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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 34 samples taken in and around ground zero from October 2 to October 3. All samples showed results less than the 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 (Link to map). This brings the total number of air samples collected and analyzed for lower Manhattan to 510, with 27 samples above the standard.
Four air samples taken in New Jersey on October 1 were all below the school re-entry standard. The total samples taken for New Jersey is 62, with zero above the standard.
Dust - Eight samples were taken on October 3 at various sites in lower Manhattan. All results either showed no detection of asbestos or asbestos present at concentrations of less than 1%, the level that indicates that a material is abestos-containing. The total number of dust samples taken for lower Manhattan is 136, with 34 greater than 1%.
Staten Island Landfill (Asbestos)
Air - Eleven air samples were taken from Oct. 2 to Oct. 3 and analyzed for asbestos. All test results were below the AHERA standard used for re-entry into schools.
Dust - Eight samples taken on October 3 were analyzed for asbestos. All results either showed no detection of asbestos or asbestos present at concentrations of less than 1%.
Ambient Air Sampling:
Metals - Ten samples were taken on October 2 in the vicinity of the World Trade Center. Of these, chromium results for four samples exceeded EPA's removal action guideline, which is based on exposure over 30 years, 24 hours per day. When this guideline is adjusted for a one year exposure, none of the levels exceeded the adjusted guideline. All levels were less than the most conservative National Institute of Occupational Safety and Health (NIOSH) standard for chromium.
Ambient Air Samples
VOCs - Sampling for volatile organic compounds (VOC) was conducted on Oct. 3. Benzene was detected above the OSHA limit at three locations in the smoke plume on the debris pile. Benzene was not detected at three perimeter locations.
PM 2.5 - Monitoring for fine particulate matter (particles less than 2.5 micrometers in diameter) was conducted from September 26 to October 2 at Pace University and the Borough of Manhattan Community College. Particulate monitoring was also conducted on October 2 at the U.S. Coast Guard building located in Battery Park. All of the 24-hour averages were below the stringent National Ambient Air Quality Standard of 65 ug/m3.
U.S. Government Website