Health-harming ozone spikes amid fires’ haze
Officials recommend constructing “safe rooms” for protection against particulates
Beyond wildfire smoke, the air quality in Denver has deteriorated as residents also are barraged with infusions of multiple lung-irritating pollutants — including ozone, which has spiked in recent days to levels 28% above federal health limits.
Ground-level ozone levels in metro Denver this week reached as high as 90 parts per million, exceeding the health limit of 70 ppm, state monitoring data shows. Ozone levels at 11 of the 15 air-testing sites broke that health limit. Ozone causes acute respiratory problems and triggers asthma attacks.
Colorado public health officials issued a special “multiple pollutants” alert through at least 4 p.m. Tuesday. Health authorities focused most urgently on the harm from inhaling tiny “particulates” spreading in the smoke from burning forests and grasslands. California’s big fires brought more smoke, thickening the haze from the four major fires still burning across more than 193,000 acres in western Colorado.
These particulates piqued concerns because they easily waft inside homes and vehicles, penetrate masks residents wear to combat the coronavirus, cannot be exhaled, and quickly enter bloodstreams to cause broader harm.
The bad air over Colorado also gained
potency this week from continued high temperatures — Denver hit 97 again Monday in a heat wave that has brought more than 60 days this summer with temperatures topping 90 degrees. Heat accelerates the formation of more ozone from the same amount of precursor pollution from vehicles and industrial facilities.
Front Range air conditions ranked about the worst since at least 2010, matching heavy smoke from wildfires in 2018, Colorado Department of Public Health and Environment officials said. And the officials advised all residents — not just older people, children and people with asthma — to stay indoors and, if possible, set up “safe rooms” inside their homes.
“This is happening across the West, and people in those sensitive categories should be staying inside. Even for healthy and fit people, we recommend staying inside during peak conditions because of the effects this can have on your respiratory and cardio systems, especially pregnant mothers and children,” said John Putnam, the health department’s environmental programs director.
“We are strongly encouraging people to try to take it easy,” Putnam said.
Wildfire smoke has thickened the air pollution over much of California and other western states, including Idaho, Utah, Wyoming, Washington and Oregon. The smoke from lightningsparked blazes in California that wafted over Colorado Springs, Denver and other Front Range cities over the weekend was shifting eastward to the high plains and spreading northward to Wyoming, state air quality meteorologist Scott Landes said.
Colorado officials on Monday recommended increased protections, including:
• Create a “safe room” using a portable air-filtering system. This should be “where you spend the most time,” Landes said.
• Find a landmark 5 miles away that usually is visible. “If you know the landmark is 5 miles away and you cannot see it, you know the air quality is not safe,” Landes said. Assessing peak pollution also can be done using the federal website fire.airnow.gov, which presents readings from air testing stations.
• Close windows and adjust household and vehicle air systems to re-circulate air, minimizing intake of particulates.
Cumulative impact of smoke
Any boosting of resiliency this week likely will help in the future, Landes said, referring to science projections that climate warming will lead with some variability to rising temperatures for decades. “With climate change,” he said, “you’re going to start seeing more and more of these events.”
The particulates from wildfires originate as wood that breaks down into bits of carbon less than 2.5 microns wide — easily inhaled.
“You cannot exhale them back out. They enter your respiratory system and then can get into your bloodstream,” Landes said. “This has a cumulative effect. You’re going to feel it for days, maybe weeks afterwards, even after the smoke clears. It affects your heart, can give you headaches and fatigue. These fine particulates really have an impact on many parts of your body.”
Other pollutants hanging in the haze included heattrapping greenhouse gases
— carbon dioxide and methane — and toxics such as sulfur dioxide and hydrogen sulfide in smaller amounts from factories and the Suncor oil refinery north of Denver in Commerce City.
Colorado wildfires kicked out heavy smoke due to aggressive wildfire suppression in the past to protect the multiplying houses and other buildings built near forests. Wildfires are natural, essential in ecological balancing. The suppression has led to thicker forests that, when hot temperatures and lightning — or humans — spark fires, burn more intensely because flames find plenty of fuel.
Wildfires also emit carbon monoxide and other gases that can irritate lungs and hearts, health officials said. Among them: benzene, formaldehyde and acrolein. Firefighters bear the greatest risks because these don’t spread as far as smoke.
The ozone stands out as a problematic pollutant inhaled by masses of people in Denver and other Front Range cities, worsening respiratory and heart ailments.
Ozone comes from the mixing of volatile organic compounds, or VOCs, and nitrogen oxides in heat and sunlight — typically reaching elevated levels during summer on hot days without wind.
The biggest sources of the
VOCs and nitrogen oxides, according to Regional Air Quality Council data, include oil and gas production (44% of VOCs and 28% of nitrogen oxides).
Other main sources: household personal care products, solvents and paints (19% of VOCs) and vehicles (15% of VOCs).
“Serious” air quality violator
Colorado officials for years have faced federal orders to reduce ozone air pollution, yet have failed for more than a decade to attain health standards. The Environmental Protection Agency has relegated Colorado to “serious” violator status for failure to meet the 2008 ozone limit of 75 ppm, let alone the current 70 ppm.
EPA spokesman Rich Mylott on Monday confirmed this summer’s highest levels of particulate and ozone pollution, noting that wildfire smoke typically contains ozone precursor pollution and that “the higher levels of ozone we have seen over the past few days are likely influenced by smoke from western fires.”
Heat and sunlight boost ozone formation, “however the volumes of chemical compounds reacting in the air, particularly nitrogen oxides and volatile organic compounds, have much more of an effect on ozone levels,” Mylott said, acknowledging state efforts to reduce pollution. “We expect these efforts will have an impact on improving air quality … in upcoming years.”
The EPA will take into consideration “exceptional events” — the big wildfires — in assessing Colorado’s compliance with federal orders, state officials said.
A climate shift toward hotter, drier conditions in Colorado and the West means state air quality officials will be forced to do more to reduce air pollution, Putnam said.
“We’re not going to have the ability to control the 90degree days and the transport of wood smoke. This means we’re going to have to reduce emissions that much more from our big sectors — transportation and oil and gas,” he said.
The Colorado Air Quality Control Commission rulemaking process aims at reducing emissions from oil and gas operations in the state.
“It’s going to be a continuous process to keep reducing emissions,” Putnam said. “Because we are going to have a warmer climate, we are going to have to reduce emissions more.”