The number of first responders who have died from 9/11-related illnesses now almost equals the number of firefighters who died during the terror attacks themselves.

A total of 341 New York City Fire Department firefighters, paramedics and civilian support staff who died from post-911 illnesses are now memorialized at the FDNY World Trade Center Memorial Wall, according to the Uniformed Firefighters Association.

The memorial commemorates both first responders who died during the attacks and those who died from related illnesses in the years since.

That count almost equals the 343 New York firefighters who died during the 2001 attacks.

The fire department added 43 names to the memorial on September 6, according to a news release.

"As we approach the 22nd anniversary of 9/11, the FDNY continues to feel the impact of that day. Each year, this memorial wall grows as we honor of those who gave their lives in service of others," said Fire Commissioner Laura Kavanagh in the release.

"These brave men and women showed up that day, and in the days and months following the attacks to participate in the rescue and recovery efforts at the World Trade Center site. We will never forget them."

Exposure to the dust at the World Trade Center has been tied to heightened risk of cardiovascular disease among firefighters who responded to the scene. Additionally, respiratory disease and thousands of cancer diagnoses have been linked to the toxic pollutants released during the attacks.

More than 71,000 people are currently enrolled in the World Trade Center Health Registry, a long-term study seeking to understand the physical and mental health effects of the terror attacks. In addition to first responders, the attacks have left lasting health impacts on workers in the World Trade Center who evacuated their workplaces, passersby, residents of the surrounding buildings and volunteers who spent time at Ground Zero in the weeks after.

Lt. Joseph Brosi was one of the dozens of firefighters added to the memorial last week. The FDNY veteran died in February after a long battle with lung cancer.

His son Jim Brosi said not a day has gone by where he has not thought about his father.

"We just miss him," he told CNN. "He was just always present in everything we did."

Joseph Brosi was at Ground Zero on September 11 and continued working there "day in and day out," his son said.

Jim Brosi and his brother, Joe, are also firefighters who worked alongside their father the day the twin towers fell.

Brosi said the number of first responders who died from illness related to attacks "has grown each year and my fear is it will continue to grow."

Asked about concerns regarding the impacts of the attacks on his health, he said, "I monitor my health very closely."

He added: "I will not live my life in worry."