Ground Zero Construction

Construction at Ground Zero; formerly the site of the World Trade Centers destroyed on 9/11/01.

The destruction of the Twin Towers at 9:59 AM and 10:29 AM choked Lower Manhattan with vast dust clouds rising over 1000 feet, each time plunging the surrounding streets into a pitch-black gloom that lasted for minutes. Propelled by the wind, the cloud moved south over Brooklyn and Staten Island, depositing its fallout. Many people in the immediate area, and particularly rescue workers, were subjected to an unknown cocktail of gases and airborne particulates. In the days after September 11 the EPA and OSHA took air samples and reported that they found no excessive levels of asbestos, lead, or volatile organic compounds in the air, except in or around Ground Zero. Contrary to these reports, dust samples taken from surfaces near Ground Zero did show very high levels of asbestos. Significant quantities of asbestos had remained in the Twin Towers despite asbestos abatement programs.

The WTC towers were built from 1968 to 1972. A slurry mixture of asbestos and cement was sprayed on as fireproofing material. But this practice was banned by the New York City Council in 1971. This halted the spraying, but not before hundreds of tons of the material had been applied. Some but not all of it was later removed in an abatement program. Asbestos was also used in other applications that ordinarily do not leave a friable (crumbly) residue, but that can be turned to dust under the extraordinary conditions that existed on Sept. 11. The combustion of building materials and furnishings by jet fuel might also be expected to generate some rather exotic chemicals.