It's been nearly 16 years since cleanup work officially ended at New York City's ground zero, but the health effects for rescue and recovery workers are still making themselves known.
Two studies published Thursday in the journal JAMA Oncology suggest that the firefighters who came to lower Manhattan after the Sept. 11, 2001, attacks on the World Trade Center face a heightened risk of cancer -- and will continue to do so for years to come.
From the time that airliners flew into the twin towers through the months it took to remove the wreckage, ground zero was replete with substances that are either known or suspected carcinogens.