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Daily Environmental Monitoring Summary

Wednesday, February 13, 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 10:30 a.m. on 2/14

Air: Fixed Monitors in New York:
Asbestos - EPA analyzed 53 samples taken in and around ground zero on February 6 and February 7. 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 5,880, with 16 samples above the standard (11 of these were collected prior to September 30, the other five were collected on October 9, November 27, December 27, January 14 and February 5).

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) - Thirty-eight air samples collected on February 6 and February 7 were analyzed for asbestos. Samples taken at one of the Wash Tents (Location W-11), showed 110.2 structures per square millimeter on February 6, and 170.6 structures per square millimeter on February 7, both of which exceed the AHERA school re-entry standard. In addition, a sample taken on February 7 at the Mess Tent (Location T-15) was just above OSHA's permissible exposure limit (PEL) of 0.1 fibers per cubic centimeter. All other samples were below the school re-entry standard.

Air (Particulates) - EPA used portable monitors to collect samples of particulates on February 8, 9 and 11 at the Staten Island Landfill. There were no significant readings.

Ambient Air Samples:
PM 2.5 - Monitoring for fine particulate matter (particles less than 2.5 micrometers in diameter) was conducted from February 2 through February 8 at Chambers & West Streets, Park Row, and Wall Street. All 24-hour averages were below the National Ambient Air Quality Standard (NAAQS) of 65 ug/m3 for all stations. These results were also less than 40 ug/m3, a level on the EPA Air Quality Index indicating that air quality is unhealthy for sensitive populations (e.g., those with respiratory illnesses).

PM10 - Monitoring for particulate matter (particles less than 10 micrometers in diameter) was conducted from February 2 through February 8 at a location on Wall Street. All 24-hour average values were below the National Ambient Air Quality Standard of 150 ug/m3.

Particulate Monitoring - EPA used portable monitors to collect samples on February 12 in the following locations: L (north east side of Stuyvesant High School); N (south side of Pier 25); and R (north west 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 12 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.

A sample taken at Austin Tobin Plaza on February 12 exceeded the OSHA PEL for both benzene and 1,3-butadiene. Note that this sample was collected in the vicinity of a burning acetylene cylinder.

All samples taken on February 12 at EPA's Wash Tent (West & Murray Streets), the South Tower debris pile, and the North Tower debris pile showed no detectable levels of VOC's, or the levels of VOC's did not exceed OSHA standards.

Latest Available Daily Environmental Monitoring Summary

EPA information about the events of September 11

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