Air pollution in national parks, including four in Colorado, has reached unhealthy levels, obscuring the most stunning landscapes, according to an analysis unveiled Tuesday by a conservation group.
The Great Sand Dunes, Rocky Mountain, Black Canyon of the Gunnison and Mesa Verde national parks had ozone air pollution at levels nearly as high as in cities, the National Parks Conservation Association found.
The average ozone pollution in those parks ranged between 67 and nearly 74 parts per billion, NPCA’s analysis found. And haze reduced visibility by 38 to 55 miles.
By comparison, the elevated ozone along Colorado’s urban Front Range hovers around and often exceeds a federal 75 ppb health standard.
NPCA officials released their study, based on federal and state air data, as the White House reviews a rule aimed at cutting pollution in parks.
“Clean air is exactly why we go to national parks. We expect them to be clean. Under the law, they are supposed to have clean air,” said Ulla Reeves, NPCA’s clean-air program director. “The regional haze rule needs to be strengthened.”
The parks in Colorado were among 36 — of the 48 studied nationwide — that had moderate or severe ozone pollution. Fifteen parks in the southwestern United States — including Joshua Tree, Sequoia, Kings Canyon and Yosemite — had air pollution at levels considered risky for sensitive people such as children with asthma.
Development, drought and a surge in oil and gas activity drive the air pollution in southwestern parks, NCPA officials said.
At Rocky Mountain National Park, rangers have been working with state and federal agencies to improve air, including efforts to reduce ozone and haze. Park air exceeded the health standard three times in 2013 but not since then, park spokeswoman Kyle Patterson said, compared with 35 such instances in metro Denver in 2013 and 17 in 2014, Patterson said.
Bruce Finley: 303-954-1700, bfinley@denverpost.com or twitter.com/finleybruce
The haze and lows
Ozone levels for Colorado’s four national parks (five-year averages in parts per billion from 2008 to 2012):
Rocky Mountain: 73.9 ppb
Great Sand Dunes: 71.5 ppb
Black Canyon: 67.7 ppb
Mesa Verde: 67.3 ppb
Note: Federal health standard is 75 parts per billion
