Many phone apps offer general but nonspecific information about airborne particles. To help increase public safety amidst LA fire season, scientists are making new, real-time, advanced air pollutant measurements available online for free to the public.

The Atmospheric Science and Measurement Network, or ASCENT project, is a state-of-the-art air quality monitoring network of 12 sites spread among urban and remote environments in the U.S., with three sites in Southern California. These are in Pico Rivera in Los Angeles, Rubidoux in Riverside, and Joshua Tree National Park.

The network measures PM2.5 aerosols, particles with a size smaller than 2.5 microns, which can easily be inhaled and cause negative health impacts, including asthma attacks and irregular heartbeat. The network is also measuring other chemical components of the air.

“Some of what was released into the atmosphere during the LA fires is merely irritating to the eyes or lungs, while some of it could be toxic or carcinogenic,” said Roya Bahreini, UC Riverside professor of atmospheric science and co-principal investigator of the ASCENT project. 

“As the Santa Ana winds continue to blow and increase fire danger, we felt it was important for people to see the impact in their neighborhoods.”

Emissions from fires that burn structures like houses and their contents are very different than those of pure wildland fires. For example, during the height of the Eaton fire, which is still burning, Bahreini said the Pico Rivera site saw measurements of chlorine, bromine, and lead in PM2.5 jump by orders of magnitude. 

“We think these chemicals are being emitted as structures and household materials like carpets, furniture, electronics, piping, cars are burning,” Bahreini said. 

For example, chlorine is a common component of polymers used in PVC piping and insulation for wires and brominated organic compounds are used as fire retardant in many household items.

Lead has long been recognized as a harmful environmental pollutant that is particularly harmful to children and their cognitive development. 

In the early days of the LA fires, Bahreini said the Pico Rivera monitoring site saw massive spikes of airborne lead. At its worst, levels jumped to 472 nanograms of lead per cubic meter of air. The EPA safe value for lead in total suspended particulate matter, over the course of three months, is 150 nanograms per cubic meter of air. 

Chlorine also spiked to greater than 13,000 nanograms per cubic meter of air during this same time, when the background level is usually less than 50 nanograms. 

“If you go out there without a mask during the peak of a fire, you’re probably getting a good dose of lead, and other chemicals as well, Bahreini said. 

When air quality scientists want information about the specific aerosols in the air, they generally have to collect samples and ship them to laboratories for analysis. The samples are typically collected every three to five days, which is suboptimal for understanding air quality events that happen more frequently or unexpectedly. 

Because these particles can affect the climate as well as human health, scientists wanting to mitigate them needed a real-time look not only at the chemicals in the air, but also at the frequency with which they appear, their origin, their quantity, and age. For this reason, the National Science Foundation initially funded the ASCENT project in 2021.

“As long as there continues to be concern in the community, and the chance of more large fires breaking out, we’ll keep the information live online for everyone to access,” Bahreini said.

(Cover image: Oliver Knight/iStock/Getty)