Researchers at the University of Michigan have found a potential link between storing chemicals in attached garages and an increased risk of developing amyotrophic lateral sclerosis (ALS). The study, published in Amyotrophic Lateral Sclerosis and Frontotemporal Degeneration, adds to the growing body of evidence connecting environmental toxins to the development of ALS.
The ALS Exposome
Over the past decade, researchers have been investigating the “ALS exposome,” which refers to the buildup of exposures to environmental toxins that may contribute to the development of the disease. These exposures can come from various sources, including pesticides used in agriculture, volatile organic compounds in the manufacturing industry, and even recreational activities such as woodworking and gardening.
Chemicals Stored in Garages
The latest study from Michigan Medicine focused on the storage of chemicals in residential settings. Investigators surveyed more than 600 participants, both with and without ALS, and found that storing chemicals such as gasoline, lawn care products, pesticides, paint, and woodworking supplies in attached garages was significantly associated with ALS risk.
“Identifying disease-provoking exposures can inform and motivate interventions to reduce exposure, risk and, ultimately, the ALS burden,” said Stephen Goutman, M.D., M.S., the study’s first author and director of the Pranger ALS Clinic at the University of Michigan.
The Airflow Connection
Interestingly, storing chemicals in a detached garage did not show as strong of an association with ALS risk. Researchers believe this may be due to the flow of air and airborne pollutants from attached garages into the living space.
Stuart Batterman, Ph.D., senior author and professor of environmental health science at the U-M School of Public Health, explained, “Especially in colder climates, air in the garage tends to rush into the house when the entry door is opened, and air flows occur more or less continuously through small cracks and openings in walls and floors. Thus, it makes sense that keeping volatile chemicals in an attached garage shows the stronger effect.”
Activities vs. Exposures
The study raises questions about whether it is the activities themselves, such as woodworking and gardening, or the exposures to related products that contribute to ALS risk. “This begs the question: is it the activities that associate with ALS risk or the exposures to related products? This requires further research,” said Goutman.
Building on Previous Research
This study builds upon previous research by the University of Michigan team, which found higher concentrations of pesticides in the blood of people with ALS compared to those without the condition. Another study linked organochlorine pesticides and polychlorinated biphenyls (PCBs) to worsening survival for ALS patients.
Eva Feldman, M.D., Ph.D., senior author and director of the ALS Center of Excellence at U-M, emphasized the importance of these findings: “With each study, we better understand the types of exposures that increase the risk of developing ALS. We now need to build on these discoveries to understand how these exposures increase ALS risk. In parallel, we must continue to advocate to make ALS a reportable disease. Only then we will fully understand the array of exposures that increase disease risk.”
Ongoing Research
Researchers continue to study how environmental exposures contribute to the development of ALS and other neurodegenerative diseases in people with and without a family history of the condition. As more evidence emerges, it may lead to targeted interventions and behavioral modifications that could potentially reduce the risk of developing ALS.
