Dusty days and airborne sand plague valley drivers and lungs, but delight other desert dwellers

Palm Spring may not have snow days, but we do have sand days. The gate on Indian Canyon Road at Whitewater Wash swung shut again this week, and plows are at work moving three-foot piles of the fine stuff that closes roads and clogs throats, frustrating commuters, ambulance drivers and even pulmonologists. But the local wildlife is probably loving it, experts say.

Geography and weather are the reasons for the dusty season. The same prevailing winds that make North Palm Springs a wind energy hot spot make it a natural sand dune factory. There are health risks associated with the dust, both coarse and fine, yet air regulators are no longer required in some cases to reduce levels of the coarse particulate prevalent in the Coachella Valley, 

The main cause of this spring's particularly frequent dust-ups is a gigantic Valentine's Day storm that dumped a historic 3.71 inches of rain on the valley. Like a relationship gone bad long after the chocolate and roses are gone, the after-effects of that storm, combined with normal wind patterns, will linger through early summer, experts predict. 

"I was actually out there after the storms hit, and you could literally see piles of mud and dirt and silt covering the roads," said Brian Wilson, a Palm Springs real estate agent and amateur meteorologist.

He and others said the Whitewater River in the northern valley dragged tons of sand from area mountains to south of the Interstate 10.

More: Blowing sand keeps shutting down Indian Canyon. Here’s how much sand is still out there

Floodwaters filled the Whitewater Wash with silt, leaving fresh, loose sand piled up in a nearly 7-mile desert area between Whitewater and Indian Canyon.

"When we have a rainy year, it brings down a lot of new alluvial material to be picked up in the air," said James Cornett, senior biologist with JWC Ecological Consultants. But he noted, "this is a process that's been occurring in our area for 20 million years."

Prevailing high-pressure temperatures from the coast hit predominantly low-pressure weather at the San Gorgonio Pass, he explains, particularly in April, May and June, in a process dubbed the Venturi effect. That effect can quickly kick up winds as high as 40 or 50 mph.  

When the alluvial — or water-transported — silt from winter storms goes airborne it becomes aeolian — or wind-borne sand or dust. That leads to the white-outs and road closures. The sand quickly piles up in places like the aptly named Windy Point neighborhood in N. Palm Springs or on Indian Canyon Drive, the first north-to-south paved road below the howling winds of the San Gorgonio Pass.

That leads to the trucks' and plows' Sisyphean task of moving the sand from one side of the road to the other, where it can blow east into a preserve where animals depend on it.

Cornett said while this year may seem bad, June 1979 saw record blasts of 103 mph that toppled trucks, and stripped paint off cars overnight that had been abandoned by frightened drivers on what was then called Indian Avenue. 

The wind-blown particles can also sink into the lungs, aggravating asthma and cardiopulmonary problems, according to published research. While the risks of so-called fine particulate, or microns of 2.5 or less in diameter, are well-proven according to air regulators, the health impacts of exposure to larger particulate matter, known as PM 10, the mixture of coarse and fine dust for which the Coachella Valley has long been known, are less understood. 

More:Palm Springs: One of the smoggiest spots in the US?

Desert dust may be particularly dangerous. A 2006 study of senior citizens in the Coachella Valley found a 2% increase in daily cardiac-related deaths per 10 microgram per cubic meter increase in course particulate levels. Similar results were found in another study in Phoenix.

That increases in cardiac deaths could be due to the unique source and composition of particles in the desert, experts said. Linda Smith, chief of the California Air Resources Board's health and exposure assessment branch, said the study was an excellent one, but there is a gap in follow-up research on a larger population that still needs to be filled. But there are known dangers, and the state does have a PM 10 coarse particulate rule.

Federal annual legal amounts were revoked in 2006, after mining companies and other industries complained that they were being wrongly targeted for costly and unnecessary regulations. Independent health experts and scientists disagreed, but the then head of Pres. George W. Bush's U.S. Environmental Protection Agency sided with the industry groups. There are some longstanding programs in the Coachella Valley to control harmful dust, including street sweeping and required watering on construction sites.

Dr. Ziad Tannous, a pulmonologist at Desert Regional Medical Center, said after 20 years in the area, he has come to expect additional calls and visits from patients on windy days complaining of shortness of breath, coughing or other symptoms that could be caused by breathing the dust. 

"It typically happens in certain areas of town," Tannous said. "Honestly it's the north Palm Springs area, Desert Hot Springs and Sky Valley that are notorious for me."

He said he's had patients with illnesses including chronic lung disorders, asthma and pulmonary fibrosis, whose health could be worsened by exposure to dust.  

More: State air cleaner info

Pending further research or stronger regulations, Smith and Tannous offer similar recommendations: stay indoors if at all possible. If you're in a car during a dust event, set the air intake to recirculate. And if you're able to breathe through it, wear an N95 mask that fits properly, which is often not possible with kids, who can be most affected. Harmful dust can also leak around doors or through windows. The air board has a list of preferred air monitors and says they can help clear the air in your home. They strongly advise against any filter or cleaner that generates ozone — itself a dangerous air pollutant.

Some creatures are probably thriving in this year's dust, said Cornett and Katie Barrows, director of environmental resources for the Coachella Valley Association of Governments. The fringe-toed lizard has evolved to dive into and swim though sand, with flaps over its eyes and mouth and fringey, webbed feet.

"We saw a lizard out in the middle of Whitewater Creek on a little sand island!" said Cornett, who helped prepare surveys of the lizard and its habitat, which were among those used by federal wildlife officials to declare the species threatened. "They love blow-sand."

The Coachella Valley milk vetch, a pretty pinkish purple wildflower, is a member of the pea family that depends on winds to carry and disperse its seed pods. And burrowing owls, "a charming little creature about 6 inches high," relies on round-tailed squirrels to dig its home in sandy creek banks, then settles in, according to Barrows.

"These are critters that exist only here and nowhere else," said Barrows of the sand-loving species. "And 95% of their habitat is gone now, because of development. Just imagine a picture of the valley in the 1940s, where we've now developed most of the area from Palm Springs all the way to Indio. It would have been one big sand dune."

CORRECTION: An earlier version of this story incorrectly spelled Dr. Ziad Tannous' name.

Janet Wilson is senior environment reporter with The Desert Sun, and authors the Climate Point newsletter for USA TODAY. She can be reached at janet.wilson@desertsun.com and @janetwilson66.

Desert Sun staff writer Colin Atagi contributed to this report.