Chemicals of Concern status list, May 2002

NYC 9/11 Public Portal Document

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1 The following COCs are still under consideration gypsum Lime calcite portlandite

The following COCs are candidates for deletion PCBs PBDEs - chromium - cadmium — mercury — benzene — mold

Clearance level will be the higher of background or long-term risk-based numbers The workgroup will provide the reasoning behind making a COC a candidate for deletion. Background levels are needed for data analysis. A recommendation was made to take PAHs off the COC list. However, the existing data should be reviewed before that decision can be made. Although no longer airborne, there may be depositions of PAHs and dioxin on surfaces inside the buildings. Objectives of the pilot clean-up will include — to determine the level of clean-up required to reduce COCs - determine how COCs relate to the WTC - develop criteria for settled as well as airborne dust The workgroup will establish risk-based COC levels by the next meeting. The workgroup will have a revised list of COC candidates for deletion by next the next meeting (CNOC - contaminants of no concern). A list should be developed of COCs of historical concerns (COHC).

2. Background Study • Background levels are needed. • The pilot background study will be a small volume of samples • EPA will take the lead on designing the study • EPA will review the indoor air quality data they have available. EPA Region 5 has indoor air quality data on their website. EPA Region 2 will review that information as well. • A recommendation was made that environmental consultants throughout the city should be approached for their existing indoor air data. • A consistent sampling method is required.

3. The Need for Peer Review/Science Advisory Panel • Peter said EPA already has a contractor lined up to start the work and there are funds available to support it.

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