Preliminary health report, World Trade Center, Oct 2001

NYC 9/11 Public Portal Document

| vyori^ f rade Center.pdf Pa^13|

Table 6. Airborne asbestos concentration in two building interiors near the collapsed WTC towers as measured by PCM and TEM.

Phase Contrast Transmission Electron Microscopy Microscopy EPA Level II, □ 3:1 particle aspect ratio (NOISH Method 7400) Asbestos Asbestos Total Asbestos (>5 pm) Cone. (0.5 - 5 pm) (□0.5 urn) Asbestos Cone. Sample (structures/cc) Cone. Cone. (f/cc) (structures/cc) (s/cc) s/mm^ 1 <0.007 (NSD) 0255 0.255 369 0.049 0.155 0.464 2.16 140 0.053 y <0.007 (NSD) CTT7 0.117 170 0.046 <0.007 (NSD) 0078 -COTS" “W 0.064 5“ <0.007 (NSD) 0008 0.008 10 <0.005 y <0.158 (NSD) <0.158 (NSD) <0.158 <10 0.062 y 0?167 5.19 5.36 319 TiATir’ y <0.171 (NSD) 3.43 3.43 199 0.247 (2) y 0.346 sen 5.35 309 0.536 (2) ■io <0.008 (NSD) 0.031 ■o^osT 40 0.016 y <0.008 (NSD) COAT ■'CO??' 60 0.034

NOTE ON LABORATORY REPORT (SCILAB-VA NYSDOH ELAP 10984) Indirect sample preparation performed. (1) Analyst was unable to quantify fiber concentration because of overloading of particulate material on the filter. (2) Moderate to heavy particulate matter is present on the filter which may obscure some fibers causing results with a low bias. (3) NSD = No Asbestos Structures Detected.

NYC-WTC_000178066