BTS | Table 4-47: Air Pollution Trends in Selected Metropolitan Statistical Areas

Table 4-47: Air Pollution Trends in Selected Metropolitan Statistical Areas

(Number of days with AQI values greater than 100 at trend sites and all monitoring sites)

(R) Metropolitan Statistical Area	All sites		(R)Number of trend sites	Trend sites
	Total number of sites in 2008	Number of days with AQI > 100 (2008)		Trend sites
	Total number of sites in 2008	Number of days with AQI > 100 (2008)		1994	1995	1996	1997	1998	1999	2000	2001	2002	2003	2004	2005	2006	2007	2008
Akron, OH	18	8	7	23	21	26	16	37	40	14	28	38	15	10	30	5	22	8
Albany-Schenectady-Troy, NY	26	8	5	13	12	9	8	9	15	3	18	17	9	5	8	2	13	7
Albuquerque, NM	75	24	17	5	3	5	2	3	5	7	1	11	15	5	9	3	1	0
Allentown-Bethlehem-Easton, PA-NJ	24	9	5	10	18	19	22	39	31	16	34	38	13	12	16	10	12	9
Atlanta-Sandy Springs-Marietta, GA	62	31	18	27	(R) 54	(R) 44	(R) 50	(R) 78	(R) 88	(R) 66	(R) 39	(R) 41	(R) 23	(R) 21	(R) 30	(R) 40	(R) 37	24
Austin-Round Rock, TX	25	2	1	8	28	5	2	9	14	14	5	8	9	8	9	13	4	2
Bakersfield, CA	54	152	15	129	133	127	94	104	161	164	158	186	169	160	122	137	131	147
Baltimore-Towson, MD	74	23	17	61	57	43	46	70	54	39	50	59	31	31	36	34	45	23
Baton Rouge, LA	53	16	20	(R) 25	(R) 36	(R) 20	(R) 39	(R) 32	(R) 43	(R) 51	(R) 20	(R) 18	(R) 24	(R) 22	(R) 44	(R) 28	(R) 24	8
Birmingham-Hoover, AL	60	14	21	11	50	25	29	38	65	68	41	28	17	17	35	33	41	11
Boston-Cambridge-Quincy, MA-NH	123	8	16	0	(R) 1	(R) 1	0	0	(R) 6	0	3	(R) 11	8	1	4	1	3	0
Bradenton-Sarasota-Venice, FL	27	5	8	7	6	3	14	15	11	16	14	3	10	18	11	5	4	5
Bridgeport-Stamford-Norwalk, CT	38	19	11	28	28	22	31	35	29	22	33	41	19	11	25	21	27	19
Buffalo-Niagara Falls, NY	41	4	10	13	12	6	5	26	22	7	24	29	13	8	23	(R) 6	18	4
Charleston-North Charleston, SC	23	1	9	3	1	5	5	12	13	9	0	4	3	3	8	7	5	1
Charlotte-Gastonia-Concord, NC-SC	52	24	8	15	32	40	41	67	62	(R) 38	(R) 31	(R) 41	12	(R) 16	(R) 25	21	33	16
Chicago-Naperville-Joliet, IL-IN-WI	230	3	61	(R) 24	(R) 42	(R) 25	(R) 23	(R) 36	(R) 46	(R) 31	(R) 66	(R) 39	(R) 28	(R) 20	(R) 36	(R) 11	(R) 27	2
Cincinnati-Middletown, OH-KY-IN	106	16	23	(R) 35	(R) 39	(R) 35	(R) 24	(R) 43	(R) 50	(R) 26	(R) 34	(R) 44	(R) 26	(R) 12	(R) 38	(R) 18	(R) 42	14
Cleveland-Elyria-Mentor, OH	82	13	24	32	(R) 28	(R) 28	(R) 21	(R) 32	(R) 47	(R) 25	(R) 33	(R) 34	(R) 19	(R) 20	(R) 33	(R) 16	(R) 10	12
Colorado Springs, CO	61	2	5	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
Columbia, SC	41	8	10	7	10	4	14	32	29	25	16	14	3	9	11	10	7	7
Columbus, OH	31	10	7	23	27	26	17	40	37	16	20	38	12	3	20	5	13	4
Dallas-Fort Worth-Arlington, TX	130	32	13	(R) 56	(R) 60	(R) 35	(R) 47	(R) 58	(R) 41	(R) 54	(R) 43	(R) 40	(R) 40	(R) 32	(R) 56	(R) 39	(R) 16	20
Dayton, OH	23	9	5	(R) 12	(R) 10	(R) 17	(R) 11	(R) 9	(R) 18	(R) 6	(R) 13	(R) 20	(R) 6	(R) 0	(R) 12	(R) 1	(R) 3	0
Denver-Aurora, CO	85	13	22	13	11	12	7	18	9	15	17	26	32	2	11	27	21	10
