1930

California's population is less than 6 million people. Total registered vehicles in California reaches 2 million.

Meuse Valley, Belgium, air inversion results in 60 dead and thousands sick from exposure to industrial air emissions.

1938

Sulfur Dioxide and Dust Fall Air Sampling stations are set up in the U.S. under the Federal Works Progress Administration.

1939

World War II Begins -- Explosion of California's population soon to occur to meet the needs of the war.

1940

California's population reaches 7 million people. Number of registered vehicles in California approaches 2.8 million and the total vehicle miles traveled (VMT) is 24 billion.

1943

First recognized episodes of smog occur in Los Angeles in the summer of 1943. Visibility is only three blocks and people suffer from smarting eyes, respiratory discomfort, nausea, and vomiting. The phenomenon is termed a "gas attack" and blamed on a nearby butadiene plant. The situation does not improve when the plant is shut down.

1945

World War II Ends -- Urban sprawl begins to take root in much of the U.S.

The City of Los Angeles begins its air pollution control program, establishing the Bureau of Smoke Control in its health department.

1946

Raymond R.Tucker studies the Los Angeles area's smog problem and recommends that county-wide collaboration is needed.

1947

June 10, 1947, California Governor Earl Warren signs into law the Air Pollution Control Act, authorizing the creation of an Air Pollution Control District in every county of the state.

The Los Angeles County APCD is established. It is the first of its kind in the nation.

California officially adopts the Ringelmann System, which measures the opacity of smoke arising from stacks and other sources.

1948

Donora, Pennsylvania, air pollution episode kills 20 people and numerous animals, and half of the town's 12,000 residents become ill due to uncontrolled emissions from industrial facilities.

1950

California's population reaches 11 million people. Total registered vehicles in California exceed 4.5 million and Vehicle Miles Traveled (VMT) is 44.5 billion.
More than 100 electric transit systems are replaced with buses in 45 U.S. cities including Los Angeles.
California Rule 50A passed, limiting smoke based upon the Ringelmann System.

1952

Over 4000 deaths attributed to "Killer Fog" in London, England.

Dr. Arie Haagen-Smit discovers the nature and causes of photochemical smog. He determines that nitrogen oxides and hydrocarbons in the presence of ultraviolet radiation from the sun forms smog (a key component of which is ozone).

1953

Los Angeles County starts "Smoke School Program" for black smoke, beginning the standardization of "Visible Emission Programs" nationwide.

Fuel switching from coal to natural gas implemented throughout much of the U.S. and England. Noticeable reduction in particulate levels occurs.

1955

Federal Air Pollution Control Act of 1955 is enacted, providing for research and technical assistance and authorizing the Secretary of Health, Education and Welfare to work towards a better understanding of the causes and effects of air pollution.
The Bay Area APCD is established. It includes the counties of Alameda, Contra Costa, Marin, Napa, San Francisco, San Mateo, Santa Clara, and portions of Solano and Sonoma counties.
Los Angeles County Motor Vehicle Pollution Control Laboratory begins within the Los Angeles APCD.
Bureau of Air Sanitation is formed within the State Department of Public Health.

1956

"Killer Fog" envelops London, England, resulting in 1000 deaths above normal.

Interstate Highway Act of 1956 passed, paving the way for increased highway construction.

1959

California enacts legislation requiring the state Department of Public Health to establish air quality standards and necessary controls for motor vehicle emissions.

1960

California's population reaches 16 million people. Total registered vehicles approach 8 million and VMT is 71 billion.

The Motor Vehicle Pollution Control Board is established. Primary function is to test and certify devices for installation on cars for sale in California.

Federal Motor Vehicle Act of 1960 is enacted. Requires federal research to address pollution from motor vehicles.

1961

The first automotive emissions control technology in the nation, Positive Crankcase Ventilation (PCV), is mandated by the California Motor Vehicle State Bureau of Air Sanitation to control hydrocarbon crankcase emissions. PCV withdraws blowby gases from the crankcase and re-burns them with the fresh air and fuel mixture in the cylinders.

1962

Rachel Carson's "Silent Spring" is published. It brings to public attention a stunning awareness of the disruptive impact humans have upon the earth's fragile ecosystems.

1963

PCV Requirement of 1961 goes into effect on domestic passenger vehicles for sale in California.

First Federal Clean Air Act of 1963 enacted. Empowers the Secretary of the federal Health, Education, and Welfare to define air quality criteria based on scientific studies. Provides grants to state and local air pollution control agencies.

