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Denver Region's Air Hits Risky Smog Level

Posted on: Thursday, 14 July 2005, 09:00 CDT

Smog in the metro area surpassed federal health limits for the second time this summer on Tuesday, a spike driven by the combination of chemical emissions and a string of hot, cloudless days.

Two of the region's 14 air pollution monitors registered levels of smog, or ground-level ozone, at or above 85 parts per billion during an eight- hour stretch - a reading considered unhealthy by the Environmental Protection Agency.

Meteorologists at the Colorado Department of Public Health and Environment predict that ozone levels could stay high through the rest of the week, as hot, clear weather persists.

Officials at the health department and at Rocky Mountain National Park warned people Wednesday of elevated smog levels and of the accompanying health risks, particularly for the young, the elderly and those with breathing ailments.

Tuesday's elevated ozone levels mark the second smoggy day this summer.

The first came June 18, when two monitors recorded levels of 85 parts per billion and 86 parts per billion.

Ozone comes in large part from natural sources, but levels can be pushed up with the addition of emissions from automobiles, lawnmowers, backyard grills and a wide variety of industries.

"We're obviously concerned, and we're watching it and sending out those advisories to the population so people are aware of it and taking appropriate precautions," said Howard Roitman, director of environmental programs at the health department.

On the other hand, Roitman said, occasional spikes in ozone are to be expected.

That's why federal officials look at averages, not single events, to determine when a region formally violates EPA limits.

Such a violation can stigmatize a city, branding it with a dirty- air designation by the federal government.

In 2003, a long string of smog- heavy days sent pollution in the area to the worst level since the EPA tightened standards in the late 1990s. By July 15 of that year, the region had seen six days of elevated ozone.

That smoggy summer, along with another in 2002 and the threat of economic penalties and a dirty-air label from the EPA, brought tougher state regulations.

The rules target smog-forming "flash emissions" from the oil and gas industry in Weld County, emissions that scientists believe wash up the South Platte Valley and contribute to metro-area pollution.

Companies are adding emission controls to oil and gas operations this year and next, and by the end of 2006, they must cut their smog- forming pollutants by nearly half.

In addition, beginning last summer, EPA required refineries to provide gasoline in the metro area that produces fewer chemicals known as volatile organic compounds, which contribute to smog.

The lower volatility means fewer smog-forming vapors are released while pumping gas and fewer polluting emissions leave the tailpipe.

State health officials are watching ozone levels closely, in hopes that the new rules are enough to hold pollution down.

If not, they may have to go back to the drawing board.

"We all have a stake in protecting Colorado's air quality," said Vickie Patton, a senior attorney with Environmental Defense, who closely tracks the region's air pollution.

"Because our children, the elderly and those who work and play in Colorado's great outdoors are at risk when the smog levels are unhealthy."

INFOBOX

Health effects * Smog, or ground-level ozone, can be harmful to everyone, particularly the young and the elderly. * It also can trigger asthma attacks and breathing difficulties for people with pre-existing respiratory ailments. * Others, including people who exercise outdoors, can experience breathing difficulties, eye irritation, and reduced resistance to lung infections and colds with prolonged exposure.

Source: Rocky Mountain News

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