Colorado Dept. of Public Health and Environment

Denver’s ozone levels have improved and even a slightly higher particle pollution level since last year remains well below national standards, according to the American Lung Association’s 2018 “State of the Air” report released Tuesday.

Nine cities across the West and Southwest had fewer high ozone days, according to the report, “including five that experienced their fewest days since the report began: Modesto-Merced, CA; Las Vegas; Denver; El Centro, CA; and Dallas-Fort Worth.” The remaining four also improved their ozone levels over last year’s report, including Phoenix, Houston, and Fort Collins, Colo.

The ALA used the Environmental Protection Agency’s 2015 ozone national air quality standard for comparison.

“The Southwest continues to fill most of the remaining slots, with seven of the 25 most ozone-polluted. Texas has two cities in the 25 most-polluted list: Houston and Dallas-Fort Worth. Colorado has two, as well: Denver and Fort Collins. Arizona, Nevada and Utah each have one,” the ALA wrote.

Jeremy Neustifter, an air quality planner at the Colorado Department of Public Health and Environment, told Western Wire via email that the department appreciates the ALA’s concerns, and is still reviewing the full report.

“CDPHE is encouraged to see ALA ozone grades have improved for four counties in Colorado since last year. Moreover, ALA particulate grades have improved for two counties since last year,” Neustifter said.

Despite a mixed result, the headline was not alarming, and CDPHE welcomed the new findings. “The Department is pleased to see improving trends in air quality,” Neustifter added.

Neustifter acknowledged there was a slight increase in annual average particle pollution from the group’s 2017 report, but said those concentrations in Denver and the rest of the state were well below the National Ambient Air Quality Standards (NAAQS).

Neustifter also offered some clarification of data and methodology employed by ALA in reaching determinations that assign poor grades.

“As the ALA admits, with its methodology, some counties will receive a grade of ‘F’ in the report, while still meeting EPA’s most restrictive 2015 standard,” Neustifter said. “The ALA also used all ozone data in EPA’s database, including from sites that may not meet all EPA-required quality control and assurances, such as U.S. Forest Service sites that are used for helping determine forest health, particularly in rural and high elevation areas.” These high elevation monitors, according to the CDPHE official, “are more prone to the effects of natural events, such as the intrusion of ozone from the stratosphere, and do not accurately represent the air at lower elevations the citizens of those counties breath.”

Some of the ALA’s findings “overstate” exposure, Neustifter added, addressing Colorado residents concerned with ALA’s conclusions.

“The ALA report’s grading methodology also overstates exposure to ozone by assuming the population of an entire county was exposed to the level of ozone at the worst monitor, even when other monitors in the same county showed healthy concentrations,” Neustifter said.

“In real life, all county residents do not travel to the site of the highest ozone; actual exposures are lower,” he added.

CDPHE noted that the “vast majority of the days that counted against Colorado counties for the ALA grading system were ‘orange,’ which is defined by EPA as unhealthy for sensitive populations.”

“Colorado’s citizens should know the ALA report cites very few days in Colorado where ozone concentrations were at levels considered by EPA to be unhealthy for the general population,” Neustifter said.

Instead of doom-and-gloom, Neustifter said the ALA’s report supports CDPHE’s own findings that air quality in Colorado is improving considerably, even as population and energy demand in the state has soared.

“Colorado has come a long way in improving air quality since the days of the notorious ‘brown cloud.’ Even using the ALA’s methodology, Colorado’s citizens are breathing air that is far cleaner of particle pollution than in years past,” he said. According to CDPHE, ozone concentrations in the Denver-metro area and Colorado as a whole have been declining in recent years, thanks to the implementation of new Colorado regulations that reduce emissions of ozone forming pollutants.

Neustifter cautions that the new report “does not include data for 2017, which was one of Colorado’s cleanest ozone years in the recent past.”

Outdated data has plagued the ALA in previous report editions, such as 2015, when the group’s findings were challenged by CDPHE’s Will Allison, then Director of the state’s Air Pollution Control Division.

Allison, who has since retired, rejected the group’s sensational headlines that Colorado’s air quality was deteriorating to levels not seen in decades.

“We do have some concerns with their annual report, and those concerns are not new. It doesn’t provide a complete picture,” he said. “This year’s report asserts that air quality has somehow gotten worse, but in fact our data shows it’s getting better.”

“I very much disagree with the contention that air quality is as bad or worse than in the 1970s. It’s very much better,” Allison told the Denver Post’s Vincent Carroll. Air quality levels among all emissions had plunged from the 1970s and 1990s so that by 2015, ozone levels had “certainly gone down significantly.”

The ALA was forced to backtrack, saying, “ozone is not worse than in the 1970s.”

State regulators in Texas, Indiana, and Maryland also challenged ALA’s 2015 findings that year.

“The TCEQ [Texas Commission on Environmental Quality] agrees with the American Lung Association that Texas air quality is improving,” TCEQ said in a statement to E&E News. “Where we differ, however, is with ALA claims that ozone levels in the Dallas-Fort Worth area have deteriorated. … For Texas as a whole, ozone levels decreased 29 percent from 2000 to 2014.”

“They use their own yardstick. We don’t agree with their methodology,” said Maryland Department of Environment spokesman Jay Apperson. “So we do like to get this report out at the same time. Our report is consistent with the data as it’s used under the Clean Air Act.”