Ozone (ppm)
Current Value
0.057 ppm
Definition
Story Behind the Curve
Chittenden County meets National Ambient Air quality Standards (NAAQS) for ozone levels. The red dotted line indicates the attainment level for ozone and levels should not exceed this amount.
This indicator measures tropospheric, or ground level ozone. Ozone is formed when pollutants emitted by cars, power plants, industrial boilers, refineries, chemical plants, and other sources chemically react in the presence of sunlight. Ozone at ground level is a harmful air pollutant. Ozone is likely to reach unhealthy levels on hot sunny days in urban environments. Ozone can also be transported long distances by wind.
Why Is This Important?
Ground-level ozone can make it harder to breathe, especially during the summer. People with lung disease, children, older adults, and people who are active outdoors may be particularly sensitive to ozone. Ozone also affects sensitive vegetation and ecosystems, including forests, parks, wildlife refuges and wilderness areas.
If the NAAQS are revised to be more stringent - or air pollutant levels increase - so that we exceed the NAAQS, additional and costly environmental regulations will apply to our region.
Note on Methodology
Ozone is measured using the 3-year average ozone concentration and the final year of the 3-year period is plotted. The 3-year average ozone concentration is compared to the National Ambient Air Quality Standards (NAAQS) 3-year average of the 4th highest daily maximum 8-hour concentration in a year to determine attainment. Ozone monitoring is collected in Underhill, VT.