At 15 John Street, about a half-mile from the World Trade Center site, inspectors continued finding asbestos in July 2002.

In late October 2001, then-Mayor Rudolph W. Giuliani acknowledged that the air sometimes smelled terrible, but said officials had told him it did not pose a health danger.

“Every test that has been done says the air quality was in acceptable limits,” then-Mayor Michael R. Bloomberg said months later.

But a February 2002 memo to top City officials raised concerns about whether New Yorkers were receiving enough information about potential health risks in Lower Manhattan.

The memo detailed then-U.S. Rep. Jerrold Nadler’s concerns about asbestos, indoor air quality and the federal Environmental Protection Agency’s oversight, noting that the City’s Health Department had advised residents to clean buildings with wet mops and rags.