All of the above sources contribute to air pollution in urban areas, with vehicle exhaust being a particularly significant contributor.

The Clean Air Act is the primary federal law in the United States that regulates air quality. It sets national air quality standards and limits on emissions from various sources.

Air pollution control refers to the process of removing pollutants from the air, typically through the use of control technologies such as filters, scrubbers, and catalytic converters.

Primary air pollutants are emitted directly into the air from sources such as power plants and vehicles. Sulfur dioxide is a primary air pollutant that is released when fossil fuels are burned.

Odor control refers to the process of controlling odors from industrial or commercial facilities, typically through the use of control technologies such as scrubbers, biofilters, and thermal oxidizers.

Secondary air pollutants are formed in the atmosphere from reactions between primary pollutants. Ozone is a secondary air pollutant that is formed from reactions between nitrogen oxides and volatile organic compounds in the presence of sunlight.

Air quality standards are the maximum allowable concentrations of pollutants in the air, as set by regulatory agencies to protect public health and the environment.

Electrostatic precipitators are used to remove particulate matter from the air by applying an electrical charge to the particles, causing them to be attracted to a collection plate.

Climate change mitigation refers to the process of reducing emissions of greenhouse gases, which contribute to climate change.

Activated carbon filters are used to remove odors from the air by adsorbing the odor-causing compounds onto the surface of the carbon.

Air quality assessment refers to the process of assessing the impact of air pollution on human health and the environment, typically through the monitoring of air quality and the evaluation of potential health risks.

Selective catalytic reduction (SCR) is a control technology used to reduce nitrogen oxide emissions by converting them to nitrogen and water vapor using a catalyst.

Air quality management refers to the process of managing air quality in a specific region, typically through the implementation of air quality regulations and control measures.

Flue gas desulfurization (FGD) is a control technology used to reduce sulfur dioxide emissions from power plants and other industrial facilities by removing sulfur dioxide from the flue gas.

Air pollution prevention refers to the process of developing and implementing strategies to reduce air pollution, typically through the use of control technologies, regulations, and incentives.