Environmental Protection Agency (EPA): The EPA is a government agency responsible for implementing and enforcing environmental regulations, including those related to air quality.
National Ambient Air Quality Standards (NAAQS): NAAQS are the set of guidelines established by the EPA to protect public health and welfare by limiting levels of harmful pollutants in outdoor air.
Emissions Trading Program: Also known as cap-and-trade, this program allows companies to buy or sell permits that allow them to emit certain amounts of pollutants. It provides economic incentives for reducing emissions while still achieving overall pollution reduction goals.