Air monitoring weekly summary report, Feb 2002

NYC 9/11 Public Portal Document

ATc/t^asa. Measurement Data Weekly Summary February 2 to February 8, 2002

Start End Highest % #Lg88 % teas Report Report # Samples #of Highest Shift Adj. of Shift Job than Half tharWM Period Period Analyte Class Collected Analysts OEL %OEL OEL Adj. OEL Analyte Description #NQ'8* %NQ*8 OEL OEL spotter cleaned debris on NW section of Bl @ 302/2002 3090002 Silica 29 58 0.05 420.00% 0.024 875% Quartz wrC6 47 81% 52 90%

Towerl grappler Diesel ExlieusI operator in 3/220002 3/29/2002 Diesel Fume 11 11 0.02 188.50% 0.02 189% Particuletes depression 5 45% 9 82%

drilling for tieback rvTO/Tnrw 7 7 0.08 88.13% 0.08 86% Ozone W slurry wall 6 88% 6 86% spotter in depression tower 3/220002 3/290002 Asbestos 32 32 0.1 57.00% 0.05 114% Asbestos #2 17 53% 31 97% Worker top of ramp to 3020002 3090002 Sulfides 15 16 2 17.04% 2 17% Sulfur Dicwdde depression 13 87% 15 100%

Torch Cutter In 3020002 3/290002 Metals 9 189 10 7.48% 10 7% Total Dust Depression 2VVTc 128 87% 189 100%. Torch Cutter on Surface Church & 3020002 3090002 A^ 6 36 1 0.84% 1 1% Sulfuric Add VesseyExil 33 92% 36 100%

laborer drllllne team N slurry wall 302/2002 3/29/2002 Aromatics 2 8 50 0,01% 34 0% Toluene (SWTCeLvI B5 2 25% 8 100% 3020002 3/29/2002 Mercury 10 10 0.00% 0% 10 100% 10 100% Worker using gas pwrd cut off sew to cut conduit & 26 TWA 104% TWA Carbon pipe, level 81, 3/23/2002 3/290002 Carbon Monoxide 25 25 200 P9aX 724% Peak 17 156% Monoxide WTC6 n/a n/a 23 92% operator, level 2. 303/2002 3090002 Noise 30 30 90dBA 101 dBA n/a n/a Noise WrC6 n/a n/a 8 27%

Notes:

o * All Quantification levels for the sampling methods used were well below OELs.

The PEL for quartz is determined by the formula PEL = 10 mg/m3 / (% quartz +2). I For dusts with high quartz content this works out to be a quartz concentration of approximately 0.1 mg/m3.

OEL = Occupational Exposure Limit, the lower of OSHA's PEL or the ACGIH TLV

o "NQ" = Not quantifiable. Sufficient quantity of contaminant not present to report a value. o I o o

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