Air quality test reports cover letter, Jan 2002

NYC 9/11 Public Portal Document

ENVIROSCIENCE CONSULTANTS, INC. 2150 SMITHTOWN AVENUE RONKONKOMA, NEw YORK 11779-7348 PHONE: (631) 580-3191 • FACSIMILE (631) 580-3195

B. GALLAGHER P. DERMODY C. GI* BERT, PH.D. E. DETWEILER T. KLUENDER G. NEUBCHWENDER 18 December 2001 J. DRISCOLL G. MENEGIO L•SAVARESE

Ms. Carol Hoover, Assistant to the Chairman American Stock Exchange 86 Trinity Place New York, New York 10006-1872

Subject: December 2-3, 2001 Air Sampling Results for the SIAC, American Stock Exchange, New York, NY.

Dear Ms. Carol Hoover.

This report includes the results of air sampling conducted 20:22 hours December 2 through 21:31 Asbestos samples hours December 3, 2001. The air sampling locations and results are reported below. analyzed according to U.S. were collected according to New York State and U.S. EPA standards and were collected and analyzed EPA standards using Transmission Electron Microscopy. Other substances using the National Institutes for Occupational Safety and Health protocol. of Based on our experience and direction from U.S. EPA and the New York State Department met the U.S. EPA AHERA clearance criteria of 70 Labor we recommend that those samples that structures/square millimeter are considered acceptable and are considered safe for reoccupancy. The schools from U.S. AHERA regulations were developed to protect all children, faculty, and staff in asbestos exposure. The two different methodologies, U.S. EPA AHERA methodology; and OSHA used structures per square methodology differ from the beginning of the protocol. The U.S. EPA uses 70 children, faculty, and staff millimeter (s/mm2) as the value considered safe for school reoccupancy by with a magnification of after asbestos abatement. The AHERA protocol requires an electron microscope to up to 480,000 20,000 times. The electron microscope in our laboratory is capable of measuring up phase contrast light microscope with a magnification of up to times. The NIOSH 7400 method may use a electron microscope. AHERA allows a blank filter to have 400 times. The NIOSH 7402 method uses an fibers, clusters, bundles, and matrixes that up to 70. structures per square millimeter. Structures are work area samples are contain asbestos fibers greater than 0.5 micrometers in length. If the average samples are found to be greater found to have less than the 70 s/mm2 no further action is required. If the compared with the work area than 70 s/mm2 then the asbestos air concentration outside the work area is work area may be re-cleaned and air concentration and subjected to a Z-Test statistical technique or the filter area and divided by the air volume the air re-sampled. The filter concentration is multiplied by the The NIOSH 7400 or 7402 sampled (in cubic' centimeters) to produce the asbestos air concentration. values of fibers per cubic centimeter. methods used by OSHA to evaluate worker exposure results in in diameter are counted. Fibers greater than 5 micrometers in length and greater than 0.25 micrometers and includes much Structures counted in AHERA include the fibers in the NIOSH OSHA approach the attached tables are more smaller structures. Therefore, the AHERA air concentration presented in protective than the NIOSH OSHA approach millimeter are Samples that met the U.S. EPA AHERA clearance criteria of 70 structures/square considered acceptable and are considered safe for reoccupancy. ENVIRONMENTAL & INDUSTRIAL HYGIENE CONSULTANTS WWW.ENVIROHEALTH.ORG

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