Brad Racette, MD, FAAN, the Kemper and Ethel Marley Chair for Neurology at Barrow Neurological Institute, discussed his keynote lecture on the neurologic health effects of electric vehicles and the global implications of environmental exposure.

The 2025 Baptist Health Neuroscience Symposium is a two-day event from November 6-7th highlighting emerging science and clinical insights across neurology subspecialties. The keynote lecture, focused on the neurologic health effects of electric vehicles, will be given by Brad Racette, MD. The annual symposium gathers experts from across the field to explore timely intersections between technology, environment, and neurological health, offering clinicians new perspectives on how modern innovation can both reduce and redistribute global health risks.

Racette, who serves as the Kemper and Ethel Marley Chair for Neurology at Barrow Neurological Institute, has spent more than two decades investigating environmental risk factors for Parkinson disease (PD). His work began with studies on manganese exposure and has expanded to address broader questions surrounding air pollution, industrial toxins, and environmental inequality. Through this long-standing research, Racette has become a leading voice in understanding how environmental change influences neurological disease worldwide.

In this discussion with NeurologyLive®, Racette outlined the central themes of his keynote, emphasizing the dual narrative of progress and consequence as the world transitions to electric vehicles. He explored the environmental trade-offs behind this shift, the neurological implications of metal extraction and pollution, and the ethical challenges of shifting environmental burdens from industrialized nations to the global south.

NeurologyLive®: Discuss more about your presentation itself, what you’re planning to talk about, and why this was a topic of interest for you.

Brad Racette, MD: I’ve spent the last 25 years studying environmental risk factors for Parkinson disease, with much of that work focused on environmental manganese exposure. Manganese is a neurotoxic metal that neurologists recognize as a basal ganglia neurotoxicant, causing a syndrome known as manganism, which produces Parkinson symptoms, dystonia, and cognitive impairment. Over the years, my research has expanded to better understand the broader effects of environmental pollution on Parkinson’s disease risk. It’s not just about manganese as a neurotoxicant, but also about particulate matter in the air generated from automobiles, trucks, and other combustion processes.

Our interest evolved from studying occupational exposures to examining environmental pollutants more broadly, including solvents, pesticides, and toxins that have not yet been deeply studied in relation to Parkinson disease. We began with occupational settings to understand workplace risks, but our work now heavily focuses on environmental health and the effects of air pollution on people simply living in polluted areas. This work has become global, spanning the United States and South Africa, and has generated particular interest in how our efforts to mitigate air pollution in developed regions are impacting the global south. Understanding how environmental burdens shift from one part of the world to another has become a strong area of focus in our research.

From your perspective, how much does the public understand about the neurological effects of electric vehicles, and how can we continue to raise awareness?

My presentation focuses on the give and take between air pollution generated by combustion engines and the downstream effects of shifting to electric vehicles, which create a new set of environmental health burdens that we have to consider. The public generally understands that driving SUVs or other combustion-engine vehicles generates air pollution, and that this pollution affects health. In the medical community, it is well known that air pollution contributes to heart disease, lung disease, and respiratory infections. Increasingly, we’re recognizing that air pollution also contributes to diseases such as Alzheimer’s disease, and we recently published a study showing its effect on Parkinson’s disease, supported by similar findings from others.

As that body of research grows, public awareness of the connection between air quality and neurological health is improving. But what’s less understood—by both the public and physicians—is that while electric vehicles themselves do not emit combustion products, the production process behind them carries substantial environmental consequences. Manufacturing these vehicles requires mining and refining metals to create the large batteries that power them, and this activity largely occurs outside the United States. Although there is an effort to bring some of that production domestically, few communities would welcome large-scale mining nearby.

As a result, the environmental burden of metal production is shifted to the global south. Electric vehicles are primarily used in wealthier regions such as North America and Europe, with the exception of China. Yet, the mining and refining of metals like cobalt, copper, and manganese are concentrated in regions such as the Democratic Republic of Congo, India, and South Africa. Many of these operations take place under unsafe and unethical conditions, including child labor and toxic exposures.

For example, we are developing a research project in Zambia, where workers have been poisoned at a manganese battery facility, showing a clinical syndrome that hasn’t been seen for 75 years. These are serious, real-world examples of how the shift from combustion engines to electric vehicles has global neurological implications. Beyond production, we also have to consider what happens at the end of these vehicles’ lifespans. A single large electric truck, for instance, contains an enormous battery that poses recycling and disposal challenges. If the United States were to shift entirely to electric vehicles, we would face an enormous environmental health burden related to battery recycling and waste management. The public remains largely unaware of these downstream consequences, which are critical to understanding whether this shift is truly a net positive for global health.

From a research perspective, where do we still need to direct more attention, and what areas remain under-explored?

In Parkinson research, we’ve invested heavily in understanding genetic risk factors. This work has been productive because identifying single-gene mutations in large families is relatively straightforward, and genetic technologies have advanced quickly. As a result, we now know dozens of genetic risk factors for Parkinson’s disease. However, those genetic factors only explain about 10 to 20 percent of cases. The remaining 80 percent likely result from complex interactions between genetics, environmental exposures, and other influences across a person’s lifetime.

Despite this, there has been only modest investment from the NIH and other agencies in studying environmental risk factors for neurodegenerative diseases. It’s easier to pursue genetic studies, which are more controlled and yield faster, clearer answers. Studying environmental exposures is more difficult because we often don’t know the critical window in which an exposure occurs. By the time a patient develops Parkinson’s, typically around age 60 or 65, the relevant exposure may have happened decades earlier. We currently have limited tools to estimate lifetime environmental exposure, and that uncertainty makes research in this area challenging.

We and others have had some success examining exposures that occurred 5 to 15 years prior to diagnosis, but even then, the data contain uncertainty that can bias results toward finding no association. Another challenge is that Parkinson disease is unlikely to be caused by a single pollutant. Unlike mesothelioma, which is almost entirely caused by asbestos exposure, Parkinson likely results from a combination of pollutants interacting with genetic susceptibility and lifestyle factors. For example, particulate matter exposure may increase risk when combined with smoking or other conditions.

We have not yet fully studied the complexity of the exposome—the totality of environmental exposures across a person’s life—in relation to neurodegenerative disease. It’s a difficult and expensive challenge, but one we need to address to understand how these environmental factors truly shape neurological health.

Any final comments or messages you’d like to share about your presentation and its broader implications?

The key question I hope people take away from this presentation is, what is the impact of shifting our environmental burden from the global north to the global south? We may reduce air pollution and improve health in developed countries, but we are simultaneously increasing toxic exposure risks for populations in lower-income regions. This creates an imbalanced equation where health gains in one part of the world come at the expense of another. As we continue to promote cleaner technologies like electric vehicles, we must also confront the ethical and public health implications of where and how these technologies are produced.

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