Repost from SF Gate

This is where air quality was the worst in the Bay Area in 2018

By Drew Costley, March 13, 2019 12:30 pm PDT

Residents of San Francisco experienced the worst air quality in the city’s recorded history in 2018 because the historic Camp Fire in Butte County. The rest of the region was choking on smoke from the wildfire, too. At one point in November 2018, Northern California had the worst air quality in the world.

During the Camp Fire, Vallejo residents experienced the worst air quality of the year on November 16, the eighth day of the fire, according to the measurements taken by the Bay Area Air Quality Management District (BAAQMD). On that same day, several other Bay Area spots also recorded their worst air quality of the year.

READ MORE: San Francisco AQI jumps to 271, worst air quality ever recorded in the city

“A few really big events can really affect the air quality in the Bay Area,” Charley Knoderer, meteorology manager for the BAAQMD, said. He added that the frequency and intensity of wildfires in Northern California in recent years is “highly unusual and causes a lot of problems.”

Kristine Roselius, communications manager for the BAAQMD, said that climate change is “supercharging and exacerbating” wildfires in the region. “We’ve got more extreme weather and more extreme weather is causing more catastrophic wildfires that are larger in scale, that are harder to put out, and they put out a lot of smoke.”

Outside of the historically bad air quality of November 2018, where in the Bay Area do we find the worst air quality? SFGATE averaged the highest recorded Air Quality Index (AQI) ratings to start to get an idea of where it was the worst.

Click through the slideshow at the top of this story to see where air quality was best and worst in 2018.

The AQI is a combination of air quality measures – carbon monoxide, nitrogen dioxide, ozone, particulate matter and sulfur dioxide – taken by the BAAQMD.

Knoderer said traffic congestion is the largest contributor to poor ambient air quality. The amount of traffic in West Oakland and near Laney College, along with action along the Port of Oakland, make the air quality in the area so poor.

Ambient is a key distinction from the moments, like during a wildfire, when there’s unusually poor air quality. Knoderer pointed out that if it hadn’t been for the smoke from the Camp Fire, the Bay Area would not have had any days that exceeded federal standards for the level of particulate matter in the air last year.

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“We generally have two seasons that affect air pollution differently,” Koderer said. “You have summer, when ozone is the primary pollutant, primarily from cars. And then you have the winter, which is primarily particulate matter or PM2.5, and that’s more local forces like fireplaces.”

Roselius added, “Wood fires are the number one source of winter time air pollution.”

The good news is that most of the monitoring stations in the Bay Area had monthly averages of particulate matter – different from the average of all of the monthly AQI highs – that were all under the federal health standard of 35 micrograms per cubic meter per day.

Two of the three monitoring sites with the highest monthly averages in 2018 were in Oakland, at Laney College and West Oakland. The other was on Owens Court in Pleasanton. All three sites averaged 14.4 micrograms per cubic meter per day last year.