In a recent viewpoint published in JAMA Neurology, neurologists Eva L. Feldman, M.D., Ph.D., and Stephen A. Goutman, M.D., M.S., highlight the environment's critical role in neurodegenerative diseases, calling on state and national leaders, as well as the public, to take action.

Feldman and Goutman, from Michigan Medicine's ALS Center of Excellence and NeuroNetwork for Emerging Therapies, are part of a long standing University of Michigan trend of caring about the environment. Fifty years ago this week, the inaugural Earth Day was held due in part to U-M's legacy of civic engagement.

The two have collaborated with the U-M School of Public Health to show that exposures to environmental pollutants, such as pesticides, flame retardants and manufacturing byproducts, are associated with an increased onset and the progression of ALS. Other neurodegenerative diseases, such as Alzheimer's disease, may also be linked to environmental exposure.

In their publication, the researchers explain that the Midwest, including Michigan, has the highest ALS prevalence in the U.S., and the state's history could be the cause.

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"For generations, our livelihood in Michigan has been a hybrid of agriculture and manufacturing," Feldman says.

"These important industries were unregulated until 1970, when the U.S. government established the Environmental Protection Agency. Over the ensuing years, the EPA has regulated pesticide usage, industrial and toxic waste disposal. However, these materials biodegrade very slowly and therefore still persist in our ground and waterways today. Michigan currently has 67 Superfund sites on the National Priorities List, sites known to contain hazardous environmental pollutants and toxic waste."

Understanding individual susceptibility to environmental toxins is the next step in their research. Currently, Feldman and Goutman are comparing the genes of ALS patients to healthy individuals to understand how genetics determines how a person's health responds to lifestyle, diet and daily environmental exposures. The idea is to understand what makes certain people susceptible to diseases, like ALS, so the lifestyle, diet and environmental triggers can be identified and modified to prevent new cases.

Paper cited: "Voicing the Need for Amyotrophic Lateral Sclerosis Environmental Research," JAMA Neurology. DOI: 10.1001/jamaneurol.2020.0051