Ozone and particle pollution can flow easily across the nation and around the world, often far from the sources that created them. This movement can occur within a county, a state, a region or across national boundaries. To look at pollution solely on a county-by-county, or state-by-state basis overlooks the fluid nature of these pollutants. The discussion that follows uses the regional divisions set up by the U.S. Environmental Protection Agency to examine changes that occurred from the American Lung Association State of the Air 2004 report. Analyses cover the state and metropolitan areas, as defined by the U.S. Census. However, many of the large urban centers with elevated air pollution levels overlap two or more EPA regions, such as the New York-Newark-Bridgeport, NY-NJ-CT-PA metropolitan area, which covers parts of four states and three EPA regions. To make it easier to see a complete picture of the region, those multi-state areas are reviewed in each region they overlap.

Most states in New England saw their unhealthful ozone days increase slightly, though the grades generally remained unchanged. Much of this ozone may come from transported pollution added to local sources. A few counties improved with fewer days in the unhealthful ranges. Looking at particle pollution, most New England states had the same or more days with unhealthy levels. Several saw their grades decline.

Thanks to their location as suburbs of one of the nation’s largest metropolitan areas, the New York-Newark-Bridgeport, NY-NJ-CT-PA metropolitan area, parts of Connecticut were included in the 9th most ozone-polluted city in the nation, the 25th city most polluted by short-term particle pollution and tied for 12th most polluted by long-term particles. Connecticut has the 13th most ozone-polluted county in the nation: Fairfield County.

The nation’s largest city, New York-Newark-Bridgeport, NY-NJ-CTPA metropolitan area, ranks 9th in the 25 most ozone-polluted cities, 25th most polluted by short-term particle pollution, and tied for 12th most polluted by long-term particles. These are worse rankings than in the 2004 report, due in part to the increase in ozone and particle pollution days and in part by the improvement of other areas. Philadelphia-Camden-Vineland, PA-NJ-DE-MD ranked 10th most ozone-polluted city and 20th on the most polluted by short-term particles. Buffalo-Niagara-Cattaraugus, NY ranked 20th in the list of most ozone-polluted cities. Allentown-Bethlehem-Easton, PA-NJ ranked 22nd on the most polluted for short-term particles list. Like New England, these states face pollution blown in from outside of the state as well as that generated by local sources.

Both ozone and short-term particle pollution was generally worse in counties in New York. New York County moved from 22nd last year to 15th most polluted county for year-round particle pollution. Still, no grades for year-round particle pollution changed in New York.

Some counties in New Jersey recorded increases in the number of ozone and particle pollution days while others showed decreases, though their grades remained generally stable. New Jersey still has two counties, Camden and Ocean, which are ranked as the 15th and 16th most ozone-polluted counties in the nation. Good news in New Jersey: Gloucester County’s air improved enough to drop off the list of 25 most ozone-polluted counties and Hudson County’s year-round particle pollution levels dropped enough to move to a passing grade. Union County continued with failing grades for year-round particle levels.