Beyond wildfire smoke, the air quality in Denver has deteriorated to exceptionally poor conditions with residents barraged by 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 billion, exceeding the health limit of 70 ppb, 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.