Fine Particulate Matter Monitoring
PM is an abbreviation for Particulate Matter. PM2.5 is the abbreviation for fine Particulate Matter with a diameter smaller than 2.5 microns. (By comparison, human hair diameters range from 40 to 120 microns.) PM2.5 is produced by combustion, including vehicle exhaust, and by chemical reactions between gases such as sulfur dioxide, nitrogen oxides, and volatile organic compounds.
Adverse health effects from breathing air with a high PM2.5 concentration include: premature death, increased respiratory symptoms and disease, chronic bronchitis, and decreased lung function particularly for individuals with asthma.
The EPA has promulgated health based standards for the concentration of PM2.5 in the atmosphere. The National Ambient Air Quality Standards (NAAQS) for the 24-hour average and annual average have been set at 35 and 15 µg/m3, respectively. The data presented here has been gathered using EPA's Federal Reference Method (FRM). Only FRM data will be used for determining compliance with the health based standards.
The PM2.5 FRM is a filter based method whereby one 24 hour sample is collected every third day, except for a few sites where daily sampling takes place. There are also monitors using this technology, modified to collect PM10 samples. PM10 is the abbreviation for fine Particulate Matter with a diameter smaller than 10 microns. Two sites' (IS 52 in the Bronx and Rochester) PM10 samples are further analyzed to determine concentrations of selected metals.
DEC also complements the FRM network with real-time direct reading hourly PM2.5 measurements that can be found at the Current Air Quality Measurement Data web page.