Danger in the dust: Coachella Valley residents struggle to breathe

Outside her home in Riverside County, near the north shore of the Salton Sea, Sara Renteria is struggling to breathe. She has to speak in short sentences, and pauses often to take a breath. 

When she was diagnosed with asthma as an adult about five years ago, Renteria said her doctor gave her a choice: Leave her home in the Coachella Valley or take an array of medications to treat her condition. It was the air, he told her, that worsened her asthma. 

Although by now Renteria is no stranger to this desert region’s poor air quality, she has noticed this year that dust storms kicking up clouds of particles have been increasing. She points to the horizon — it’s often so hazy that she can’t clearly see the desert mountains nearby.

People in the Coachella Valley, especially in Renteria’s low-income, Mexican American community, breathe some of the nation’s unhealthiest concentrations of a pollutant known as PM10 — particles of dust small enough to inhale. The particles exceed federal health limits, mostly when they are stirred up on windy days, and come from a variety of sources, including unpaved roads, construction sites, fallow farm fields and the dried-up Salton Sea.

Renteria’s impression that the pollution has been severe in her community recently is backed up by the data: So far this year, 24 health warnings for windblown dust pollution have been issued in the region, each lasting several days. The latest was this week, along with odor and wildfire smoke warnings that added to the Coachella Valley’s pollution woes.

Unhealthy peak levels of PM10 around Renteria’s community have been recorded on five days so far this year, based on preliminary South Coast Air Quality Management District data. Last year, five days exceeded the health standard and 10 days in 2022; in the decade before that, violations were rare.

During the past two years, some Coachella Valley residents breathed maximum concentrations — usually recorded on high-wind days — two to three times higher than the amount deemed safe. Those are often the days when people, especially those with asthma or allergies, feel sick.

Famous for two music festivals — Coachella and Stagecoach — the region draws hundreds of thousands of people each spring, when winds often stir up dust. Festival-goers and workers breathed high levels of particle pollution for several hours on the two days before the Stagecoach festival, and on its first day, April 26.

Local leaders and residents say more dust is covering cars and driveways, and even surfaces inside their homes. A brown-gray haze lingers after high winds — so bad that it can cause car accidents. Hotels, restaurants and other businesses have expressed concerns that the dust is driving away tourists and raised their cleanup costs.

“There’s no doubt in my mind that the air quality has been worse than I’ve certainly ever experienced it in my 28 yrs in the Coachella Valley,” said Tom Kirk, executive director of the Coachella Valley Association of Governments, which represents the area’s cities and tribes.

But South Coast air district officials say the data doesn’t indicate there’s anything “out of the ordinary” this year.

“We think dust levels are within the typical year-to-year variation we’d expect to see,” said Scott Epstein, the agency’s planning and rules manager who oversees air quality assessment. “It’s very unsatisfying for us because we want to confirm what the community is saying. But the science says things are within the realm of what we’ve seen in the past.”

Desert dust is usually coarse and packed into the ground. But when storm Hilary hit the area last August, the  torrent of rain disturbed the dust and brought mud from mountains that turned into a fine, loose silt that raised PM10 levels.

But Epstein said much of the dust that people are now seeing isn’t actually PM10 — it’s larger particles that do not pose a major health threat because they cannot be inhaled.

Some local leaders and residents disagree, based on the physical symptoms they feel and the fine dust they see.

“Despite assertions to the contrary, air quality has not shown significant improvement,” state Assembly members Greg Wallis and Eduardo Garcia wrote in a letter to the air district. “The spring season, characterized by windy conditions, has exacerbated the issue by stirring up dust and clay deposits left behind in the wake of Tropical Storm Hilary.” 

Air pollution, particularly from dust-blown particles, has been a problem in the Coachella Valley for decades. The region was declared a federal PM10 “serious nonattainment” area back in 1993 — making it one of the nation’s worst areas for the pollutant.

Since then, air quality and local officials have been struggling to figure out how to reduce the pollution, and residents have long pushed for more action.

A state plan, mandated by the U.S. Environmental Protection Agency, outlines state and local efforts to require certain sources, including farms and construction businesses, to control dust. Local leaders already have a decades-old street-sweeping program to collect dust before it’s ground into finer particles, and other local rules have required dust control at construction sites and farm fields. 

