Burning wood produces an array of harmful chemicals. Carbon monoxide, hydrocarbons, and formaldehyde (and at least 100 other compounds which damage indoor and outdoor air) are given off when wood is burned. Tiny particles of material commonly known as particulate matter are created by wood smoke. These particles get inhaled into our lungs. Breathing wood smoke can increase cardiovascular problems such as angina, irritate lungs and eyes, trigger headaches, hinder judgment, slow reflexes, and worsen respiratory diseases such as asthma, emphysema and bronchitis. While wood smoke harms us all, it is especially harmful to babies, children, pregnant women, their unborn children and the elderly.
About five percent of Denver's wintertime brown cloud is caused by wood smoke.