4000bce - 399
400 - 1399
1400 - 1499
1500 - 1599
1600 - 1699
1700 - 1799
1800 - 1899
1900 - 1999
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.
Air: Fixed Monitors in New York:
Asbestos - EPA analyzed 44 samples taken in and around ground zero from December 10 through December 11. 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 3,377, with 29 samples above the standard (27 of these were collected prior to September 30, one was collected on October 9 and the other on November 27).
Staten Island Landfill:
Air (Asbestos) - Nineteen air samples collected on December 11 were analyzed for asbestos. One of these samples, taken at "Barge" Location #14, was above the school re-entry standard. All other eighteen samples were below the standard.
VOCs - Sampling for volatile organic compounds (VOCs) was conducted on December 13 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 standard at two locations on the debris pile -- the North Tower and South Tower. Two other samples taken at EPA's Wash Tent (West St. and Murray) and Austin Tobin Plaza showed no detectable levels of benzene. One sample results also showed an exceedance above the OSHA standard for 1,3-Butadiene at the South Tower. There was no detection for 1,3-Butadiene in three other samples taken.
U.S. Government Website