Detroit-Warren-Livonia, MI	73	7	31	21	20	26	18	33	41	17	41	(R) 33	25	11	(R) 37	12	21	7
El Paso, TX	60	17	12	8	6	10	5	12	7	15	13	10	10	3	8	8	6	5
Fresno, CA	39	92	20	90	91	105	118	86	164	164	186	204	167	84	95	97	93	89
Grand Rapids-Wyoming, MI	13	1	6	(R) 14	(R) 15	(R) 11	(R) 9	(R) 4	(R) 10	(R) 6	(R) 15	(R) 17	(R) 10	(R) 3	(R) 16	(R) 7	(R) 8	1
Greenville-Mauldin-Easley, SC	22	7	5	(R) 3	(R) 15	(R) 17	(R) 13	(R) 17	(R) 36	(R) 20	(R) 23	(R) 28	(R) 7	(R) 2	(R) 11	(R) 10	(R) 8	6
Harrisburg-Carlisle, PA	16	12	8	28	28	17	21	37	31	17	42	35	13	8	19	13	19	11
Hartford-West Hartford-East Hartford, CT	35	10	7	(R) 25	(R) 28	(R) 14	(R) 19	(R) 26	(R) 26	14	(R) 27	(R) 34	13	(R) 11	19	(R) 15	(R) 24	10
Honolulu, HI	31	0	11	0	0	0	0	0	2	2	2	2	2	2	2	1	0	0
Houston-Sugar Land-Baytown, TX	126	29	23	55	82	38	58	61	64	57	42	40	47	37	49	31	25	17
Indianapolis-Carmel, IN	83	5	25	45	39	32	27	36	43	17	27	38	17	4	34	14	24	3
Jacksonville, FL	28	0	14	1	1	2	1	14	6	3	5	1	0	4	6	7	8	0
Kansas City, MO-KS	85	3	13	(R) 19	(R) 32	(R) 13	(R) 20	(R) 23	(R) 13	(R) 19	(R) 9	(R) 22	(R) 20	1	(R) 18	24	10	0
Knoxville, TN	51	18	18	(R) 34	(R) 51	(R) 49	(R) 60	(R) 88	(R) 92	(R) 58	(R) 39	(R) 63	31	14	39	(R) 27	(R) 50	18
Las Vegas-Paradise, NV	94	12	6	22	6	21	9	9	8	6	2	13	10	4	9	12	7	0
Little Rock-North Little Rock-Conway, AR	28	2	6	8	24	9	10	13	16	29	17	18	3	0	19	11	11	2
Los Angeles-Long Beach-Santa Ana, CA	157	80	51	145	(R) 123	97	65	(R) 63	71	(R) 85	105	(R) 95	(R) 107	99	60	56	59	53
Louisville/Jefferson County, KY-IN	56	9	17	47	41	28	32	48	78	29	36	50	21	9	39	15	30	8
Madison, WI	17	1	3	1	15	7	5	8	12	3	7	10	8	1	9	1	10	1
McAllen-Edinburg-Mission, TX	8	1	1	0	0	0	0	0	0	0	0	0	2	0	0	0	0	0
Memphis, TN-MS-AR	49	10	12	37	56	39	35	55	56	52	33	34	29	11	37	30	35	10
Miami-Fort Lauderdale-Pompano Beach, FL	83	5	26	(R) 6	(R) 10	(R) 4	(R) 6	(R) 11	(R) 12	(R) 10	(R) 5	(R) 3	(R) 2	(R) 3	(R) 1	(R) 6	(R) 9	5
Milwaukee-Waukesha-West Allis, WI	55	3	12	17	23	15	6	16	(R) 25	(R) 8	25	(R) 21	17	6	(R) 21	6	11	3
Minneapolis-St. Paul-Bloomington, MN-WI	131	2	20	4	9	0	4	4	4	8	10	4	5	0	7	1	5	1
Nashville-Davidson-Murfreesboro-Franklin, TN	51	11	18	31	46	46	44	45	66	(R) 48	23	33	20	7	26	17	(R) 33	9
New Haven-Milford, CT	50	11	7	(R) 19	(R) 23	(R) 15	(R) 25	(R) 15	(R) 22	(R) 18	(R) 22	(R) 32	(R) 17	(R) 6	(R) 19	(R) 8	(R) 13	9
New Orleans-Metairie-Kenner, LA	61	5	7	(R) 12	(R) 33	(R) 11	(R) 15	(R) 17	(R) 35	(R) 29	(R) 18	(R) 4	(R) 15	(R) 12	(R) 13	(R) 13	(R) 17	2
New York-Northern New Jersey-Long Island, NY-NJ-PA	254	35	57	(R) 56	(R) 44	(R) 43	(R) 42	(R) 57	(R) 53	(R) 35	(R) 54	(R) 61	(R) 33	(R) 32	(R) 41	(R) 38	(R) 38	29
Oklahoma City, OK	34	5	9	21	29	10	15	35	17	16	24	10	13	6	12	31	4	4
Omaha-Council Bluffs, NE-IA	40	3	12	1	(R) 3	0	1	(R) 3	(R) 5	3	2	0	1	1	1	0	1	0
Orlando-Kissimmee, FL	25	2	13	7	9	6	6	23	13	14	12	5	4	5	8	8	8	1
Oxnard-Thousand Oaks-Ventura, CA	38	31	14	97	100	95	75	54	54	57	52	26	47	41	36	31	22	30
