Though California was one of the first states in the nation to pass clean air legislation, air quality continues to be a major health and environmental concern in the state.
Air pollution causes approximately 2 million premature deaths worldwide every year, according to the World Health Organization. The Los Angeles Times reports that the health impacts from air pollution exposure—including premature deaths and illnesses—costs the state of California $28 billion annually.
Air pollution can occur indoors or outdoors; the primary source is vehicle emissions. Particulate matter (PM), which comes from pollutants such as diesel exhaust and fireplace soot, is a mixture of particles suspended in the air; smaller particles are worse for health than larger ones, because they are inhaled deeply into the lungs. Ozone (O3) comes from the reaction between sunlight and both nitrogen oxides and volatile organic compounds. Nitrous oxides (NOx) and sulfur dioxide (SO2) come from burning fossil fuels. All of these pollutants cause a shockingly long list of harmful and fatal health problems, including asthma, heart disease, and lung cancer.
Children are affected by air pollution more than adults, because their bodies are still developing and they breathe faster. Childhood asthma has become an epidemic in California; the American Lung Association says it is the leading cause of hospitalizations among children and of school absenteeism due to a chronic condition in California. Asthma rates have increased 75% for all Californians since 1980.
Notably, greenhouse gas emissions are now considered air pollution (see "global warming").
Example of action to improve air quality: California’s Carl Moyer program offers incentives for the retrofitting or replacement of dirty engines (such as diesel trucks or stationary equipment) with new equipment. In 2004, AB 923 was passed into state law to permanently fund that program.
Example of action that fails to improve air quality: The state’s massive ports in Long Beach, Los Angeles, and Oakland are collectively a major source of pollution, especially particulate emissions from diesel fuel. Environmental hero State Senator Alan Lowenthal fought the tough fight by carrying legislation to clean up the ports every year since at least 2004. However, former Governor Schwarzenegger had a shameful port veto trifecta: he vetoed Senator Lowenthal’s important “polluter pays” port legislation in 2004, 2006, and 2008.