Hundreds of other chemicals, known as toxic or hazardous air pollutants, enter the atmosphere from a wide variety of sources but are not subject to ambient, health-based standards. Because of limited air quality data, the level of public health and environmental damage caused by toxic air pollutants is largely unknown. Air pollution causes lung disease and worsens existing respiratory and cardiopulmonary disease, sometimes hastening death for persons afflicted with such diseases. Widespread citizen concerns about air pollution and its effects on public health and quality of life caused Congress and state legislatures to pass broad air quality protection laws. In 1990, Washington residents ranked air pollution the number one environmental threat in the state.
More recent polls rank air quality near the top of citizen environmental concerns.
This law recognizes that there are many and varied sources of air pollution and directs government agencies to approach problems and solutions comprehensively. The law contains detailed, prescriptive programs that specify performance standards, emission limits, fees, and constraints on regulatory agencies. This law establishes authority for motor vehicle emission testing. Much of the content of Washington's air quality laws are based on the goals, objectives, standards, and control requirements of the federal clean air act. Ecology provides financial and technical assistance to the local air agencies.