Particulate matter, which consists of small particles of solid or liquid matter suspended in the air, is the primary component of air pollution that is harmful to human health.

Particulate matter can come from both natural sources, such as dust storms and volcanic eruptions, and human activities, such as burning fossil fuels and industrial processes.

Exposure to particulate matter has been linked to a range of health problems, including asthma, chronic bronchitis, heart disease, and even premature death.

Atmospheric chemistry encompasses the chemical reactions that occur in the atmosphere, including photochemistry, heterogeneous chemistry, and gas-phase chemistry.

Carbon dioxide, methane, and nitrous oxide are all major greenhouse gases that contribute to climate change.

Deforestation, burning fossil fuels, and industrial processes are all major contributors to the increase in greenhouse gas concentrations in the atmosphere.

Rising sea levels, more extreme weather events, and changes in agricultural yields are all potential consequences of climate change.

Deposition, precipitation, and advection are all processes by which air pollutants are removed from the atmosphere.

Tobacco smoke, radon, and asbestos are all major sources of indoor air pollution.

Advection is the process by which air pollutants are transported from one location to another by the wind.

Motor vehicles, power plants, and industrial facilities are all major sources of outdoor air pollution.

Heterogeneous chemistry is the term used to describe the chemical reactions that occur between air pollutants and surfaces.

Ozone, nitrogen dioxide, and particulate matter are all major air pollutants that contribute to smog.

Chemical transformation is the term used to describe the process by which air pollutants are transformed into different chemical species.

Burning biomass for cooking and heating is a major source of air pollution in developing countries.