DEP advisory to residents regarding WTC dust, Oct 2001

NYC 9/11 Public Portal Document

While environmental air sampling results outside of the debris pile and outside of the plume continue to show that levels of dust and other substances are within the levels specified by federal standards. City and State health agencies are communicating with physicians in the community to determine health conditions.

What is fine paiticuiate matter and why is it being monitored?

The explosion at the WTC released very small airborne particles into the air known as “fine particulate matter,” or “PM” for short. Particulate matter comes mostly from the process of combustion (burning). Fires are a source of particulate matter, as is the exhaust from cars, trucks, buses, and other operations that involve the burning of fuel.

Particulate matter ranges in size from very small to larger particles. The most commonly measured sizes are PM 2.5 and PM w PM 2.5 refers to particles that are 2.5 microns or less in diameter. These particles are extremely small and are therefore more likely to be inhaled deeper into the lungs. PM w refers to particles that include 2.5 microns in size as well particles up to 10 microns in diameter, which, because of their relatively larger size, cannot travel as deep into the lungs. Increased levels of fine particulate matter can cause eye, nose, throat and lung irritation, which can trigger coughing and sneezing. Such exposures may aggravate symptoms for persons with underlying respiratory conditions.

Even prior to September 11, the Nev/ York State Department of Environmental Conservation (NYSDEC) has had continuous (real-time) air particulate monitors (PM2.s) collecting samples at eleven sites in New York City. These routine monitors are located in each Borough. The data from these monitors are evaluated daily. Additional monitors have been set up to collect particulate data (PM2.S and PM 10) in the community near the site. Results from the air monitors are compared to the National Ambient Air Quality Standard. For PM 10 the standard is 150 micrograms of particles per cubic meter of air .1 (ug/m3). For PM 2.s. the standard is 65 ug/m3 for the general population. The PM 2.5 standard is 40 ug/m3 for people with respiratory illnesses, individuals with heart problems and the elderly or young, since these individuals may be more susceptible to more severe symptoms.

What are the resuits of the PM 2.5 and PMio monitoring?

Testing at the monitoring sites set up both before and after September 11 “’has revealed that, in general, levels of fine and course Particulate Matter have been within the EPA standards.

Where can i find more information on the WTC-related environmentai testing?

Daily WTC-related reports that contain results of sampling for air, water, and dust- including asbestos and Particulate Matter - are posted online at the U.S. Environmental Protection Agency’s website, epa.gov. DEP results are posted atnyc.gov/dep.

January 2002

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