What Are Other Causes of Lung Cancer Besides Smoking?

In the U.S., smoking tobacco cigarettes is responsible for about 90% of cancers that start in the lungs. However, among 236,000 new cases annually, even 10% is a significant number. Moreover, the odds of lung cancer mortality in people who never smoked is high among all types of cancer-related death. Consequently, besides smoking, other causes of lung cancer are still a major risk for many Americans today.

Exposure to pollution and smog, radon, and asbestos is known to cause lung cancer. Known carcinogens, or cancer-causing substances, may lead to types of cancer like adenocarcinoma (tumors begin in mucus-producing cells) or squamous cell carcinoma (tumors begin in flat cells lining the lungs). Overall, 50% to 60% of people with lung cancer who never smoked have adenocarcinomas while 10% to 20% have squamous cell carcinomas.

Sources of exposure may come from industrial sources (like vehicle exhaust or power plants) in addition to environmental ones (like wildfires).

Biggest Risk Factors for Lung Cancer

The biggest risk factor for all cancers that start in the lungs, besides smoking, is exposure to airborne toxins. Inhaling toxins such as asbestos fibers, diesel exhaust, or metal dust over long periods of time greatly increases your risk of lung cancer. While smoking multiplies the damage carcinogens have on the body, even non-smokers are at risk.

Since the exposure amount generally affects risk levels, people with daily exposure should be looking for early signs of breathing trouble and respiratory damage. For instance, workers in high-risk exposure industries and people living in contaminated areas more often breathe in carcinogens.


In major cities with poor air quality, the danger is real and immediate. In 2013, in China, an 8-year-old girl was diagnosed with lung cancer because of high levels of exposure to air pollution.

Commonly, respiratory damage is caused by particle pollution, or contamination in the air by pieces of ash, metals, dusts, acids, and more. Typically, particles are too small to see. They measure a small fraction of the width of a strand of human hair. Consequently, pollution can travel deep into the pathways of the lungs and is more difficult for the body to expel.


Asbestos is a mineral fiber once popular in many fireproof building materials and commercial products. Though it’s known to cause cancers like lung cancer, colon cancer, and mesothelioma, it was never completely banned from use or manufacturing. As a result, asbestos-containing home construction materials include siding, roofing shingles, flooring tiles, pipe duct tape, vinyl adhesive, and more.

Inhaling asbestos, however, doesn’t cause any immediate symptoms. Usually, people aren’t aware of internal damage for years or decades. Today, home and workplace contact with asbestos-contaminated products causes over 40,000 deaths each year.


Radon is a natural, yet radioactive, gas that comes up naturally through the ground. Sometimes, when it seeps into the foundation of houses, radon is called indoor pollution.

High concentrations of radon, like the type that builds up indoors, increases your risk of lung cancer throughout your life.

Workplace Exposure

Even today, the workplace can be dangerous. Manufacturing uses thousands of chemicals. Yet, only a small percentage of industrial chemicals have been evaluated for safety to humans or the environment.

Cancer-causing workplace risks in the U.S. include:

  • Arsenic
  • Benzene
  • Beryllium
  • Chromium
  • Coal and coal tar pitch
  • Diesel exhaust
  • Nickel
  • Silica

Years later, many retirees diagnosed with work-related lung cancer seek legal compensation to cover high medical costs.

Early Signs and Symptoms

Primarily, the two types of lung cancer include small cell and non-small cell. In general, the early signs of both types are the same. Too, many people don’t experience symptoms until cancer spreads. As such, if you have any of the symptoms below, talk with your doctor as soon as possible.

Lung cancer symptoms include:

  • Chest pain that gets worse with movement
  • Coughing up blood or brown phlegm
  • Hoarse voice
  • A persistent cough that gets worse
  • Repeated respiratory infections (like bronchitis and pneumonia)
  • Wheezing

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