Dust from California’s Salton Sea Disrupts Lung Microbiome

Research has revealed that dust from the evaporating Salton Sea in California may be disrupting the lung microbiome, potentially leading to significant health issues. A study published in the journal mSphere by researchers from the University of California, Riverside (UC Riverside) found that this environmental exposure alters microbial populations in the lungs and affects the immune response.

While much is known about the gut microbiome, the role of microbes in the lungs has been less understood. The UC Riverside team discovered that certain dust particles can irritate lung microbes, leading to detrimental health effects. This research highlights the importance of environmental factors in lung health, an area previously overshadowed by genetic and bacterial infection studies.

Impact of Salton Sea Dust

During their investigation, the researchers exposed laboratory mice to dust collected from the Salton Sea, which is a saline, landlocked lake. The findings were striking. According to Mia Maltz, a mycologist at UC Riverside and lead author of the study, “Even Salton Sea dust filtered to remove live bacteria or fungi is altering what microbes survive in the lungs. It is causing deep changes to our internal environment.”

The study builds on the researchers’ prior concerns about environmental factors contributing to respiratory issues. Talyssa Topacio, co-first author and graduate student at UC Riverside, noted that while collecting dust samples, the team experienced lung discomfort, reinforcing suspicions held by residents near the Salton Sea regarding a link between their environment and respiratory illness. Some researchers even reported that the dust emitted a foul odor.

Changes in Microbial Populations

The experimental results revealed alarming trends. Mice exposed to the dust showed a significant spike in the populations of the bacteria Pseudomonas and Staphylococcus, both of which are associated with lung inflammation. The most potent dust samples contained bacteria that produced lipopolysaccharides (LPS), which trigger immune responses.

As Maltz explained, “We think microbial products like LPS are part of what’s causing the inflammation. It’s like breathing in a chemical fingerprint of dead bacteria.” Mice exposed to these dust samples exhibited a 60 percent increase in lung immune cells marked by neutrophils, which are essential for combating infections. In contrast, those breathing filtered air showed only 10 to 15 percent immune cell levels.

These findings challenge existing knowledge in pulmonology, where similar microbial shifts are typically observed in patients with pre-existing conditions like cystic fibrosis. As noted by David Lo, a distinguished professor of biomedical sciences at UC Riverside, “This was a clean slate, and it still happened.”

As the Salton Sea continues to recede, releasing more harmful dust into the atmosphere, the research team emphasizes the potential long-term health implications for the local population. “Breathing in the dust over time may have chronic impacts in the lung,” Lo remarked. The implications extend beyond dust; the researchers ponder the effects of wildfire smoke, cigarette smoke, and vehicle exhaust on lung health as well.

Maltz concluded, “We’ve only just begun to understand how dust exposure changes the lung microbiome. We don’t yet know how long the changes last, or whether they’re reversible. That’s another big question.”

This research underscores the significance of environmental factors in respiratory health, calling for further studies to explore the long-lasting impacts of airborne pollutants on the lung microbiome.