Study shows increased signs of dementia in 9/11 first responders

New research is giving a deeper look into how dust and debris from the fallen World Trade Center may play a role in the brain health of first responders. 

In the study, published Wednesday in JAMA Network Open, researchers at Stony Brook University in New York found severe exposure to building debris was significantly associated with a higher risk of dementia before age 65 versus those who weren't exposed or who wore personalized protective equipment such as masks or hazmat suits. 

The findings, which used data from 5,010 responders who were part of the Stony Brook WTC Health and Wellness Program, were consistent even after adjusting for demographic, medical and social factors.

Sean Clouston, one of the study's authors, told CBS News the most surprising thing about the findings were "how common the outcome seems to be already," given responders' relatively young ages. The median age of participants at the beginning of the study was 53.

"Dementia is a concern mostly for people in their 70s or 80s. Here, we found that rates were very high," he said.

This study builds on previous research from the Stony Brook team. In a 2022 study, the researchers found 9/11 first responders show signs of cognitive impairment at roughly three times the rate of the general population.

The latest study, however, is the first to "show an association between exposure and dementia, and to show that PPE might have helped mitigate the exposures," Clouston said.

While the exact mechanism is unknown, he said, the literature shows "very fine particles and chemicals" in the air at the World Trade Center were "neurotoxic and can pass through the blood brain barrier to affect the brain."

An estimated 400,000 people were exposed to toxic contaminants, risk of physical injury and physical and emotional stress in the days to months following the attacks, according to the Centers for Disease Control and Prevention. 

Dr. Benjamin Luft, co-author and director of the Stony Brook WTC Health and Wellness Program, believes research on the cognitive health of responders must continue.

"These findings are a major step forward in establishing that the dust and toxins which were released as a result of the calamitous terrorist attacks on 9/11 continue to have devastating consequences on the responders," Luft, who has been evaluating these responders for 20 years, said in a news release. "The full extent of neurodegenerative disease still needs to be determined."

Many responders now also suffer from mental illnesses including PTSD, and others have died from an array of cancers, chronic inflammatory lung disease and lung disease.

The air quality responders were exposed to at the World Trade Center was more severe than bad air quality we experience daily, Stefania Forner, a director of medical and scientific relations at the Alzheimer's Association, told CBS News.

"It included a wide range of hazardous materials," she said. Still, air pollution and dementia are both global public health crises, Forner said. 

"It's known that air pollution is bad for the health of our brains and our overall health, and may be associated with amyloid buildup in the brain and higher risk of cognitive decline," she said.

Clouston hopes the latest research will also have implications for how others can respond in the aftermath of an "uncontrolled disaster where consumer goods and buildings collapse or are burned."

Such exposures could include terrorist attacks, he said, but could also include natural disasters like wildfires.

"We should assume that the air is unsafe to breathe and act accordingly," he said. 

There is good news, he said: "Wearing PPE seemed to help."

In:
• Dementia
• World Trade Center
• 9/11
• New York

Sara Moniuszko

Sara Moniuszko is a health and lifestyle reporter at CBSNews.com. Previously, she wrote for USA Today, where she was selected to help launch the newspaper's wellness vertical. She now covers breaking and trending news for CBS News' HealthWatch.

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