Final answer:
The Environmental Protection Agency (EPA) is the national agency responsible for controlling air pollution. Established under the Clean Air Act and other laws, the EPA sets and enforces air quality standards through a command-and-control framework.
Step-by-step explanation:
The agency that controls air pollution on a national level is the Environmental Protection Agency (EPA). Established in 1970, the EPA is tasked with protecting human health and the environment through a variety of regulations based on laws passed by Congress. Specific to air quality, the EPA's authority was bolstered by the Clean Air Act, a piece of command-and-control legislation aimed at reducing air pollution.
The EPA has been instrumental in setting national standards, including those for water quality, through a command-and-control approach. They have jurisdiction over creating and enforcing regulations to ensure that environmental quality is maintained and pollution is controlled, covering both air and water ecosystems and pollutants.
Command-and-control regulations are those where the government sets specific limits or standards, and may include requirements for technology or practices, while market incentive-based policies involve economic incentives to encourage compliance, such as taxes and tradable permits.