NYC 9/11 Public Portal Document
Mr. Bernard P. Orlan July 10, 2002
Air Sampling for Metals Page 2
H.S. of Economics & Finance (M833) ATC Project No. 15-19125-0291
Results
Chromium (Cr) was found above the limits of detection in all four samples and in the blanks..
sample results are listed in the table:
Sample ID/ Concentration in Sample Concentration after
Location (pg) Blank Correction
(Pg/m^)
ATC-0622-833M-M1/ Main Lobby 0.396 0.002
ATC-0622-833M-M2 / 5* floor by Stair 0.413 0.016
B
ATC-0622-833M-M3/ 9*" floor by Stair B 0.346 BDL
ATC-0622-833M-M4/ Roof 0.417 0.019
ATC-0622-833M-M5/Blank 0.415
ATC-0622-833M-M6/Blank 0.394
After blank-correction, the Cr concentration in Sample # ATC-0622-833M, ATC-0622-833M-
M2, ATC-0622-833M-M3, ATC-0622-833M-M4 were lowered to 0.002, 0.016, 0.000, 0.019
micrograms per cubic meter (pg/m^) respectively.Sample # ATC-0622-833M-M6 was used for
blank correction.
The Environmental Protection Agency (EPA) has set a screening level for hexavalent Cr (the
more toxic form) in air of 0.6 pg/mc this assumes a continuous exposure for one year. The
samples here were analyzed for total Cr (trivalent and hexavalent). These results were below the
EPA’s screening level for hexavalent Cr.
Aluminum (Al) was detected in Sample # ATC-0622-833M-M4 at a concentration of 1.47
micrograms per cubic meter (pg/m^) .There is no ambient air standard or recommended screening
level for Aluminum.
ATC appreciates the opportunity to provide this indoor air quality service to the BOE. Please call
(212) 353-8280 extension 212 or extension 290 if you have any questions.
Sincerely,
ATC Associates, Inc.
■I
Prasad Doddapaneni James R. Cohn, CIH, CSP
Senior Project Manager Regional Manager
Industrial Hygiene Division
Attachment
CONFIDENTIAL, CITY_21MC100_003463183
SUBJECT TO PROTECTIVE ORDER NO. 2, SEPT. 2008
NYC-WTC_000180111
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