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Daily Environmental Monitoring Summary

Tuesday, April 23, 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 3:00 p.m. on 4/23

Lower Manhattan:

Air Sampling for Asbestos - EPA analyzed 71 samples taken in and around ground zero from April 15 through April 17. 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 asbestos in lower Manhattan to 8,346, with 21 samples above the standard (11 of these were collected prior to September 30; the other 10 were collected on October 9, November 27, December 27, January 14, February 5, February 11, March 9, March 29, March 30 and April 2).

Air Sampling for Dioxin - A total of 10 samples were collected on March 29 from several locations in lower Manhattan. All samples collected were below the EPA Removal Action guidelines (based on a 30-year exposure).

Air Sampling for VOC's - Sampling for volatile organic compounds (VOC's) was conducted on April 22 in the direct area of the excavation at ground zero. To protect workers at the work site, EPA takes grab samples of VOC's 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 April 22 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.

Staten Island Landfill:

Air Sampling for Particulates - There were no significant readings from samples collected on April 19.

Latest Available Daily Environmental Monitoring Summary

EPA information about the events of September 11

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