In recent years, a growing body of evidence has suggested that air pollution exposure is linked to neurodegenerative diseases including dementia, Alzheimer's, Parkinson's, and amyotrophic lateral sclerosis (ALS).
In 2016, researchers found that ALS patients had unusually high levels of pesticides in their blood. Further research revealed that organic pollutants can accelerate the progression of ALS and cause worse outcomes for patients. Now a new effort by this research group has outlined an environmental risk score that characterizes a person's risk of developing ALS and how severe their case may be based on their pollutant exposure level. The work has been reported in the Journal of Neurology, Neurosurgery and Psychiatry.
"For the first time, we have a means [of] collecting a tube of blood and looking at a person's risk for ALS based on being exposed to scores of toxins in the environment," said first study author Stephen Goutman, MD, MS, director of the Pranger ALS Clinic, among other appointments.
In this study, the investigators collected blood samples from more than 250 Michigan residents, some of whom have ALS. The level of exposure to 36 persistent organic pollutants was then correlated with individual ALS risk and survival. This revealed several pollutants that have a significant connection to the risk of developing ALS. The strongest connection to ALS came from a pesticide mixture in the blood.
People who had the highest levels of exposure to this mix of pesticides were twice as likely to get ALS compared to individuals with the lowest level of exposure.
"Our results emphasize the importance of understanding the breadth of environmental pollution and its effects on ALS and other diseases," noted senior study author Professor Eva Feldman, MD, PhD, director of the NeuroNetwork for Emerging Therapies at Michigan Medicine, among other appointments.
Assessing levels of environmental pollutants in blood samples may one day help clinicians understand who is at risk for certain diseases, and how to prevent those problems. "Environmental risk scores have been robustly associated with other diseases, including cancers, especially when coupled with genetic risk. This is a burgeoning application that should be further studied as we deal with the consequences of pollutants being detected throughout the globe," said Feldman.
Sources: University of Michigan, Journal of Neurology, Neurosurgery and Psychiatry
