It was only after Hurricane Katrina flooded her New Orleans home that mold toxin expert Joan Bennett started to believe moldy homes could, in fact, make people sick—and only because she witnessed the effects firsthand. Those effects (dizziness, nausea, headache) were actually triggered by the smell of the mold in her home, and that smell was caused by something called microbial volatile organic compounds, or MVOCs.

After embarking on a nearly decades-long study using samples from her own house to learn more about MVOCs and their potential neurological effects, Bennett and a team of colleagues recently published their findings in the Proceedings of the National Academy of Sciences. Long story short, the researchers believe the mushroom alcohol MVOC released by mold may trigger symptoms of Parkinson’s disease. Here’s why:

Working with fellow scientists, Bennett experimented with her house mold samples using ordinary fruit flies. When forced to inhale the aroma released by the mushroom alcohol (comparable to what a human would inhale in a severely moldy home), the flies showed evidence of neurological impairment similar to that displayed by humans with Parkinson’s—tremors, impaired balance, slower movement.

What’s more, the brains of the exposed flies had “significantly fewer dopamine-producing nerve cells,” further proof that the mold odor was doing to the flies what Parkinson’s does to the human brain. And when those flies were given a common Parkinson’s drug called L-dopa? Sure enough, the symptoms resolved.

Although previous studies have made a connection between MVOCs and other health problems including allergies and asthma, the link to neurological effects has not been thoroughly examined. Bennett and her team plan to continue their research and hope to eventually test their findings in mice. She points out, however, that the health risks involved are associated with heavily water-damaged buildings (as from flooding or signficant water damage) and not from trace amounts of mold.