Yes, smoking is the No. 1 risk factor for lung cancer. People who smoke are up to 30 times more likely to get lung cancer than people who don’t. Even the occasional cigarette raises your risk, as does hanging around someone who smokes. (More than 7,000 nonsmokers die from lung cancer due to secondhand smoke each year.)
But anyone can get lung cancer. Here are the other risk factors that help explain the 10 to 20 percent of lung cancer deaths not linked to tobacco.
Exposure to this gas is the second-leading cause of lung cancer. Radon exists naturally in soil, where it can get into buildings through gaps and cracks in the floor, walls, and foundation. One out of every 15 homes is subject to radon exposure. (If you’re worried yours might be one of them, buy a test kit from a hardware store. And if you find elevated levels, contact a pro about installing something called a radon-mitigation system.)
Survivors of breast cancer, Hodgkin’s lymphoma, and other cancers who have had radiation therapy to the chest have an increased risk of lung cancer.
While there’s been a dramatic drop in the use of asbestos since the 1970s, people who work in construction or live in an older home that’s being remodeled may be exposed to this heat-resistant mineral, which is often used as insulation. Exposure to asbestos, as well as diesel exhaust and other hazardous chemicals, can cause lung cancer.
Small amounts of arsenic are naturally occurring in the air we breathe, the water we drink, and the food we eat (seafood, rice, mushrooms, and chicken tend to have the highest levels). These organic compounds are not thought to be linked to cancer. The kind of arsenic found in pressure-treated wood and contaminated water, however, tends to be more toxic and has been linked to cancer.
If you’ve ever been stuck behind a truck that’s spewing diesel fumes, you’ve been exposed to particle pollution, a mix of tiny solid and liquid particles that float in the air. Power plants, cars, and agriculture can all create particle pollution, which increases your risk of lung cancer when you’re exposed over extended periods of time.
Some risk factors for lung cancer can cause changes, or mutations, to the DNA of your lung cells. These mutations can cause the DNA to “turn on” the genes that help your cells grow and divide and “turn off” the ones that suppress tumors. Some people inherit these mutations from their parents, which raises their cancer risk. Others inherit a reduced ability to break down chemicals that can cause cancer.