AUGUSTA — Aroostook was one of three Maine counties receiving an ozone grade of A in the American Lung Association’s 17th annual State of the Air report released April 20.
Aroostook, Androscoggin and Oxford counties rated the healthiest in levels of ozone pollution. The County also had a slightly improved level of annual particle pollution; however, its short-term particle pollution went from an A to a B due to one day with red, or unhealthy, air quality.
Each year the State of the Air report looks at the two most widespread types of pollution: ozone and particle pollution. Ozone, also known as smog, is created in the atmosphere by the reaction of warm air and sunlight on emissions from vehicles and other pollution sources. Particle pollution, called fine particulate matter or soot, is a mixture of very tiny solid and liquid particles which come directly from car exhaust, wood fires, coal burning power plants and other smokestacks.
Overall, the report indicated, Maine’s air quality was improved but still had high levels of ozone pollution, with York County receiving the worst grade of F.
The report uses the most recent quality-assured air pollution data, collected by federal, state and local governments and tribes in 2012, 2013 and 2014.
