Editing Radon (section)

=== Scientific ===
Radon emanation from the soil varies with soil type and with surface uranium content, so outdoor radon concentrations can be used to track [[air mass]]es to a limited degree.<ref>{{Cite journal |last1=Lambert |first1=Gérard |last2=Polian |first2=Georges |last3=Taupin |first3=D. |date=1970-04-20 |title=Existence of periodicity in radon concentrations and in the large-scale circulation at lower altitudes between 40° and 70° south |url=http://doi.wiley.com/10.1029/JC075i012p02341 |journal=Journal of Geophysical Research |language=en |volume=75 |issue=12 |pages=2341–2345 |doi=10.1029/JC075i012p02341|bibcode=1970JGR....75.2341L }}</ref>{{efn|See [[radon storm]].}} Because of radon's rapid loss to air and comparatively rapid decay, radon is used in [[hydrology|hydrologic]] research that studies the interaction between groundwater and [[stream]]s. Any significant concentration of radon in a river may be an indicator that there are local inputs of groundwater.<ref>{{Citation |last1=S. |first1=Sukanya |title=Radon Distribution in Groundwater and River Water |date=2023 |work=Environmental Radon: A Tracer for Hydrological Studies |pages=53–87 |editor-last=S. |editor-first=Sukanya |url=https://link.springer.com/chapter/10.1007/978-981-99-2672-5_3 |access-date=2024-10-15 |place=Singapore |publisher=Springer Nature |language=en |doi=10.1007/978-981-99-2672-5_3 |isbn=978-981-99-2672-5 |last2=Joseph |first2=Sabu |editor2-last=Joseph |editor2-first=Sabu}}</ref>

Radon soil concentration has been used to map buried close-subsurface geological [[fault (geology)|faults]] because concentrations are generally higher over the faults.<ref>{{cite journal |author=Richon, P. |author2=Y. Klinger |author3=P. Tapponnier |author4=C.-X. Li |author5=J. Van Der Woerd |author6=F. Perrier |name-list-style=amp |date=2010 |title=Measuring radon flux across active faults: Relevance of excavating and possibility of satellite discharges |url=http://www.ipgp.fr/~klinger/page_web/biblio/publication/Richon_RadMeas2010%20.pdf |journal=[[Radiat. Meas.]] |volume=45 |pages=211–218 |doi=10.1016/j.radmeas.2010.01.019 |issue=2 |bibcode=2010RadM...45..211R |hdl=10356/101845 |access-date=2011-08-20 |archive-date=2013-06-26 |archive-url=https://web.archive.org/web/20130626115736/http://www.ipgp.fr/~klinger/page_web/biblio/publication/Richon_RadMeas2010%20.pdf |url-status=dead }}</ref> Similarly, it has found some limited use in prospecting for [[geothermal gradient]]s.<ref>{{cite conference |last1=Semprini |first1=Lewis |last2=Kruger |first2=Paul |date=April 1980 |title=Radon Transect Analysis In Geothermal Reservoirs |conference=SPE California Regional Meeting, 9–11 April, Los Angeles, California |doi=10.2118/8890-MS |isbn=978-1-55563-700-2}}</ref>

Some researchers have investigated changes in groundwater radon concentrations for [[earthquake prediction]].<ref>{{Unbulleted list citebundle|{{cite journal |author=Igarashi, G. |author2=Wakita, H. |date=1995 |title=Geochemical and hydrological observations for earthquake prediction in Japan |journal=[[Journal of Physics of the Earth]] |volume=43 |pages=585–598 |url=http://www.jstage.jst.go.jp/article/jpe1952/43/5/43_5_585/_pdf |doi=10.4294/jpe1952.43.585 |issue=5|doi-access=free }}|{{Cite journal |first1=Masayasu |last1=Noguchi |last2=Wakita |first2=Hiroshi |date=10 March 1977 |journal=[[Journal of Geophysical Research]] |doi=10.1029/JB082i008p01353 |title=A method for continuous measurement of radon in groundwater for earthquake prediction |pages= 1353–1357 |volume=82 |issue=8|bibcode=1977JGR....82.1353N }}}}</ref><ref name="Mindoro">{{cite journal |author=Richon, P. |author2=Sabroux, J.-C.|author3=Halbwachs, M.|author4=Vandemeulebrouck, J.|author5=Poussielgue, N.|author6=Tabbagh, J. |author7=Punongbayan, R. |date=2003 |title=Radon anomaly in the soil of Taal volcano, the Philippines: A likely precursor of the M 7.1 Mindoro earthquake (1994) |journal=[[Geophysical Research Letters]] |volume=30 |issue=9 |page=34 |doi=10.1029/2003GL016902|bibcode=2003GeoRL..30.1481R|s2cid=140597510 }}</ref> Increases in radon were noted before the [[1966 Tashkent earthquake|1966 Tashkent]]<ref>{{Cite book |editor-last=Cothern |editor-first=C.Richard | editor-last2=Smith | editor-first2=James E. |date=1987 |title=Environmental Radon |url=https://books.google.com/books?id=K7WvwZlc72MC&pg=PA53|series=Environmental Science Research |volume=35 | publisher=Springer Science & Business Media | publication-place=New York |isbn=978-0-306-42707-7|page=53}}</ref> and [[1994 Mindoro earthquake|1994 Mindoro]]<ref name="Mindoro" /> earthquakes. Radon has a half-life of approximately 3.8 days, which means that it can be found only shortly after it has been produced in the radioactive decay chain. For this reason, it has been hypothesized that increases in radon concentration is due to the generation of new cracks underground, which would allow increased groundwater circulation, flushing out radon. The generation of new cracks might not unreasonably be assumed to precede major earthquakes. In the 1970s and 1980s, scientific measurements of radon emissions near faults found that earthquakes often occurred with no radon signal, and radon was often detected with no earthquake to follow. It was then dismissed by many as an unreliable indicator.<ref>{{cite news |url=https://www.npr.org/templates/story/story.php?storyId=102804333 |title=Expert: Earthquakes Hard To Predict |newspaper=NPR.org |access-date=2009-05-05}}</ref> As of 2009, it was under investigation as a possible earthquake precursor by [[NASA]];<ref name="EARTHq">{{cite web |url=https://www.earthmagazine.org/article/earthquake-prediction-gone-and-back-again/ |title=EARTH Magazine: Earthquake prediction: Gone and back again |date=2012-01-05}}</ref> further research into the subject has suggested that abnormalities in atmospheric radon concentrations can be an indicator of seismic movement.<ref>{{Cite journal|doi=10.1038/s41598-024-61887-6 |last1=Tsuchiya |first1=Mayu |last2=Nagahama |first2=Hiroyuki |last3=Muto |first3=Jun |first4=Mitsuhiro |last4=Hirano |first5=Yumi |last5=Yasuoka |title=Detection of atmospheric radon concentration anomalies and their potential for earthquake prediction using Random Forest analysis |journal=[[Sci Rep]] |volume=14 |issue=11626 |date=2024|page=11626 |pmid=38821969 |bibcode=2024NatSR..1411626T |pmc=11143197 }}</ref>

