Exposure to air pollution, even for just a month or two, may be enough to increase the risk of developing diabetes, especially for obese people, says a new study from the Southern California Environmental Health Sciences Center at the University of California’s Keck School of Medicine.

Researchers studied more than 1,000 people living in southern California. Short-term exposure to contaminated air was linked to an increased risk of high cholesterol and impaired blood sugar processing, both of which are risk factors for diabetes.

Notably, scientists weren’t able to explain the reasons behind such a link. One suggestion is that air pollution leads to inflammation in the body, which triggers a chain reaction that makes it harder to process blood sugar. Rats have also been shown to experience higher rates of obesity and diabetes when exposed to air pollution.

Study results suggest that people who live in cities and areas with poor area quality should limit outdoor exercise during peak commute times (when traffic fumes are at their worst), avoid running or biking alongside major highways, and use HEPA filters inside to trap harmful pollutants.

Local health departments should help educate their communities, particularly vulnerable populations such as those with disabilities, on the importance of minding air quality alerts, developing habits that promote clean air, and eating healthy. NACCHO’s health and disability and environmental health projects provide numerous tools and resources to help booster local public health practice.