Study calculates how much emissive dust comes from sea
It’s no secret that the lakebed at the receding Salton Sea is a growing health concern for the residents of the Imperial and Coachella valleys.
Despite the fact dust along the Salton Sea carries particles which can have an adverse effect on human health, there hasn’t been data to quantify how much of that dust is affecting the air of the Valley, until now.
Associate professor of environmental sciences at the University of California Riverside, Roya Bahreini led a group of researchers who set themselves to try to answer the question of how much dust is coming from the exposed lake bed near the sea. The team of scientists collected air and soil samples from the exposed playa and surrounding desert area to get a better understanding of particulate matter (PM) concentrations in the vicinity of the Salton Sea.
The most significant finding that came from the research is that the exposed playa has a significant contribution to PM10 in the air with a 10 percent contribution, while 45 percent comes from the surrounding desert land in the area. Bahreini said the other sources of PM10 were not accounted for in the research, but likely a portion of it is due to manmade pollution.
“We do see a big signature of dust from the playa in the air; the concentration is measurable,” Bahreini said.
She noted, one of the main concerns with the additional PM10 source was the possible toxicity levels in the concentration of certain elements. The study found that the particulate matter coming from the exposed lake bed have high concentrations of sodium, calcium and selenium, but the concentrations of calcium and selenium, however, are still below toxicity levels, Bahreini said.
Although calcium and selenium concentrations are below toxic levels, they are still a serious health concern because they are irritants and can lead to severe health problems.
“In general PM can affect different parts of the respiratory system,” Bahreini said. “Interaction with particular matter can lead to irritation in the nose, sinus, throat, and lungs and ultimately lead to chronic asthmatic, cardiovascular and pulmonary diseases.”
Any additionally exposed lakebed that emits PM10 is a major concern because as higher concentrations of PM are released, they can continue to deteriorate the health of the local communities.
Imperial County has the worst areas in the state of California when it comes to air quality. According to data from the California Department of Public Health, the county has the highest rate of asthma related emergency services visits in the state for children aged 5-17. While the state has an average of 72.4 emergency visits per 10,000, the rate in the Valley is more than twice that with 163 per 10,000 per year.
The findings made by Bahreini and her team offer just a first glimpse in beginning to understand the composition of the air basin in the Salton Sea area and the potential health impact it may carry. Her team of researchers collected samples for a total of 18 days in Aug. of 2015 and Feb. 2016, and the samples taken only came from the communities of Salton City and Bombay Beach.
In order to expand on their first results, begin to get a bigger picture and learn more about PM10 exposure, Bahreini already has a plan on hand for the next research project. She said the team expects to collect samples from additional locations as far as Palm Desert to the north of the sea, the Sonny Bono Wildlife Refuge to the south and do so over a longer period of time.
Although she’s aware of the current efforts at the state level to mitigate the impact of the exposed playa at the Salton Sea, Bahreini said she is not well versed on how effective some of the techniques the state is considering in suppressing dust can be, but acknowledged anything that can be done to cover the playa should be done.
To date, the Salton Sea Management Program has only received $80.5 million in funding from the water bond, which Gov. Brown allocated in his 2016-17 state budget. In March, the California Natural Resources Agency released a 10year plan which lays a roadmap for the state to build dust suppression projects to cover nearly 30,000 acres of exposed lake bed by 2028, which is only half of the acres that will have become exposed by then.
The state’s plan has a price tag of $383 million, a much more manageable figure than the $1.5 to $2 billion price tag for the full mitigation and restoration of California’s largest lake, but still, needs an additional $300 million to receive full funding.