Donate to Hurricane Recovery

PM2.5 Design Values for 2011-2013 in NC Counties

There are no counties with a 3-year average of the annual mean PM2.5 for each year above the annual standard and no counties with a 3-year average of the 98th percentile above the daily standard.

Table 1. The following table shows 30 counties with a 3-year average of the annual mean PM2.5 for each year below the established annual standard and 3-year averages for the 98th percentile of PM2.5 concentrations below the established daily standard. The first column lists the county; the second lists the average value for that county (rounded to the specifications of the annual standard); the third lists the average value for that county (rounded to the specifications of the daily standard). In Counties with more than one PM2.5 monitoring site, the value reported is the highest 3-year average among the inclusive sites.

Notes:

  • The annual Fine Particle (PM2.5)standard is designed to protect against health effects associated with both long- and short-term exposure to PM2.5
  • Meeting the annual standard of 12 µg/m3 occurs when the 3-year average of annual averages of PM2.5 concentration is 12 µg/m3 or less.
  • The 24-hour (Daily) standard is designed to provide supplemental health protection against short-term fine particle exposures. It is especially applicable if areas have high spikes in PM2.5 concentrations.
  • The daily PM2.5 standard is met if the 98th percentile of 24-hour PM2.5 concentrations in one year, averaged over 3 years is 35 µg/m3 or less.
  3-Year Averages
County Annual Standard
(12 µg/m3)
Daily Standard
(35 µg/m3)
Alamance 8.9 µg/m3 20 µg/m3
Buncombe 8.6 µg/m3 17 µg/m3
Caswell 8.3 µg/m3 18 µg/m3
Catawba 9.5 µg/m3 19 µg/m3
Chatham 7.6 µg/m3 18 µg/m3
Cumberland 9.1 µg/m3 19 µg/m3
Davidson 10.1 µg/m3 20 µg/m3
Duplin 8.1 µg/m3 19 µg/m3
Durham 8.4 µg/m3 18 µg/m3
Edgecombe 8.3 µg/m3 19 µg/m3
Forsyth 8.9 µg/m3 19 µg/m3
Gaston 9.4 µg/m3 21 µg/m3
Guilford 8.7 µg/m3 20 µg/m3
Haywood 9.1 µg/m3 20 µg/m3
Jackson 8.3 µg/m3 16 µg/m3
Johnston 8.1 µg/m3 18 µg/m3
Lenoir 8.3 µg/m3 21 µg/m3
Martin 7.7 µg/m3 22 µg/m3
McDowell 9.0 µg/m3 18 µg/m3
Mecklenburg 9.8 µg/m3 22 µg/m3
Mitchell 8.5 µg/m3 18 µg/m3
Montgomery 8.5 µg/m3 19 µg/m3
New Hanover 7.3 µg/m3 21 µg/m3
Pitt 7.8 µg/m3 19 µg/m3
Robeson 8.9 µg/m3 19 µg/m3
Rowan 9.4 µg/m3 19 µg/m3
Swain 8.8 µg/m3 19 µg/m3
Wake 10.1 µg/m3 22 µg/m3
Watauga 7.6 µg/m3 16 µg/m3
Wayne 9.0 µg/m3 20 µg/m3