Top 101 counties with the highest Ozone (1-hour) air pollution readings in 2005 (ppm)
1.
Los Angeles County, CA
(
Los Angeles
,
Long Beach
,
Glendale
), pop. 9,519,338: 0.171
2.
San Bernardino County, CA
(
San Bernardino
,
Ontario
,
Fontana
), pop. 1,709,434: 0.166
3.
Harris County, TX
(
Houston
,
Pasadena
,
Baytown
), pop. 3,400,578: 0.156
4.
Fairfield County, CT
(
Bridgeport
,
Stamford
,
Norwalk
), pop. 882,567: 0.146
5.
Riverside County, CA
(
Riverside
,
Moreno Valley
,
Corona
), pop. 1,545,387: 0.142
6.
New Haven County, CT
(
New Haven
,
Waterbury
,
Meriden
), pop. 824,008: 0.141
7.
Hartford County, CT
(
Hartford
,
New Britain
,
West Hartford
), pop. 857,183: 0.139
8.
Cecil County, MD
(
Elkton
,
Perryville
,
North East
), pop. 85,951: 0.138
9.
Ocean County, NJ
(
Toms River
,
Lakewood
,
Point Pleasant
), pop. 510,916: 0.137
10.
Tarrant County, TX
(
Fort Worth
,
Arlington
,
North Richland Hills
), pop. 1,446,219: 0.134
11.
Middlesex County, CT
(
Middletown
,
East Hampton
,
Clinton
), pop. 155,071: 0.134
12.
Kern County, CA
(
Bakersfield
,
Delano
,
Oildale
), pop. 661,645: 0.131
13.
Mecklenburg County, NC
(
Charlotte
,
Huntersville
,
Matthews
), pop. 695,454: 0.131
14.
Fresno County, CA
(
Fresno
,
Clovis
,
Reedley
), pop. 799,407: 0.131
15.
Crittenden County, AR
(
West Memphis
,
Marion
,
Earle
), pop. 50,866: 0.130
16.
Wyandotte County, KS
(
Kansas City
,
Bonner Springs
,
Edwardsville
), pop. 157,882: 0.130
17.
Harford County, MD
(
Edgewood
,
Aberdeen
,
Joppatowne
), pop. 218,590: 0.130
18.
East Baton Rouge Parish, LA
(
Baton Rouge
,
Shenandoah
,
Baker
), pop. 412,852: 0.129
19.
Lake County, OH
(
Mentor
,
Willoughby
,
Eastlake
), pop. 227,511: 0.129
20.
Milwaukee County, WI
(
Milwaukee
,
West Allis
,
Wauwatosa
), pop. 940,164: 0.129
21.
Sacramento County, CA
(
Sacramento
,
Citrus Heights
,
Elk Grove
), pop. 1,223,499: 0.129
22.
New Castle County, DE
(
Wilmington
,
Newark
,
Pike Creek
), pop. 500,265: 0.128
23.
Philadelphia County, PA
(
Philadelphia
), pop. 1,517,550: 0.128
24.
Parker County, TX
(
Weatherford
,
Willow Park
,
Reno
), pop. 88,495: 0.127
25.
Hampden County, MA
(
Springfield
,
Chicopee
,
Westfield
), pop. 456,228: 0.127
26.
St. Clair County, IL
(
Belleville
,
East St. Louis
,
O'Fallon
), pop. 256,082: 0.127
27.
Brazoria County, TX
(
Pearland
,
Lake Jackson
,
Alvin
), pop. 241,767: 0.126
28.
El Paso County, TX
(
El Paso
,
Socorro
,
San Elizario
), pop. 679,622: 0.125
29.
Middlesex County, NJ
(
Edison
,
New Brunswick
,
Perth Amboy
), pop. 750,162: 0.125
30.
Montgomery County, TX
(
The Woodlands
,
Conroe
,
Pinehurst
), pop. 293,768: 0.124
31.
Tolland County, CT
(
Vernon
,
Mansfield
,
Tolland
), pop. 136,364: 0.124
32.
Fulton County, GA
(
Atlanta
,
Sandy Springs
,
Roswell
), pop. 816,006: 0.124
33.
Suffolk County, NY
(
Brookhaven
,
Islip
,
Babylon
), pop. 1,419,369: 0.124
34.
