Radon-222 is primarily a problem in?

Radon-222 is primarily a problem in confined spaces and underground wells over radon-containing deposits because this radioactive gas is produced naturally from the decay of uranium in soil and rock. When radon emanates from the ground, it can accumulate in enclosed areas such as basements and mines where proper ventilation is lacking. These confined spaces allow radon levels to build up, posing health risks to individuals who may be exposed, as prolonged exposure to high levels of radon has been linked to lung cancer.

In contrast, open air environments tend to disperse radon, limiting its concentration. Residential structures without basements might not experience the same accumulation problem due to lack of subterranean entry points for radon. Areas with high levels of groundwater may indicate uranium-rich conditions but do not necessarily lead to significant radon exposure unless there are also confined spaces allowing for accumulation. Thus, confined environments over radon sources are the primary concern for radon exposure.