Environmental Resources Management Division -- Ozone Data

Water, Land, Air

Fine Particle Readings

View the Current Air Quality Index for Central Indiana

Fine Particles
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What is Particulate Matter 2.5 Micron?

Particulate Matter 2.5 Micron (Fine Particles) is suspended particles in the air with diameters of 2.5 micrometers or less. Fine Particles are made up from a variety of particles. Many of the particles are the result of combustion

The sampler on the right is the Fine Particles inlet for the equipment seen in the picture below.

sources such as diesel and gasoline motor vehicles, open burning, residential wood burning, and utility and commercial boilers. These sources cause the formation of carbon (soot), organic carbon particles, trace metal compounds, and ammonium sulfate and nitrate particles. Other Fine Particles are soil-related and are the result of road dust, construction, and agriculture.

The EPA decided to establish ambient air quality standards for Fine Particles in 1997. The reason for this is that recent health studies indicate that

This equipment measures the amount of Fine Particles in the air you breath.

Fine Particles are a problem for some individuals. Smaller particles travel deeper into the lungs of individuals. These particles can irritate and damage the lungs and cause breathing problems. People that are most affected are individuals with asthma or other lung or heart disease. The elderly and children are also vulnerable to the effects of Fine Particles.