NYC-WTC_000226942

NYC 9/11 Public Portal Document

Mr. Bernard P. Orlan March 21, 2002 Wipe Samples for Dioxins Page 2 Stuvvesant Hieh School (Manhattan) ATC Project No. 15-19125-0246

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. Copies of the draft analysis reports are 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^)

...LOCATION :h'- ' < ’ jj) : ‘ Floor Lobby . Main Entrance / DXl 0.00031 2^ Floor Lobby Bridge Entrance /DX2 ; 0.00015 HVAC #1 Mixed Air Plenum/ DX3 0.00061

Field Blank/DX4 0.0023

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).

The concentrations on indoor surfaces ranged from 0.00015 to 0.00061 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 this sample was deposited. Dioxin samples were not collected from these locations prior to November 8, 2001, and therefore a background sample is not available for comparison purposes.

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

Sincerely, ATC Associates, Im

James R. Cohn, CIH, CSP Regional Manager, Industrial Hygiene Division

Attachment

CITY_21MC100_002896378

NYC-WTC_000226943