1964

Chrysler exhaust control system is approved by the Motor Vehicle Pollution Control Board. Four other independent companies also received approvals.

1965

Ozone: Reliable measurements of ozone concentrations begin to be recorded. The maximum one-hour ozone concentration for this year in the South Coast Air Basin is 0.58 parts per million.

Federal Clean Air Act of 1963 is amended by the Motor Vehicle Air Pollution Control Act of 1965. Direct regulation of air pollution by the federal government is provided for, and the Department of Health, Education, and Welfare is directed to establish auto emission standards.

1966

Auto tailpipe emission standards for hydrocarbons and carbon monoxide are adopted by the California Motor Vehicle Pollution Control Board. They are the first of their kind in the nation.

California Highway Patrol begins random roadside inspections of vehicle smog control devices.

1967

California Air Resources Board is created from the merging of the California Motor Vehicle Pollution Control Board and the Bureau of Air Sanitation and its Laboratory. Enacting legislation is the Mulford-Carrell Air Resources Act, signed into law by governor Ronald Reagan.

Federal Air Quality Act of 1967 is enacted. Establishes framework for defining "air quality control regions" based on meteorological and topographical factors of air pollution. Allows the State of California a waiver to set and enforce its own emissions standards for new vehicles based on California's unique need for more stringent controls.

1968

Dr. Arie J. Haagen-Smit is appointed Chairman of the Air Resources Board by Governor Reagan. First meeting of the State ARB is held in Sacramento on February 8, 1968.

Santa Cruz and Monterey Counties combine to form the Monterey County Unified Air Pollution Control District.

1969

First state Ambient Air Quality Standards are promulgated by California for total suspended particulates, photochemical oxidants, sulfur dioxide, nitrogen dioxide, and carbon monoxide.

1970

California's population reaches 20 million people. Total registered vehicles exceed 12 million and VMT is 110 billion. Statewide average for NOx emissions per vehicle (new and used) are 5.3 grams/mile; per vehicle for hydrocarbons are 8.6 grams/mile. Cumulative California vehicle emissions for nitrogen oxides and hydrocarbons are about 1.6 million tons/year.

Ozone: The South Coast Air Basin's maximum one-hour ozone concentration recorded is 0.58 parts per million, which is nearly 5 times greater than the health-based national standard of < 0.12 ppm that will be adopted in '71.

Backyard burning is banned in selected areas of California.
National Environmental Protection Act (NEPA) signed.
U.S. Environmental Protection Agency (U.S. EPA) created to protect all aspects of the environment.

The first Earth Day held April 22, 1970.

Federal New Source Performance Standards for opacity are published.

Federal Clean Air Act Amendments of 1970 enacted. They serve as the principal source of statutory authority for controlling air pollution. Establishes basic U.S. program for controlling air pollution.

1971

ARB adopts the first automobile nitrogen oxide standards in the nation.

Federal EPA promulgates National Ambient Air Quality Standards for particulates, photochemcial oxidants (including ozone), hydrocarbons, carbon monoxide, nitrogen dioxide and sulfur dioxide.

1972

California submits its State Implementation Plan (SIP) to U.S. EPA. It is rejected.

ARB adopts guidelines to control agricultural burning.

1973

OPEC Oil Embargo results in rising fuel cost, the use of smaller, more fuel efficient automobiles, more cost conservative use of fuel by industry, and corresponding lower air emissions.

1975

Ozone: The South Coast Air Basin's maximum one-hour ozone concentration recorded is 0.39 parts per million. The area exceeds Stage 1 Smog Alerts (0.20 ppm ozone) on 118 days this year.

First Two-Way Catalytic Converters come into use as part of ARB's Motor Vehicle Emission Control Program.

California Air Pollution Control Officers Association (CAPCOA) created.
EPA Working Group established to develop strategies for State Implementation Plan activities.

1976

The regional South Coast Air Quality Management District is formed. It includes portions of Los Angeles, Orange, Riverside, and San Bernardino counties.

The Toxic Substance Control Act is established by Congress in response to an increasing awareness of toxic substances used by industry.

ARB limits lead in gasoline.

Volvo introduces 1977 year car billed as "Smog-Free". Features the first Three-Way Catalytic Converter to control hydrocarbons, nitrogen oxides, and carbon monoxide.

1977

Federal Clean Air Act Amendments of 1977 enacted. Requires review of all National Ambient Air Quality Standards by 1980.

