From afar, the largest storms can look like they’re from another world — towering walls of dust that can reach as high as 10,000 feet.
But dust storms are a fixture in California and many other Western states, and they’re here to stay. In fact, scientists predict they will likely become more and more frequent. That’s because we have reshaped the land, diverted water to cities and farms and continue to churn out planet-warming greenhouse gases.
And these storms are hazardous. They pollute the air with tiny particles linked to lung and heart conditions. In total, nearly 5 million Californians now live in regions prone to dust storms, according to a new report by the UC Dust center.
Southern California is especially vulnerable. The Imperial Valley and eastern San Diego County are among the regions most prone to dust storms, along with the Coachella Valley and eastern Riverside County.
Nellie Perez grew up on the north end of the Imperial Valley, along the eastern edge of the Salton Sea. She said the towering storms would come through almost every monsoon season, tearing the tarpaulins off of cars and tossing canopies and trampolines into the air.
“The sky kind of darkens,” Perez said. “And then you can look out in the distance and you can see it coming towards you.”
KPBS spoke with William Porter, a professor with UC Dust, about how to stay safe if you see a storm on the horizon.
What can I do to stay safe?
The next time a dust storm happens, here are three things Porter recommends.
Mask up. If you have to be outside during a dust storm, Porter said masking is a highly effective way to protect your lungs.
“PM 10 can be really effectively filtered by some of the masks and respirators that we have available,” he said.
When it comes to the type of mask, Porter said to follow guidelines for COVID-19. Cloth masks won’t do very much, but N95 masks will do an effective job of filtering out those particles.
Stay inside. If you can, staying indoors and keeping the windows shut will also help reduce your exposure to dust.
But even indoors, Porter said, it’s always difficult to keep dust out entirely.
“There's always going to be some gaps,” he said. “Having some form of indoor air filtration is going to be the next important thing.”
Make a filter. Even if you’re able to stay inside, it’s still likely that some dust will be able to creep in — like when you need to open and shut the door, for example.
Because of that, Porter recommends making your own DIY air filter.
It’s easier than it sounds. For less than $100, Porter said, you can put your own filter together using a regular box fan and an HVAC filter with a MERV 13 rating.
Here’s a video of what it looks like to put a filter like this together. These filters, Porter added, can dramatically improve air quality indoors.
“People have been doing this for many years,” he said. “It's a really effective design.”
Why are dust storms harmful?
On a basic level, dust storms are harmful because they carry tons of tiny particles that can get into our lungs.
Larger dust fragments are often actually less hazardous, Porter said. Those don’t stay airborne for very long, and our bodies do a good job of filtering them out before they can travel past our throat.
It’s the smaller particles that can pose a greater risk.
Dust storms carry large amounts of particles smaller than 10 microns across, also known as PM 10. According to the California Air Resources Board, breathing in PM 10 can make asthma and other lung diseases worse.
Sometimes, these storms can carry even smaller particles, known as PM 2.5. Those are able to breach the lungs and get deep into your body. Exposure can actually lead people to die sooner, especially people with lung or heart conditions.
In places like the Salton Sea basin, scientists have also warned that dust storms may carry toxic materials like pesticides or heavy metals. The UC Dust center is working on a state-funded study about that right now.
In the Central Valley, dust storms have also been raising alarms about growing numbers of Valley Fever infections.
