NYC-WTC_000208298

NYC 9/11 Public Portal Document

Mr. Bernard P. Orlan November 25, 2002 Wipe Samples for Dioxirs Page 2 Murray Berirtraum Hich School (M52O) ATC Project No. 15-19125-0351

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 estal lished 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 m the following table.

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

Main] obby/DXl 0.000043

3rd Floor Hallway / DX2 0.000028

Hallway / DX3 0.000044

The New York State Department of Health (NYSDOH) established guidelines for dioxin for the re-occupancy of the B nghamton State Office Building following a PCB fire. The N’rSDOl 1 guideline for dioxin on surfaces is 25 nanograms per square meter (25 ng/m^).

The concentrations on ndoor surfaces ranged from 0.000028 to 0.000044 nanograms per square meter (ng/m^). The lev.ds found in all of these samples are below the NYSDOH guideline of 25 ng/m^.

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 Di\ ision

Attachment

CITY_21MC100_003021581

NYC-WTC_000208299