Calaveras County, CA
(
Arnold
,
Rancho Calaveras
,
San Andreas
), pop. 40,554: 0.124
35.
Westchester County, NY
(
Yonkers
,
New Rochelle
,
Mount Vernon
), pop. 923,459: 0.123
36.
Tulare County, CA
(
Visalia
,
Tulare
,
Porterville
), pop. 368,021: 0.123
37.
Allegan County, MI
(
Allegan
,
Wayland
,
Plainwell
), pop. 105,665: 0.123
38.
Hampshire County, MA
(
Amherst
,
Northampton
,
South Hadley
), pop. 152,251: 0.123
39.
Rowan County, NC
(
Salisbury
,
China Grove
,
Spencer
), pop. 130,340: 0.123
40.
Iberville Parish, LA
(
Plaquemine
,
St. Gabriel
,
White Castle
), pop. 33,320: 0.122
41.
Ozaukee County, WI
(
Mequon
,
Cedarburg
,
Port Washington
), pop. 82,317: 0.122
42.
Bucks County, PA
(
Levittown
,
Morrisville
,
Croydon
), pop. 597,635: 0.121
43.
Imperial County, CA
(
El Centro
,
Calexico
,
Brawley
), pop. 142,361: 0.121
44.
Davis County, UT
(
Layton
,
Bountiful
,
Clearfield
), pop. 238,994: 0.121
45.
Bergen County, NJ
(
Hackensack
,
Teaneck
,
Fort Lee
), pop. 884,118: 0.120
46.
Hudson County, NJ
(
Jersey City
,
Union City
,
Bayonne
), pop. 608,975: 0.120
47.
Salt Lake County, UT
(
Salt Lake City
,
West Valley City
,
Sandy
), pop. 898,387: 0.120
48.
Kenosha County, WI
(
Kenosha
,
Pleasant Prairie
,
Somers
), pop. 149,577: 0.120
49.
Dallas County, TX
(
Dallas
,
Garland
,
Irving
), pop. 2,218,899: 0.120
50.
Putnam County, NY
(
Carmel
,
Patterson
,
Putnam Valley
), pop. 95,745: 0.119
51.
Nevada County, CA
(
Truckee
,
Grass Valley
,
Alta Sierra
), pop. 92,033: 0.119
52.
Porter County, IN
(
Portage
,
Valparaiso
,
Chesterton
), pop. 146,798: 0.119
53.
Sheboygan County, WI
(
Sheboygan
,
Plymouth
,
Sheboygan Falls
), pop. 112,646: 0.119
54.
Placer County, CA
(
Roseville
,
Rocklin
,
Granite Bay
), pop. 248,399: 0.119
55.
Sublette County, WY
(
Pinedale
,
Marbleton
,
Big Piney
), pop. 5,920: 0.119
56.
Litchfield County, CT
(
Torrington
,
New Milford
,
Watertown
), pop. 182,193: 0.119
57.
Delaware County, PA
(
Chester
,
Drexel Hill
,
Springfield
), pop. 550,864: 0.119
58.
Kent County, RI
(
Warwick
,
Coventry
,
West Warwick
), pop. 167,090: 0.118
59.
Queens County, NY
, pop. 2,229,379: 0.118
60.
Racine County, WI
(
Racine
,
Caledonia
,
Mount Pleasant
), pop. 188,831: 0.118
61.
Washington County, UT
(
St. George
,
Hurricane
,
Washington
), pop. 90,354: 0.117
62.
Richmond County, NY
(
Concord
,
Bloomfield
,
Clifton
), pop. 443,728: 0.117
63.
Denton County, TX
(
Denton
,
Lewisville
,
Flower Mound
), pop. 432,976: 0.117
64.
Lake County, IN
(
Gary
,
Hammond
,
East Chicago
), pop. 484,564: 0.116
65.
Clark County, NV
(
Las Vegas
,
Paradise
,
Henderson
), pop. 1,375,765: 0.116
66.
St. Charles County, MO
(
St. Charles
,
St. Peters
,
O'Fallon
), pop. 283,883: 0.116
67.
DeKalb County, GA
(
North Atlanta
,
Redan
,
Dunwoody
), pop. 665,865: 0.116
68.
