Volcanic eruptions release various gases and particles into the atmosphere, including sulfur dioxide, ash, and carbon dioxide.

Vehicle exhaust is a major contributor to air pollution in urban areas, releasing pollutants such as carbon monoxide, nitrogen oxides, and particulate matter.

Primary air pollutants are emitted directly from sources, while secondary pollutants are formed in the atmosphere through chemical reactions. Sulfur dioxide is a primary air pollutant released from industrial processes and fossil fuel combustion.

Photochemical smog is formed through the reaction of sunlight with nitrogen oxides and volatile organic compounds (VOCs). Ozone is a major component of photochemical smog and is harmful to human health and the environment.

Secondary air pollutants are formed in the atmosphere through chemical reactions. Ozone is a secondary pollutant formed from the reaction of nitrogen oxides and VOCs in the presence of sunlight.

Industrial emissions, such as those from power plants and factories, are a major source of particulate matter air pollution. PM can also be generated from vehicle exhaust, residential heating, and agricultural activities.

Exposure to particulate matter air pollution has been linked to a range of health effects, including respiratory problems such as asthma and bronchitis, cardiovascular disease, and an increased risk of cancer.

Carbon dioxide is the primary greenhouse gas emitted by human activities, primarily from the burning of fossil fuels for energy production and transportation.

Fluorinated gases, such as hydrofluorocarbons (HFCs) and perfluorocarbons (PFCs), have high global warming potentials, meaning they trap heat more effectively than carbon dioxide.

Methane emissions come from various sources, including agriculture (livestock and rice cultivation), landfills, and natural gas production and distribution.

Reducing air pollution from vehicle exhaust involves a combination of strategies, including the use of catalytic converters to reduce emissions, promoting the use of electric vehicles, and improving public transportation to reduce the number of vehicles on the road.

Industrial emissions, particularly from power plants and factories that burn fossil fuels, are the primary source of sulfur dioxide emissions.

Exposure to sulfur dioxide air pollution is primarily associated with respiratory problems, such as asthma and bronchitis, and can also contribute to cardiovascular disease.

Vehicle exhaust is the primary source of nitrogen oxides emissions, particularly from diesel engines. NOx emissions also come from industrial processes and power plants.

Exposure to nitrogen oxides air pollution has been linked to a range of health effects, including respiratory problems, cardiovascular disease, and an increased risk of cancer.