NYC-WTC_000209427

NYC 9/11 Public Portal Document

preferable to test a piece from a flat, upper hoiizontal surface which would be more contaminated.

ASTM microvacuum method is inadequate for carpets and other woven fabrics

Some argue that testing carpet and fabrics with the hand-held ASTM microvacuum suction pump would be a good enough test, since it would get out the easily releasable asbestos. In this method, carpet and other fabrics are sampled by a hand-held air suction pump. The fabric is essentially vacuumed by the pump. The asbestos is caught on a filter, and then the filter is sent to the lab for testing.

However, this ASTM microvacuum sampling pump is only a first-line test for carpet and other woven fabrics, and is not definitive. The microvacuum pump does not apply any greater suction than a good vacuum cleaner. High impacts, such as a child running or rolling on the carpet, will release much more asbestos than any vacuuming process. The EPA ultrasonication method will extract over 100 times the amount of asbestos from carpet compared to the ASTM microvacuum method. The ultrasonication method is also an official EPA method specific to carpet, and is thus preferred.’

NYC APT. BUILDING USES ULTRASONIC CARPET TESTING

The New York Environmental Law and Justice Project*” obtained carpet samples from one NYC apartment building on Hudson St., near the intersection with Thomas St. The samples were taken on May 29, 2002, over 8 months after the collapse of the WTC. The samples were tested by EPA’s ultrasonication method. The results are given in Table 1. The building is 9 blocks north of Ground Zero, and 4 blocks north of W^arren St. Warren St. was defined by the New York City Department of Health as the northernmost point of contamination from WTC fallout.

The building does not have central forced air heating and cooling. Heat is by floorboard hot water pipes. Air conditioning is by individual window units. There is forced air circulation in the hallways only. The building is a well mairtained with a clean boiler room and basement. As seen in a later section of this memo, these levels are high, indicating a major asbestos release. The pattern of the contamination, roof and lower hallway, is indicative of the asbestos source being the World Trade Center.

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