NYC-WTC_000210270

NYC 9/11 Public Portal Document

GCI ENVIRONMENTAL ADVISORY, INC. 655 Third Avenue New York, NY 10017 (212) 986-9460 Fax: (212)986-9464

September 28, 2001

Mr. Frank Vasta Rockrose Development Corp. 309 East 45‘*^ Street New York, NY 10017

Re: 99 John Street, NYC - Apt. #PH-04

Dear Mr. Vasta,

GCI Environmental Advisory, Inc. has collected ambient air samples within the above referenced apartment as well as the apartments and common areas of the above referenced building during September 20 - 26, 2001.

Air sampling was conducted within the apartment utilizing 0.8 u, MCE sampling cassettes employing high volume air sampling pumps during "normal" building activities.. A minimum of Nine Hundred (900) liters of air was collected to provide a detection limit below 0.01 f/cc (fibers per cubic centimeter). All samples were pre- and post-calibrated by means of a precision rotometer that had been calibrated with a primary standard. Sampling blanks were collected and submitted with each group of samples analyzed. Air sample analysis was according to NIOSH Analytical Method 7400 with results reported as fibers per cubic centimeter (f/cc). Laboratory Analysis performed by an ELAP approved and NIOSH PAT proficient laboratory.

Laboratory analysis indicated airborne levels below the current recommended "Clearance Air Criteria" of 0.01 fibers per cubic centimeter (f/cc) of air according to Phase Contrast Microscopy (PCM).

Should you have any questions or need additional information, please contact me at (212) 986-9460.

Sincerely,

JanTc n

ronmental Advisory, Inc.

JFG/gj

GCI ENVIRONMENTAL ADVISORY, INC. PROJECT 2001 N01-B4085.99.APT.PCIVI

CITY_21MC100_002843102

NYC-WTC_000210270