Clean air group gives Weld County an F for ozone, says Denver, Fort Collins among most polluted cities in country
April 19, 2017
DENVER — Ozone pollution has improved in Denver and Fort Collins, but both cities remain among the 15 worst in the nation, the American Lung Association said.
Denver had the 11th-worst ozone levels and Fort Collins had the 15th-worst, the association said in its 2017 clean air report released Tuesday.
The report, which ranked the 25 most polluted and 25 least polluted cities in the country, did not mention Greeley. The report gave Weld County an F for the number of high ozone days, making Weld one of 10 Colorado counties on the Front Range or in nearby foothills to earn a D or an F.
Denver and the northern Front Range have long struggled to meet federal ozone standards.
Ozone can be harmful to people with respiratory problems and other vulnerable groups, including children and the elderly. People who are active outdoors can also suffer.
The American Lung Association said Colorado's ozone problem has multiple causes, including vehicle exhaust, the oil and gas industry, trees, coal-burning power plants and weather conditions. Some of Colorado's ozone drifts in from out of state.
Nationwide, ozone levels and year-round particle pollution have declined since the association's 2016 report, but short-term spikes in particulate pollution increased.
Denver's short-term particulate pollution also worsened, the report said.
The report also gave Weld a passing grade for high particle pollution days.
Colorado officials were reviewing the report and questioned some of the methodology, said Jeremy Neustifter, a spokesman for the Department of Public Health and Environment.
The report gave some counties a failing grade even if they met federal standards, Neustifter said. And the report assumes everyone in a county is exposed to the highest level of ozone recorded, even if most residents don't travel to the site where the worst concentrations were found, he said.
The report used data from 2013-15 gathered from federal, tribal, state and county agencies. The association said it was the most recent verified data available.
Residents of most U.S. cities can breathe easier than people in some other parts of the world. Last August, Mexico City issued an alert after ozone levels hit more than 150 percent of acceptable levels. In December, Beijing issued a warning when particulate pollution reached more than 15 times the safe level.
Last year, Denver was eighth and Fort Collins 10th.
Dawn Mullally, director of air quality and transportation for the American Lung Association in Colorado, said Denver has made great strides over several decades.
"We've come a long way since the smoggy days of the 1970s," she said.
Mullally said regulations under the federal Clean Air Act shouldn't be relaxed.
"This is the air we breathe. We must protect it," she said.