Chain of Custody Form Instructions for WTC Building Sampling

NYC 9/11 Public Portal Document

Screening Guidelines/Recommendations

The screening guidelines that follow were developed for use in interpreting the results of the sampling effort. If contaminants are below screening guidelines, further health evaluation of the data is not necessary. If guidelines are exceeded, additional review of the data and the sample collection circumstances is necessary. If a guideline is exceeded, it does not automatically indicate that a health concern exists.

ASBESTOS InterQretation_ofbuUc.and_airjam£les: The following table provides a general guide for determining public heallh actions based upon sampling of both bulk material and indoor air. The table integrates the Environmental Assessment Workgroup multi-agency recommendations for reoccupation of residences in lower Manhattan (see attachment 1). It is important to note that the ultimate decision criteria for reoccupation is the ambient air level of asbestos. Bulk asbestos determinations are useful for (1) determining the potential for decontaminating ambient air and (2) for determining die type of further sampling needed. In general the sampling and resampling strategy encompasses testing of bulk material and clean up until such a time that furflier clean up will not lower bulk asbestos levels. Confirmation is made by air sampling; reoccupation of residents is acceptable below 0.01 f / cc. ATSDR, with multi-agency concurrence, has provided guidance for re-entry into New York City buildings and has concluded that the 0.1 f/cc OSHA PEL is not acceptable for schools or residences (see attachment 1 ATSDR, CDC, EPA, OSHA Environmental Assessment Workgroup Asbestos Action Levels for World Trade Center Response October 11,2001).

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