Radon is a known pollutant emitted from [[Geothermal power|geothermal power stations]] because it is present in the material pumped from deep underground. It disperses rapidly, and no radiological hazard has been demonstrated in various investigations. In addition, typical systems re-inject the material deep underground rather than releasing it at the surface, so its environmental impact is minimal.<ref>{{cite web |title= Radon and Naturally Occurring Radioactive Materials (NORM) associated with Hot Rock Geothermal Systems |publisher= Government of South Australia—Primary Industries and Resources SA |access-date= 2013-07-16 |url= http://www.pir.sa.gov.au/__data/assets/pdf_file/0013/113341/090107_web.pdf |archive-url= https://web.archive.org/web/20120402134109/http://www.pir.sa.gov.au/__data/assets/pdf_file/0013/113341/090107_web.pdf |archive-date= 2012-04-02 |url-status= dead }}</ref> In 1989, a survey of the [[collective dose]] received due to radon in geothermal fluids was measured at 2 man-[[sievert]]s per [[Kilowatt-hour#Multiples|gigawatt-year]] of electricity produced, in comparison to the 2.5 man-sieverts per gigawatt-year produced from [[carbon-14|{{sup|14}}C]] emissions in [[nuclear power plants]].<ref>{{Cite journal|url=https://www.iaea.org/sites/default/files/publications/magazines/bulletin/bull31-2/31205642131.pdf |title=Radiation versus radiation: Nuclear energy in perspective |journal=IAEA Bulletin |issue=2 |date=1989 |first1=Abel J. |last1=Gonzalez |first2=Jeanne |last2=Anderer}}</ref>

In the 1940s and 1950s, radon produced from a radium source was used for [[industrial radiography]].<ref>{{Unbulleted list citebundle|{{cite journal |doi=10.1088/0950-7671/23/7/301 |title=Radon. Its Properties and Preparation for Industrial Radiography |date=1946 |author=Dawson, J. A. T. |journal=[[Journal of Scientific Instruments]] |volume=23 |page=138 |issue=7 |bibcode = 1946JScI...23..138D }}|{{cite journal |title= Use of radon for industrial radiography |first= A. |last= Morrison |journal= [[Canadian Journal of Research]] |date= 1945 |volume= 23f |issue= 6 |pages= 413–419 |doi= 10.1139/cjr45f-044 |pmid= 21010538 }}}}</ref> Other X-ray sources such as [[Cobalt-60|{{sup|60}}Co]] and [[Iridium-192|{{sup|192}}Ir]] became available after World War II and quickly replaced radium and thus radon for this purpose, being of lower cost and hazard.<ref>{{Unbulleted list citebundle|{{Cite web|url=https://www.orau.org/health-physics-museum/collection/radioactive-sources/radium-industrial-radiography-source.html |website=ORAU Museum of Radiation and Radioactivity |title=Radium Industrial Radiography Source (ca. 1940s) |access-date=22 August 2024}}|{{Cite web|url=https://www.nde-ed.org/NDETechniques/Radiography/Introduction/history.xhtml |website=[[Iowa State University]] Center for Nondestructive Evaluation |title=History of Radiography |access-date=22 August 2024}}}}</ref><!--{{Unbulleted list citebundle|{{Cite journal|doi=10.1002/maco.19550060317 |title=Memorandum on gamma-ray sources for radiography. Prepared by a committee of the industrial radiology group, London, 1952 |date=1955 |last=Scheichl |first=L. |journal=Materials and Corrosion |issue=6 |pages=163-163}}|{{Cite journal|url=https://www.nature.com/articles/174726a0.pdf |journal=Nature |date=October 16, 1954 |volume=174 |title=Gamma-Ray Sources for Radiography}} Sources for continued availability of radon, radium in the 1950s as a gamma ray source - along with others-->