Vehicle emissions are the primary source of air pollution in urban areas, contributing to high levels of particulate matter, nitrogen oxides, and carbon monoxide.

Lead is not a criteria air pollutant regulated by the Clean Air Act, although it is a toxic metal that can cause serious health problems.

Photochemical smog is a mixture of pollutants that forms in the atmosphere under the influence of sunlight. The main component of photochemical smog is ozone (O3).

Tobacco smoke, radon gas, asbestos fibers, and volatile organic compounds (VOCs) are all major sources of indoor air pollution.

A catalytic converter is a device that reduces emissions of nitrogen oxides (NOx) from a vehicle's exhaust system.

Solar energy, wind energy, and hydropower are all renewable energy sources that do not produce air pollution.

Air pollution control is the process of removing pollutants from the air, typically through the use of various technologies and strategies.

Incineration is not a common method of air pollution control, as it can release harmful pollutants into the atmosphere.

The National Ambient Air Quality Standards (NAAQS) are the maximum allowable concentrations of pollutants in the air, as set by the U.S. Environmental Protection Agency (EPA).

Deforestation, burning fossil fuels, agricultural activities, and industrial processes are all major causes of climate change.

Waste reduction is the process of reducing the amount of waste produced, typically through source reduction, reuse, and recycling.

Catalytic converters are not a common type of air pollution control device, as they are typically used in vehicles to reduce emissions.

Recycling is the process of converting waste into usable materials, typically through the use of various technologies and processes.

Oxygen (O2) is not a common type of air pollutant, as it is a naturally occurring gas that is essential for life.

Water pollution control is the process of removing pollutants from water, typically through the use of various technologies and strategies.