NYC-WTC_000208296

NYC 9/11 Public Portal Document

Mr. Bernard P. Orlan November 25, 2002 Wipe Saniple.s for Dioxin; Page 2 Murray Benjtraum Hiah .School (M520) ATCProjectNo. 15-19125-0351

Each sample wa.s analysed 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 estal lished equivalency factor. This provides a single value (in nanograms) for the analytical result 1 for each sample. A copy of the laboratory analysis report is attached. The results are shown i i the following table.

DIOXIN WIPE SAMPLE RESULTS 2, 3, 7, 8 TCDD EQUIVALENTS - Nanograms per square meter (ng/m^) September 11, 2002 LOCATIO^ /SAMPLE ID DIOXIN CONCENTRATION

Mainlobby/DXl 0.000043

3rd Floor Hallway / DX2 0.000028

4th Floor /tallway / DX3 0.000044

The New York State Department of Health (NYSDOH) established guidelines for dioxin for the re-occupancy of the Binghamton State Office Building following a PCB fire. The NYSDOH guideline for dioxin on surfaces is 25 nanograms per square meter (25 ng/m2).

The concentrations on ndoor surfaces ranged from 0.000028 to 0.000044 nanograms per square meter (ng/m^). The levels 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. Dioxin 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 p'ovide 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 Div sion

Attachment

CITY_21MC1OO_OO3O2157O

NYC-WTC_000208297