September 11, 2001 : Attack on America
Daily Environmental Monitoring Summary Thursday; October 25, 2001

Daily Environmental Monitoring Summary

Thursday, October 25, 2001

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 more than 20 fixed air monitors in and around ground zero and additional monitors in the Bronx, Brooklyn, Queens and Staten Island. The Agency is also using portable sampling equipment to collect data from a range of locations.

Results as of 5:00 p.m. on 10/25

Air: Fixed Monitors in New York and New Jersey:

Asbestos - EPA analyzed 79 samples taken in and around ground zero from October 22 through October 24. 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 1243, with 27 samples (all collected prior to September 30) above the standard. Eight air samples taken in New Jersey from October 21 and October 22 showed results less than the school re-entry standard. This brings the total number of samples collected and analyzed in New Jersey to 146, with zero above the standard.

Staten Island Landfill:

Air (Asbestos) - 92 samples were collected on October 21. All of these samples showed results less than the school re-entry standard.

Ambient Air Sampling:

PCBs - Sampling for polychlorinated biphenyls (PCBs) was conducted on October 11. PCBs were not detected in seven of the samples. Three of the samples showed trace amounts, well below levels of concern.

VOCs - Sampling for volatile organic compounds (VOCs) was conducted on October 24 in the direct area of the debris pile at ground zero. Benzene exceeded the OSHA time-weighted average permissible level at two locations. EPA detected elevated readings of a compound, which has tentatively been identified as Freon-22 (chlorodiflouromethane) in samples collected from within the debris pile using extended probes. EPA will do additional sampling and analysis to both confirm if the compound is Freon-22 and to determine the actual levels detected. EPA is working with the local agencies and health and safety officers working at ground zero to closely monitor this situation so that workers can take appropriate precautions.

Particulate Monitoring - EPA used portable monitors to collect samples on October 24 in the following areas, which are also the locations of Fixed Air Monitors: L (north east side of Stuyvesant High), R (north west side of Stuyvesant High School), and N (South side of Pier 25). All readings were all below the OSHA time-weighted average permissible level for particulates.

Asbestos (Supplemental Monitoring) - Ninety-nine asbestos samples were taken at the locations of the following fixed particulate matter (PM 2.5) monitoring stations: Pace University, Manhattan Boro Community College, the Coast Guard Building in Battery Park, Public School (PS) 154 at 333 E. 135th St in the Bronx, Intermediate School 143 at 511 W. 182nd St in Manhattan, PS 274 at 800 Bushwick Ave. in Brooklyn, PS 44 at 80 Maple Parkway in Staten Island, and PS 199 at 3290 48th Ave. in Queens. Ninety-seven of the samples showed results less than the school re-entry standard, with two samples - one in Manhattan, one in Queens -above the standard.

Direct Air Readings - Using portable monitors, direct air readings were taken in and around ground zero on October 24. Low levels of chlorine below the OSHA permissible level were detected. Several carbon monoxide readings were 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 on October 8 from rooftops in the vicinity of the former World Trade Center. Both samples detected trace concentrations PCBs that were well below levels of concern.

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