NYC-WTC_000199314

NYC 9/11 Public Portal Document

Mr. Bernard P. Orlan November 25, 2002 Wipe Samples for Dioxins Page 2 Beni. Altman School (P. £. 42 Manhattan) ATC Project No. 15-19125-0342

Each sample was analyzed for sixteen (16) PCDD/PCDF isomers. The results for each isomer were then converted to 2, 3, 7, 8 tetrachloro-dibenzo-p-dioxin (2, 3, 7, 8-TCDD) equivalents by multiplying by an estab ashed equivalency factor. This provides a single value (in nanograms) for the analytical results for each sample. A copy of the laboratory analysis report is attached. The results are shown in the following table.

DIOXIN WIPE SAMPLE RESULTS 2, 3, 7, 8 TCDD EQUIVALENTS - Nanograms per square meter (ng/m-) September 4, 2002 WCATIO^ /SAMPLE ID DIOXIN CONCENTRATION

Mam Lobby/DXl 0.013

2nd Floor by Room 207 I)X2 0.00068

3rd Floor by Room 309 / DX3 0.0013

The New York State Department of Health (NYSDOH) established guidelines for dioxin for the I re-occupancy of the B nghamton State Office Building following a PCB fire. The NYSDOH guideline for dioxin on surfaces is 25 nanograms per square meter (25 ng/m^).

The concentrations on indoor surfaces ranged from 0.00068 to 0.0013 nanograms per square meter (ng/m^). The lev‘Is found in all of these samples are below the NYSDOH guideline of 25 ng/m2.

It is not possible to determine when the 2, 3, 7, 8 - TCDD equivalents detected in these samples was deposited. Dioxir samples were not collected from these locations prior to these samples therefore a background sample is not available for comparison purposes.

It is our pleasure to provide these indoor environmental services to the NYC Department of Education. If you have any questions about this report, please call (212) 353-8280, extension 212.

Sincerely, ATC Associates, Inc

James R. Cohn, CIH, C SP Regional Manager Industrial Hygiene Division

Attachment

CITY_21MC100_003049031

NYC-WTC_000199315