Key Facts
- PM10 size
- Below 10 μm, about 1/4 diameter of human hair
- PM2.5 size
- 2.5 μm, can enter bloodstream
- Record AQI July 2026
- 800-900+ in Ohio and Michigan
- Natural PM sources
- 90% from dust, volcanoes, sea salt, forest fires
- N95 filter efficiency
- Filters at least 95% of particles above 0.3 μm
Background
The Great Lakes, Northeast, Pacific Northwest and many other regions have experienced wildfire smoke in recent months and years. The EPA tracks particulate matter, often shortened to PM, as a major air pollutant. Some particles are visible to the naked eye, while others are not.
Particulate matter ranges in size: fine beach sand can be about 90 microns (μm) in diameter, and human hair varies from 40-70 μm wide. The EPA starts tracking particles below 10 μm, which can include mold spores, pollen and dust.
Tiara Gonzalez, environmental education coordinator with Lake Erie West Regional Council, explained that smaller particles are more harmful. PM10 is about 1/4 the diameter of a human hair, already quite small.
Current Situation
In July 2026, air quality index readings were greatly tested, with some stations in Ohio and Michigan setting new records by nearly 2 to 3 times over, reaching 800-900+ AQI, well into 'Hazardous' territory.
Wildfire smoke contains a wide range of particle sizes and molecules. When large forest fires occur, they release volatile organic compounds, which are naturally occurring combinations of elements, also found in manmade products like paints and cleaning supplies.
When a forest fire is large enough, released material can reach high into the atmosphere where the Sun's ultraviolet rays break down some less-complex compounds. Days later, when smoke settles near the ground, it may contain benzene, acrolein, and formaldehyde, with a more acrid smell than a campfire.
| Category | Size/Value | Notes |
|---|---|---|
| Fine beach sand | 90 μm | Diameter |
| Human hair | 40-70 μm | Average width |
| PM10 | Below 10 μm | EPA tracking threshold |
| PM2.5 | 2.5 μm | Can enter bloodstream |
| N95 filter | 0.3 μm | Filters 95% of particles above this size |
| Natural PM share | 90% | From dust, volcanoes, sea salt, forest fires |
| Manmade PM share | 10% | From combustion and other sources |
Impacts
PM2.5, which is 2.5 μm in diameter, can bypass the mucous membranes in the lungs and embed itself, or even enter the bloodstream, traveling through the body to the heart, according to Gonzalez.
The resulting mixture from wildfire smoke causes respiratory issues and visibility issues if thick enough. Ambient air pollution is considered the leading environmental risk factor for premature death worldwide, with millions affected both indoors and outdoors.
About 90% of particulate matter comes from natural sources such as dust storms, volcanoes, sea salt, and forest fires. The remaining 10% from human activities can upset the balance. Gonzalez noted that while society has moved from coal burning, anything that combusts produces particulate matter.
Future Outlook
Scenario analysis: The possibilities below are not certain predictions.
If wildfire seasons continue to intensify, record AQI levels could become more frequent, increasing health risks from PM2.5 exposure. However, if mitigation efforts succeed, such as reducing combustion emissions, particulate matter levels may decline.
Individuals can protect themselves by using N95 masks, which filter out at least 95% of particles above 0.3 μm, and HEPA air filters, which capture a range of aerosols. Staying aware of daily air quality via AirNow.gov can help reduce exposure.
The next episode will explore ozone, with three oxygen atoms making a difference in the atmosphere.
Source: 13abc.com
