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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 39 samples taken in and around ground zero October 18 through October 19. 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 1065, with 27 samples above the standard.
Staten Island Landfill:
Air (Asbestos) - 19 samples were collected from 6:00 p.m. on October 19 through 7:30 a.m.on October 20. All samples showed results less than the AHERA standard.
Particulate Monitoring - Samples collected on October 19, 20, and 21 using portable monitors showed no significant readings. Samples collected on October 22 showed an increase from previous results.
Ambient Air Sampling:
PM 2.5 - Monitoring for fine particulate matter (particles less than 2.5 micrometers in diameter) was conducted on October 21 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.
Particulate Monitoring - Samples collected on October 22 using personal monitors (datarams) from Fixed Air Monitoring L (north east side of Stuyvesant High), R (north west side of Stuyvesant High School), and N (South side of Pier 25) were all below the OSHA time-weighted average permissible level for particulates.
Direct Air Readings - Using portable monitors, direct air readings were taken in and around ground zero on October 22. Carbon monoxide was detected above the National Ambient Air Quality Standard (NAAQS) 8-hour average of 9 ppm, however the readings were below the NAAQS 1-hour average of 35 ppm and the OSHA permissible level of 50 ppm.
PCBs - Two dust samples were collected and analyzed from rooftops in the vicinity of the former World Trade Center on October 10. These samples were analyzed for pesticides and PCBs. Pesticides were not detected and PCBs were detected at trace concentrations, well below levels of concern.
Asbestos - Asbestos was detected above 1% chrysotile in 5 of 87 samples collected from structural steel taken from the debris pile to metal recycling facilities.
U.S. Government Website