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Daily Environmental Monitoring Summary

Thursday, March 14, 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 5:30 p.m. on 3/14

Air: Fixed Monitors in New York:
Asbestos - EPA analyzed 70 samples taken in and around ground zero from March 7 through March 10. All but one sample 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.

One sample, taken on March 9 at Location "W" (Wash Tent Common Area) showed 144 structures per square millimeter. This brings the total number of air samples collected and analyzed for asbestos in lower Manhattan to 6,868, with 18 samples above the standard (11 of these were collected prior to September 30; the other seven were collected on October 9, November 27, December 27, January 14, February 5, February 11 and March 9).

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.

Staten Island Landfill:
Air (Asbestos) - A total of 77 air samples collected on February 27, and March 3, 4 and 6, were analyzed for asbestos. All samples were below the school re-entry standard.

Ambient Air Samples:
Dioxin - A total of 20 samples were collected on February 21 and February 26 at various locations in lower Manhattan. All samples collected were below the EPA Removal Action guidelines (based on a 30-year exposure).

Metals - Ten samples were collected on January 25 at various locations in lower Manhattan. All metals were either not detected or were below applicable EPA Removal Action level guidelines, OSHA PELs, and the NAAQS for lead.

PCBs - A total of 20 samples were collected on February 26 and February 28 at various locations in lower Manhattan. PCBs were not detected.

PAHs - A total of 19 samples were collected on February 19 and February 28 at various locations in lower Manhattan. PAHs were not detected.

VOCs - Sampling for volatile organic compounds (VOCs) was conducted on March 13 in the direct area of the excavation 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 March 13 at EPA's Wash Tent (West & Murray Streets), Austin Tobin Plaza, and the North Tower and South Tower excavation areas either showed no detectable levels of VOCs, or the levels of VOCs did not exceed OSHA standards.

Latest Available Daily Environmental Monitoring Summary

EPA information about the events of September 11

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