OCR status: ok · source: pdftotext
NYC 9/11 Public Portal Document
Mr. Bernard P. Orlan April 29, 2002 Air Sampling for Metals Page 2 H.S. of Economics & Finance f833M) ATC Project No. 15-19125-0291
Resuits
Mas-ck 9
Chromium (Cr) was detected in all four samples and in the blank. Blank-correcting the Cr concentrations lowers them to below or just above the limit of detection.
7! The only other metal found was iron (Fe) which was detected at 0.00231 milligrams per cubic meter (mg/m^) in the sample collected on the Roof (#M4).
Mas-ch 16
The metals detected were Cr, Fe and lead (Pb). Cr was found in one sample and m the blank at approximately the same concentration. Fe was detected in the sample collected in the Main Lobby ((#M1) at 0.000273 mg/m3 it was not present in the other samples or in the blank.
Pb was detected in all four samples and in the blank. The blank-corrected Pb concentrations are all below the limit of detection.
Mai-ck 23
Cr was detected in all four samples and in the blank. The blank-corrected Cr concentration was greater than the limit of detection only in the sample collected in the 10“’ floor hallway (#M3). The Cr concentration in this sample was 0.00026 mg/m^.
The only other metal detected was copper (Cu). Cu was detected in the roof sample at a concentration of 0.000334 mg/m^ Cu was not detected in the other samples or in the blank.
The Environmental Protection Agency (EPA) has set a screening level for hexavalent chromium (the more toxic form) in air of 0.6 ug/m\ this assumes a continuous exposure for one year. The samples here were analyzed for total chromium (trivalent and hexavalent).
The EPA’s ambient air standard for Pb is 1.5 ug/m^ (three-month average). The EPA has no screening level or standard for Cu in ambient air.
ATC appreciates the opportunity to provide this indoor air quality service to the BOE. Please call me at (212) 353-8280 extension 212 if you have any questions.
Sincerely, ATC Associates, Inc.
James R. Cohn, CIH, CSP Regional Manager, Industrial Hygiene Division
Attachment
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NYC-WTC_000227066
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NYC-WTC_000175577
Letter report detailing air sampling for metals conducted on March 15, 22, and 29, 2002, at the referenced school.
12 shared non-person entities · 1 shared topics · similarity 0.994
machine-extracted · confidence unavailable · Check page ↗NYC-WTC_000175567
Letter report detailing air sampling for metals conducted on multiple dates between May and June 2002 at the referenced school.
12 shared non-person entities · 1 shared topics · similarity 0.989
machine-extracted · confidence unavailable · Check page ↗NYC-WTC_000180110
Report of air sampling for metals conducted at the referenced school on June 22, 2002.
14 shared non-person entities · 1 shared topics · similarity 0.988
machine-extracted · confidence unavailable · Check page ↗NYC-WTC_000175558
Letter report detailing air sampling for metals conducted on June 22, 2002, at the School of Economics and Finance.
14 shared non-person entities · 1 shared topics · similarity 0.988
machine-extracted · confidence unavailable · Check page ↗14 shared non-person entities · 1 shared topics · similarity 0.988
machine-extracted · confidence unavailable · Check page ↗11 shared non-person entities · 1 shared topics · similarity 0.988
machine-extracted · confidence unavailable · Check page ↗12 shared non-person entities · 1 shared topics · similarity 0.986
machine-extracted · confidence unavailable · Check page ↗12 shared non-person entities · 1 shared topics · similarity 0.986
machine-extracted · confidence unavailable · Check page ↗11 shared non-person entities · 1 shared topics · similarity 0.986
machine-extracted · confidence unavailable · Check page ↗14 shared non-person entities · 1 shared topics · similarity 0.985
machine-extracted · confidence unavailable · Check page ↗12 shared non-person entities · 1 shared topics · similarity 0.985
machine-extracted · confidence unavailable · Check page ↗12 shared non-person entities · 1 shared topics · similarity 0.985
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NYC-WTC_000175577
Letter report detailing air sampling for metals conducted on March 15, 22, and 29, 2002, at the referenced school.
Similarity score 0.991 (not a probability)
machine-extracted · confidence unavailable · Check page ↗NYC-WTC_000175567
Letter report detailing air sampling for metals conducted on multiple dates between May and June 2002 at the referenced school.
Similarity score 0.986 (not a probability)
machine-extracted · confidence unavailable · Check page ↗Similarity score 0.985 (not a probability)
machine-extracted · confidence unavailable · Check page ↗Similarity score 0.984 (not a probability)
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NYC-WTC_000175577
Letter report detailing air sampling for metals conducted on March 15, 22, and 29, 2002, at the referenced school.
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NYC-WTC_000175567
Letter report detailing air sampling for metals conducted on multiple dates between May and June 2002 at the referenced school.
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NYC-WTC_000180110
Report of air sampling for metals conducted at the referenced school on June 22, 2002.
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Letter report detailing air sampling for metals conducted on June 22, 2002, at the School of Economics and Finance.
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