Smoke tilts Sacramento air quality to unhealthy range — which wildfire is causing it?
Smoke coming from the large Dixie Fire, burning about 100 miles north of the city, has pushed air quality in Sacramento into the unhealthy range Wednesday.
Air quality monitors from the Sacramento Metropolitan Air Pollution Control District registered an AQI reading of 172, or “unhealthy,” downtown just after noon, and a reading of 205, or “very unhealthy,” in Arden Arcade around 3 p.m.
At that level, residents with respiratory or heart disease, the elderly and children are most at risk from the poor air quality and all residents should limit their outdoor exposure.
Emily Heller, a meteorologist at the National Weather Service’s Sacramento office, said that the smoke arrived due to expected northerly winds at the Dixie Fire.
“As well as the winds, there was a strong inversion this morning, sort of keeping the smoke confined to lower levels of the atmosphere,” Heller added. The inversion — a bubble of warmer-than-expected air — explains why so many residents can smell the smoke.
Jamie Arno, a spokeswoman for the Sacramento Metropolitan Air Pollution Control District, said that the thickness of the smoke from the fire came as a surprise for air quality experts. AQI levels spiked quite quickly just before noon as smoke rapidly blew into the area.
“While we did expect smoke from the Dixie Fire to enter the region today, we didn’t expect it to be so dense,” Arno told The Bee. “... The best sensor and monitor for these things is your nose. When you smell smoke, it means you are breathing it, which is unhealthy, and you should go inside. So Sacramento residents should rely on their nose as well as on our air quality readings.”
Heller said the wind is expected to switch directions and the inversion should lift a bit into the afternoon, and most of the smoke should leave the area by late afternoon.
Arno added that the a Delta breeze from the southwest should keep the smoke from the Dixie Fire out of Sacramento at least through the weekend. Arno expects all smoke to be out of the area by Thursday morning.
The Dixie Fire has burned over 217,000 acres in Plumas, Butte and Tehama counties as of Wednesday morning.
Wondering why the sky looks hazy/smoky today? Satellite view shows that smoke is streaming from the Dixie Fire through Feather River Canyon then southward down the Central Valley. #dixiefire #CAwx pic.twitter.com/bP9REV5JNJ
— NWS Sacramento (@NWSSacramento) July 28, 2021
Sacramento has dodged the smoke for most of the summer, while major wildfires pumping out toxic emissions in California, Oregon and Western Canada have moved across the continent to the Midwest and East Coast.
Wednesday’s hint of smoke is a reminder that southerly winds will shift in the coming months to northerly winds, which are known in California as Diablo or Santa Ana winds. That shift could push more dangerous pollutant into the capital region if wildfires continue to rage to the north and east.
Scientists have long known that smoke inhalation can have significant health effects on humans. Weather and air quality experts say that if you can smell smoke in the air, air quality is likely unhealthy enough that you should limit outdoor time.
But recent studies are showing that wildfire smoke may be more dangerous than previously suspected, and could pose significant risks even when inhaled for a short amount of time.
This month, the California Air Resources Board released a study that analyzed the smoke from a number of California wildfires, including the 2018 Camp Fire, California’s deadliest wildfire to date. The study found that smoke from structure-destroying wildfires contains an array of toxic chemicals such as lead and zinc.
In Chico, the site measured nearest to the Camp Fire, lead concentration in the air spiked to over 50 times the normal average when smoke from the fire descended into the city.
In another study published in March, a team of researchers from the Scripps Institute of Oceanography at UC San Diego found that the fine particulate matter in the air during wildfires may be up to 10 times more dangerous to humans than those same fine particles when they exist in non-smoky air.
Fine particulate matter can lodge in the lungs and sink into the bloodstream, and are therefore the cause of most pollution and smoke-related illnesses.
According to the Centers for Disease Control and Prevention, cloth masks used to curb the spread of COVID-19 “offer little protection against wildfire smoke.”
“They might not catch small, harmful particles in smoke that can harm your health,” the agency writes.
The CDC says N95 and KN95 respirators can provide protection from wildfire smoke. The CDC does not recommend N95 masks, saying they should be reserved for health workers, making KN95s the better bet.
