Those tests quickly fed residents’ worries, particularly because management was about to clean the ducts. The tenants, fearing that the work would send pollutants throughout the building, and eager to know what chemicals they may have been exposed to since Sept. 11, urged management to do more testing and cooperate with their consultant.

"It frightened us," said Louis Songster, who lives in the tower with his wife, Miriam. "There’s been no clear analysis of what may or may not be in this building."

Other tenants, like Catherine Davis and her boyfriend, moved out. They moved into another Related building, on the Upper West Side, because otherwise the company wouldn’t release them from their lease. They are paying double their previous rent for a slightly larger apartment, Davis said.

"I was concerned about my health and the landlord is playing hardball with people trying to get out," she said. She believes many have recently left.

Jeff Brodsky, president of Related and a partner in Tribeca Equity Partners, the affiliate that owns Tribeca Tower, said management had done more than 200 ambient air tests, finding no asbestos and no health hazard, and had distributed several written updates to tenants.

"We’ve been extremely responsive and done in excess of what is expected of us," he said. "It’s irresponsible to characterize the building as unsafe or to say that we’re not following appropriate guidelines. It’s fear-mongering."

He said relatively few tenants were complaining and that as many people were moving into Tribeca Tower as were leaving.

Brodsky also said that the asbestos "wipe test" done by the tenants’ consultant is not accepted by the city’s Department of Environmental Protection (DEP) and doesn’t address the health risk because it measures settled dust rather than airborne dust.

Tenants counter that settled dust won’t show up in management’s air tests but can easily be recirculated. And a Dec. 19 report by a scientist at the federal Environmental Protection Agency criticizes the DEP’s standards and says that wipe tests are appropriate to measure indoor dust when there’s not enough to collect for other tests.

Related executives delayed the duct cleaning by a week and met with tenants and the tenants’ consultant. They agreed to changes in cleaning methods that the consultant said were necessary.

The cleaning began on Dec. 27, over some tenants’ continued objections, and a number of them left for a few days. "This whole thing has just been a nightmare," said Nina Lavin, who left with her two pets.

The struggles aren’t over. Air ducts in individual apartments are scheduled to be cleaned this month.