Key Takeaways
- Dry, sparsely vegetated landscapes and some crop types were associated with higher Valley fever rates, while other crop types were associated with lower rates.
- Fallowed — or farmland newly left uncultivated — was linked to higher rates of Valley fever, but associations varied depending on previous land use.
- Findings support dust control and protective measures as California’s landscapes and land use patterns change.
Researchers from University of California San Diego and University of California, Berkeley have found that certain landscapes surrounding California communities are associated with differing rates of Valley fever, a fungal respiratory infection caused by inhaling spores carried in windblown dust.
Naturally dry, sparsely vegetated landscapes and some types of farmland were associated with higher disease rates, while other agricultural land uses were associated with lower rates. The findings also suggest that fallowing farmland may influence Valley fever rates in some circumstances. The study was published on August 21, 2026, in Science Advances.
“California is undergoing a major transformation of its agricultural landscape, and we need to understand how those changes may affect public health,” said Alexandra Heaney, PhD, assistant professor at the Herbert Wertheim School of Public Health and Human Longevity Science at UC San Diego and first author of the study. “Our findings suggest that land management decisions can have consequences that extend beyond agriculture and water use. As more land is taken out of production, we may see health risks and therefore have the opportunity to build prevention measures into how California’s landscapes are managed.”