This article is from the BC Lung Association:
Sure. Unfortunately, natural doesn’t always mean harmless. A growing number of studies are associating wood smoke with an array of illnesses like asthma, heart disease and other lung and respiratory illnesses—many of the same illnesses that are associated with smoking.
In fact, wood smoke has similarities to cigarette smoke. It contains over 200 chemicals and compounds, including carbon monoxide, benzene, formaldehyde, sulfur dioxide, nitrogen oxides (NOx), dioxins and polycyclic aromatic hydrocarbons (PAHs).
Burning impact on health
Aside from being so similar to cigarette smoke, wood smoke is especially unhealthy due to the size of the particles contained within.
Most wood smoke is thick with tiny particulates known as PM2.5. Think about it like this: A grain of sand is roughly 90 micrometers. The width of a human hair is between 50-70 micrometers. Dust is considered 10 micrometers, or PM 10. Your body’s natural defense mechanisms are able to reject much of PM 10 exposure by coughing, sneezing or blowing your nose. But ultrafine wood smoke particles are too small to be filtered out by the upper respiratory system and therefore get trapped deep inside the lungs, causing irritation and decreased lung function.
Research also indicates these particles can cross into the blood stream and induce inflammatory responses in other areas of the body at a quicker rate than exposure to fine particles, leading to asthma attacks, cardiovascular disease, acute bronchitis and increased susceptibility to respiratory infections.
At greatest risk from wood smoke exposure?
People who already suffer from heart or lung disease may experience negative health effects earlier and at lower levels than healthy people. As well, children are more susceptible to smoke because their respiratory systems are still developing, they breathe more frequently than adults and they’re more likely to be active outdoors.