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pollutant emissions , such as implementing vehicle emissions inspections or the use of special <br /> gasoline additives . Under extreme cases , non- attainment areas may lose sources of Federal <br /> funding (e . g . , for highway construction) for failure to take adequate action to meet Clean Air Act <br /> requirements . Geographic areas, usually metropolitan statistical areas (MSAs) are used to draw <br /> the non- attainment areas . Chapel Hill is generally considered to be part of the <br /> Raleigh/Durham/Chapel Hill MSA for the purposes of reporting air quality . But, with respect to <br /> ility that the Raleigh/Durham/Chapel Hill area may be a non- attainment area for ozone , <br /> the possib <br /> the non-attainment area has not been drawn. Definition of the area is part of a "designation" <br /> process , which has not begun yet . Based on discussions with staff at the NC Division of Air <br /> Quality, there are three options for how non- attainment areas could be drawn . <br /> Table 24 National and North Carolina Ambient Air Quality Standards' <br /> Pollutant Averaging Type of Primary Secondary North Carolina <br /> Period Summary National National Standard <br /> Standard Standard <br /> PM15 1 year Average mean 15 g/m3 15 g/m3 15 g/m <br /> (24- hr avg) b ( 3 years) <br /> 1 day Average 981 65 g/m3 65 g/m3 65 g/m <br /> percentile <br /> PM10 1 year Average mean 50 g/m3 50 g/m3 50 g/m <br /> (24 -hr avg)b ( 3 years) <br /> 1 day Average 98t 150 g/m3 150 g/m 150 g/m <br /> percentile <br /> CO ( 1 -hr avg) 8 hours 2nd maximum 9 ppm 9 ppm <br /> 1 hour 2n maximum 35 ppm 35 ppm <br /> 03 ( 1 hr avg) 1 hour 2nd maximum 0 . 12 ppm 0 . 12 ppm 0 . 12 ppm <br /> 8 hours Average mean 0 . 08 ppm 0 . 08 ppm 0 . 08 ppm <br /> S02 ( 1 -hr avg) 1 year Mean 0 . 03 ppm 0 . 03 ppm <br /> 1 day 2nd maximum 0 . 14 ppm 0 . 14 ppm <br /> 3 hours 2nd maximum 0 . 50 ppm 0 . 50 ppm <br /> NO2 ( 1 -hr avg) 1 year Mean 0 . 053 ppm 0 . 053 ppm 0 . 053 ppm <br /> Pb (24-hr avg) 1 quarter Mean 1 . 5 g/m 1 . 5 g/m 1 . 5 g/m <br /> a Abbreviations ; PM : Particulate Matter; CO : Carbon Monoxide ; 03 : Ozone; S02: Sulfur Dioxide ; <br /> NO2 * Nitrogen Dioxide ; Pb : Lead; Mean : Arithmetic Mean ; Avg : Average <br /> b PM2 . 5 : Fine (respirable ) particulate matter with diameter of less than 2 . 5 in ; PM10 : particulate <br /> (inhalable matter with diameter less than 10 m <br /> 2 <br />