No, actually that was Krypton. Radon is an odorless, colorless, tasteless radioactive gas. It is the heaviest of all gasses, about 8 times heavier than air, and is naturally occurring from the radioactive decay of uranium. The U.S. Environmental Protection Agency (US EPA) and the Surgeon General's Office have estimated that more than 20,000 lung cancer deaths are caused each year by radon, making it the second leading cause of lung cancer in the United States. It is usually found in conjunction with uranium in igneous rock, such as granite, and in soil, but in some cases well water may also be a source of radon. The US EPA's proposed Radon Rule applies to all community water systems that use groundwater or mixed groundwater and surface water supply sources. The Radon Rule includes a two pronged approach that allows states and water suppliers to reduce radon risks in indoor air while protecting public health from the highest levels of radon in drinking water. The proposed rule includes the following provisions:
-A Maximum Contaminant Level (MCL) Goal of zero;
-An MCL of 300 picocuries per liter (pCi/L);
pCi is the abbreviation for picocurie, the standard unit for radiation, named after Marie and Pierre Curie for their pioneering work on radioactivity.
The AMCL provision of the rule applies to water systems that adopt and comply with a Multimedia Mitigation (MMM) educational program aimed at reducing household indoor/air health risks from soil and tap water. The AMCL of 4,000 pCi/L is based on the National Research Council recommended estimates of 0.4 pCi/L as the outdoor background level in air, which is equivalent to 4,000 pCi/L in water. If a water system chooses not to adopt an MMM program, they would have to comply with the MCL of 300 pCi/L in all source water. Santa Barbara County and Ventura Counties are the two counties in California with the highest potential for harmful levels of radon to exist as identified by the US EPA. This rule is still in the proposal phase, and has not yet become a regulation.
