Everyone knows that smoking is the leading cause of lung cancer in the United States. What most people do not know, however, is the second-leading cause of lung cancer in the country. If forced to guess, many people might select asbestos contamination, due to the large number of asbestos-related ads placed by law firms on late-night television. They would be wrong, however. Instead, studies have shown that exposure to radon gas is the second-leading cause of lung cancer.
In many instances, people have never even heard of radon gas or suppose that it is some sort of industrial effluvium that affects specialized populations such as miners. However, radon gas exposure is actually found in many homes across the country, and is especially concentrated in certain regions of the nation such as Colorado. This does not mean that radon is not a problem elsewhere—just that it is a larger problem in those areas where it is especially prevalent.
Radon and its so-called daughters are found everywhere on earth, but concentration levels are low in outdoor areas due to constant air movements. Inside, however, radon levels elevate due to the confined nature of air movements inside most homes. Without an opportunity to disperse naturally, radon levels rise to the point where they become an increasing risk as they become ever more present in the environment.
One European study examined radon levels in 9 different EU-area nations and found that the average level of radon present in the homes of control group participants was approximately 97 Becquerel per square meter whereas the average level in homes of study participants found to have some sign of lung cancer was 104 Becquerel. While this showed how relatively small increases in radon levels can have an effect on health, the truly alarming results were found in homes with increasingly higher levels of exposure.
A series of American studies that looked at homes in Missouri, Idaho, New Jersey, Utah, and Iowa found basically the same thing—namely, that lung cancer rates rose in direct correlation with rising levels of radon gas in the home. In all of these radon studies, the rate of lung cancers kept rising as the radon levels rose. No ceiling to the relationship was uncovered, which is to say that at no level of radon exposure did the lung cancer rate finally level off to the point where it did not continue to rise. The radon gas study published by the US EPA is especially alarming.
In general, lung cancers rose at a rate of about 8 percent over the otherwise expected lifetime rate for every 16 percent rise in radon gas exposure rates. Of course these rates are much less alarming when viewed as a totality of population rather than as observable laboratory incidents. Since the lung cancer death rate for people who have lived to their mid-70s and not died of something else is less than one percent for non-smokers and about 10 percent for those who do smoke, the rises due to radon gas reach to a level of about 16 percent for smokers and still well under one percent for non-smokers in heavy-radon home environments over 400 Becquerel per square meter.
The disparity in these two rates reveals that radon might be the number two cause of lung cancer, but it is an impossibly long way from challenging for the number one spot held by smoking. In addition, radon testing can lead to relatively simple radon reduction methods that will drop the overall home exposure without requiring any exertion of willpower or change in human behavior on the part of the residents.