Panel agenda for Air Quality After 9/11 conference, March 2004

NYC 9/11 Public Portal Document

smooth surfaces which have been cleaned with any wet wiping or washing techniques. The quantitative wipe method for asbestos is ASTM Method 6480, and was the method used by EPA in its 110 Liberty St. cleaning study. The microvacuum method, ASTM Method 5755 is only suitable for freshly deposited dust layers that have not been touched by wet wiping, washing, etc. This is because water and detergents will temporarily bind residual dust-bome contaminants to the surface so that they will not be picked up by the dry vacuuming technique used in the ASTM microvacuum mefliod. As discussed in my 12/19/01 memorandum, wipe testing has been demonstrated to pick up 4 times more asbestos from smooth surfaces compared to microvacuum sampling.”

“The surfaces tested by the residents at 114 Liberty showed elevated levels of asbestos, most from 10,000 to over 1 million structures per square centimeter (s/cm). These laboratory results demonstrate the presence of significant dust after the two abatements by EPA/NYCDEP.”

“Although acknowledging that dust testing was useful in determining abatement effectiveness, EPA/NYCDEP dismissed the residents’ asbestos dust testing as being irrelevant to showing that there were any kinds of risk from, or hazards associated with the high levels of asbestos in the dust after the cleaning at 114 Liberty.”

“The EPA Inspector General (IG) also does not agree with EPA that settled dust test levels should be ignored, and recommended that EPA develop a standard to establish risk levels for settled dust tests:

‘We believe EPA should...develop health-related screening levels for asbestos in dust K-factors’

“For the reasons given above, EPA should acknowledge the fact that the elevated levels of asbestos found by the residents at 114 Liberty St. represents a health risk, although of uncertain exact numerical magnitude, as it demonstrates that asbestos is above backgroimd levels.”

Ms. Jenkins concluded:

“It appears that the EPA/NYCDEP contractors responsible for the clean­ up at 114 Liberty were on a tight schedule, which took precedent over performing the abatement to specifications. The exposed structural supports in the exposed walls and ceilings would have required the use of nozzles attached to HEPA vacuums and wet wiping of small area surfaces. This detail work would have consumed much more time than cleaning large flat surfaces like floors and walls. The contractors also may have violated the sampling protocols themselves (not using-

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