New Salton Sea report says dust isn’t its only pollution problem

A new study that compiles decades of data on air quality in the Salton Sea region says there is more to worry about than polluted dust from the exposed beach of the shrinking sea. 

Ozone, hydrogen sulfide gas, algal blooms, black carbon, wildfires, incinerators, landfill fires and unpaved roads contribute to the cocktail of bad air, according to the report, published on Thursday by Pacific Institute, a California-based sustainability research organization. 

The report says that polluted air in the Salton Sea basin will continue to plague the Imperial and Coachella Valley communities for years to come. It also says efforts to suppress polluted dust from the Salton Sea are expensive and don’t fully address the problem.

To arrive at these conclusions, the Pacific Institute drew on almost a thousand publications on dust emissions, and public health data, sourcing from public agencies and peer- reviewed articles. Michael Cohen, a lead author and senior fellow at the Pacific Institute, intends the report to serve as a reference for the many data points and ongoing projects at the Salton Sea.

“There’s all these different components, and I’m trying to bring it all together and summarize it, and then say, ‘What’s the big takeaway here?’” Cohen said.

Straddling two counties, Imperial and Riverside, the Salton Sea has been receding for years and exposing shoreline, called “playa,” which is laden with pesticide runoff from nearby farms. Exposed playa combined with regular dust storms have long made headlines, but emerging research suggests there is a lot we don’t yet know about what in the air is causing health problems.

Amato Evan, a climate science professor at U.C. San Diego who manages a U.C.-wide research program called UC Dust, and whose work is featured in the study, says there are still many missing pieces of critical data to understand the precise causes of airborne illness in the basin.

At a community meeting in Imperial Valley, Evan said that the history of the Salton Sea makes it “probable” that the dust is toxic, but what it actually is composed of still needs further study.

“What is special about the Salton Sea?” Evan said. “Nobody can answer that question … and so that’s what we’re trying to do.”

Cohen’s study compiles the knowns and unknowns under one umbrella, and from there ventures to understand what could be key approaches to a healthier future in the Salton Sea Basin.

He says, for example, the dust problem is made worse by climate change. With dust storms amping up, and new data on dust sources trickling in, Cohen recommends leaders invest more resources in meeting the problem where people feel it most: indoors, meaning in homes, schools, day cares and workplaces.

“It may be better use of state and local funds to protect people where they are exposed,” said Cohen.

The study acknowledges that over the last decade an increase of dust suppression projects and regulations have improved air quality in the region. The state has spent $49 million on projects that preliminary estimates suggest have reduced 75% of dust from the areas they cover.

But the region’s numbers for ozone, particulates and hydrogen sulfide continue to surpass both federal and state standards, the sea continues to recede and intensifying weather patterns present persisting challenges.

“If we somehow magically fix the Salton Sea, air quality in the region would still be very poor. So conditions in the region are very bad, and the Salton Sea exacerbates that,” Cohen said.

He says that protecting residents is something that can be done more quickly, and that public health should be a priority.

“The analogy is climate change,” Cohen said. “There’s adaptation and mitigation … people now are shifting towards this idea of adaptation.”

A cocktail of dust

Although Imperial Valley residents have been bearing the impacts of polluted air for decades, it’s only now in this last decade that there have been a surge of studies on air quality and public health in the Salton Sea region.

“While there is a history of goals not being well-aligned between researchers and communities, I do think that that’s improving,” said Alexandra Heaney, a public health researcher with UC Dust, at a community meeting in Imperial Valley.

Ten years ago, there were only two public health studies conducted in the region, as compared with 37 today. The results suggest bad health outcomes could be related to all sorts of factors, not all stemming from the exposed playa itself.

Recent studies have been considering how pollutants can become aerosolized. Attention has turned toward levels of hydrogen sulfide emanating from the lake that surpass federal and state standards. Though studies are limited as to the long-term effects of chronic exposure to the gas, it has been linked with gastrointestinal and respiratory issues.

Black carbon from fuel combustion is also a component in the air, as well as unpaved roads. These issues in particular have been in focus as Imperial County looks to build out a lithium industry on the southern edge of the Salton Sea. 

Construction itself will require extensive dust mitigation projects. The county’s plan also says the construction phase of a new lithium plant could produce as much as 9 tons of particulate matter annually, referring to dust particles that can be inhaled by the lungs.

Other studies have opened up questions as to how bacteria in the lake and lake bed may be affecting respiratory health. David Lo, a researcher at UC Riverside, and his team have been studying how dust particles are causing inflammation in mice.

“The ecosystem in the Salton Sea Lake,” Lo said, “helps support the growth of these bacteria, the algae, the fungi, all those kinds of things. I mean, it’s an ecosystem, right? And so as those microbes grow in the water, and they die, they release all their components.”

Though large-scale concepts of refilling the sea with ocean water do exist in the state’s long-range plan, Cohen said those ideas are far too expensive, complicated and far-off to bank on. He also said that would potentially involve negotiating with Mexico, another complication.

“There doesn’t seem to be really much strong political support for this,” Cohen said.

As for suppressing dust at its source, the study suggests such projects are not cost effective, sufficient, or feasible.

Cohen said leaders should rather focus on what they can directly address — investing in air filters, weatherizing buildings and expanding alert systems.

“I think it’s ultimately the goal of public policy,” he said.