1980

California population reaches 24 million people. Total registered vehicles surpasses 17 million and VMT is 155 billion. Statewide average for NOx emissions per vehicle are 4.8 grams/mile; per vehicle for hydrocarbons are 5.5 grams/mile. Cumulative California vehicle emissions for nitrogen oxides and hydrocarbons remain at 1970 levels of 1.6 million tons/year despite a rise of 45 billion in VMT over those ten years.

Ozone: The South Coast Air Basin's maximum one-hour ozone concentration recorded is 0.49 parts per million. The area exceeds Stage 1 Smog Alerts (0.20 ppm ozone) on 102 days this year. This is an improvement of 16 days since 1975.

Compliance testing performed by ARB on autos in use to determine whether they continue to comply with emission standards as they age. This is a strong incentive for manufacturers to develop more durable emission control equipment to avoid the risk of recall.

1984

California Smog Check Program goes into effect to identify vehicles in need of maintenance and to assure the effectiveness of their emissions control systems on a biennial basis.

AB 1807 Toxic Air Contaminant (TAC) bill becomes effective.

1985

Ozone: The South Coast Air Basin's maximum one-hour ozone concentration recorded is 0.39 parts per million. The area exceeds Stage 1 Smog Alerts (0.20 ppm ozone) on 83 days this year, an improvement of 19 days since 1980.

1988

California Clean Air Act is signed by Governor Deukmejian. Sets forth the framework for how air quality will be managed in California for the next 20 years.

ARB adopts regulations effective on 1994 model cars requiring that they be equipped with on-board computer systems to monitor emission performance and alert owners when there is a problem.

1990

California's population reaches 30 million people. Total registered vehicles reaches 23 million and VMT is 242 billion. Statewide average for NOx emissions per vehicle are 3.0 grams/mile; per vehicle for hydrocarbons are 2.7 grams/mile. Cumulative California vehicle emissions for nitrogen oxides and hydrocarbons are about 1.4 million tons/year. This is 200,000 tons/year less than in 1980 despite a rise of 87 billion in VMT.

Ozone: The South Coast Air Basin's maximum one-hour ozone concentration recorded is 0.33 parts per million. The area exceeds Stage 1 Smog Alerts (0.20 ppm ozone) on 42 days this year, an improvement of 41 days since 1985.

ARB approves standards for Cleaner Burning Fuels and Low and Zero Emission Vehicles.

The Clean Air Act Amendments of 1990 are signed into law by President George Bush. They rely largely on elements of the California Clean Air Act, and require a number of new programs aimed at curbing urban ozone, rural acid rain, stratospheric ozone, toxic air pollutant emissions and vehicle emissions, and establishes a new, uniform national permit system.

1992

Phase I California Cleaner Burning Gasoline (CBG) comes to market. The result is 220 tons less ROG released every day (6% reduction), and elimination of the use of lead in gasoline. In November of the same year, ARB requires addition of oxygenates to gasoline to cut CO emissions by 10%.

1993

ARB enacts new standards for cleaner diesel fuel, resulting in a reduction of diesel particulate emissions by approximately 14 tons/day, 80 tons/day less sulfur dioxide and 70 tons/day nitrogen oxide (NOx) emissions. Diesel busses and trucks are a major source of NOx.

California Diesel Fuel comes to market.

SCAQMD adopts Regional Clean Air Incentives Market (RECLAIM) program for NOx and SOx.

1994

U.S. Court orders U.S. EPA to develop Federal Implementation Plan (FIP) for numerous non-attainment areas in California.

California "SIPs the FIP" with submittal of more cost effective State Implementation Plan to U.S. EPA.

Smog Check II signed into law by Governor Wilson following lengthy negotiations with the federal EPA, designed to meet the requirements of the Federal Clean Air Act as amended in 1990. This program targets vehicles which pollute at least 2 to 25 times more than the average vehicle and requires repairs and re-testing of offending vehicles.

1995

Total registered vehicles reaches 26 million and VMT is 271 billion. Statewide average for NOx emissions per vehicle are 2.2 grams/mile; per vehicle hydrocarbons are 1.8 grams/mile. Cumulative California auto emissions for nitrogen oxides and hydrocarbons are about 1.1 million tons/year, a 31% reduction compared 1970 levels, despite a 147% increase in VMT from 1970 levels. Statewide averages for nitrogen oxide and hydrocarbon emissions per vehicle reduced respectively by 58% and 80% from 1970 levels.

