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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 on October 9 and 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 727, with 27 samples above the standard.
Four air samples taken in New Jersey on October 9 showed results less than the school re-entry standard. This brings the total number of samples collected and analyzed in New Jersey to 94, with zero above the standard.
Staten Island Landfill
Air (Asbestos) - 17 samples were taken between 6:00 AM and 10:00 PM on October 10; all of the results were below the AHERA standard used for allowing re-entry into schools.
Particulate Monitoring - Samples were collected at the landfill from October 6 through October 11 using portable monitors. There were no significant readings on October 6, 9 and 10. On October 7 and 8, at Location #9, which is in the area where the debris is being sifted, elevated particular matter levels were detected based on a daily average concentration. It was also observed that there were elevated wind speeds on October 7 and 8, which may have contributed to the elevated readings.
Ambient Air Sampling:
PM 2.5 - Monitoring for fine particulate matter (particles less than 2.5 micrometers in diameter) was conducted October 9 and 10 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.
Particulate Monitoring - Using portable monitors, EPA also collected particulate matter samples on October 11 in the same area of the following Fixed Asbestos Air Monitors: L (North side of Stuyvesant High), M (Western end of Harrison Street at West Street), and N (South side of Pier 25). All samples were well below the OSHA time-weighted average for particulates.
VOCs - Sampling for volatile organic compounds (VOCs) was conducted on October 11 in the smoke plume on the debris pile at ground zero. There was a general increase in VOC levels, including benzene, compared to data collected on October 10. Benzene exceeded the OSHA time-weighted average permissible exposure level at two locations in the smoke plume.
Dioxin - Ten samples were collected on September 27 and analyzed for dioxin/furans. Two of the samples showed results above the guideline level at which EPA would take some type of action to reduce people's exposure. This guideline level assumes a 30-year exposure scenario. One of the samples (Location A at West Broadway and Barclay) was nominally above the EPA guideline level when adjusted to a 1-year exposure duration. These levels do not pose a short-term health affect but should be monitored if they persist for a longer period of time. All other locations had results that were generally lower than previous dioxin data reported on September 16 and 23.
U.S. Government Website