Bad air days – 464 years of them

1542: Explorer Juan Rodriguez Cabrillo christens San Pedro Bay “La Bahia de la Fumos” — Bay of Smokes — for the way smoke from Indians’ fires hug the ground.

1868: The L.A. area’s 5,000 residents are perplexed by “an atmosphere ... so filled with smoke as to confine the vision within a small circumference.”

1901: An episode of dirty air is mistaken for an eclipse of the sun.

1905: First recorded use of the word “smog,” by physician Harold A. des Voeux, to describe London’s bad air.

July 26, 1943: After a series of bad-air episodes, visibility in downtown L.A. is reduced to less than three blocks.

1950s: Smudge pots (fires used to keep fruit trees warm at night) are banned.

1955: Highest ozone level — 0.68 parts per million in downtown Los Angeles — reported in the Southland.

1956: The first air-quality monitoring stations are established; today the Air Quality Management District has 35.

1958: Backyard incinerators are banned.

1966: California is the first in the nation to set auto emission standards.

1974 Creation of Stage 1 (bad), 2 (worse) and 3 (gasp!) smog alert system.

1975: South Coast Air Basin has 118 Stage 1 smog alerts. Catalytic converters are required on new cars sold in California.

1977: The South Coast Air Quality Management District, or SCAQMD, is formed; it now regulates air quality in 10,743 square miles populated by more than 16 million. 1995: The South Coast air basin has 14 Stage 1 smog alerts.

1999, early 2000s: Ozone levels in Houston are worse than L.A’s for several years running. L.A. recovers, and holds, its lead.

2006: The South Coast air basin has had no Stage 1 smog alerts since 2003, no Stage 2’s since 1988, no Stage 3’s since 1974.

Sources: SCAQMD, California Air Resources Board, “Don’t Breathe the Air” by Scott Dewey, Times research