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Daily Environmental Monitoring Summary

Thursday, February 21, 2002

The U.S. Environmental Protection Agency (EPA) and other federal, state and local agencies have collected extensive environmental monitoring data from the World Trade Center site and nearby areas in Manhattan, Brooklyn and New Jersey. Since September 11, EPA has taken samples of the air, dust, water, river sediments and drinking water and analyzed them for the presence of pollutants that might pose a health risk to response workers at the World Trade Center site and the public. The samples are evaluated against a variety of benchmarks, standards and guidelines established to protect public health under various conditions. EPA is collecting data from more than 20 fixed air monitors in and around ground zero and additional monitors in the Bronx, Brooklyn, Queens and Staten Island. The Agency is also using portable sampling equipment to collect data from a range of locations.

Results as of 4:45 p.m. on 2/21

Air: Fixed Monitors in New York:
Asbestos - EPA analyzed 67 samples taken in and around ground zero from February 14 through February 16. EPA also sampled for asbestos at two additional lower Manhattan locations on February 12 and February 13. All samples showed results less than 70 structures per square millimeter, which is the Asbestos Hazard Emergency Response Act (AHERA) standard for allowing children to re-enter school buildings after asbestos removal activities.

This brings the total number of air samples collected and analyzed for lower Manhattan to 6,172, with 17 samples above the standard (11 of these were collected prior to September 30; the other six were collected on October 9, November 27, December 27, January 14, February 5 and February 11).

This number of exceedances is lower than reported on prior daily summaries. Earlier sampling results included an additional, unnecessary adjustment for the volume of air sampled. Using a more appropriate method, those results have been recalculated and the true levels of asbestos measured are generally lower. Consequently, the standard was actually exceeded less often than previously stated.

Air: Fixed Monitors outside Lower Manhattan:
Asbestos - Samples were collected from additional asbestos monitors at Intermediate School 143 (511 W. 182nd St., Manhattan), Public School 154 (333 East 135th St., Bronx), P.S. 274 (800 Bushwick Ave, Brooklyn), P.S. 199 (3290 48th St., Queens), and P.S. 44 (80 Maple Parkway, Staten Island) on February 12 and February 13. None showed exceedances of the AHERA re-entry standard.

Staten Island Landfill:
Air (Asbestos) - Twenty air samples collected on February 15 were analyzed for asbestos. A sample taken at one of the Wash Tents (Location W-11) showed 78.7 structures per square millimeter, which exceeds the AHERA school re-entry standard. All other samples were below the school re-entry standard.

Air (Particulates) - EPA used portable monitors to collect samples of particulates on February 15, 19 and 20 at the Staten Island Landfill. There were no significant readings.

Ambient Air Samples:
Particulate Monitoring - EPA used portable monitors to collect samples on February 20 at Location "L" (northeast side of Stuyvesant High School); Location "N" (south side of Pier 25); and Location "R" (northwest side of Stuyvesant High School). All readings were below the OSHA time-weighted permissible exposure limit for particulates.

VOCs - Sampling for volatile organic compounds (VOCs) was conducted on February 20 in the direct area of the debris pile at ground zero. To protect workers at the work site, EPA takes grab samples of VOCs where smoke plumes have been sighted. The results are snapshots of the levels at a moment in time. OSHA's protective standards set a permissible exposure limit (PEL) averaged over an 8-hour day.

All samples taken from February 20 at EPA's Wash Tent (West & Murray Streets), Austin Tobin Plaza, the South Tower debris pile, and the North Tower debris pile showed no detectable levels of VOC's.

Latest Available Daily Environmental Monitoring Summary

EPA information about the events of September 11

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