Air Pollutants

Primary pollutants come directly from sources like and .

Cars; factories.

Secondary pollutants happen when primary pollutants __ with each other in the air.

React.

One major air pollutant is __, which consists of tiny particles like dust and soot.

Particulate Matter (PM).

__ (SO2) is a gas released when fossil fuels are burned.

Sulfur Dioxide.

__ (NOx) is emitted mainly from cars and other burning processes.

Nitrogen Oxides.

__ (VOCs) are chemicals that can form harmful ozone.

Volatile Organic Compounds.

__ (O3) is a pollutant that can cause breathing problems.

Ozone.

__ (CO) is a gas that comes from car exhaust.

Carbon Monoxide.

Photochemical smog occurs when sunlight reacts with and .

NOx; VOCs.

Air pollution can come from natural sources, like __, or human activities.

Volcanoes.

Laws like the __ help reduce harmful pollutants, such as lead.

Clean Air Act.

The __ (AQI) is used to measure how clean or polluted the air is.

Air Quality Index.