NYC-WTC_000232813

NYC 9/11 Public Portal Document

Asbestos Data

Based on the results that were received, it appears that eleven wipe samples and sixteen microvacuum samples were collected by Ambient Group Inc. and analyzed by EMSL Analytical Inc. for asbestos. An additional wipe sample and two microvacuum samples were submitted as blanks. A summary of the results is presented below.

Location Matrix Sample Average Maximum Size Concentration Concentration (s/cm’l (s/cm^)

All locations Wipe II 4,327,650

Below floor Wipe 1 11,681

Wall Tracking Wipe 9 726,108 4,327,650

Below Light Wipe 1 8,652 Switch

Blank Wipe 1 2,164

All Locations Microvacuum 284,488 1,115,570

Below Floor Microvacuum 10 369,830 1,115,570

Wall Tracking Microvacuum 1 15,058

I-beam Microvacuum 2 7,636 8,038 (ND)

Column Microvacuum 1 8,038 (ND)

Pipe Shaft Microvacuum 1 71,592

Front Office Microvacuum 1 743,552

Blank Microvacuum 803

ND= asbestos not detected

The interpretation of these results is constrained by the scientific uncertainty regarding the potential for the measured concentrations in settled dust to become airborne. There are no standards currently available for assessing potential health consequences from asbestos through the evaluation of wipe or microvacuum samples. A scientific peer review panel (World Trade Center October 21- 22, 2002 Peer Review Meeting Notes. Available at www.tera.org.) recently evaluated the technical soundness of estimating airborne asbestos concentration as a function of asbestos concentration in settled dust for the purpose of setting health-based benchmarks. The panel recommended against such an

CITY_21MC100_009481712

NYC-WTC_000232814