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Daily Environmental Monitoring Summary

Wednesday, April 10, 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 3:45 p.m. on 4/10

Lower Manhattan:

Air Sampling for Asbestos - EPA analyzed 67 samples taken in and around ground zero on March 24, April 1 and April 2. 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 April 2 at Location "W" (Wash Tent Common Area) showed 80 structures per square millimeter, which exceeds the AHERA standard. This brings the total number of air samples collected and analyzed for asbestos in lower Manhattan to 7,806, 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 Particulates - EPA collected samples on April 9 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.

Air Sampling for Metals - Ten samples were collected on February 5 at various locations in lower Manhattan. One sample, collected at Location "A" (northeast corner of West Broadway and Barclay Street), showed 0.048 micrograms per cubic meter (ug/m3) of arsenic, which nominally exceeds EPA's Removal Action level guideline of 0.041 ug/m3, based on a 30-year exposure. However, the sample was below the EPA Removal Action level guideline adjusted to 1-year exposure, as well as the NIOSH REL (2 ug/m3), and the OSHA PEL (10 ug/m3). Metals in all other samples were either not detected or were below applicable EPA Removal Action level guidelines, OSHA PELs, and the NAAQS for lead.

Air Sampling for VOC's - Sampling for volatile organic compounds (VOC's) was conducted on April 9 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 9 at EPA's Wash Tent (West & Murray Streets), Austin Tobin Plaza, and the North Tower and South Tower excavation areas showed no detectable levels of VOC's.

Staten Island Landfill:

Air Monitoring for Particulates - There were no significant readings from samples collected on April 5 and April 9.

Latest Available Daily Environmental Monitoring Summary

EPA information about the events of September 11

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