Exposure to tobacco smoke — even occasional smoking or secondhand smoke — causes immediate damage to your body that can lead to serious illness or death, according to a report released today by U.S. Surgeon General Regina M. Benjamin. The comprehensive scientific report, titled How Tobacco Smoke Causes Disease: The Biology and Behavioral Basis for Smoking-Attributable Disease, describes specific pathways by which tobacco smoke damages the human body and leads to disease and death.

The information the more-than-700-page document contains is important for both the general public and for researchers, said David Scott, one of the report’s reviewers and an associate professor of oral health and systemic disease research at the University of Louisville School of Dentistry.

“It is important for the population as a whole to understand why tobacco smoke is so toxic,” he said. “Scientists who develop ways to treat diseases need to know that the same disease may develop differently when it results from exposure to tobacco and when it results from another cause, and both the public and the scientific community will benefit from knowing the physiological ways in which tobacco exposure affects the body.”

The report, he said, “is the first to address the mechanisms by which tobacco causes disease.”

It finds that cellular damage and tissue inflammation from tobacco smoke are immediate, and that repeated exposure weakens the body’s ability to heal the damage.

Some of the report’s other findings are that:

  • The chemicals in tobacco smoke reach the lungs quickly each time a person inhales and cause immediate damage. Inhaling even the smallest amount of tobacco smoke can damage a person’s DNA, which can lead to cancer.
  • Today’s cigarettes deliver nicotine more quickly and efficiently than cigarettes of many years ago, making them more addictive.
  • The delicate lining of the lungs becomes inflamed as soon as it is exposed to the chemical mixture in cigarette smoke. Over time, the smoke can cause chronic obstructive pulmonary disease, including emphysema and chronic bronchitis.
  • Chemicals from tobacco smoke quickly damage blood vessels and make blood more likely to clot.