Jump to main content.

Daily Environmental Monitoring Summary

Tuesday, January 29, 2002

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 5:30 p.m. on 1/29

Air: Fixed Monitors in New York:
Asbestos - EPA analyzed 84 samples taken in and around ground zero from January 24 through January 26. All samples showed results less than 70 structures per square millimeter, 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 5,380, with 31 samples above the standard (27 of these were collected prior to September 30, the other four were collected on October 9, November 27, December 27 and January 14).

Staten Island Landfill:
Air (Asbestos) - Thirty-seven air samples collected on January 24 and January 25 were analyzed for asbestos. All samples were below the school re-entry standard.

Ambient Air Samples:
PM 2.5 - Monitoring for fine particulate matter (particles less than 2.5 micrometers in diameter) was conducted from January 21 through January 26 at Chambers & West Streets, Park Row, and Wall Street. All 24-hour averages 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, a level on the EPA Air Quality Index indicating that air quality is unhealthy for sensitive populations (e.g., those with respiratory illnesses).

PM10 - Monitoring for particulate matter (particles less than 10 micrometers in diameter) was conducted from January 21 through January 26 at a location on Wall Street. All 24-hour average values were below the National Ambient Air Quality Standard of 150 ug/m3.

Particulate Monitoring - EPA used portable monitors to collect samples on January 28 at Location N (south side of Pier 25), Location R (northwest side of Stuyvesant High School) and Location L (northeast side of Stuyvesant High School). All readings were below the OSHA time-weighted permissible exposure limit for particulates.

Isocyanates - A total of 24 samples were collected on December 11 and December 19 at numerous locations in lower Manhattan. The level of MDI (4,4'-Methylenediphenyl Isocyanate) identified at Location R (northwest side of Stuyvesant High School) on December 19 was above the EPA action guidance level. (Note that winds, at the time of this sampling event, were off the Hudson River.) Isocyanates in all other samples were either not detected or were below the OSHA PEL and NIOSH REL.

VOCs - Sampling for volatile organic compounds (VOCs) was conducted on January 28 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.

All samples taken on January 28 at EPA's Wash Tent (West & Murray Streets), Austin Tobin Plaza, the South Tower debris pile, and the North Tower debris pile showed no detectable levels of VOC's.

Latest Available Daily Environmental Monitoring Summary

EPA information about the events of September 11

Jump to main content.