http://www.nytimes.com/2003/04/22/nyregion/22WEAP.html
For more than a month, specially trained National Guard members have been testing for biological agents in New York City hotels, tourist sites, government buildings, office buildings like the World Financial Center, and other places on a list of possible targets, primarily in Midtown and Lower Manhattan, the New York Times reports. They have made repeated visits to as many as 30 sites.The 22-member unit, based in Scotia, N.Y., and is one of 32 Weapons of Mass Destruction Civil Support Teams around the country. It is the only one now testing for unconventional weapons in urban areas. The Pentagon began forming the teams in 1998 to help assess the scope and severity of possible terrorist attacks by testing for unconventional weapons and advising civilian agencies on how best to deal with them.
Tests in many locations for a wide range of biological agents, including smallpox and anthrax, have come back negative since they started on March 19.
Link: http://www.nytimes.com/2003/04/22/nyregion/22WEAP.html