As dozens of wildfires rage across California, air pollution levels are skyrocketing.
The United States Environmental Protection Agency (EPA) measures air pollution with the Air Quality Index - an AQI of 50 or below represents good air quality.
A score of between 201 and 300 is considered 'very unhealthy,' while anything above 300 is considered 'hazardous,' with emergency conditions in effect for all residents.
In some regions of the California now, the AQI is above 700, according to the U.S. government's AirNow website.
The result is an environmental crisis that could easily become a health crisis.
AirNow's map of the air quality across the western United States. Yellow is considered moderate, while red is 'unhealthy,' purple is 'very unhealthy' and maroon is 'hazardous'
'In my experience, the impact of the current fires is unprecedented and exposures may prove dangerous for many people,' Michael Kleinman of the University of California, Irvine's Division of Occupational and Environmental Health told Newsweek.
While California faces wildfires every year, experts say climate change has greatly increased their frequency and intensity.
'The debate is over around climate change,' Governor Gavin Newsom said Friday while touring the fire-ravaged town of Oroville. 'Just come to the state of California, observe it with your own eyes,'
Newsom cited August being the hottest in state history, 14,000 dry lightning strikes in three days, plus record-breaking temperatures and droughts.
The Bobcat Fire consumes trees in the Angeles National Forest on September 10, 2020. Particulates can travel miles and impact the health of people far from a blaze
This year's season is already the worst on record, with two months still to go.
More than three million acres have been incinerated, with 19 recorded deaths and 4,000 buildings burned across the state.
'It's a historic season on top of a historic season that replaced a historic season,' Sean Norman, a battalion chief with the California Department of Forestry and Fire Protection, told the AP.
A chart indicating the Air Quality Index levels and their meanings. Anything about a 200 is considered 'very unhealthy,' and above 300 is 'hazardous. Parts of California have registered over 700 all week
'We just keep setting new precedents, and then we keep destroying them.'
In addition to devastating the landscape, the fires pose a threat to human health.
Particles from burning biomass can drift miles to reach areas far from a fire.
The worst of these fine particulates, known as PM2.5, irritate the respiratory tract and lungs