9/11 death toll keeps growing decades later as toxic exposure haunts survivors

Those who were present at Ground Zero on Sept. 11, 2001, continue to experience the physical effects of their exposure.

As Lower Manhattan was engulfed in dust and debris from the remnants of both towers, first responders and survivors were forced to breathe in toxic air.

More than 400,000 people were exposed to toxic contaminants, physical-injury risks and stressful conditions in the days, weeks and months following the attacks, according to the World Trade Center Health Program.

SCIENTISTS...