Research from USC reveals that wind-driven dust from the diminishing Salton Sea negatively impacts the respiratory health of local children, leading to conditions like asthma, coughing, wheezing, and sleep disturbances.
The study suggests that children living in closer proximity to the sea, where dust exposure is higher, are particularly vulnerable.
According to findings published in Environmental Research, 24% of children in the region suffer from asthma — a significantly higher rate compared to the national averages of 8.4% for boys and 5.5% for girls. This alarming statistic raises concerns among health professionals about the well-being of children in this largely low-income and racially diverse community located 150 miles southeast of Los Angeles.
Experts warn that as the climate warms, the dust problem could worsen, with increased evaporation revealing more of the lakebed, or playa, and resulting in more frequent dust storms.
Ironically, while water conservation initiatives aim to reduce agricultural runoff into the Salton Sea, they are inadvertently exacerbating the issue by causing the body of water to shrink. Additionally, development and lithium mining in the area may offer economic advantages, but could also lead to increased truck traffic that generates more dust and worsens respiratory problems.
“These rural communities facing environmental justice issues are suffering health repercussions from local dust storms,” said Jill Johnston, the study’s lead author and an associate professor of environmental health at USC. “The agricultural sector in Imperial Valley has consumed excessive water, yet one outcome of conservation efforts is the gradual loss of the sea.”
The Salton Sea was formed by accident in 1905 due to a breach in a canal system. Historically, it was maintained primarily by irrigation runoff from nearby farmland. However, in the past 20 years, reduced water flow has exposed 16,000 acres of new playa, resulting in significant dust exposure. Lake beds that are saline often contain dangerous particles, including sulfates, chlorides, pesticides, and toxic metals like arsenic, lead, and chromium.
To investigate how airborne dust affects respiratory health, researchers studied 722 school-aged children from this predominantly Latino/Hispanic neighborhood between 2017 and 2019. Parents were asked to fill out a comprehensive 64-question survey regarding their child’s health over the past year, covering issues such as asthma incidents, persistent coughs lasting three months, and prolonged congestion or phlegm production.
Using data from a network of air quality monitors, researchers assessed the exposure to “dust events,” which are periods when hourly dust concentrations surpassed 150 micrograms per cubic meter. These monitors track air pollutants, including fine PM2.5 particles (often from vehicular traffic and combustion) and larger PM10 particles (mainly dust and soil).
Researchers also calculated how far children lived from the edge of the Salton Sea, designating those within 7 miles as “close” for analysis purposes.
The results revealed that dust events had a more significant effect on wheezing and sleep disruptions in children near the sea. Furthermore, for every average annual increase in fine PM2.5 levels, there was a corresponding increase of 3.4% in wheezing and 3.1% in bronchitis symptoms among the children.
“The community has long suspected that air pollution from the sea could be harming children’s health,” Johnston noted, “and this is the first scientific study indicating that children near the receding shoreline may be experiencing more serious health effects. It is vital that public health considerations are incorporated into future mitigation strategies.”
Alongside Johnston, the research team included Shohreh Farzan, Elizabeth Kamai, Dayane Dueñas Barahona, Sandrah Eckel, all from USC; Christopher Zuidema and Edmund Seto from the University of Washington; and Luis Olmedo, Esther Bejarano, and Christian Torres from Comité Civico del Valle, a community organization in Imperial Valley.
This research was partially funded by R01ES029598 and 5P30ES007048-21S1 grants from the National Institute of Environmental Health Sciences.
