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

There are no counties with a 3-year average of the annual mean PM_2.5 for each year above the annual standard and no counties with a 3-year average of the 98^th percentile above the daily standard.

Table 1. The following table shows 30 counties with a 3-year average of the annual mean PM_2.5 for each year below the established annual standard and 3-year averages for the 98^th percentile of PM_2.5 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 PM_2.5 monitoring site, the value reported is the highest 3-year average among the inclusive sites.

Notes:

• The annual Fine Particle (PM_2.5)standard is designed to protect against health effects associated with both long- and short-term exposure to PM_2.5
• Meeting the annual standard of 12 µg/m³ occurs when the 3-year average of annual averages of PM_2.5 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 PM_2.5 concentrations.
• The daily PM_2.5 standard is met if the 98th percentile of 24-hour PM_2.5 concentrations in one year, averaged over 3 years is 35 µg/m³ or less.