Philadelphia-Camden-Wilmington, PA-NJ-DE-MD	141	30	48	(R) 56	(R) 62	(R) 43	(R) 42	(R) 63	(R) 55	(R) 39	(R) 57	(R) 60	(R) 37	(R) 23	(R) 36	(R) 30	(R) 42	28
Phoenix-Mesa-Scottsdale, AZ	160	188	23	33	(R) 39	(R) 45	(R) 32	(R) 47	(R) 47	(R) 34	25	22	26	9	23	25	11	11
Pittsburgh, PA	125	39	41	(R) 37	(R) 38	(R) 31	(R) 40	(R) 59	50	40	56	(R) 62	42	40	54	41	44	22
Portland-Vancouver-Beaverton, OR-WA	68	7	10	5	4	12	0	9	6	5	4	7	2	4	4	2	5	3
Poughkeepsie-Newburgh-Middletown, NY	8	8	2	12	14	14	10	16	18	7	17	16	5	4	6	1	11	5
Providence-New Bedford-Fall River, RI-MA	61	6	8	(R) 21	(R) 20	(R) 16	(R) 20	(R) 16	(R) 18	(R) 17	(R) 27	(R) 33	(R) 17	(R) 9	(R) 19	(R) 12	(R) 12	4
Raleigh-Cary, NC	37	11	2	11	10	13	29	46	43	(R) 15	11	39	8	3	12	7	17	5
Richmond, VA	35	17	9	26	28	23	40	50	39	17	24	40	14	5	23	14	19	15
Riverside-San Bernardino-Ontario, CA	146	128	43	167	154	147	131	117	151	171	183	175	158	147	141	128	135	119
Rochester, NY	17	4	1	8	10	1	10	11	17	2	14	16	5	0	0	(R) 1	(R) 5	2
Sacramento--Arden-Arcade--Roseville, CA	111	62	22	69	61	70	39	55	(R) 94	65	72	90	66	55	58	74	32	44
St. Louis, MO-IL	158	9	35	49	(R) 47	35	32	(R) 46	45	30	(R) 35	(R) 48	29	(R) 12	(R) 45	22	34	6
Salt Lake City, UT	49	17	11	27	8	14	3	20	18	23	29	34	20	38	32	(R) 20	28	15
San Antonio, TX	41	10	2	7	32	7	10	12	20	5	4	26	18	6	10	8	3	7
San Diego-Carlsbad-San Marcos, CA	64	37	24	90	94	(R) 60	39	51	49	58	53	35	40	27	26	39	33	35
San Francisco-Oakland-Fremont, CA	116	12	28	(R) 5	(R) 13	(R) 9	(R) 2	(R) 11	(R) 23	(R) 14	(R) 20	(R) 28	(R) 14	(R) 10	(R) 6	(R) 13	(R) 5	7
San Jose-Sunnyvale-Santa Clara, CA	38	15	6	(R) 13	(R) 21	(R) 37	(R) 7	(R) 21	(R) 14	(R) 9	(R) 9	(R) 24	(R) 14	(R) 7	(R) 4	(R) 13	(R) 3	13
San Juan-Caguas-Guaynabo, PR	51	1	5	0	0	1	1	0	0	0	1	0	0	0	0	0	1	0
Scranton--Wilkes-Barre, PA	19	5	10	19	25	14	19	26	25	(R) 7	(R) 23	30	(R) 6	4	12	3	7	5
Seattle-Tacoma-Bellevue, WA	120	7	14	(R) 3	(R) 3	(R) 5	(R) 0	(R) 6	(R) 7	(R) 18	(R) 14	(R) 13	(R) 10	(R) 4	(R) 6	(R) 10	(R) 9	7
Springfield, MA	42	11	10	28	17	8	22	24	18	7	28	24	13	9	16	12	21	10
Stockton, CA	16	21	5	6	11	7	2	19	22	14	11	13	6	3	5	16	11	10
Syracuse, NY	19	3	5	8	10	3	6	10	12	2	13	19	4	0	8	3	8	3
Tampa-St. Petersburg-Clearwater, FL	73	7	24	10	14	8	24	20	23	29	18	5	13	11	15	9	12	7
Toledo, OH	20	4	6	12	15	20	8	15	18	9	24	23	15	9	25	4	5	1
Tucson, AZ	51	3	20	10	14	8	8	7	8	5	0	7	7	0	8	9	1	2
Tulsa, OK	35	9	8	26	39	23	12	24	24	21	21	22	16	1	19	24	2	7
Virginia Beach-Norfolk-Newport News, VA-NC	29	15	7	19	22	12	37	34	32	23	14	31	10	5	12	11	9	15
Washington-Arlington-Alexandria, DC-VA-MD-WV	120	22	37	43	54	39	51	65	61	(R) 34	41	54	21	21	36	31	38	16
Wichita, KS	21	1	8	1	7	3	8	12	9	9	20	10	7	1	4	2	0	1
Worcester, MA	21	8	2	20	15	2	8	14	14	4	9	15	9	3	8	5	20	8
Youngstown-Warren-Boardman, OH-PA	23	11	11	(R) 23	(R) 18	(R) 20	(R) 17	(R) 45	(R) 24	(R) 12	(R) 43	(R) 33	(R) 13	(R) 5	(R) 25	(R) 8	(R) 17	8

