Toxic materials are continuing to be released from the smouldering wreckage of the World Trade Center 鈥� some at levels far in excess of national safety levels, according to US government agency reports.
On 11 October, exactly one month after the attack, levels of the carcinogenic compound benzene at one site close to ground zero were 58 times higher than the US Occupational Safety and Health Administration鈥檚 permissible exposure limit. On 2 October, levels of benzene at three spots around the site were 42, 31 and 16 times higher than the OHSA standard.
High levels of dioxins, PCBs, benzene, lead and chromium have also been found. But although some monitoring stations have detected asbestos in the air, very few of the measurements exceeded national safety guidelines.
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The data was collected by the US Environment Protection Agency and contained in reports obtained by the New York Daily News.
鈥淲hat I鈥檝e seen of the data is troubling,鈥� Paul Bartlett, a PCB and dioxin expert at Queens College, New York, told the Daily News.
Smoke plumes
The detection methods used around the site by the EPA have been inadequate, Bartlett says. 鈥淭heir detection limits are aimed at threshold levels for occupational exposure. They aren鈥檛 treating this as a disaster, so they鈥檙e not asking what to extent people are being exposed or who is possibly being affected by the releases of chemicals. They鈥檙e just checking what emissions are exceeding regulations.鈥�
The EPA says that although levels of toxic chemicals and metals at some points around the site are high, they decrease dramatically just a short distance from the smoke plumes.
The long-term effects of relatively short-term exposure to chemicals such as benzene are unclear. But the EPA recommends that all rescue and cleanup workers use respirators 鈥� and most currently do.
However, another report has found that few workers used protective equipment in the immediate aftermath of the attack.
The National Institute of Environmental Health Sciences concluded that almost 1000 injuries at the site might have been prevented if search and rescue teams had worn hardhats and received better basic training.
鈥淰ery few of the workers were wearing even the most basic protective equipment,鈥� said John Moran, who drew up the report.