MERCED, Calif. — The wind whipped around UC Merced graduate student Adeola Fagbayibo one afternoon as he pulled on some latex gloves. He needed the gloves to take out a filter from an air sampling machine, called an “active air respirator,” near UC Merced’s smart farm.
“You can think of it as a vacuum, but this is more specialized toward air sampling,” Fagbayibo explained.
He quickly unscrewed the filter, which was caked in dust, and put it in a sterilized bag. After that, Fagbayibo headed back to the lab and put the filter in a freezer stuffed with other dirty filters. All that filth is data, he said.
“We have bacteria, fungi spores. We have toxins, endotoxins. We have allergens. We have pollens,” Fagbayibo said. “These are the things that dust carries.”
Fagbayibo has routinely collected those samples every two weeks for over a year. It’s part of research he’s working on with UC Merced professor and immunologist Katrina Hoyer looking at what makes up dust particles in the Central Valley. They expect to release some findings within the next year.
For most people, dust is something we only think of when wiping it off counters or windowsills. But researchers at UC Merced and throughout California say these particles affect many parts of life — and it's crucial to know about the risks they carry.
“What dust can do is it can aggravate asthma. It'll aggravate allergy,” Hoyer said. “Dust alone getting into your lungs will activate your immune system.”
Where the Valley’s dust comes from
Hoyer and another UC Merced researcher, Adeyemi Adebiyi, are finding ways to help people to limit the amount of dust we breathe in.
They both said they remember seeing dust storms as kids. Adebiyi is from Nigeria.
“The initial interest started from when I was little, being able to see dust in my backyard,” Adebiyi said. “It's a similar story that happens in the Central Valley, across the other part of California, where there's a lot of dust storms that happen all the time.”
Last year, he and his colleague John Abatzoglou found Valley farmers generate a huge amount of the state’s dust through fallowed land that doesn’t have crops planted on it.
Specifically, they found the Central Valley makes up “about 77% of total fallowed land areas in California, where they are associated with about 88% of major anthropogenic dust events,” according to the study published in 2025 in the peer-reviewed scientific journal "Nature Communications Earth and Environment."
Adebiyi plans to show farmers how that dust gets kicked up into the air by using a machine he refers to as a “makeshift dust generator.” It looks like a leaf blower with a box of soil placed next to it.
“I think it could give [farmers]… a visual representation of the damage or the danger around fallowing, and then the dust generation that could come from it,” he said.
The model is a start for getting everyone on the same page about dust’s consequences, he said.
He and Hoyer are part of a team of researchers throughout the state called the UC Dust Team. The consortium started several years ago because of the increasing prevalence of dust in California. Since launching, the team has published research that studied dust’s correlation with health, environmental drivers, and even the meteorology of dust storms in the state. Their goal is to inform people about dust’s impact.
In a report the team released last year, they cited dust particles contributing to car accidents from dust storms, injuring livestock and even melting snowpack.
“Airborne dust is transported over long distances and contributes to adverse health outcomes for populations near and far from its sources,” the report noted.
In the future, Adebiyi wants to expand the public’s knowledge by implementing better and more accessible dust forecasting tools.
“We can maybe put something together that will allow California residents, particularly residents in the Central Valley, to be able to have a warning system,” Adebiyi said. “If there's a dust storm coming, they will know to stop on the road, so that will lessen the amount of traffic accidents that we get because of low visibility that's associated with those storms.”
How dust affects our health
Hoyer has studied the impact of dust on human health for quite some time, starting with her research on the fungal disease known as valley fever.
She said she was “looking at how the fungus coccidioides that causes valley fever, how it interacts in the host, but also got pulled into what's happening out in the environment, and how much of that fungus might be out in the dust.”
The more dust you breathe in, Hoyer said, the harder it is for your body to contain it. Then, a stuffy nose can become something worse.
Aside from valley fever, exposure to dust has also been found to lead to strokes, heart attacks and even cancer. According to the dust report, other research has shown connections between dust and an increased risk of infant mortality and pulmonary disease.
“It can clog up your immune cells, whose job it is to eat up those particles as they get into your lungs,” Hoyer said. “So if you're not able to push it out with your mucus in your nasal passageway, it can get deep into your lungs and can start to alter your immune response.”
Dustier times ahead require more awareness
Members of the UC Dust team feel their work is creating change. Since the team started, Hoyer said, information has slowly started to spread to local leaders.
“Dust wasn't really part of the climate conversation four years ago, and I think we have definitely gotten that information out to the policymakers so that they're having conversations,” Hoyer said. “But I don't know that the general public is necessarily more aware of it.”
This lack of public perception is the team’s next challenge as dust becomes more prevalent. It’s imperative that residents know, she said, because the more dust in the air, the hotter the weather — and the hotter the weather, the drier the soil.
Hoyer and Adebiyi said this means that a dustier spring time can make for dustier conditions in September, October and November.
The bottom line is more people should know what’s coming and what they’re already facing when it comes to dust’s impact, Hoyer said.
“The dust is there,” Hoyer said. “Even if we can't see it, it's there.”
