ANA2022 Presidential Symposium Spotlight: Frances Jensen, MD | Environmental Neurotoxicology

The Exposome: Uncovering the role of environmental neurotoxicants in disease across the lifespan

“Neurologic Dark Matter: Exploring the Exposome that Drives Neurological Disorders,” is the topic of our ANA2022 Presidential Symposium. The Symposium takes place Sunday, October 23, from 1:15 to 3:15 p.m. Register now to attend the Annual Meeting in Chicago!

Environmental contaminants are emerging as a major public health and health equity issue, yet their role in nervous system disorders has been little recognized until recently. The emerging field of environmental neurotoxicology, the subject of this year’s Presidential Symposium, seeks to bridge the gap between neurobiology and public health to understand disease risk and seek new treatments for neurologic disease.

The Presidential Symposium is chaired by ANA President Frances Jensen, MD, Professor and Chair of the Department of Neurology at the Perelman School of Medicine, University of Pennsylvania, and will be co-moderated by Walter J. Koroshetz, MD, Director of the National Institute of Neurological Disorders and Stroke, and Rick Woychik, PhD, Director of the National Institute of Environmental Health Sciences and the National Toxicology Program. We spoke with Dr. Jensen about this crucial emerging field.

What is the exposome, and what are we learning about its effects on neurological health?

Chemical toxicants in the environment have largely been overlooked as factors in the pathogenesis of both neurodevelopmental and neurodegenerative disorders. Yet research is now showing that the brain and nervous system may be one of the most sensitive organ systems to the effects of pollutants, chemical additives, pesticides, heavy metals, and the like—the exposures collectively known as our “exposome.” Across the lifespan, there are specific toxicants in the workplace, in manufacturing, and in the home that can alter your brain and its function, and increase the risk for diseases including dementia, Parkinson’s, ALS, and peripheral nerve disease.

What are some promising developments in the field?

It’s a brand new field right now. While we have an established body of evidence in some cases, we are early in the process of cataloguing neurotoxic environmental contaminants, learning what parts of the nervous system are affected by a given toxicant, the mechanism of action, at what point in the age span people are affected, how much exposure is required to manifest disease, and, perhaps most importantly, whether there are antidotes that can reverse those effects. This emerging field builds on a long history of knowledge about lead, but goes well beyond that: air pollution, nanoplastics—the 20th and 21st centuries have brought new threats to our health and nervous systems that have yet to be examined.

How do the effects of neurotoxic contaminants manifest as a public health threat?

We will provide a couple of examples where there is a clear or suspected link with environmental toxicants contributing to neurological diseases. For example, ALS, where a subgroup of cases are regionally clustered in ways that suggest an environmental influence, and Parkinson’s, where more robust evidence suggests that certain pesticides can increase risk among people who are not otherwise predisposed to develop the disorder.

When you begin to look, you can immediately see that this issue also brings up racial and socioeconomic disparities. For example, exposure to air pollution from highways, contaminants in the soil, lead in building materials, pesticide exposure from low-quality food—all of these may be more prevalent in disadvantaged or lower income communities. With a few exceptions, that hasn’t been discussed much before with regard to neurological health.

Read a recent article on environmental neurotoxicology by Dr. Jensen.