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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 19 fixed air 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 57 samples taken in and around ground zero, from October 14 through October 16. 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 933, with 27 samples above the standard.
Staten Island Landfill:
Air (Asbestos) - 15 samples were collected on October 15; fourteen of these showed results below the AHERA standard use for allowing re-entry into schools. One sample taken near the barge loading area exceeded this standard.
Particulate Monitoring - Samples collected on October 16 and 17 using portable monitors showed no significant readings.
Dioxin - Four archived samples originally collected on September 11 were analyzed for dioxin/furans. All samples showed levels of dioxin below the residential clean-up goal of 1 part per billion.
Ambient Air Sampling:
Dioxin - Ten samples were collected in the restricted work area near ground zero on October 4 and analyzed for dioxin/furans. Four of the samples showed results above the level at which EPA would take some type of action to reduce people's exposure. This action level, however, is based on a 30-year exposure scenario.
Two of the samples taken at the southwest corner of Building #5 of the World Trade Center and at West Broadway and Barclay were slightly above the EPA's action 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.
PM 2.5 - Monitoring for fine particulate matter (particles less than 2.5 micrometers in diameter) was conducted from October 14 to October 16 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 Standards (65 ug/m3) for all stations.
PM 10 - Monitoring for fine particulate matter (particles less than 10 micrometers in diameter) was conducted from October 2 to 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 Standards (150 ug/m3) for all stations.
Monitoring for PM 10 was conducted from October 3 through October 8 at P.S. 274 in Brooklyn and from October 4 to October 7 at the Canal Street Post Office. All 24-hour average values were below the National Ambient Air Quality Standards (150 ug/m3) for all stations.
VOCs - Sampling for volatile organic compounds (VOCs) was conducted on October 16 in the plume in the debris pile. Benzene exceeded the OSHA time-weighted average permissible level (1 part per million) at two locations in the pile at ground level. (Note: In a previous Daily Summary EPA identified benzene's permissible level as 0.5 ppm.) This concentration of .05 ppm represents an OSHA action level used to trigger certain monitoring requirements.
Particulate Monitoring - EPA collected samples using portable monitors at the following locations where EPA has fixed air montiors: on October 16 at Locations M1 (West Street south of Harrison) and N (south side of Pier 25), and on October 17 at Locations L (North side of Stuyvesant HS near North Park), N (south side of Pier 25) and R (TAGA bus location). No significant readings were found.
U.S. Government Website