PM2.5 Design Values for 1999-2001 in NC Counties

A map of estimated annual mean PM2.5 in 24 hour concentrations for January 1999 through December 2001.


Figure 1 Annual Design Values (Mean) (click for larger image)

Table 1. The following table shows 11 counties with a 3-year average of the annual mean PM2.5 for each year below the established standard. The first column lists the county; the second lists the average value for that county. Some entries have an additional comment indicating the design value given is based on incomplete data.

CountyAverage valueAdditional comment
Alamance14.6 µg/m3 
Buncombe14.4 µg/m3at least one calendar quarter was not valid
Caswell14.5 µg/m3at least one calendar quarter was not valid
Chatham13.4 µg/m3at least one calendar quarter was not valid
Duplin12.6 µg/m3 
Lenoir12.3 µg/m3 
New Hanover12.2 µg/m3 
Onslow12.1 µg/m3 
Orange14.3 µg/m3 
Pitt13.7 µg/m3at least one calendar quarter was not valid
Swain14.1 µg/m3 

Table 2. The following table shows 14 counties with a 3-year average of the annual mean PM2.5 for each year above the established standard. The first column lists the county; the second lists the average value for that county. Some entries have an additional comment indicating the design value given is based on incomplete data.

Note: Nonattainment designations may not follow county boundaries and will be based on later data than are shown in this table.

CountyAverage valueAdditional comment
Cabarrus15.6 µg/m3 
Catawba17.0 µg/m3at least one calendar quarter was not valid
Cumberland15.4 µg/m3 
Davidson17.3 µg/m3at least one calendar quarter was not valid
Durham15.3 µg/m3 
Forsyth16.1 µg/m3 
Gaston15.3 µg/m3 
Guilford16.3 µg/m3 
Haywood15.2 µg/m3 
McDowell15.8 µg/m3 
Mecklenburg16.6 µg/m3 
Mitchell15.3 µg/m3 
Wake15.3 µg/m3 
Wayne15.3 µg/m3 

Table 3. The following table shows 6 counties that were monitored in 2001 but did not have enough historical data to calculate a valid 3-year average of the annual mean PM2.5 that could be compared to the established standard.

CountyAverage value
EdgecombeN/A µg/m3
JacksonN/A µg/m3
MontgomeryN/A µg/m3
PasquotankN/A µg/m3
RobesonN/A µg/m3
WataugaN/A µg/m3