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EPA Releases Study that Shows Recommended Methods for Cleaning World Trade Center Dust Work

Release Date: 06/04/2003
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(#03064) New York, New York -- The U.S. Environmental Protection Agency (EPA) today released the results of a study confirming that cleaning methods used by residents and professionals in lower Manhattan in the aftermath of the World Trade Center collapse are effective. In its Confirmation Cleaning Study, the Agency tested a variety of cleaning methods in a heavily impacted building near Ground Zero. The Agency also released its study of levels of pollution in homes not impacted by the collapse. Both studies were funded by the Federal Emergency Management Agency and conducted in cooperation with New York City.

EPA conducted its Confirmation Cleaning Study to determine the adequacy of various methods that were used by residents and professional cleaning companies to clean World Trade Center (WTC) dust in residential spaces in lower Manhattan. For its study, EPA used a five-story, mixed use building containing thirteen apartments and five commercial spaces located at 110 Liberty Street. The apartments and businesses in this building had varying amounts of dust and debris present after the World Trade Center collapse. EPA tested the effectiveness of several different cleaning techniques, including using high efficiency particulate air (HEPA) filtered vacuums, mops and wet cloths. In addition, the Agency cleaned carpets and cleaned air ducts using standard methods. Before and after cleaning, EPA tested for lead, dioxin, polycyclic aromatic hydrocarbons (PAHs), man-made vitreous fibers (fibrous glass) and crystalline silica and tested the air for asbestos. The study found that the cleaning methods all reduced concentrations of WTC-related contaminants to levels below health-based benchmarks. In some cases, repeated cleaning was necessary. The results are reassuring and show that residents who followed the recommendations are likely to have effectively eliminated the potential threat posed by residual WTC dust. The Agency recommends that any resident who may have lingering concerns about dust in their homes clean several times using methods EPA has recommended since September 2001, which include wet wiping and mopping, and the use of a HEPA vacuum. These methods will allow residents to be certain that they have removed as much of the dust as possible.

EPA also conducted a Background Study to determine indoor concentrations of contaminants of potential concern in areas of New York City that were not physically impacted by the dust or debris from the WTC collapse. The data collected from this study are consistent with other studies and background data.

For full reports of these studies or for more information on EPA's Indoor Air Residential Assistance Program, visit the Agency's Web site at .