NYC-WTC_000208300

NYC 9/11 Public Portal Document

Mr. Bernard P. Orlan November 25, 2002 Wipe Samples for Dioxins Page 2 Murray Bergtraum High .School (M520) 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 estaldished equivalency factor. This provides a single value (in nanograms) for the analytical results for each sample. A copy of the laboratory analysis report i.s 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 11, 2002 LOCATION /SAMPLE ID DIOXIN CONCENTRATION

Mam I obby / DXl 0.000043

3rd Floor Hallway / DX2 0.000028

4th Floor 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^fSDOH 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 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 m 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_OO3O21592

NYC-WTC_000208301