Jump to main content.

Daily Environmental Monitoring Summary

Wednesday, November 7, 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 11/7

Air: Fixed Monitors in New York:
Asbestos - EPA analyzed 46 samples taken in and around ground zero from November 3 through November 4. 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 1,747, with 28 samples above the standard (27 were collected prior to September 30 and one was collected on October 9).

Air: Fixed Monitors outside Manhattan:
Asbestos - Additional asbestos monitors have been placed at Public School (P.S.) 154 (33 East 135th St., Bronx), Intermediate School 143 (511 W. 182nd St., Manhattan), P.S. 274 (800 Bushwick Ave, Brooklyn), P.S. 44 (80 Maple Parkway, Staten Island) and P.S. 199 (3290 48th St., Queens). On October 25, a total of ten samples were collected from these locations. All the samples showed results less than the school re-entry standard.

Staten Island Landfill:
Air (Asbestos) - Seventy-two samples were collected from November 3 through November 5. All the samples showed results less than the school re-entry standard. During this period, one sample located around the sifting and wash operations areas was not analyzed due to filter overloading and three locations experienced sampler pump failure deeming the results invalid.

VOCs - Sampling for VOCs was conducted on November 2, 3 and 5 in the direct area of the debris pile at ground zero. To protect workers at the work site, EPA takes grab samples of VOCs where smoke plumes have been sighted. The results are snapshots of the levels at a moment in time. OSHA's protective standards set a permissible exposure limit (PEL) averaged over an 8-hour day.

Benzene exceeded the OSHA PEL of 1 part per million (ppm) in some samples taken from the North Tower and South Tower debris piles. The samples taken at North Park Pier did not find any benzene, toluene, ethyl benzene, and styrene levels above the detection limit of 20 parts per billion by volume (ppbv). Elevated levels of toluene, ethyl benzene and styrene were found in a sample collected from the North Tower debris pile; however, all levels were below their respective OSHA PELs. Chlorodifluoro-methane (Freon-22) was not found in any samples above the detection limit of 20-50 ppbv.

PM 2.5 - Monitoring for fine particulate matter (particles less than 2.5 micrometers in diameter) was conducted on November 3 through November 5 at Pace University, Borough of Manhattan Community College, and the Coast Guard building in Battery Park. All 24-hour average values were below the National Ambient Air Quality Standard (NAAQS) of 65 ug/m3 for all stations. These results were also less than 40 ug/m3, an EPA air quality index which would indicate that the air quality is unhealthy for sensitive populations (e.g., those with respiratory illnesses).

PM 10 - Monitoring for particulate matter (particles less than 10 micrometers in diameter) was conducted from October 16 through October 24 at Pace University, Borough of Manhattan Community College, the Coast Guard building, Public School (P.S.) 274 in Brooklyn, and the Canal Street Post Office. All 24-hour average values were below the National Ambient Air Quality Standard of 150 ug/m3 for all available stations.

Particulate Monitoring - EPA used portable monitors to collect samples on November 4 and 5 at the following locations: L (north east side of Stuyvesant High School); N (south side of Pier 25); and R (north west side of Stuyvesant High School). All readings were below the OSHA time-weighted permissible exposure level for particulates.

Direct Air Readings - Direct readings taken on November 3 through November 5 showed no levels of significance. No readings were noted above the carbon monoxide NAAQS 8-hour average of 9 ppm.

Latest Available Daily Environmental Monitoring Summary

Resources on the World Wide Web:

EPA information about the events of September 11

Jump to main content.