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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 17 fixed monitors in and around ground zero and is using portable sampling equipment to collect data from a range of locations.
Air: Fixed Monitors in New Jersey:
Asbestos - Four air samples taken in New Jersey on October 4 showed results less than 70 structures per millimeter squared, 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 samples collected and analyzed in New Jersey to 74, with zero above the standard.
Staten Island Landfill
Air (Asbestos) - 33 air samples were taken from October 4 through October 5. All test results were below the AHERA standard used for allowing re-entry into schools.
Particulates - EPA detected a rise in the average concentration of particulates at several locations on October 4 and 5th, mostly in the areas of the landfill where the screening of debris is being conducted. EPA continues to emphasize that workers follow dust suppression procedures (wetting down debris) as specified in the site health and safety plan.
Ambient Air Sampling:
PM2.5 - Monitoring for fine particulate matter (particles less than 2.5 micrometers in diameter) was conducted on October 4 from stations at Pace University, Borough of Manhattan Community College and the U.S. Coast Guard Building located at Battery Park. All of the 24-hour averages were below the stringent National Ambient Air Quality Standard of 65 ug/m3.
VOCs - Sampling for volatile organic compounds (VOCs) was conducted on October 5. Benzene was detected above the OSHA limit at three locations in the plume of the debris pile. Benzene was not detected at four perimeter locations.
PCBs - On September 28, at that request of the Ground Zero Elected Officials Task Force, EPA took wipe samples inside three lower Manhattan schools. Eight samples were collected from Borough of Manhattan Community College and seven samples were collected from Stuyvesant High School. All samples showed no detectable levels of PCBs.
Dioxin - On September 28 and 29, EPA collected six wipe samples from inside Borough of Manhattan Community College, Stuyvesant High School and Public School 234. All samples showed no detectable levels of dioxin.
U.S. Government Website