With this population growth came expanding urban areas, shrinking agricultural lands, and the building of housing developments farther from urban centers. For the first time in many years, cars were available, affordable, and now necessary to reach the new suburbs.

The term "smog," originally coined to describe the combination of smoke and fog prevalent in London, soon became a household word in the Bay Area, with open fires from dumps and wrecking yards burning 24 hours a day. Initially measured in levels of eye irritation, air pollution was becoming a major problem, causing significant damage to Bay Area crops.

In the late 1940's scientists began exploring the causes of smog. In 1950, Dr. A. J. Haagen-Smit, a biochemist at the California Institute of Technology, discovered that photochemical reactions were responsible for the formation of smog's primary ingredient, ground-level ozone.

	The Air District's first years were fraught with controversy over Regulation 1--the proposal to ban open burning at dumps and wrecking yards--but it was eventually adopted in 1957.

In 1946, the California Legislature enacted the first air pollution control law authorizing the formation of county air pollution control districts. Los Angeles County opened the first air pollution control office in early 1947 and Santa Clara County followed soon after.

By 1950, it was evident that pollution overflowed political boundaries, and that a single-county district was not the answer for the Bay Area. In 1955, the Bay Area Air Pollution Control Law was adopted, establishing the Bay Area Air Pollution Control District as the first regional air pollution control agency in the nation.

At first, the Air District included Alameda, Contra Costa, Marin, San Francisco, San Mateo, and Santa Clara counties.  (Three other counties - Napa, Solana, and Sonoma - were included in the legislation as "inactive" members.  Napa and the southern portions of Solano and Sonoma counties joined the Air District in 1971.)

The Air District's Board of Directors appointed Benjamin Linsky as the Air District's first Air Pollution Control Officer. During this period, state law also established an Advisory Council-- composed of representatives from community, health, environmental, and other organizations--to advise on technical and policy matters.

By 1958, the Air District's laboratory was fully operational, performing chemical analyses of air quality samples.

As the Air District began its mission to control air pollution, the Bay Area's population was just over three million people, and there were 1.75 million motor vehicles on the road, at that time accounting for about 25 percent of the gaseous emissions in the region. (Today the Bay Area's population has more than doubled, almost reaching 7.2 million people, with more than 5 million cars on the road. These vehicles currently account for more than 50 percent of emissions.)

Charged with regulating stationary sources of air pollution emissions, the Air District drafted its first two regulations in the 1950s: Regulation 1, which banned open burning at dumps and wrecking yards, and Regulation 2, which established controls on dust, droplets, and combustion gases from certain industrial sources.

Much research and discussion went into the shaping of Regulation 2, but there was no doubt about the need for it. During a fact-finding visit to one particular facility, Air District engineers discovered that filters were used over air in-take vents to protect the plant's machinery from its own corrosive emissions! This much-debated regulation was finally adopted in 1960.

In 1959, California established the Motor Vehicle Pollution Control Board (the forerunner of today's California Air Resources Board) and this agency began to explore methods to reduce motor vehicle emissions.

While the 1950s brought air pollution control to the forefront of public concern, the next decade would see a rise in technical innovations that would assist in the fight for clean air.

1955

The Bay Area Air Pollution Control Law is enacted, establishing the Bay Area Air Pollution Control District (later renamed the Bay Area Air Quality Management District).

The Air District's Board of Directors meets for the first time.

Benjamin Linsky is named the first Air Pollution Control Officer.

1956

The Air District's Advisory Council is appointed.

1957

The Air District adopts Regulation 1, banning open burning at dumps and wrecking yards.

1958

The first draft of Regulation 2--limiting industrial emissions of sulfur dioxide, particulate matter, and smoke--is referred by the Air District's Board of Directors to the Advisory Council.

The Air District's laboratory becomes operational under the direction of chemist Milton Feldstein, who would later serve as the Air Pollution Control Officer.

1959

The Motor Vehicle Pollution Control Board (MVPCB) is established by the state of California, later renamed the California Air Resources Board (ARB).

1960

Regulation 2 is adopted, establishing industrial controls (see entry for 1958).