The Salton Sea, an area rich in lithium, is a hotspot for childhood respiratory problems.

The findings also indicate that children who live closer to the sea, who are exposed to more airborne dust, may be the most affected.

The study, published in Environmental researchfound that 24% of children in the area have asthma, which is much higher than the national rate of 8.4% for boys and 5.5% for girls. The abnormally high rate raises health experts’ concerns about the health of children in this predominantly low-income community of color 150 miles southeast of Los Angeles.

Additionally, experts say, the dust problem is likely to intensify in a warmer climate, with evaporation exposing more and more of the lake or beach bed, leading to more dust events.

Ironically, successful water conservation efforts are exacerbating the problem. As state conservationists reduce agricultural runoff into the Salton Sea, the lake is slowly disappearing. A combination of lithium development and mining may promise more economic opportunities, and an increase in truck traffic will likely stir up more dust and further exacerbate respiratory health problems.

“These rural environmental justice communities face health consequences due to local dust events,” said first author Jill Johnston, associate professor of environmental health at USC. “The agricultural industry in the Imperial Valley has used excessive amounts of water, but one of the impacts of water conservation is sea shrinkage.”

The Salton Sea was created by accident in 1905 by a breach in the canal system. Until recently, the sea was largely supported by irrigation runoff from adjacent agricultural land. However, over the past two decades, declining water flow has exposed 16,000 new acres of beach and plenty of dust. Saline lake beds often contain various harmful particles: sulfate, chloride, pesticides, and toxic metals such as arsenic, lead, and chromium.

To better understand the relationship between airborne dust and respiratory health, researchers recruited 722 school-aged children from the predominantly Latino/Hispanic community between 2017 and 2019. Parents and guardians completed a 64-item survey about history of their children’s health in the previous 12 months. , including asthma episodes, daily cough for three months in a row, congestion or excess phlegm for three months in a row.

The researchers then used data from a network of regulatory air monitors to estimate exposure to “dust events” in which hourly dust concentrations exceeded 150 micrograms per cubic meter. The monitors measure levels of particles in the air, including PM2.5 particles (typically from traffic and combustion) and larger PM10 particles (typically dust and dirt).

The researchers also calculated the distance from the boy’s home and the edge of the Salton Sea. Participants who lived within 7 miles of the sea were considered “close” for the analysis.

The research showed that dust events had a greater impact on wheezing and sleep disorders among children who lived closer to the sea. Additionally, each deviation increase from the annual average of PM2.5 resulted in a 3.4 and 3.1 percentage point increase in wheezing and bronchitis symptoms, respectively.

“The community has long suspected that air pollution near the sea may be affecting children’s health,” Johnston said, “but this is the first scientific study to suggest that children living near the coast are declining. may experience more severe direct health impacts. Health must be integrated into mitigation plans.”

In addition to Johnston, other authors included Shohreh Farzan, Elizabeth Kamai, Dayane Dueñas Barahona and Sandrah Eckel, all of USC; Christopher Zuidema and Edmund Seto of the University of Washington; and Luis Olmedo, Esther Bejarano and Christian Torres of the Valle Civic Committee, a community organization in the Imperial Valley.

This work was supported in part by grants R01ES029598 and 5P30ES007048-21S1 from the National Institute of Environmental Health Sciences.