KEY: AQI = Air Quality Index; R = revised.

NOTES

The Air Quality Index (AQI) integrates information on 6 major pollutants (particulate matter less than 10 microns in diameter, particulate matter less than 2.5 microns in diameter, sulfur dioxide, carbon monoxide, ozone, and nitrogen dioxide) across an entire monitoring network into a single number that represents the worst daily air quality experienced in an urban area. An AQI greater than 100 indicates that at least 1 criteria pollutant exceeded air quality standards on a given day; therefore, air quality would be in the unhealthful range on that day. Air quality monitoring sites are selected as "trend sites" if they have complete data for at least 8 of the 10 last years.

The major reason for revisions to the historical data for the AQI is that changes in the National Ambient Air Quality Standards (NAAQS) are retroactively applied to the data for previous years to provide consistent comparisons over time. In addition, data from monitoring stations that have fallen below/surpassed the criterion to qualify as a 'trend site' is excluded/included in the latest calculation of the index. Thus, this edition of this table is not comparable to previous editions.

Data for 1999 to 2008 include particulate matter 2.5 micron in diameter (PM 2.5).

Particulate matter is the term for solid or liquid particles found in the air.

SOURCE

U.S. Environmental Protection Agency, Office of Air and Radiation, Air Trends, Air Quality Index Information, available at http://www.epa.gov/air/airtrends/aqi_info.html as of Jan. 20, 2010.