Despite these efforts, over the past 20 years, PM10 remains a “serious” health problem in the region, according to the EPA. Average annual concentrations have improved in some areas, particularly in Indio, but not enough to meet health standards, air district data shows. The town of Mecca, on the north shore of the Salton Sea, has the worst problem. 

“The biggest driver of changes in PM10 is the wind,” said William Porter, an atmospheric physicist at UC Riverside who studies the air pollutant. “We get these big winds that blow very strong from the east. Whenever we have those conditions we see big increases in blow dust.” He added that the pollution also can worsen with “changes in the surface properties of the land.” 

The desert, of course, is dusty, with little rainfall and not much vegetation to hold soil in place. But there are human sources, too, that officials are struggling to control. The region is a transportation corridor, with exhaust spewed by trucks, trains and cars driving from Los Angeles. Dust on roadways is ground up into finer pieces that can be picked up and distributed throughout the air. Particles also flies off farm fields and construction sites.

And the receding playa of the Salton Sea generates small particles that are picked up by winds. Created by Colorado River flooding, the shallow, salty lake now is made up mostly of contaminated runoff from Imperial Valley farms that have been draining its water supply.

At risk: elderly, children and those with lung disease

PM10 — particles that are 10 microns or smaller, a fraction of the diameter of a human hair — is considered a health threat because the particles are small enough to be inhaled. They are larger than another pollutant, PM2.5 or fine particles of soot, which can travel farther into the respiratory system and enter the bloodstream, triggering heart attacks. PM10 is more likely to be trapped in the upper respiratory system — the nose and throat.

Geoffrey Leung, Riverside County’s public health officer, said when PM10 is inhaled, it can worsen symptoms for people with asthma and lung diseases, such as chronic obstructive pulmonary disease. Symptoms can range from moderate to severe, from coughing, wheezing and eye irritation to asthma attacks. 

People with lung and heart diseases, the elderly, pregnant people and children are most vulnerable, Leung said. Leung advises people with those conditions to stay indoors and limit physical activity on days with poor air quality. 

In the Riverside County portion of the Coachella Valley, about 41,422 adults and 10,675 children have been diagnosed with asthma, according to county data. That’s about 12% of the population, compared with the national average of about 7%.

The Salton Sea is part of the reason that pollutant levels are so dangerous in the region. Porter’s unpublished research indicates that particles blown from the direction of the Salton Sea is linked to a larger increase in hospitalizations for respiratory or cardiovascular problems compared to when wind blows from other directions. The explanation could be the content of its dust, since it picks up metals, pesticides and other hazardous substances.

Many residents living near the Salton Sea know to stay indoors to avoid the dust if winds are blowing from that direction. On two days earlier this week, odor advisories were issued when noxious sulfur fumes, which can cause headaches and nausea, blew in from the inland lake.

“When it’s coming from the sea, we definitely don’t go outside. When it’s coming from L.A. it’s less worrisome,” said Conchita Pozar, who lives just about a mile from the shore of the Salton Sea. 

Asthma attacks, allergies and headaches

On a recent evening at her home in North Shore — a tiny desert community of about 2,600  people, 97% of them Hispanic, next to the Salton Sea — Renteria recalled a scary asthma attack she had just a few weeks earlier. On the drive home from visiting her siblings, she started hyperventilating, seemingly out of the blue. 

“I felt like there was a rock on my chest,” Renteria said, mimicking the short, quick breaths she felt that day. “And like needle pricks all over my skin.” 

She spent a night in the hospital before her breathing stabilized.

Renteria, a farmworker, has to carry her inhaler with her at all times, especially when she’s active and working in date fields part of the year. At home, she has a nebulizer, which is a machine with a mask that delivers medicine to her airways, and vials of medications.

Pozar, recruited by UC Riverside researchers, is one of a handful of “promotoras” or community workers who interview their neighbors about their symptoms. Many report bloody noses, allergies and eye irritation. Some children don’t have an asthma diagnosis but struggle with similar symptoms and are instructed to use inhalers. 

Pozar’s teenage daughter suffers from allergies that give her eye irritation so severe that she often keeps her home from school. On windy days with poor air quality, Pozar keeps her daughters home and they wear masks when they go outside.

