EPA interim final report on WTC background study, April 2003

z z o o i 1^ CD

“0 o c o Table 6-2. Summary of the analytical results for the organic and inorganic compounds from the background study. The table presents the sample CT o size, frequency of detection, minimum and maximum detected concentrations, arithmetic mean, and the statistic used, and the upper confidence o' tn "0 CD limit (UCL) for each compound and matrix sampled. The values in this table were calculated using only the data sets from the residence areas for o CaJ each analyte. 03

o o o c Residential Data Set Range 3 o Freq. Of Arithmetic 3

Analyte Matrix n Minimum* Maximum Statistic UCL Detection Mean Asbestos Bulk Dust 3 0/3 <0.5% Air-PCM 50 21/50 0.1SBH6 f/cc 0.007 fee 0.0014 fee 95% Chebyshev 0.0023 fee (Mean, STD) Air-TEMAHERA 48 2/48 0.0002 s/ee 0.0004 s/ee 0.1SO22 s/ee 95% Chebyshev 0.1 24 s/ee (Mean, STD) Air-TEMPCMe 48 2/48 0.0002 s/ee 0.'BW s/ee 0.1SO22 s/ee 95% Chebyshev 0.00024 s/ee (Mean, STD) Microvacuum - All 143 15/143 317 s/cm^ 72,094 s/cm^ 2,234 s/cm^ Microvacuum - Carpet 60 10/60 317 s/cm^ 72,094 s/cm^ 2,861 s/cm^ Microvacuum - Couch 71 4/71 317 s/cm^ 24,138 s/cm^ 1,732 s/cm^ Microvacuum - Drapes 12 1/12 791 s/cm^ 12,288 s/cm^ 2,071 s/cm^ 95% Chebyshev 6,149 s/cm^ (Mean, STD) Wipe-All 104 14/104 592 s/cm^ 83,893 s/cm^ 2,309 s/cm^ 95% Chebyshev 6,192 s/cm^ (Mean, STD) Wipe - Ceiling 24 3/24 592 s/cm^ 83,893 s/cm^ 4,683 s/cm^ 97.5% Chebyshev 26,295 s/cm^ (Mean, STD)

* Minimum detected value includes values that may be ’A of the detection limit Table 6-2