NYC-WTC_000202101

NYC 9/11 Public Portal Document

Mr. Bernard P. Orlan Fcbrmarj’ 20, 2002 Wipe Samples for Dioxins Page 2 P. S. 89 (Manhattan) ATC Project No. 15-19125-0297

Combustion of PCB-containing oils, such as during an electrical transformer fire, is known to produce dioxins. Burning of some plastics may also produce dioxins. Dioxins are toxic and are considered to be carcinogenic.

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/m^). The New York State Department of Environmental Conservation (NYSDEC) has set 0.0006 parts per million (ppm) as the allowable concentration of dioxin in soil. The EPA has established a residential clean-up goal of 1 part per billion (ppb).

WIPE SAMPLLNG RESULTS

ATC submitted three (3) wipe samples for PCDDs/PCDFs (plus one blank) to Pace for analysis. Copies of the draft laboratory analysis results are provided in Attachment 1. Samples were taken from areas specified by the parents association consultant. The sample area was one square, meter (m^).

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 established equivalency factor. This provides a single value (in nanograms) for the analytical results for each sample. The sample locations and the results are shown in the table:

DIOXIN WIPE SAMPLE RESULTS (2, 3, 7, 8 TCDD EQUIVALENTS) January 25, 2002 DIL

1st Floor Hallway-north/DXl O.O0O24 1 st Floor Hallway-south/DX2 0.00014 2^*1 Floor Hallway near Staircase/DX3 0.00038 Field Blank/DX4 0.00

The concentrations on indoor surfaces ranged from 0.00014 to 0.00038 nanograms per square meter (ng/m^). The dioxin concentrations in these sample are below the NYSDOH guideline.

It IS not possible to determine when the 2, 3, 7, 8 - TCDD equivalents detected in these samples were deposited. Dioxin samples were not collected from these locations prior to December 20, 2001.

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