The Metro Index: Air Apparent
Year the term smog was coined: 1905
Worst hour for smog in summer: 2 p.m.
Best time of day in L.A. Basin for air: 6 a.m.
Number of August days exceeding federal ozone limit in past decade: 274
Number of January or December days over limit: 0
Last Stage 3 ozone episode in basin: 1974
Last Stage 2 ozone episode: 1988
Total smog episode days in 1978: 139
Smog episodes last year: 13
Days with smog episodes in Pasadena in 1978: 93
Pasadena smog episodes in 1995: 1
Days with health advisories in basin last year: 59
Tons of carbon monoxide emitted daily: 6,200
Tons emitted in San Francisco area: 3,200
Tons emitted in San Diego: 1,400
Square miles covered by South Coast Air Quality Management District: 12,000
Population of the basin in 1950: 4.8 million
Population of the basin in 1990: 13 million
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