“Her allergies are so bad that we sometimes can’t turn on the lights or go outside because it irritates her eyes,” Pozar said. “A specialist told me that it was because of the dust that surrounds her.”

Many people have already moved out — North Shore’s population has dropped almost 13% in just one year. But moving isn’t an option for Pozar. She’s lived in the Coachella Valley half of her life after immigrating from Michoacan, Mexico. She wants to stay connected to her indigenous Purepecha friends, neighbors and family members who live there, and she and her husband have made their livelihoods here. 

“We’ve adapted, and with housing prices so high, I don’t think we’d be able to find a home that we’d be comfortable in somewhere else,” she said.“The government should make an effort to resolve the problems here.”

Alianza Coachella Valley, a nonprofit that focuses on improving the health of the valley’s vulnerable communities, has trained Renteria and other community members to use air monitors in their homes to provide localized data and help protect themselves from the pollution, said Silvia Paz, the organization’s executive director. 

The group has educated residents about air quality, especially in the eastern Coachella Valley where the towns of Mecca, Thermal and North Shore are separated by miles of open desert and farm fields. 

“These communities are mostly rural and they’re lacking in infrastructure,” said Silvia Paz, the organization’s executive director. “We have less parks, we have less trees, we have less roads. We can experience the difference in exposure because we have less elements to keep dust down or protect us from the dust blowing.” 

In 2017, Alianza deployed air monitors throughout the eastern Coachella Valley that tracked real-time data. This provided evidence that the region should be included in a state program to reduce pollution in communities with the poorest air quality, Paz said. 

The program, mandated by a 2017 law, holds meetings with community members and has recently set aside $4.6 million to pave public and private roads in the eastern Coachella Valley, as well as $2.8 million to provide household air filters in communities statewide.

Sweeping streets: Local efforts to fix the problem 

The South Coast air district monitors 24-hour average PM10 levels at three stations in Indo, Mecca and Palm Springs, and tracks when levels exceed the federal health standard, which is 150 micrograms of particles per cubic meter of air, as well as a state standard of 50.

Emily Nelson, an environmental consultant for Coachella Valley Association of Governments, was part of a district working group that studied PM10 in the 1990s to develop ways to solve the problem. 

In 2003, the agency approved its plan to reach PM10 standards. Under the plan, cities implemented ordinances that directed certain industries, such as construction and agricultural businesses, to reduce dust. That includes such practices as spraying soil stabilizers and nonpotable water on construction sites and implementing certain methods when mowing golf courses.

“There were a lot of implemented appropriate meaningful strategies that in the end saved many of these industries money and made them better neighbors,” Nelson said. 

In 2010, the state Air Resources Board and South Coast district asked the U.S. EPA to redesignate the area as in attainment with the health standard based on 2005-2007 data. The request was denied “and we started exceeding it again,” Nelson said. 

The Coachella Valley Association of Government spends more than $760,000 a year on street sweeping as part of the state’s plan for cleaning up PM10, according to a 2022 contract effective through 2025. Street sweepers clean 896 miles of roads at least on a biweekly basis.  

Kirk, executive director of the association, said street sweepers have recently picked up more dust than they have in the past. 

He said the cities need more funding from the South Coast air district and that agency officials should spend time in the Coachella Valley to see the problem themselves.

“We rely on the district’s expertise to not just understand the air quality problem but solve it,” Kirk said. “The air district isn’t in the problem-solving mode because they don’t see there’s a problem.” 

In response to community concerns, South Coast air district officials say they are trying to get a better picture of the pollution by deploying a temporary monitor in Indio that can measure total suspended particulates and one in Whitewater Wash. The agency is also analyzing satellite data in collaboration with Colorado State University researchers. 

Even if the recent pollution concentrations are mostly larger particles, not smaller, inhalable ones, Nelson said she worries about how it affects the region’s welfare. More research is needed to see  how they affect visibility, crops and other industries, like tourism. 

“The wind will stop and the valley still looks like we’re in a soup of dust,” Nelson said. “Everything is coated with this very fine dust. I mean the car washes have been doing the best business ever.” 

John Osborn D’Agostino, CalMatters’ data and interactives editor, contributed to the reporting on this article.