Smoke from burning leaves, grass, brush, and most plants contain high concentrations of pollutants, such as carbon monoxide, particulate matter (soot), toxic chemicals, and reactive gasses that can contribute to smog formation.
The smoke can be an immediate health concern for some people. Pollution levels adjacent burn areas can exceed human health standards.
What's in Leaf Smoke?
Carbon monoxide binds with hemoglobin in the bloodstream to reduce oxygen flow. Carbon monoxide can be dangerous for young children, smokers, the elderly, and people with chronic heart or lung disease.
Particulate matter refers to microscopic soot particles. Too small to be seen individually with the unaided eye, dense concentrations are visible as smoke. These particles are less than 2.5 microns in size -- roughly the thickness of a human red blood cell. They can become embedded in lung tissue and are known to contribute to premature death, affect persons with heart conditions and trigger asthmatic reactions for some people.
Hazardous chemicals; Benz(a)pyrene is known to cause cancer in animals and is believed to be a factor in lung cancer caused by smoking. It is present in leaf smoke.
Please learn not to burn. Composting, mulching and bagging are cleaner options. The Iowa DNR provides information about disposal options, assistance and other resources.