The smoke particles of concern are so small that they filter into homes even with all the doors and windows closed. A host of recent scientific studies have shown that children, the elderly, adults who exercise rigorously, asthmatics, and those with impaired lung function can suffer illness and even premature death from short-term exposure to ambient PM10. Animal toxicology studies show that wood smoke exposure compromises important pulmonary immune defense mechanisms, thus increasing the body's susceptibility to respiratory infections like pneumonia and influenza. Surprisingly, wood smoke is active in the lungs up to 40 times longer than cigarette smoke. The increase in mortality was higher among people over 65, which occurred from cardiovascular and respiratory causes several days after exposure.
Asthmatics are perhaps the most affected by periodic wood smoke exposure.
Americans have asthma. More than 9.6 million Americans over 18 have asthma. Asthma breathing problems usually happen in episodes. Triggers range from viral infections to irritating gases and particles in the air . Nationwide, asthma accounts for 10 million lost school days annually.