The Environmental Protection Agency is currently considering whether it will implement stricter particle pollution standards — which could force Utah officials to make significant changes.
PM2.5 — extremely small particles emitted after combustion, like power plant ash or vehicle exhaust — are responsible for the fog-like haze that builds and stagnates over the Salt Lake Valley during winter. Breathing these particles can irritate one’s airway and cause heart and lung problems, including death, according to the EPA.
The EPA has proposed lowering the annual PM2.5 standard to 9-10 micrograms per cubic meter of air, down from 12, which may not have a significant impact on Utah.
But the federal agency is also considering a stricter 24-hour monitoring standard, which would force the state to make changes. And the EPA is asking the public to weigh in.
Reducing the annual standard wouldn’t impact Utah as much because the state already registers below 10 micrograms per cubic meter of air at most monitoring sites, Division of Air Quality director Bryce Bird said. The outlier is a site in Salt Lake County off Interstate-15, where levels register near the top of the newly proposed standard because of car-caused pollution.
Lowering the 24-hour standard would mark a much greater impact, however, because Utah is already “very close to exceeding” the current 24-hour standard, and decreasing it would require intervention to reduce emissions, Bird said.
That intervention could look like stricter restrictions on vehicle emissions, or more outreach and education on other ways to cut down on air pollution.
Bird added that the EPA’s proposals are based on research showing the longterm and acute health impacts of breathing in particulate matter.
How to share your thoughts with the EPA
To comment on the EPA’s proposal, visit https://www.regulations.gov/document/EPA-HQ-OAR-2015-0072-1543 and click the blue “comment” button on the left side of the screen.
The agency recommended commenters be concise and support claims with “sound reasoning, scientific evidence, and/or how you will be impacted.”
The public comment period ends March 28.
The majority of the independent Clean Air Scientific Advisory Committee, whose research the EPA relied on to make its recommendation, determined both the annual and 24-hour standards should be lowered.
The EPA even stated in its proposal, “Based on the current evidence and quantitative information, as well as consideration of CASAC advice and public comment thus far in this reconsideration, the Administrator proposes to conclude that the current primary PM2.5 standards are not adequate to protect public health with an adequate margin of safety.”
Despite that, the EPA proposed only to lower the annual standard. The administration found the evidence to change the 24-hour standard “less clear” and noted that “a more stringent annual standard is expected to reduce both average (annual) concentrations and peak (daily) concentrations.”
Utah sites do exceed the 24-hour standard for PM2.5 during bad inversions — like the one earlier this month — but violations of the standard are based on the 3-year average of 98th percentile value at a site.
Last weekend, many sites in Utah recorded PM2.5 levels around 40 or 50 microgram per cubic meters of air. In Cache County, one site reported 97.5 micrograms per cubic meters of air.
A tool based on research from the environmental data science nonprofit Berkeley Earth calculated that breathing the air for 24 hours when it reaches around 50 micrograms per cubic meters of PM2.5 is like smoking nearly three cigarettes. Air at the Cache County site was like smoking nearly five cigarettes.
Air quality on west side consistently worse
Salt Lake County received an F when graded for high ozone days by the American Lung Association, and air quality monitors frequently show the west side experiencing some of the worst hot spots.
If you are a west-side resident and air quality has affected your life, The Salt Lake Tribune and KUER want to hear from you for our “Reaching for Air” project.
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Correction • Feb. 10, 11 a.m.: The story has been updated to correct the unit of measurement for PM2.5 in air.
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