Macomb County, MI
(
Warren
,
Sterling Heights
,
Clinton
), pop. 788,149: 0.116
69.
St. Louis city, MO
, pop. 348,189: 0.116
70.
Essex County, MA
(
Lynn
,
Lawrence
,
Haverhill
), pop. 723,419: 0.115
71.
Lucas County, OH
(
Toledo
,
Oregon
,
Sylvania
), pop. 455,054: 0.115
72.
Maricopa County, AZ
(
Phoenix
,
Mesa
,
Glendale
), pop. 3,072,149: 0.115
73.
Douglas County, GA
(
Douglasville
,
Lithia Springs
,
Winston
), pop. 92,174: 0.115
74.
Warren County, OH
(
Mason
,
Lebanon
,
Landen
), pop. 158,383: 0.115
75.
Monmouth County, NJ
(
Long Branch
,
Asbury Park
,
Tinton Falls
), pop. 615,301: 0.115
76.
Jefferson County, KY
(
Louisville
,
Jeffersontown
,
Valley Station
), pop. 693,604: 0.115
77.
Henry County, GA
(
Stockbridge
,
McDonough
,
Hampton
), pop. 119,341: 0.115
78.
Gloucester County, NJ
(
Glassboro
,
Williamstown
,
Woodbury
), pop. 254,673: 0.114
79.
Madison County, IL
(
Granite City
,
Alton
,
Collinsville
), pop. 258,941: 0.114
80.
Door County, WI
(
Sturgeon Bay
,
Washington
,
Egg Harbor
), pop. 27,961: 0.114
81.
El Dorado County, CA
(
South Lake Tahoe
,
El Dorado Hills
,
Cameron Park
), pop. 156,299: 0.114
82.
Creek County, OK
(
Sapulpa
,
Bristow
,
Drumright
), pop. 67,367: 0.114
83.
Manitowoc County, WI
(
Manitowoc
,
Two Rivers
,
Kiel
), pop. 82,887: 0.114
84.
Orange County, FL
(
Orlando
,
Pine Hills
,
Apopka
), pop. 896,344: 0.114
85.
Utah County, UT
(
Provo
,
Orem
,
Pleasant Grove
), pop. 368,536: 0.114
86.
Alameda County, CA
(
Oakland
,
Fremont
,
Hayward
), pop. 1,443,741: 0.113
87.
Camden County, NJ
(
Camden
,
Pennsauken
,
Lindenwold
), pop. 508,932: 0.113
88.
Prince George's County, MD
(
Bowie
,
Chillum
,
Clinton
), pop. 801,515: 0.113
89.
Richland County, SC
(
Columbia
,
St. Andrews
,
Dentsville
), pop. 320,677: 0.113
90.
Pointe Coupee Parish, LA
(
New Roads
,
Livonia
,
Fordoche
), pop. 22,763: 0.113
91.
Pinal County, AZ
(
Apache Junction
,
Casa Grande
,
Florence
), pop. 179,727: 0.113
92.
Cook County, IL
(
Chicago
,
Cicero
,
Arlington Heights
), pop. 5,376,741: 0.113
93.
Dukes County, MA
(
Edgartown
,
Oak Bluffs
,
West Tisbury
), pop. 14,987: 0.113
94.
Lincoln County, MO
(
Troy
,
Elsberry
,
Moscow Mills
), pop. 38,944: 0.113
95.
Kings County, CA
(
Hanford
,
Lemoore
,
Avenal
), pop. 129,461: 0.112
96.
Providence County, RI
(
Providence
,
Cranston
,
Pawtucket
), pop. 621,602: 0.112
97.
Ventura County, CA
(
Oxnard
,
Thousand Oaks
,
Simi Valley
), pop. 753,197: 0.112
98.
Sussex County, DE
(
Milford
,
Seaford
,
Georgetown
), pop. 156,638: 0.112
99.
Anne Arundel County, MD
(
Glen Burnie
,
Annapolis
,
Severn
), pop. 489,656: 0.112
100.
Platte County, MO
(
Parkville
,
Platte City
,
Riverside
), pop. 73,781: 0.112
101.
West Baton Rouge Parish, LA
(
Port Allen
,
Addis
,
Brusly
), pop. 21,601: 0.112
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