Seventy percent of workers who spent time cleaning up after the 9/11 attacks are now afflicted with lung problems, according to a study released Tuesday by Mount Sinai Medical Center. The study results show the attacks left many first responders with severe and long-term health ailments. Researchers found a third of workers enrolled in the study registered abnormal lung test results. The same study revealed that 61 percent of first responders who had no lung problems at the time of the attacks now do. Doctors believe breathing in asbestos, pulverized concrete, mercury and other toxins are likely behind some of the first responders? health issues.