Triangle air quality improved this summer

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CORRECTION

A story about air quality on the front page Tuesday misidentified a spokesman for the state Department of Environment and Natural Resources. He is Tom Mather.

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Your eyes and lungs are not fooling you.

North Carolina's air quality this summer was the best it's been in more than three decades -- the combined result of environmental laws, balmy weather and the recession.

The N.C. Department of Environment and Natural Resources said Monday that the state had just six "code orange" days in which ground-level ozone levels exceeded federal clean air standards. That's the lowest number since some local governments began tracking air quality in the state in the early 1970s. In the summer of 2008, the state had 36 days of unhealthy ozone levels, and 66 the year before that.

Ground-level ozone is the main ingredient in smog and forms when nitrogen oxides react with sunlight and hot air to produce reactive oxygen that irritates the lungs and eyes. Ozone is an invisible pollutant, unlike the smoke and haze more commonly associated with auto exhaust and smokestacks.

On "code orange" days, state officials urge children, the elderly and people with asthma to avoid strenuous outdoor activity.

The Triangle air quality improved noticeably this year, with no "code orange" days compared with 12 last year. The Charlotte-metro area -- which has the state's worst air quality -- was down to five "code orange" days this summer from 28 last year, when three days were bad enough to be tagged "code red."

Rules on coal helped

The primary reason for the decline in ozone levels is lower emissions from coal-fired power plants and automobiles, according to DENR. The state's Clean Smokestacks Act of 2002 required the state's 14 coal-burning plants to cut ozone-forming emissions by three-fourths by 2012. Coal is used to generate more than half the state's electricity.

Tom Mather, DENR spokesman, said that the recession likely contributed to reduced ozone levels this year as factories and other industries laid off workers, cut shifts or shut down operations. The state's two major power companies reported dramatic declines in industrial energy sales.

Progress Energy, the Raleigh-based electric utility, reported a 15.5 percent reduction in electricity sales to industrial customers this year, while Charlotte-based Duke Energy saw an 18.6 percent decline.

The environment has also benefited from the state's expansion of its motor vehicle emissions testing program from nine urban counties to 48 counties in 2006. The program checks whether catalytic converters and other equipment are working properly.

The estimated emissions from cars and trucks declined by 38 percent since 2002, DENR said.

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