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Daily Environmental Monitoring Summary

Friday-Monday, March 1-4, 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 4:15 p.m. on 3/4

Air: Fixed Monitors in New York:
Asbestos - EPA analyzed 102 samples taken in and around ground zero from February 16 through February 19. 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 6,274, 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:
VOCs - Sampling for volatile organic compounds (VOCs) was conducted on February 28 and March 1 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 on February 28 and March 1 at EPA's Wash Tent (West & Murray Streets), Austin Tobin Plaza, and the South Tower and North Tower excavation areas 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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