A new study by researchers at Stony Brook University found memory problems in a number of Sept. 11 first responders.

"The study found that first responders with PTSD were at increased risk of cognitive impairment," says Sean Clouston, an assistant professor of public health at the school.

Clouston is part of the research team that discovered the link.

Researchers say that of the 813 first responders they tested,104 had a cognitive impairment and 10 showed signs of possible dementia.

Clouston said the numbers are staggering because the average age of the responders in the study was only 53.

Researchers say if the study's findings are representative of all first responders, up to 5,300 people who responded to the World Trade Center attack may be at risk of cognitive impairment.

More studies are underway to determine if that is the case.

Researchers have known for years that cancers and respiratory problems have afflicted Sept. 11 responders. The names of 600 responders who died from attack-related illnesses are etched on a memorial wall in Nesconset.

John Feal, of the Feal Good Foundation that led the fight for the Zadroga Act to provide Sept. 11 survivors with billions of dollars in relief, says he will now fight to add Stony Brook's new findings to the official coverage.

"This will be another illness that we take to the scientific technical advisory committee, and we force-feed them the numbers, statistics and the facts, and show them these men and women, uniform and non-uniform that are sick from the aftermath of 9/11," he says.