After the 9/11 attacks, Glenn Garamella spent months at Ground Zero, helping families who lost loved ones from the New York City Police Department. He worked around-the-clock as an employee relations manager.
"It was a difficult job but it felt meaningful that we were assisting them," he told CBS News' Marlie Hall.
Since then, Garamella -- like many survivors and first responders and other workers -- has contended with serious, chronic diseases. Garamella, now 61, has asthma and sleep apnea and was treated for cancer. He has also grappled with post-traumatic stress disorder and depression.
"People didn't realize how dangerous the air was," he said. "The coughing got much worse. I was really having a tough time of it. Eventually they found out I had throat cancer."
It's estimated that as many as 90,000 people were exposed to potential dangerous debris and toxins at the World Trade Center site. Currently, more than 60,000 people are in programs to monitor their health.
Dr. Michael Crane runs the World Trade Center Health Program at Mount Sinai Hospital in New York City. "To this day, we really don't know everything that was in that dust cloud," he told CBS News. "Certainly we are going to see more cancer."
Though cancer can take years or even decades to develop, there are a number of studies that find exposure to the site is associated with the disease. The New York City Fire Department estimates as many as 9,000 firefighters are at higher risk for cancer. The World Trade Center Health Registry has already identified a slight increase in prostate and thyroid cancer diagnoses, as well as certain blood cancers among rescue workers and clean-up crew. However, the same increase was not found among residents of Lower Manhattan.
So far, health officials say there have been around 2,000 cancer diagnoses related to 9/11.
Several studies have also found a high incidence of sarcoidosis among rescue, recovery and clean-up workers, an inflammation that can affect any organ, but typically affects the lungs.
And PTSD remains a persistent problem. A number of large studies conducted by New York City's Department of Health and Mental Hygiene looked at the vast impact the events had on the population. The agency estimates that up to 20 percent of people present during the attacks experienced PTSD, which is approximately four times more than what is typically seen in the general population.
Acute injury from 9/11 has also been associated with an increased risk for chronic health problems. A study published earlier this month analyzed data from the World Trade Center Health Registry, and identified 14,087 people who were present during the attacks or spent time on the site shortly after; none of the people were known to have preexisting chronic conditions before 2002. Of that number, 1,980 people reported sustaining one or more acute injuries, such as a serious burn or broken bones. The survey data was used to estimate the probability of developing chronic health conditions in the future.
The researchers found people who had more than one acute injury from the attacks, as well as PTSD, were 3 times more at risk for developing heart disease later in life than people who did not sustain multiple injuries and did not have PTSD. Additionally, people who had no physical injuries but later developed PTSD had twice the risk for developing respiratory illness.
For his part, Garamella stresses the importance of seeking out help as soon as possible, even though facing these serious illnesses is scary. "We owe it to ourselves and to our families to get checked," he said. "Don't put your head in the sand. These things don't go away; they only get worse."