Urban Air Pollution - Air Pollution and Global Warming: History, Science, and Solutions - page 82

by the League of California Cities, who believed
that air pollution could be regulated more effectively at
the county level rather than at the city level. The bill
passed 73 to 1 in the California State Legislature and 20
to 0 in the State Assembly; it was signed by Governor
Earl Warren on June 10, 1947. On October 14, 1947,
the Board of Supervisors created the first regional air
pollution control agency in the United States, the Los
Angeles Air Pollution Control District. On December
30, 1947, the district issued its first mandate, requiring
major industrial emitters to obtain emission permits.
In the late 1940s and early 1950s, the district further
regulated open burning in garbage dumps (e.g., Figure
4.7a), emission of sulfur dioxide from refineries,
and emission from industrial gasoline storage tanks
(1953). In 1954, it banned the use of 300,000 backyard
incinerators in Los Angeles, effective October 1, 1957
(Figure 4.7b). Nevertheless, smog problems in Los
Angeles persisted, resulting in serious respiratory and
cardiovascular disease and death, eye irritation, and
general discomfort (Figure 4.8).
In 1950, 1957, and 1957, Orange, Riverside, and San
Bernardino counties, respectively, established their own
air pollution control districts. These districts merged
with the Los Angeles district in 1977 to form the South
Coast Air Quality Management District (SCAQMD),
which currently controls air pollution in the four-county
Los Angeles region.
The chemistry of photochemical smog was first elu-
cidated by Arie Haagen-Smit (1900-1977), a Dutch
professor of biochemistry at the California Institute of
Technology (Figure 4.9). In 1948, Haagen-Smit began
studying plants damaged by smog. In 1950, he found
that plants exposed to ozone sealed in a chamber exhib-
ited the same type of damage as plants exposed to out-
door smog (e.g., Figure 4.10). Symptoms of damage
included the silvering or bronzing of the underside of
the leaves of spinach, sugar beets, and endives, and the
bleaching of alfalfa and oats. About fifty other chemi-
cals in the air tested did not produce the same damage,
indicating that ozone was present in the smog and was
causing the damage (Haagen-Smit, 1950).
Haagen-Smit also found that ozone caused eye irrita-
tion, damage to materials, and respiratory problems.
Meanwhile, tire manufacturers discovered that their
rubber tires deteriorated faster in Los Angeles than in
other parts of the United States. Bradley and Haagen-
Smit (1951) determined that bent rubber could crack
within seven minutes when exposed to 100 ppbv ozone,
whereas such cracking took thirty to sixty minutes when
exposed to 20 to 30 ppbv ozone. Thus, ozone also dam-
aged tires and other rubber products.

(a)

(b)

Figure 4.7. (a) Dozens of open waste incineration
sites, such as this, checkered Los Angeles until the
late 1940s, when garbage collection and regulated
incineration began. Photo: August 2, 1945. (b) A
patrolman tells a new resident of Los Angeles, on
June 25, 1960, that burning waste in a backyard
incinerator was banned effective October 1, 1957 and
to extinguish the fire immediately. Photos courtesy
Los Angeles Public Library ,LosAngeles Herald
Examiner Photo Collection.