Most Ground Zero workers tested for health problems 10 to 11 months after the terrorist attacks still showed lung, throat or mental ailments, according to preliminary findings of Mount Sinai Medical Center's screening program for World Trade Center workers.

More than 3,500 workers of the estimated 30,000 who labored among the ruins have been examined. Findings were based on a random sample of 250 people from the first 500 patients who were seen from July 16, 2002, to August 29, 2002.

The $12 million program has offered free medical screening to anyone who worked at Ground Zero, including volunteers. It is scheduled to conclude in July.

Screening includes pulmonary function tests, blood tests, chest X-rays, psychological questionnaires and general physical exams. If doctors detect problems, patients are referred for treatment not covered by federal funding.