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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 York and New Jersey:
Asbestos - EPA analyzed 17 samples taken in and around ground zero on October 10. All samples 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 air samples collected and analyzed for lower Manhattan to 693, with 27 samples above the standard.
Four air samples taken in New Jersey on October 8 showed results less than the school re-entry standard. This brings the total number of samples collected and analyzed in New Jersey to 90, with zero above the standard.
Staten Island Landfill
Air (Asbestos) - Twelve samples were taken between October 3 and October 4; all of the results were below the AHERA school re-entry standard. An additional seventeen samples were collected between October 9 and October 10; all were below the AHERA standard.
Ten dust samples taken at the Staten Island Landfill on October 9 were analyzed for asbestos. All results either showed no detection of asbestos or asbestos present at concentrations of less than 1%.
Ambient Air Sampling:
PM 2.5 - Monitoring for fine particulate matter (particles less than 2.5 micrometers in diameter) was conducted October 8 at Pace University, the Borough of Manhattan Community College and the U.S. Coast Guard building, located in Battery Park. All 24-hour average values were below the National Ambient Air Quality Standard (65 ug/m3) for all stations.
VOCs - Sampling for volatile organic compounds (VOCs) was conducted on October 10 in and around ground zero. Benzene was detected above the OSHA limit in the smoke plume of the debris pile, but not at a location outside the perimeter of ground zero. Overall readings for VOCs, including benzene, have decreased in comparison with previous readings.
U.S. Government Website