Exposure to high concentrations of this gas over the course of many years can greatly increase the risk of developing lung cancer. Radon is believed to be the single most important cause of lung cancer among non-smokers in the United States. Radon levels are highest in homes built over geological formations that contain uranium mineral deposits. Many homes in northern and central New Jersey are built on these types of formations.
Radon's health effects are primarily caused by alpha particle emissions of the radon decay products, polonium-218 and polonium-214. This radioactive disintegration in the air inside homes is of little concern because the emitted alpha particles are unable to penetrate the skin. There is not as good of protection in the lungs, and the alpha particles emitted inside the air passage in the lungs by some of the disintegrating decay products are sufficiently powerful to penetrate the epithelium and damage a layer of sensitive cells called basal epithelial cells. This damage can sometimes lead to lung cancer. .
It is difficult to give precise information on the cancer risks from radon contamination in indoor air. It is apparent in studies of underground miners that high concentrations of radon in the air increase the chances of developing lung cancer.2 Exposure to large amounts of radon appears to increase the cancer risk. Quantification of the risk associated with indoor exposure to concentrations of radon that are lower than those found in the mine studies depends on what assumptions are made about the relationship between the dose of radiation received and the incident rate of cancer in those who receive the dose. Age and sex differences and other factors, especially smoking also influence the actual risk. A recent epidemiological study of household exposure risks appears to be reasonable. Estimates for radon deaths for the United States range between 5,000 and 20,000 deaths per year.
