(Sacramento, CA) — A study, conducted in California, finds that exposure to wildfire smoke leads to a higher risk of someone being diagnosed with dementia. The study was released Monday, at the Alzheimer’s Association International Conference. Researchers believe toxic chemicals found in wildfire smoke and fine particulate matter, also called PM2.5, are damaging to the brain.

The study says the risk of dementia diagnosis from wildfire smoke is higher than from exposure to other sources of air pollution that also contain PM2.5. During a period of ten years, researchers looked at the health records of more than one-point-two-million socioeconomically diverse Kaiser Permanente members. All of them were at least 60-years-old with no prior diagnosis of dementia.