Building interior survey proposal for WTC vicinity, 2002

NYC 9/11 Public Portal Document

Mark Maddaloni To: wtccocs cc: Kathy Callahan/R2/USEPA/US@EPA, Dore 03/05/02 02:44 PM LaPosta/R2/USEPA/US@EPA, Larry Reed/DC/USEPA/US@EPA, [email protected], [email protected], [email protected], [email protected], [email protected], [email protected] cc: Kathy Callahan/R2/USEPA/US@EPA, Dore LaPosta/R2/USEPA/US@EPA, Larry Reed/DC/USEPA/US@EPA, [email protected], [email protected], [email protected], [email protected], [email protected], [email protected] Subject: Meeting Notes Indoor Air Taskforce - COCs/Benchmarks Committee

Meeting Notes fro 3/4 conference call

- Reps from EPA (R II & HQ). ATSDR, NYSDOH and NYCDOH participated

- There was an initial discussion of the groups charge. No surprises here : we need to identify a select group of chemicals of concern (COCs) for the indoor environment and develop benchmarks for these chemicals to answer questions such as, "How clean is clean?" and "Is my apartment safe to live in?"

■ Two points were brought out that the group agreed were important to consider in addressing the aforementioned charge: 1) There has already been a massive clean-up of the site/source material ; 2) Apartments need not be cleaned up beyond "background," which consequently needs to be characterized.

- The following list represents the universe of potential COCs. This list will likely be reduced based on factors such as: comparison with background, review of WTC ambient air sampling data and toxicity/concentration screening. Asbestos Fiberglass Refractive ceramic fibers 7 Particulates (PM 2.5, PM 10, TSP and pH) Uvu Dioxins I PCBs PAHs Lead Chromium

- Two general approaches were discussed for developing benchmarks for the above list. One is the "tiered approach" that has previously been used for asbestos and is currently being developed for fiberglass (see attached file for example) in the indoor environment. The other is the "single value" scceening method (i.e.,'benchmarks table) that was employed to interpret results from the ambient (outdoor) air monitoring sampling data. Consensus was formed for the use of the tiered approach, principally because it allows more flexibility for data interpretation and provides a better vehicle to incorporate "background information" and exposure parameters that reflect the clean-up that has already taken place. On the down side, the tiered approach is more labor intensive (and will likely need to be developed for both air and settled dust), but by working with a limited list of COCs it was deemed doable, j__

- The next conference call for the COC/Benchmarks Committee is scheduled for Monday 3/11 (how fitting • 6 months to the day from 9/11) from 2 • 3:30 pm. The call in number along with a strawman for the tiered approach will be provided in a follow-up message.

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