Air Pollution From California Wildfires in Some Regions 'Unprecedented'

Air pollution from the California wildfires is spreading across the state, with hazardous levels being recorded in many regions. In several areas the Air Quality Index showed regions where pollution levels had gone above 500. Anything above 200 is considered unhealthy to hazardous. In some parts of California, the AQI was above 700.

"In my experience, the impact of the current fires is unprecedented and exposures may prove dangerous for many people," Michael Kleinman, from the Department of Medicine at the Division of Occupational and Environmental Health, University of California, Irvine, told Newsweek in an email.

The government's AirNow website, which tracks air quality across the country, is also recording "unhealthy" or "very unhealthy" air in many parts of California. Maps on the website show the extent of the fires, with air quality problems across almost the entire state.

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Wildfires burn across California every year between June and November, when conditions are hot and dry. This year's season, however, is already the worst on record, with over two million acres incinerated. So far six of California's top 20 biggest wildfires in history have taken place in 2020, and there are still two months left before the season comes to an end.

As well as the immediate damage caused, the smoke from the fires has a major impact on people's health through the inhalation of toxic particles. The smoke contains gases, vapors and particles that can stay airborne for long periods of time. They can travel huge distances to affect communities a long way from the site of a wildfire.

"The particles which are generated by the burning of biomass materials from trees and shrubs contain metals (some of which are toxic) and organic compounds (many of which are very irritating to the respiratory tract...and some of which cause damage to the lungs and possibly the heart," Kleinman said.

"Some of the compounds on the particles are also known carcinogens. The gases contain carbon monoxide, which is poisonous, oxides of nitrogen, and vapors such as formaldehyde and acrolein all of which can impact health. Keep in mind all of the adverse effects that we know are caused by cigarette smoking. Tobacco is just another biomass material. Many of the same toxic compounds that are found in tobacco smoke are found in wildfire smoke."

 The San Francisco Bay Bridge
The San Francisco Bay Bridge on September 9. Wildfires have been burning across California and there has been a huge impact on air pollution. BRITTANY HOSEA-SMALL/AFP via Getty Images

Suzanne E. Paulson, Director, Center for Clean Air at the University of California at Los Angeles, said the wildfires are having an "enormous impact" on pollution for areas downwind. "There are so many fires burning, and they are taking a long time to control, so populations in many directions from the fires are being impacted," she told Newsweek in an email.

For people living in affected areas now, the scientists say people need to take practical steps to protect themselves. These include staying indoors with windows and doors shut, using air conditioning units where possible. It is also advised to avoid exercise when pollution is bad.

Both Paulson and Kleinman say the best way to combat air pollution from wildfires is to address climate change. The number and intensity of the fires has been getting worse for several years, which is likely to be the result of climate change, Kleinman said. "The long term solution is to drastically reduce greenhouse gas emissions such as carbon dioxide from burning fossil fuels and methane releases from oil and gas extraction and refining," he said.