Northern California has worst air quality in the world

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Spots in Northern California right now have the worst air quality in the world.

That’s according to government readings of the Air Quality Index as well as Purple Air, a private company that tracks air quality with portable monitors throughout the globe. The company also sells air pollution sensors for personal use.

On Friday at 8 a.m., Purple Air’s map showed the AQI in Oroville, Calif., in the 500s.

As of 1:45 p.m. Air Now reported an AQI of 323 in Richmond. 

According to Purple Air, New Delhi, was hovering in the 200s. And Beijing, which typically has the reputation for having the worst air quality in the world had a reading of 93 on Friday. 

Oakland, Calif. -- to compare -- clocked in at 199 on the government website; the numbers soared to the mid-200s using Purple Air's website. 

On Thursday, the air quality, according to the official government agencies, in San Francisco was 245 and Oakland was 247 -- the highest hourly AQI since readings began more than 20 years ago.

“These numbers are incredibly high,” said Sam Atwood, spokesman for the South Coast Air Quality Management District in Los Angeles, a government agency that has partnered with Purple Air. “These are wildfire conditions.” 

A reading of 200 or more is “very unhealthy.” A reading of 300 or more is “hazardous,” according to the Environmental Protection Agency.%INLINE%

There are a few caveats with Purple Air’s map, however, Atwood explained. Company officials did not respond immediately to KTVU’s interview request.

First, private companies such as Purple Air use portable air monitors, which are more flexible than the stationary air quality sensors that government agencies use, Atwood said. 

That means anyone can put a Purple Air monitor right in the thick of things in Oroville, 31 miles south of Paradise, Calif. That's the city hardest hit by the Camp Fire in Butte County, which has been burning since last Thursday and causing the air to billow about, including two hours away from the Bay Area.

And second, government agencies such as Atwood's and the Bay Area Air Management Quality District, are federally required to use stationary air monitors that stay in one place. Government agencies also use average air quality levels over several hours, as opposed to real-time data that private companies use. In the Bay Area, there are 31 government-approved stationary sensors. Purple Air shows the AQI in real-time, which means that its numbers may be higher, Atwood said. 

Still, using the government air quality site called, the AQI in Northern California was still awful. The readings in Yuba City, Sacramento and Chico – all near the heart of the Camp Fire – showed readings of more than 300 on Friday morning. As of Friday, the highest readings in the world were in Chico and Sacramento, according to the government data.

“Bottom line is, this is terrible,” Atwood said.