NYC-WTC_000199874

NYC 9/11 Public Portal Document JUN-26-2002 14=51 THE NYC DEPT. OF HEALTH 212 964 0472 P.04/06

VATC lUA tasi zow « New York. New York 10010 www.sW'8nvifo.com 212.353.8280 Fax 212.353.S300 ASSOCIATEG INC.

Mr. Bernard P. Orlan June 6,2002 Page 2

2. IS 306X

A total of ten (10) dust wipe samples were collected from selected umt ventilators throughout the school. Laboratory analysis detected lead concentrations which ranged between 1,817.0 pg/ft? to 259.4 pg/ft^ The average concentration was 806.38 pg/ft’.

B. lead wipe sampling -hvac units 1- STUYVESANT HIGH SCHOOL

A total of fifteen (15) dust wipe samples were collected from various hvac units throughout the school. Laborat^ analysis detected lead concentrations which ranged between 253.0 pg/fr to less than the limit of detection of 9.0 pg/fi’. The average concentration was 89.16 pg/ff.

2. IS 306X

A total of eighteen (18) dust wipe samples were collected from various HVaC units throughout the school. Laboratory analysis detected lead concentrations which ranged between 466.7 pg/f^ to IS.5 pg/ft^- The average concentration was 159.45 pg/A^.

Exact sample locations and analytical laboratory results for the samples collected at each school is included in Appendix A of this report.

C. DIOXIN BULK SaMPUNG - STUYVESANT HIGH SCHOOL

ATC collected twenty-four (24) samples for PCDDs/PCDFs (plus two blanks) within Unit Ventilators and HVAC units at Stuyvesant High School All samples were submitted for laboratory analysis to Pace Analytical Services, Inc, (Pace) of Minneapolis. MN, a laboratory experienced in dioxin analysis. The analysis was performed by modified EPA Method 8290 using combined capillary column gas chromatography/high resolution mass spectrometry. Each sample was analyzed for sixteen (16) PCDDZPCDF isomers. The results for each isomer were then converted to 2, 3, 7, 8 tettachloro-dibenzo-p-dioxin (2, 3. 7, 8-TCDD)- equivalents by multiplying by an established equivalency factor. This provides a single value for the analytic^ results for each sample.

CITY_21MC1OO_O11O92939 NYC-VVTC_000199875