Number of Smoggy Days Falls, Study Says

Region Still Needs to Cut Pollution Under U.S. Clean Air Standards

The number of dangerously smoggy days in the Washington area has declined by more than 40 percent since 2003, but the region still does not meet federal standards for healthy air, according to data released yesterday.

From 2003 to 2006, the region has had 63 days in which the levels of ground-level ozone -- a harmful gas formed when the sun heats polluted air -- was high enough for Code Orange, Code Red or Code Purple warnings. From 1999 to 2002, there were 114 such days, according to the Metropolitan Washington Council of Governments.

Officials said yesterday that they were encouraged, believing the reduction in bad air days was a sign that local and national anti-pollution measures were having an effect.

"The air's cleaner," said D.C. Council member Phil Mendelson (D-At Large), chairman of COG's air quality committee. "But not clean enough."

That's because the Washington region, which has exceeded smog limits repeatedly since 1977, still hasn't improved enough to meet the smog standards the U.S. Environmental Protection Agency will begin enforcing in 2009. At that point, a violation could trigger a loss of federal transportation funding.

Moreover, local environmental groups were wary of the report, wondering whether cooler weather, not reduced smog, was partly responsible for the improvement.

This might seem like an odd year to tout progress in reducing air pollution. An early August heat wave caused several Code Orange days, with residents warned against exercising or working outside. In July, the region had a Code Purple day -- the worst rating and its first in more than a year.

Jeff King, an air quality planner at COG, said this summer offered some confirmation that progress was being made: Although it was far hotter than in 2005, it had the same number of unhealthy air days -- 19. That appeared to mean that less smog was around for the sun to heat.

"We did have some pollution problems, but it wasn't as severe as we'd had in the past," King said.

The pollutants that help create bad air days come from sources as diverse as power plants, cars, gas pumps and paint fumes. In explaining the reductions in bad air, local officials cited changes almost as varied.

Mendelson credited new federal rules limiting the amount of nitrogen oxide in power-plant emissions and curbing auto pollution, as well as several local policy changes. Montgomery County bought more energy from wind power. The District required power companies to derive more of their electricity from renewable sources. Fairfax County retrofitted its school buses to produce cleaner emissions.

Mendelson said moves such as those could continue to reduce smog, even as the region adds millions of residents and thousands of miles of roads.

"So far, the region has continued to grow significantly, and yet we're polluting less," he said.

Frank O'Donnell of Clean Air Watch said the apparent good news was tempered by the fact that the Washington area still regularly suffers through Code Orange days and worse.

"If we're still seeing eight or 10 dirty air days in the area, that to me is still a sign that we're not there yet," O'Donnell said.