.polisproject.org/PDFs/Radon%20report%20DSF.doc|title = Radon The Unfamiliar Killer|last = Boyd|first = David R.|access-date = February 1, 2015|publisher = David Suzuki Foundation|year = 2006|series = Healthy Environment, Healthy Canadians Series, Report No.1|location = Vancouver|archive-date = March 4, 2016|archive-url = https://web.archive.org/web/20160304092241/http://www.polisproject.org/PDFs/Radon%20report%20DSF.doc|url-status = dead}}</ref>

The [[National Council on Radiation Protection and Measurements]] (NCRP) recommends action for any house with a concentration higher than 8&nbsp;[[Curie (unit)|pCi]]/L (300 Bq/m<sup>3</sup>).

The [[United States Environmental Protection Agency]] recommends action for any house with a concentration higher than 148&nbsp;Bq/m<sup>3</sup> (given as 4&nbsp;[[Curie (unit)|pCi]]/L). Nearly one in 15 homes in the U.S. has a high level of indoor radon according to their statistics. The U.S. Surgeon General and EPA recommend all homes be tested for radon. Since 1985, millions of homes have been tested for radon in the U.S.<ref name=":0" />

By adding a crawl space under the ground floor, which is subject to forced ventilation, the radon level in the house can be lowered.<ref>{{Cite book|title = Design and Testing of Sub-Slab Depressurization for Radon Mitigation in North Florida Houses: Part I - Performance and Durability|last = Roessler|first = C. E.|publisher = United States Environmental Protection Agency|year = 1996|location = Research Triangle Park, NC|url = http://infohouse.p2ric.org/ref/07/06295.pdf|display-authors=etal}}</ref>

==References==
{{reflist}}
*G.K. Gillmore, P. Phillips, A. Denman, M Sperrin and G. Pearse, ''Ecotoxicology and Environmental Safety'', 2001, '''49''', 281.
*J.H. Lubin and J.D. Boice, ''Journal Natl. Cancer Inst.'', 1997, '''89''', 49. (Risks of indoor radon)
*N.M. Hurley and J.H. Hurley, ''Environment International'', 1986, '''12''', 39. (Lung cancer in uranium miners as a function of radon exposure).

== Further reading ==
*Hala, J. and Navratil J.D., ''Radioactivity, Ionizing Radiation and Nuclear Energy'', Konvoj, 2003. {{ISBN|80-7302-053-X}}

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[[Category:Radium|Environment]]
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[[Category:Radiobiology]]
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[[Category:Soil contamination]]
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