Authorities face challenges and dangers of clean-up of World Trade Centre

In the aftermath of the collapse of what for some years were the US’s tallest buildings, there is deep uncertainty as to what environmental hazards may face rescue teams and clean-up workers, reports the New York Times.

The remains of the buildings, which are strewn across Lower Manhattan, could provide enough concrete to build a five foot wide sidewalk from New York City to Washington, D.C., sufficient steel to erect more than 20 Eiffel Towers, and the remnants of nearly 14 acres of glass. “No building this high has ever collapsed,” said Eduardo Kausel, a professor of civil engineering at the Massachusetts Institute of Technology. The authorities in charge of the clean-up face problems as basic as where to put all the debris, up to complex issues such as how the heat of a jet-fuel fire might have altered the composition of the building’s components

Although asbestos was reportedly not used in the construction of the buildings in 1972 and 1973, with a spray-on ceramic fire-proofing material being used instead, officials from the Environmental Protection Agency (EPA) have said that testing has revealed elevated asbestos levels in the rubble, possibly from flooring materials or other substances. However, according to EPA Administrator Christie Whitman, the asbestos levels are only of concern to rescue workers and work crews who will be involved day after day directly at the site, and not for residents nearby. Air conditioning and heating systems in nearby buildings will have to be cleaned and tested for pollutants, including asbestos fibres.

There is confusion amongst environmental clean-up experts as to the effect of the intense heat of the fires from the jet fuel, with some saying that it could have produced hazardous dioxins from the incineration of PCBs contained in equipment such as lighting fixtures. Others say that the fires may have acted as a cleansing agent, so hot that they incinerated many hazardous compounds.

Whitman also stated that other chemicals that were of theoretical concern in the hours after the collapse, especially lead, which was legally used in paint in the years of the building’s construction, had not been detected in quantities high enough to raise alarm.

It has not yet been decided where the debris from the sky scrapers will end up, although Whitman stated that the Fresh Kills landfill in Staten Island, where the city’s waste was disposed until early this year, might take most of it for now.

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