(WHTM) — Wildfires are part of many locations across the globe, but we have been seeing our own air quality drop due to fires being out of control in Canada.

The smoke from these fires has caused a public health concern, as the smoke has drifted south into many parts of the northeastern United States. But why is wildfire smoke so dangerous?

According to the United States Environmental Protection Agency (EPA), wildfire smoke is made up of a mixture of gaseous pollutants. For example, one of these pollutants is carbon monoxide, and smoke from wildfires also contains hazardous air pollutants, water vapor, and particle pollution.

This particle pollution, also called particulate matter, is a term for a mixture of solid and liquid droplets suspended in the air. The EPA states that the air we breathe, no matter if we are indoors or outdoors, always contains particle pollution. This pollution can be anything from inorganic and organic compounds, soot, metals, soil, and dust particles.

There are two types of particles in the air that are classified by their aerodynamic diameters and are usually grouped into two categories, according to the EPA.

Coarse particles are usually over 2.5 micrometers (µm). Coarse particles are primarily generated from mechanical operations such as farming or construction, but it has been found that a small percentage is present in wildfire smoke.

This graphic shows the size comparison between the different particles found in the atmosphere. Both are found in wildfire smoke. (Courtesy: EPA)

Fine particles are ones that are 2.5 micrometers (µm) or smaller. These particles are found in wildfire smoke and are found to be the greatest concern. These particles are small enough because they can pass through the nose and throat and enter the lungs, with the smallest particles which are less than 2.5 micrometers small can get into blood circulation.

According to the EPA, individuals at greater risk of health effects from wildfire smoke include those with diseases of the heart and lungs older adults, young children, pregnant women, and outdoor workers.