The South Coast Air Basin's maximum one-hour ozone concentration recorded is 0.26 ppm, 55% less than in 1965. The area exceeds Stage 1 Smog Alerts (0.20 ppm ozone) on 14 days this year. This is an improvement of 104 days compared to 1975.

1996

The South Coast Air Basin's maximum one-hour ozone concentration recorded is 0.24 ppm, a 59% improvement from 1965. The area exceeds Stage 1 Smog Alerts (0.20 ppm ozone) on 7 days this year. This is an improvement of 111 days, or a 94% reduction as compared to 1975.

Big seven automakers commit to manufacture and sell Zero Emission Vehicles.

California Phase II Cleaner Burning Gasoline (CBG) comes to market. CBG reduces lung-damaging ozone and ozone precursors by 300 tons/day, as well as reducing airborne toxic chemicals like benzene that can cause cancer. This is equivalent to taking 3.5 million cars off the road.

California's State Implementation Plan for ozone is approved by U.S. EPA on September 26, 1996.

1998

ARB identifies diesel particulate emissions as a Toxic Air Contaminant.

The ARB amended off-road engine regulations for lawn mowers, weed trimmers, and other small engine power tools.

The ARB adopted its LEVII emission standards for most mini vans, pickup trucks and sport utility vehicles up to 8500 pounds gross vehicle weight to reduce emissions to passenger car levels by 2007.

Marine engine regulations were adopted to greatly reduce smog-forming emissions and water pollution from outboard engines and personal watercraft.

1999

The California Fuel Cell Partnership, a public-private venture to demonstrate fuel cell vehicles in California, formally began. The Partnership includes auto manufactures, energy providers, fuel cell manufacturers, and the State of California.

The ARB adopted a new regulation that reduces by over 70 percent the smog-forming emissions from portable gas cans.

Consumer products rules were adopted to cut smog-forming emissions and volatile organic compounds from an estimated 2,500 common household products ranging from nail polish remover to glass cleaners.

The Board approved a new set of gasoline rules that will ban the additive MTBE while preserving all the air-quality benefits obtained from the state's cleaner-burning gasoline program.

2000

California's population grows to 34 million. There are now 23.4 million registered vehicles in the state. Annual vehicle miles traveled (VMT) reaches 280 billion miles. The statewide average for vehicular nitrogen oxides emissions is 2.1 grams/mile; the average for hydrocarbons is 1.6 grams/mile. Cumulative California vehicle emissions for nitrogen oxides and hydrocarbons are about 1.2 million tons per year. This is 200,000 tons/year less than 1990 despite an increase in VMT of 40 billion miles per year.

Ozone: The South Coast Air Basin's maximum one-hour ozone concentration recorded is 0.18 parts per million. The area has no Stage 1 Smog Alerts (0.20 ppm ozone) this year, down from 42 Alerts in 1990.

Six communities are chosen for Children's Environmental Health Protection Program. Community studies in Boyle Heights, Wilmington (Los Angeles), Fruitvale (Oakland), Barrio Logan (San Diego), Crockett (Contra Costa County) and Fresno aim to improve our understanding of the impact of air pollution on children's health and development.

A long-term children's health study funded by the ARB reveals that exposure to high air pollution levels can slow down the lung function growth rate of children by up to 10 percent.

ARB approves a comprehensive plan to reduce harmful particulate matter emissions from diesel powered equipment.

The Board votes unanimously to keep the Zero Emission Vehicle mandate in place.

The ARB amends the state's agricultural burning guidelines to reduce the public health impact of smoke from controlled burns.

The ARB adopts regulations to further reduce air pollution from transit buses operating in California.

2001

Zero emission vehicle (ZEV) mandate upheld, with modified requirements. Automakers are required to produce between 4,450 and 15,450 zero emission cars starting in 2003.

ARB joins a new private/public fuel cell collaborative seeking to reduce demand on California's electrical grid by encouraging commercialization of stationary fuel cells.

Board adopts new rules that limit public exposure to asbestos-laden dust from construction and quarry sites. These measures will better protect Californians from the potential threat of cancer, asbestosis, and mesothelioma caused by exposure to asbestos fibers.

New standards pass that will reduce diesel soot and smog forming emissions by 90 percent from new large diesel engines. The new standards take effect with the 2007 model year and affect engines that power big-rig trucks, trash trucks, delivery vans, and other large vehicles.

The ARB adopts new Environmental Justice Policies to ensure that residents of low-income and minority communities receive equal consideration under all ARB regulations and programs.