Legal efforts are now under way to identify which of the thousands of workers with respiratory injuries stemming from their efforts at ground zero following the terrorist attacks of September 11, 2001, can proceed with lawsuits against the city.

In November, the federal judge overseeing all September 11-related cases, U.S. District Court Judge Alvin Hellerstein of Manhattan, wrote a series of questions that grant criteria for a plaintiff on the basis of his or her involvement at or around ground zero. The questions included details about the worker’s duties, liability, alleged injuries, and employment and health history, according to court documents.

At a hearing yesterday in U.S. District Court in Manhattan, Judge Hellerstein said attorneys must now systematically file answers to the questions for each plaintiff.

There are about 10,000 total respiratory injury-related individual lawsuits, he said.

Attorneys for each side must produce this core discovery for the first 1,000 cases within the next 60 days, and 2,000 cases for the each 30-day period thereafter until each case is completed, Judge Hellerstein said.

When the attorney for the plaintiffs, Paul Napoli, and the attorney representing the city, James Tyrrell, separately voiced concerns about finding the accuracy of specific details within that short time period, Judge Hellerstein said he was more interested in receiving basic information and not specifics about the plaintiffs’ activities in September 2001.