Ground Zero exposure: Retired NYPD officer survives cancer linked to 9/11 toxins

TAMPA, Fla. - A retired NYPD officer who responded to Ground Zero was diagnosed with a form of cancer that's being linked to toxic exposure.

Ground Zero exposure cancer link

What we know:

Mike Hennessy, who worked for the NYPD for 20 years, responded to the 9/11 attack on the World Trade Center.

"It ranks as the top horrific moment in my life," he said.

Hennessy and his fellow officers ran towards the chaos as the second tower collapsed. He says tens of thousands of people were running away from the site of the collapse.

"It was like an apocalypse," Hennessy said. "It was just incredible because there was so much dust in the air. More eerie was the haunting of the firemen's, they wore beepers. And that whole pile of metal was just hundreds of beeps going off."

He spent three months sifting through metal and dust at Ground Zero with other first responders.

"We'd just tie towels around our faces and did the best we could.," Hennessy said. "But unfortunately, there was just nothing, nobody survived it."

Those memories never faded, and Hennessy carried the mental load of this day for decades.

It wasn't until the beginning of this year that he faced a different health battle.

"You kind of just live your life and everything's fine and dandy until one day, you know, for me, my cancer was salivary gland cancer," he said. "I wound up with a lump in my neck."

Hennessy was diagnosed with aggressive salivary gland cancer after discovering the lump in his neck. Doctors believe the cancer is connected to the months he spent at Ground Zero.

"They were breathing all this stuff that's in the air, the carcinogens, the chemicals, all the heavy metals, etc.," Dr. Lary Robinson, a thoracic surgeon at Moffitt Cancer Center said.

Hennessy had surgery earlier this year to remove the lump, followed by six weeks of radiation at Moffitt Cancer Center.

He says he received a clean scan last week.

Long-term health impact on survivors

What we don't know:

Doctors say it's hard to know how many first responders have developed health issues related to their toxic exposure on and after 9/11.

"I think the respiratory problems that we see early on, and the cancers, I think, will start to kind of creep up," Robinson said.

Robinson says it can take at least 25 years to see the damage these carcinogens have done.

"The cancers, probably it'll be a little bit longer before we actually know what the extent of that is, because there's such a long latency period between exposure to environmental allergens, carcinogens, and so on until it shows up," he said. "For example, asbestos exposure with mesothelioma. Usually it's at least 25 to more, 30 years at least before it starts to show up."