Radon: Encyclopedia II - Radon - Occurrence

Radon - Occurrence

On average, there is one atom of radon in 1 x 10²¹ molecules of air. Radon can be found in some spring waters and hot springs. The towns of Misasa, Japan, and Bad Kreuznach, Germany boast radium-rich springs which emit radon.

Radon exhausts naturally from the ground, particularly in certain regions, especially but not only regions with granitic soils. Not all granitic regions are prone to high emissions of radon. Depending on how houses are built and ventilated, radon may accumulate in basements and dwellings. The European Union recommends that action should be taken starting from concentrations of 400 Bq/m³ for old houses, and 200 Bq/m³ for new ones. The United States Environmental Protection Agency recommends action for any house with a concentration higher than 148 Bq/m³ (given as 4 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.

Adapted from the Wikipedia article "Occurrence", under the G.N U Free Docmentation License. Please also see http://en.wikipedia.org/wiki