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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.
Air: Fixed Monitors in New York:
Asbestos - EPA analyzed 43 samples taken in and around ground zero on December 6 and December 7. In addition, EPA took three samples at three additional lower Manhattan locations on December 5. 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 3,197, with 29 samples above the standard (27 of these were collected prior to September 30, one was collected on October 9 and the other on November 27).
Air: Fixed Monitors outside lower Manhattan:
Asbestos - Additional asbestos monitors have been placed at Public School 154 (33 East 135th St., Bronx), Intermediate School 143 (511 W. 182nd St., Manhattan), P.S. 274 (800 Bushwick Ave, Brooklyn), P.S. 44 (80 Maple Parkway, Staten Island) and P.S. 199 (3290 48th St., Queens). Five asbestos samples collected on December 5 from these locations showed no exceedances of the AHERA re-entry standard.
Air: Fixed Monitors in New Jersey:
Asbestos - Four air samples were taken in New Jersey on December 6. All samples showed results less than school re-entry standard. This brings the total number of samples collected and analyzed in New Jersey to 215, with zero above the standard.
Staten Island Landfill:
Air (Asbestos) - Thirty-eight samples were collected on December 6 and 7. All of these samples were below the school re-entry standard.
PM 2.5 - Monitoring for fine particulate matter (particles less than 2.5 micrometers in diameter) was conducted on December 9 at Pace University, Borough of Manhattan Community College, the Coast Guard building in Battery Park and on 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 on December 9 at a location on Wall Street. All 24-hour average values were below the National Ambient Air Quality Standard of 150 ug/m3.
VOCs - Sampling for volatile organic compounds (VOCs) was conducted on December 9 and December 10 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. One sample of benzene taken on the debris pile at the North Tower on Dec. 9 exceeded the OSHA PEL of one part per million (ppm) and another found a detectable level in the same location. There were no exceedances on Dec. 10. Four of six samples taken at EPA's Wash Tent (West St. and Murray) and Austin Tobin Plaza showed no detectable levels of benzene.
Direct Air Readings - On December 9, EPA did air monitoring in and around ground zero for a number of compounds. No significant readings were found during the afternoon hours. No monitoring was conducted in the morning due to rain.
U.S. Government Website