Radium and radon in the environment
[1] Radium, like radon, is radioactive and is found in small quantities in nature and is hazardous to life if radiation exceeds 20-50 mSv/year.
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 carrier precipitate.
Maps of average radon levels in houses are available, to assist in planning mitigation measures.
[12] Estimates of the age of raindrops have been obtained from measuring the isotopic abundance of radon's short-lived decay progeny in rainwater.
[17] A common unit of exposure of lung tissue to alpha emitters is the working level month (WLM), this is where the human lungs have been exposed for 170 hours (a typical month worth of work for a miner) to air which has 3.7 kBq of 222Rn (in equilibrium with its decay products).
Lastly the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) consider that the exposure of the lungs to 1 Bq of 222Rn (in equilibrium with its decay products) for one year will cause a dose of 61 μSv.
[18] 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.
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 fumes).
[citation needed] 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.
[19] The danger of radon exposure in dwellings received more widespread public awareness after 1984, as a result of the case of Stanley Watras, an employee at the Limerick nuclear power plant in Pennsylvania.
[20] 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.
[22] The National Council on Radiation Protection and Measurements (NCRP) recommends action for any house with a concentration higher than 8 pCi/L (300 Bq/m3).
The United States Environmental Protection Agency recommends action for any house with a concentration higher than 148 Bq/m3 (given as 4 pCi/L).
