NYC-WTC_000223267

NYC 9/11 Public Portal Document

Mr. Bernard P. Orlan February 20, 2002 Wipe Samples for Dioxins Page 2 P. S. 234 (Manhattan) ATC Project No. 15-19125-0279

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 SAMPLING RESULTS

ATC submitted two (2) wipe samples for PCDDs/PCDFs (plus one blank) to Pace for analysis. Copies of the draft analysis results are provided in Attachment 1. Samples were taken from areas specified by the parents association consultant. The area of each sample one (1) square meter ( 1 m2).

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 (See Attachment). 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)

ist Floor Hallway - east end/DXl DaKJSj 1 st Floor Hallway - west end/DX2 0.0033 Blank/DX3 0.000073

The concentrations on indoor surfaces ranged from 0.0033 to 0.0053 nanograms per square meter (ng/m^). These levels are well 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 wipe samples were not collected from this school prior to December 6, 2001.

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, TC ASSOCL4 TESmC.

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

Attachment

CITY_21MC100_002890282

NYC-WTC_000223268