As we remember the tragedy of Sept. 11, research continues to emerge on health implications of the events that day.
One recent study indicates responding firefighters have an increased risk of developing cardiovascular disease.
Researchers studied 9,796 male New York City firefighters who responded to the World Trade Center attack.
They looked at arrival time and how long they worked at the site.
Firefighters were followed for 16 years to see if they developed cardiovascular disease.
Results show firefighters who arrived at the site on the morning of the attacks and worked on the site for at least six months had a higher risk for cardiovascular disease, compared to those who arrived later and worked less time at the site.
Cleveland Clinic cardiologist Dr. Luke Laffin was not involved in the research but said the results aren't surprising.
"Knowing what we know about the acute exposure to compounds and dust, that may cause some degree of inflammation, chronic inflammation as well," he said. "And we know inflammation plays a major role in the genesis of cardiovascular disease."
Laffin said long-term health monitoring is important for first responders in any major disaster.
"Natural disasters or man-made disasters, we need to be cognizant of the long term cardiovascular risks and follow these individuals more closely," he said.
Complete results of the study can be found online in JAMA Network Open.