With timely focus, neurologists and neuroscientists are paying serious attention to the role of environmental exposures — air pollution, pesticides, microplastics, and more — in diseases like dementia and developmental disorders. The Presidential Symposium at the American Neurological Association’s 2022 Annual Meeting (ANA2022) in Chicago will shine a spotlight on this rapidly developing field. The symposium, “Neurologic Dark Matter: Exploring the Exposome that Drives Neurological Disorders,” takes place Saturday, October 23, 1:15–3:15 p.m. CDT and is co-moderated by the heads of the ANA, the National Institute of Environmental Health Sciences, and the National Institute of Neurological Disorders and Stroke.
Research on diseases like asthma and cancer has long shown inextricable environmental links, but with the exception of lead exposure, brain science has paid only peripheral attention to the role of our many chemical exposures in disease. “We’ve really overlooked some of the contaminants in our environment,” says Symposium Chair Frances E. Jensen, MD, FANA, president of the American Neurological Association and chair of the Department of Neurology at the University of Pennsylvania’s Perelman School of Medicine. “This is a wake-up call. The Symposium will discuss the astronomical rise in Parkinson’s disease, for example, that can’t fully be explained by genetics or the aging population. Environmental exposures are lurking in the background, and they’re rising.”
“We are hitting the ceiling of what can be explained by genetics,” says Walter J. Koroshetz, MD, director of the National Institute of Neurological Disorders and Stroke and co-moderator of the ANA symposium. “What’s the rest of it? We call it the exposome — and the ways in which a panoply of exposures over the lifetime interact with our genes to cause neurologic diseases.”
Exposomics, the study of human chemical exposures and their effects, has started to take off among neurologists and neuroscientists in the past few years, spurred in part by a session convened in 2020 by the National Academies of Sciences, Engineering, and Medicine. The workshop noted that there are more than 80,000 toxic chemicals humans may encounter in the environment — so many that it is nearly impossible to determine their individual effects on a person, let alone how they may interact. This may especially be an issue for economically marginalized groups who are exposed to more toxicants through unsafe housing, jobs involving dangerous chemicals without proper precautions, urban and industrial pollution, and more. But chemical exposures at different levels are common to most people, and our genetic makeup may determine how susceptible we are to effects that lead to neurologic disease.
“Gene-environment effects are critically important,” says Rick Woychik, PhD, director of the National Institute of Environmental Health Sciences and the symposium’s other co-moderator. “It’s not just about pesticides. PFAS chemicals are ubiquitous in the environment, as are nanoplastics. And there are trillions of dollars’ worth of demand for nanomaterials, but it’s sobering how little we know about their toxicology.”
Research presentations at the ANA2022 Presidential Symposium will include:
Deborah A. Cory-Slechta, PhD, University of Rochester: “Chemical Exposures: The Ignored Environmental Risk Factor(s) for Neurodegenerative Diseases and Neurodevelopmental Disorders.”
Devon Payne-Sturges, DrPh, University of Maryland: “Racial Disparities in Exposures to Environmental Contaminants.”
Eva Feldman, MD, PhD, University of Michigan: “Leveraging the Exposome for ALS Prevention.”
Timothy Greenamyre, MD, PhD, FANA, University of Pittsburgh: “Convergent Mechanisms of Environmental Toxicant-Induced Parkinson’s Disease.”
Ray Dorsey, MD, FANA, University of Rochester: “Is the Rise in Incidence of Parkinson’s Largely Human-Made?”
A panel discussion at the end of the symposium will discuss key highlights as well as how physicians and scientists might respond to environmental exposure threats.
“Physicians have to ask their patients, ‘Where do you work?’” says Woychik. “If you’re a farmer, for example, what is it that you’re spraying on your crops?” For certain conditions where a strong role is emerging for environmental exposures — such as intellectual disability acquired early in life, or the neurodegenerative diseases ALS, Parkinson’s, and Alzheimer’s—knowing a person’s genetic risk combined with their chemical risks may help them take better precautions. “Part of the challenge may be to develop tools — for example, wearable devices to monitor exposures in farmers as they spray their fields, similar to what we already have for radiation,” Woychik says. And if a person presents with the disease, combined genetic and exposomic information may result in different treatment paths.
On the other hand, notes Jensen, “A lot of this is not about what a doctor can do for their patient anymore. We also need to rely on the non-medical parts of the community to treat neurological disease. It requires a lot of advocacy, educating the public, making some big changes in our society.” (SM/Newswise)
