Distributions of PM<sub>10</sub> and PM<sub>2.5</sub>,1999–2005, surveillance-oriented sites from contiguous U.S. region.


a<p>Following the promulgation of the National Ambient Air Quality Standard for PM<sub>2.5</sub> in 1997, routine collection of PM<sub>2.5</sub> was implemented in 1999. No attempt was made to convert PM<sub>10</sub> concentrations to PM<sub>2.5</sub>, which requires a scaling factor based on a presumptive proportion of PM<sub>2.5</sub> in the PM<sub>10</sub> mass.</p>b<p>Sites describe unique sampling points indicated by longitude/latitude. Those providing no geodetic datum information were not included.</p>c<p>While PM was typically measured at a frequency of every six days or higher, many sites took daily sampling.</p

    Similar works

    Full text


    Available Versions