Outdoor Air Pollutants

Tropospheric (bad) Ozone

• Source: Cars (NOx + VOCs + sunlight)

• Impact: Respiratory problems; damages plants.

Nitrogen Oxides (NOx)

• Source: Car engines, power plants

• Impact: Forms smog and acid rain; lung irritation.

Sulfur Oxides (SOx)

• Source: Burning coal/oil

• Impact: Forms acid rain; harms ecosystems; breathing issues.

Carbon Monoxide (CO)

• Source: Incomplete combustion (cars, stoves)

• Impact: Prevents oxygen transport in blood; deadly indoors.

Lead

• Source: Old gasoline, industrial processes

• Impact: Nervous system damage; especially harmful to children.

Carbon Dioxide (CO₂)

• Source: Burning fossil fuels, deforestation

• Impact: Major greenhouse gas; contributes to global warming.

Methane (CH₄)

• Source: Livestock, landfills, natural gas leaks

• Impact: Powerful greenhouse gas; traps heat.

Particulates (PM 2.5)

• Source: Combustion (cars, fires)

• Impact: Penetrates lungs deeply; heart/lung disease.

Particulates (PM 10)

• Source: Dust, construction, combustion

• Impact: Respiratory problems; less dangerous than PM2.5 but still harmful.

Photochemical Smog

• Source: NOx + VOCs + sunlight (city pollution)

• Impact: Eye irritation, breathing issues; damages crops.

Industrial Smog

• Source: Coal burning (SOx + particulates)

• Impact: Breathing problems; poor air visibility.

Acid Rain

• Source: NOx and SOx reacting with water vapor

• Impact: Damages forests, soils, aquatic life; erodes buildings.

Chlorofluorocarbons (CFCs)

• Source: Old refrigerants, aerosols

• Impact: Destroy stratospheric ozone layer → more UV radiation reaching Earth.