Exposure to World Trade Center Dust May Impact Cognitive Health
Michelle Milliken
It's been more than 20 years since the September 11 terror attacks on the World Trade Center. The first responders who helped at the scene have developed many health issues related to their service, including some cancers, musculoskeletal disorders, and airway and digestive disorders. As these first responders age, there are questions about possible heightened risks for cognitive issues. A new study aimed to investigate this.
Researchers at Mount Sinai's Icahn School of Medicine recently studied the impact of World Trade Center particulate matter (WTCPM) on the cognitive health of mice. The team says there's past research supporting the idea that 9/11 first responders are at a higher risk of certain brain health issues, and they wanted to study this further.
Dr. Ruth Iban-Arias, the study's first author and postdoctoral fellow in the Department of Neurology at Icahn, says, "Based on epidemiological and preliminary data, we hypothesized that first responders repeatedly exposed to Ground Zero dusts in the first week post-disaster were placed at greater risk of age-related neurological conditions like Alzheimer’s disease and Alzheimer’s disease-related dementias due to changes in blood-brain barrier permeability, and/or neuro-immune interactions."
To conduct their study, the researchers inserted WTCPM dust into the noses of two groups of mice, one group genetically engineered to develop Alzheimer's and the other wild-type mice that served as controls. The dust had been collected at Ground Zero within three days of the attacks, and the mice were exposed for a period of as little as three days or up to three weeks. This was to reflect the amount of air level exposures experienced by first responders. Researchers then tested the animals' memory and learning through a maze and conducted object recognition tests involving familiar and unfamiliar objects.
According to the team's findings, published in the Journal of Alzheimer's Disease, both groups of mice demonstrated a 10% decrease in working memory following the dust exposure. Those who had high exposure were the only ones that showed significant impairment compared to those that had not been exposed. The mice genetically engineered to develop Alzheimer's who had a high exposure also showed a 16% short-term preference to investigate a familiar object rather than a new one, and a 30% preference to do so long term. The team says this is a sign of memory alteration, as cognitively healthy mice tend to spend more time with a new object, so spending similar time with both objects indicates the animal doesn't remember what it had been exposed to before.
The team also examined the blood and hippocampus of the mice, discovering gene changes related to immune-inflammatory responses, including the neuroinflammatory profile in the brain, and blood-brain barrier disruption.
The hope is that these findings help better understand cognitive health challenges that may be coming for 9/11 first responders in the coming years.
Dr. Giulio Maria Pasinetti, senior author and Program Director for the Mount Sinai Center for Molecular Integrative Neuroresilience, says, "While we should cautiously interpret the outcomes of these preclinical studies and further investigation in the clinical setting is needed, our study provides valuable information relevant to the health of first responders. The data opens a new horizon for investigations to further understand the impact that acute exposure to WTCPM dust has on the accelerated onset of Alzheimer’s and related dementias in first responders who are now reaching older age."
Currently the team is working on studying the impact of WTCPM dust on mice with the APOE4 gene, which carries an elevated risk of developing Alzheimer's. The hope is that their research will help with preventive screening and maybe treatments for first responders who have a genetic predisposition to the disease.
