NEW YORK (WABC) -- September 11th is always a day here in Ronny Kirchner's house to remember his hard work as a member of New York City's Bravest 19 years ago.
Kirchner worked alongside so many others on the World Trade Center "pile" for hundreds of hours and painfully unaware of how it could change their lives forever.
Dawn Kirchner, his wife, says she believes that exposure exacerbated his condition.
"I absolutely feel it expedited the onset of it, yes," she said.
Unlike the heartbreaking stories of lives lost from 9/11 illness, Ronny is one much less talked about, and much less understood.
9/11 Timeline: How the September 11 attacks unfolded
He suffers from early onset of dementia - and his family cares for him 24-7.
Researchers fear there are many other first responders at risk for cognitive impairment.
Two recent studies at Stonybrook University used both imaging of the brain and bloodwork to demonstrate that these patients have less brain matter and abnormal proteins in their blood.
The studies were done on first responders over a period of 3 years but what they can't yet prove is that dementia is directly caused by the toxins on the pile.
"It is a growing reason in the next couple of steps to think about why those people might be having these types of problems," Dr. Sean Clouston, Stony Brook Epidemiologist, said.
When looking at the brains of first responders, researchers found their gray matter was thinning making their brain age about 10 years older.
"While there are many reasons for cognitive decline because of brain changes, the loss of gray matter in the brain is one of the most concerning and can be measured by cortical thickness," said Sean Clouston, PhD, lead author and Associate Professor of Family, Population and Preventive Medicine and in the Program in Public Health. "We found a direct correlation between those suffering from cognitive impairment and cortical thickness, indicating a reduction in gray matter of the brain at levels consistent with neurodegenerative disease."
Another study found blood proteins consistent with Alzheimer's in male first responders.
Related: Eyewitness News 11 p.m. newscast from September 11, 2001
"The environmental exposures and psychological pressures experienced by responders during 911 and its aftermath has had an insidious effect on their health and well-being," said Benjamin Luft, MD, Director of the Stony Brook WTC Health and Wellness Program. "Now nearly 20 years post-9/11, clinicians who care for these individuals are seeing more patients who are showing signs of cognitive disorders and possible dementia. Findings from our new studies provide data for the first time that support the idea that this population of patients who have cognitive impairment not only have psychological problems such as PTSD but may be at high-risk for neurodegenerative disorders, a possibility that needs immediate and continued investigation."
The studies were supported by the National Institute for Safety and Occupational Health (NIOSH) and the National Institute on Aging.
CLICK HERE for more Eyewitness News reflections, photos and stories marking the anniversary of 9/11
* More Long Island news
* Send us a news tip
* Download the abc7NY app for breaking news alerts
* Follow us on YouTube
9/11 first responders showing signs of cognitive impairment and dementia, research finds