South Coast AQMD is the regulatory agency responsible for improving air quality for large areas of Los Angeles, Orange County, Riverside and San Bernardino counties, including the Coachella Valley. The region is home to more than 17 million people–about half the population of the entire state of California. Despite significant improvements to air quality, more work needs to be done to protect public health through innovative and practical strategies. Air pollution can cause or worsen many health problems, including asthma attacks, heart disease, certain types of cancers and premature death. South Coast AQMD has been at the forefront of the nation’s air pollution reduction efforts for more than eight decades. What South Coast AQMD Does: South Coast AQMD is responsible for controlling emissions primarily from stationary sources of air pollution. These can include anything from large power plants and refineries to the corner gas station. There are about 28,400 such businesses operating under South Coast AQMD permits. Many consumer products are also considered stationary sources; these include house paint, furniture varnish, and thousands of products containing solvents that evaporate into the air. About 25% of this area's ozone-forming air pollution comes from stationary sources, both businesses and residences. The other 75% comes from mobile sources–mainly cars, trucks and buses, but also construction equipment, ships, trains and airplanes. Emission standards for mobile sources are established by state or federal agencies, such as the California Air Resources Board and the U.S. Environmental Protection Agency, rather than by local agencies such as the South Coast AQMD.