13 Risk Factors for Lung Cancer

Nearly 87 percent of all lung cancers are smoking-related. If caught early, chances of survival increase greatly, which is why health experts encourage current and former smokers to undergo screening.

The good news is that the percentage of U.S. adults who smoke has fallen significantly over the past decades and has continued to decline over the last 10 years. Back in the 1950s and '60s, two in every five U.S. adults smoked. In 2005, that rate had fallen to one in every five, or 20 percent. In 2014, the rate was even lower, around 16.8 percent of the adult population. Public health officials have set a goal of bringing the rate down to 12 percent by 2020.

About 3,000 people in the U.S. die from lung cancer each year, not because they were smokers but because they were exposed to secondhand smoke.

The U.S. Surgeon General estimates that living with a smoker increases a person's risk for developing lung cancer by 20 to 30 percent.

All exposure to smoke increases one's chance of developing lung cancer and that includes non-cigarettes (and non-tobacco) forms of smoking, such as hookahs, vaping, marijuana and cigars.

It doesn't matter that most people do not inhale cigar smoke—exposure to cigars and some of the products used to treat the tobacco leaves raises one's risk, because these products often contain toxic, cancer-causing materials.

That said, rates of cancer (and heart disease) are lower for cigar smokers than they are for cigarette smokers.

Radon, a radioactive gas, causes 21,000 lung cancer deaths every year. But since you can't see, smell or otherwise detect radon without special equipment, it's important to test the air in your home (especially your basement, because radon can be found in rocks, soil and groundwater).

It is especially important to know radon levels if you or someone you live with is a smoker, since the combination of both greatly increases the risk of developing lung cancer than either one of those factors alone. That said, more than 10 percent of cancers due to radon are among nonsmokers.

Some workplaces expose employees to environmental hazards that contribute to lung cancer. Jobs in agriculture, forestry and fishing; construction and painting; and manufacturing and mining often require workers to be exposed to chemicals, exhaust, certain types of dust or even asbestos. Other service industry jobs might require workers to be out in the sun too long on most (or many) work days, which also increases the risks for lung cancer.

Protective gear can go a long way in containing exposure, but only if available and used correctly.

Though asbestos use has been banned in the U.S., many countries continue to use it despite its known health risks. Moreover, some old buildings still contain the material, leaving people exposed and at risk of this highly conductive and ultimately dangerous mineral.

While no study has definitely proven that asbestos causes cancer, many studies have found a link between asbestos and greater risks for developing lung diseases, including cancer.

Thousands of Americans get water into their homes from private wells, where the water is exposed to arsenic, an element that occurs naturally in rocks and soil. Arsenic dissolves out of rock when the water level drops, allowing the element to seep into drinking, bathing and cleaning water. In addition to also being used in some agricultural chemicals, arsenic is also combined with other chemicals and used to treat outdoor wood.

Lung cancer is one illness associated with prolonged exposure to arsenic.

A lot of people swear by their diesel cars, but exposure to the fuel and fumes may contribute to an increased risk for lung cancer. Mechanics, truck drivers and others working jobs around large, diesel-fueled vehicles should also understand the risks they face (particularly if they are smokers) and receive instruction on how to minimize contact with diesel fuel and fumes.

Eating healthy is a great way to minimize risks for developing lung cancer, but too much of a good thing, like beta carotene, might have the opposite effect.

A study that wanted to test whether high doses of beta carotene would lower the risk for lung cancer among smokers went off the rails when researchers found that not only did the antioxidant not prevent lung cancer, those taking the high-dose supplements were getting cancer at higher rates. And even when they stopped taking the high doses, the higher levels of lung cancer continued.

But don't let the beta carotene studies push you away from healthy fresh fruits and vegetables. Other studies show that not eating enough of these good-for-you foods also increases your risk for developing lung cancer. It's not one miracle fruit or veg in particular that brought down the risks; rather, it was eating a variety of them as a regular part of the diet that kept study subjects healthy.

It seems unfair that getting treated for one type of cancer might lead to another. But the American Cancer Society lists previous radiation therapy to the chest as one of the risk factors for developing lung cancer, particularly if the patient is a smoker.

Those at higher risk include people treated with radiation for Hodgkin disease or following a mastectomy for breast cancer. Women who had radiation treatment after a lumpectomy of the breast are not at this increased risk.

The American Cancer Society lists X-rays as a known carcinogen and that X-rays to the chest increase a person's risk for developing lung cancer even decades later.

The most at risk are those who had been exposed to high doses of X-rays and gamma rays, which could come from being in a war or living near a nuclear disaster.

Most medical radiation is in very small doses and, while no amount is safe, one's risk for developing cancer from exposure increases as the dose of exposure increases. In other words, X-rays under safe medical supervision are relatively safe.

Lung cancer, while largely preventable, is one of those cancers that appears to be influenced by your family history. Genetics may predispose some people to lung cancer. Anyone who has an immediate family member (sibling or parent) who had lung cancer but didn't smoke might be more prone to getting the disease themselves, according to the Cancer Treatment Centers of America.