The 2001 tragedy still affects the health of thousands of people in the US, including through many instances of cancer and mental illness.
According to Newsweek, some 5,500 of the 75,000 people enrolled in the World Trade Center Health Program have developed cancer, in some cases developing more than one form of cancer concurrently. Over 70 forms of cancer have been connected to the attacks and their aftermath.
Following the demolition of the World Trade Center, a massive plume of carcinogens in the form of dust particulates was released into the air. The north tower of the twin skyscrapers alone is estimated to have contained some 400 tons of asbestos. Other carcinogens, including mercury and lead contained in office furniture, computers and fluorescent lights, burned, releasing toxic fumes and smoke.
"An environmental emergency such as this, with hundreds, if not thousands, of toxic components simultaneously discharged into the air on the scale of September 11th is unprecedented," one National Resources Defense Council representative said.
According to New York officials, the real extent of the contamination and its side-effects will likely never be known. Chemical contaminants continue to show up at Ground Zero, months after the attacks. Some fallout has been attributed to "strange fires" burning for over 90 days.
Other medical conditions include respiratory problems and mental conditions similar to those of Vietnam- and Iraq-based US war-veterans, primarily post-traumatic stress disorder (PTSD). PTSD can occur after exposure to a significant physical or emotional shock. In addition to disturbing thoughts, feelings, or dreams related to the triggering event, PTSD victims present a high suicide risk.
Newsweek's report quickly sparked alternative explanations, including one floated by James Fetzer, an emeritus at the University of Minnesota, who theorized that one major cancer source could have been a nuclear device.
"We have vast evidence of significant population-with some estimates running as high as 700,000-who have been affected by medical maladies associated with exposure to ionizing radiation," Fetzer told Press TV.
In addition to the nearly 3000 people killed in the attacks on September 11, 2001, an estimated 1140 people died in the aftermath of 9/11, primarily those who were exposed to environmental contaminants at Ground Zero.