Environmental Causes of Lung Cancer

There are many environmental exposures in addition to cigarette smoke that can raise the risk of developing lung cancer. And like smoking, many of these are avoidable as long as you are aware of them. For example, testing your home for radon, using an appropriate mask when working with certain chemicals at home or at work, reducing your exposure to wood smoke, and being your own advocate when it comes to medical radiation exposure may help.

Since the association between smoking and lung cancer is well-known, we will focus on environmental causes other than personal smoking.

Exposure to radon in the home is the second-leading cause of lung cancer and the leading cause in non-smokers. It's estimated that at least 21,000 people develop lung cancer from radon each year, and since the exposure occurs in the home, women and children theoretically have the greatest risk. To put the number of radon-induced lung cancer deaths in perspective, around 40,000 women die from breast cancer each year. If we knew of a way to eliminate half of breast cancer deaths, it would be very well known. Unfortunately, many people have not performed the simple test that could eliminate over 20,000 deaths a year.

Radon is a radioactive gas that is produced by the natural decay of uranium in the soil. It can enter homes through cracks in the foundation, around sump pumps and drains, and through gaps around pipes and wires. Having been found in homes in all 50 states, the only way to know if you are safe is to test your home for radon. Simple do-it-yourself test kits are available at most hardware stores. If the test is abnormal, radon mitigation can almost always return the radon level in your home to safe levels.

Exposure to asbestos is ordinarily considered an occupational exposure, but working with asbestos insulation in older homes (those built prior to 1970) can result in exposure as well. Asbestos is responsible for roughly 84% of cases of mesothelioma, a cancer involving the lining of the lungs, and is responsible for other forms of lung cancer as well. Left alone, asbestos poses little danger, but exposure can result if it is disturbed. If you choose to remodel a home that may contain asbestos insulation, hire a certified contractor.

Air pollution has been looked at as a possible risk factor for lung cancer because there is a significant difference between the incidence of lung cancer in urban and rural areas (lung cancer is more prevalent in urban areas). In the United States, it's thought that air pollution contributes to around 5% of lung cancers in men and 3% in women, but more than 10% of lung cancers in Europe may be secondary to air pollution.

While it's difficult to control your exposure to air pollution without moving, experts recommend monitoring the air pollution level in your region, and when high, limiting outdoor activities especially exercise.

While uncommon in the United States, fumes from coal used for cooking and other fuels is an important cause of lung cancer in women who have never smoked globally. Good ventilation, and being aware of fuels that pose more threat than others, is important for those who are currently exposed.

As with asbestos, many exposures to cancer-causing chemicals occur in the workplace. Fortunately, employers are required to provide Material Safety Data Sheets for all chemicals used. It's important that people who may be exposed to these substances on-the-job review the sheets and heed any safety measures recommended.

Certain products used in the home, such as some wood strippers, contain chemicals that are associated with an increased risk of lung cancer. It's important to read labels on any product you use in the home or garage and take appropriate precautions as directed on the packaging. This may include the use of gloves, good ventilation, and at times purchasing a respirator, as regular masks that are available at most supermarkets are inadequate to prevent exposure to some of these chemicals.

Exposure to medical radiation to the chest for other cancers, for example, Hodgkin’s lymphoma or breast cancer, can increase the risk of lung cancer. That said, the benefits of treatment usually far outweigh this risk. In Japan, exposure to atomic bomb radiation was associated with an elevated risk of developing lung cancer.

It's now thought that medical radiation used for diagnostic studies such as CT scans also raises risk. In this case, it's important to remember that the benefits of having the study done will often outweigh the potential risks. Since not all imaging studies that are ordered are necessary, it's important to talk with your doctor about exactly why a test is being ordered, and whether there is an alternative that does not involve X-rays (such as an MRI) that may be an option instead.

Secondhand smoke increases the risk of lung cancer in an exposed nonsmoker two- to- three-fold times. It is currently felt to be responsible for 1.6% of lung cancers in the United States (roughly 7,000 cases per year). No-smoking laws have greatly reduced exposure in public places, but it's important for people to limit exposure to secondhand smoke in their homes or cars.

Exposure to wood smoke may increase the risk of lung cancer. Converting from wood-burning stoves and fireplaces to other options, such as gas fireplaces, is one way to reduce this risk.

Wood dust may also raise the risk, though this is primarily an occupational exposure and can vary between soft and hard woods. Following restrictions, such as the maximum time of exposure dictated by regulations is important.