Introduction

• Breathing in toxins can cause lung cancer, which kills more than 150,000 people in the United States every year--the leading cause of death due to cancer. Although lung cancer is treatable, most people who develop the disease don't live more than five years with it. In order to prevent the continued growth of lung cancer in our society, it's important to understand what toxins cause it in order to avoid exposure to them.
  
  

Toxins Causing Lung Cancer

• Tobacco smoke is responsible for 87 percent of all lung cancer cases. Exposure to secondhand smoke leads to 3,000 lung cancer deaths of nonsmokers each year in the United States. Tobacco smoke contains at least 60 carcinogenic chemicals. These include tar, arsenic and lead. Tobacco smoke also leads to cancer of the kidney, pancreas, cervix and stomach.
  
  Radon, a radioactive gas that cannot be seen, smelled or tasted, is another toxin that causes lung cancer. This gas, formed in soil and rocks, is emitted as these break down. It makes its way into homes through basements, crawl spaces and foundations and is trapped in homes that have poor ventilation. It causes cancer by damaging lung cells. It's the second-leading cause of lung cancer deaths in the United States among smokers. It causes lung cancer in nonsmokers more than any other substance and kills 2,900 nonsmokers every year.
  
  

• Asbestos also leads to lung cancer. It's a mineral that, when broken into pieces, releases fine hairs into the air. These hairs are breathed in through the mouth or nose into the lungs, damaging their lining. Other natural substances that can be toxic if breathed in include arsenic, nickel, soot and tar. The risk of developing lung cancer after being exposed to these substances is greater for smokers than nonsmokers.
  
  Air pollution is a known cause of lung cancer. Pollution such as exhaust from vehicles and coal-powered industrial plants raises the chances of developing lung cancer when it combines with oxygen and is breathed into our longs. Those most at risk for developing lung cancer due to air pollution are people exposed to heavy pollution over a long period, such as industrial workers. Although the risk of developing lung cancer from breathing polluted air is slight for nonsmokers, it does go up for smokers.