NYC-WTC_000208745

NYC 9/11 Public Portal Document

ATC/Liberty Mutual Industrial Hygiene Measurements Summary Week of 02/08/02 to 02/15/02 #Less % Less Start Report End Report # Samples #of Highest % 12 hr Shift Highest % of Job Description #NQ's % NQ s than Half than Half Anaiyte Class OEL Analyte Period Period Collected Analysis OEL Adj. OEL Shift Adj. DEL OEL OEL

3/8/2002 3/15/2002 Concrete Driller @ Silica 24 48 0.05 mg/m3 7600% 0.024 15833% Quartz 42 88% 44 92% 5:01:00 PM 5:00:00 PM 6 WTC-Path

labor preparing site 3/8/2002 3/15/2002 Diesel Exhaust Diesel Fume 4 4 0.02 mg/m3 168% 0,02 168% fordrilling ® 6 1 25% 2, 50% 5:01:00 PM 5:00.00 PM Particulates WTC-path operator in 3/8/2002 3/15/2002 Asbestos 11 11 0.1 f/ec 60% 0,05 120% Asbestos depression @ 4 2 18% 10 91% 5:01:00 PM 5:00.00 PM WTC 3/3/2002 3/15/2002 Torch Cutter on Metals 10 208 10 mg/tn3 7% 10 7% Total Dust 132 63% 208 100% 5:01:00 PM 5:00:00 PM Surface

3/8/2002 3/15/2002 Banker Trust on Acids 9 54 1 mg/m3 4% 1 4% Sulfuric Acid 49 91% 54 100% 6:01:00 PM 5:00:00 PM Liberty St

3/8/2002 3/15/2002 driller® 6 WTC Aromatics 2 8 0.5 ppm 0% 0.24 ppm 1% Benzene 4 50% 8 100% 5:01:00 PM 5:00:00 PM path tunnel # 87

I 3/8/2002 3/15/2002 6 100% Ozone 6 6 0% 0% 6 100% 5:01:00 PM 5:00:00 PM 3/8/2002 3/15/2002 100% 4 100% Sulfides 4 4 0% 0% 5:01:00 PM 5:00:00 PM 3/8/2002 3/15/2002 14 100% Mercury 14 14 0% 0% 14 100% 5:01:00 PM 5:00:00 PM 3/3/2002 3/15/2002 Torch Cutter, WTC Carbon Monoxide 29 29 35 37% 17 73% Carbon Monoxide N/A N/A 28 97% 5:01:00 PM 6;00;00 PM 6 3/8/Z002 3/15/2002 07 dBA too dBA 48% Noise 25 25 90dBA 88dBA Noise Core drilling @ VI7 N/A N/A 12 5:01:00 PM 5:00:00 PM 266% 384%

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NYC-WTC_000208745