Summary: A new study reveals a possible link between storing chemicals in home garages and an increased risk of developing amyotrophic lateral sclerosis (ALS). Researchers identified significant associations between ALS risk and the residential storage of volatile chemicals such as pesticides, gasoline, and paint.
The study’s findings underscore the importance of the “ALS exposome”—a concept describing the cumulative exposure to environmental toxins linked to ALS. Insights from the study suggest interventions to minimize exposure and potentially reduce ALS risk by modifying storage practices in homes.
Key Facts:
- The study surveyed over 600 participants and found that storing volatile chemicals in attached garages was significantly associated with ALS risk.
- Chemicals linked to ALS included gasoline, lawn care products, and woodworking supplies, with most participants reporting storage in attached garages.
- Airflow from attached garages into living spaces may explain the heightened risk, pointing to the need for building codes that minimize such exposures.
Source: University of Michigan
Over the last decade, researchers at University of Michigan continue to find that exposure to environmental toxins — from pesticides used in agriculture to volatile organic compounds in the manufacturing industry — is linked to the development of amyotrophic lateral sclerosis, or ALS.
The buildup of exposures, which researchers call the ALS exposome, is possibly associated with recreational activities such as woodworking and gardening.
Now, a Michigan Medicine study finds that storing chemicals in a garage at home may associate with an increased risk of ALS.
The results are published in Amyotrophic Lateral Sclerosis and Frontotemporal Degeneration.
“Identifying disease-provoking exposures can inform and motivate interventions to reduce exposure, risk and, ultimately, the ALS burden,” said first author Stephen Goutman, M.D., M.S., director of the Pranger ALS Clinic and associate director of the ALS Center of Excellence at University of Michigan.
“Exposures in the home setting are an important part of the ALS exposome, as it is one place where behavior modifications could possibly lessen ALS risk.”
Storage containing volatile chemicals in garages is extremely common, whether it’s in a car or motorcycle, equipment like a chainsaw, or solvents, cleaners, paints and other items.
Investigators assessed exposures in the residential setting from a survey of more than 600 participants both with and without ALS. Through statistical analysis, they found that the storage of chemicals — including gasoline and gasoline powered equipment, lawn care products, pesticides, paint and woodworking supplies — were significantly associated with ALS risk.
All of the reported chemicals linked to disease development were volatile with toxic components. Most participants reported storing several of the items in their attached garage.
Storing chemicals in a detached garage, however, did not show as strong of an association with risk.
Researchers say the flow of air and airborne pollutants from attached garages to the living space may explain the finding.
“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,” said Stuart Batterman, Ph.D., senior author and professor of environmental health science at the U-M School of Public Health.
“Thus, it makes sense that keeping volatile chemicals in an attached garage shows the stronger effect.”
The latest building codes, Batterman notes, tackle this problem by specifying measures to reduce or eliminate these air flows.
“We are beginning to see risk factors across multiple settings that may associate with a greater ALS risk; we also see some relationships across the studies, for example, woodworking and woodworking supplies and gardening and lawn care supplies,” Goutman said.
“This begs the question: is it the activities that associate with ALS risk or the exposures to related products? This requires further research.”
In 2016, the research team found that people with ALS had higher concentrations of pesticides in their blood compared to people without the condition.
A subsequent study published in 2019 linked organochlorine pesticides and polychlorinated biphenyls, or PCBS, to worsening survival for ALS.
“With each study, we better understand the types of exposures that increase the risk of developing ALS,” said senior author Eva Feldman, M.D., Ph.D., director of the ALS Center of Excellence at U-M and James W. Albers Distinguished University Professor at U-M.
“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.”
Studies to understand how environmental exposures contribute to the development of ALS and other neurodegenerative diseases, both of people with and without family history of the condition, are underway.
Additional authors: Include Jonathan Boss, Ph.D., Dae Gyu Jang, Ph.D., Caroline Piecuch, Hasan Farid, Madeleine Batra, Bhramar Mukherjee, Ph.D all of University of Michigan.
Funding: This study was supported by the National Institutes of Health, The National ALS Registry/CDC/ATSDR, the ALS Association, the NeuroNetwork for Emerging Therapies, the Robert and Katherine Jacobs Environmental Health Initiative, the NeuroNetwork Therapeutic Discovery Fund, the Peter R. Clark Fund for ALS Research, the Sinai Medical Staff Foundation, Scott L. Pranger, and the University of Michigan.
About this ALS research news
Author: Noah Fromson
Source: University of Michigan
Contact: Noah Fromson – University of Michigan
Image: The image is credited to Neuroscience News
Original Research: Closed access.
“Residential exposure associations with ALS risk, survival, and phenotype: a Michigan-based case-control study” by Stephen Goutman et al. Amyotrophic Lateral Sclerosis and Frontotemporal Degeneration
Abstract
Residential exposure associations with ALS risk, survival, and phenotype: a Michigan-based case-control study
Background: Environmental exposures impact amyotrophic lateral sclerosis (ALS) risk and progression, a fatal and progressive neurodegenerative disease. Better characterization of these exposures is needed to decrease disease burden.
Objective: To identify exposures in the residential setting that associate with ALS risk, survival, and onset segment.
Methods: ALS and control participants recruited from University of Michigan completed a survey that ascertained exposure risks in the residential setting. ALS risk was assessed using logistic regression models followed by latent profile analysis to consider exposure profiles. A case-only analysis considered the contribution of the residential exposure variables via a Cox proportional hazards model for survival outcomes and multinomial logistic regression for onset segment, a polytomous outcome.
Results: This study included 367 ALS and 255 control participants. Twelve residential variables were associated with ALS risk after correcting for multiple comparison testing, with storage in an attached garage of chemical products including gasoline or kerosene (odds ratio (OR) = 1.14, padjusted < 0.001), gasoline-powered equipment (OR = 1.16, padjusted < 0.001), and lawn care products (OR = 1.15, padjusted < 0.001) representing the top three risk factors sorted by adjusted.
Latent profile analysis indicated that storage of these chemical products in both attached and detached garages increased ALS risk. Although residential variables were not associated with poorer ALS survival following multiple testing corrections, storing pesticides, lawn care products, and woodworking supplies in the home were associated with shorter ALS survival using nominal p values. No exposures were associated with ALS onset segment.
Conclusion: Residential exposures may be important modifiable components of the ALS susceptibility and prognosis exposome.
