Types of Indoor Air Pollutants (College Board AP® Environmental Science): Study Guide

Indoor air pollutants are substances found inside buildings that are considered harmful to health

They arise from various sources, including:

• building materials

• household products

• tobacco smoke, etc.

Carbon monoxide (CO) is an indoor air pollutant that is classified as an asphyxiant

Also known as the 'silent killer,' as it is a colorless and odorless gas, which makes it hard to detect unless CO metres are fitted

Produced by incomplete combustion of fossil fuels

Sources: gas stoves, fireplaces, furnaces, and vehicle exhaust in enclosed spaces

Effects: reduces oxygen delivery in the bloodstream, leading to dizziness, confusion, and potentially fatal poisoning

Prevention:

• Ensure adequate ventilation when using fuel-burning appliances

• Never run a car in a closed garage

• Fit CO monitors and regularly check them

It is estimated that 90% of people's time is spent inside

The air inside homes and buildings can be more polluted than outdoors, which raises the risk of illness

Asbestos

• Asbestos was a popular material used in buildings as a fire retardant

• It is a long silicate fiber that is not dangerous until the material is disturbed and asbestos particles enter the air and then the respiratory tract

• Asbestos fibers do not dissolve in water or evaporate; they are resistant to heat, fire, and chemical and biological degradation

• Found in old insulation, roofing, and tiles

• Effect: can cause skin irritation and lung diseases such as asbestosis and mesothelioma

• Management: asbestos must be removed by trained professionals using breathing apparatus, ventilation in the removal area, and plastic to seal off the area

Dust

• Composed of dead skin cells, pollen, fibers, and other particles

• Can worsen asthma and allergies

Smoke

• Includes tobacco smoke and smoke from cooking or burning wood

• Contains harmful chemicals and particulates that damage respiratory health

Radon-222

• A radioactive gas produced by the decay of uranium in rocks and soil

• Can accumulate in basements and poorly ventilated areas

• Long-term exposure increases the risk of lung cancer

Mold

• Grows in humid and damp environments

• Releases spores that can trigger allergic reactions and respiratory issues

Dust

• Common in indoor spaces

• Can carry mites, pet dander, and chemical residues

Volatile Organic Compounds (VOCs)

• Released by furniture, paneling, and carpets

• Includes chemicals such as benzene, toluene, and xylene

• Can cause headaches, nausea, and long-term health effects

Formaldehyde

• Found in building materials, furniture, upholstery, and carpeting

• Can cause eye irritation and respiratory problems and is a known carcinogen

Lead

• Found in old paints, pipes, and contaminated dust

• Exposure can lead to neurological damage, developmental delays, and other health issues

Carbon Monoxide (CO) prevents oxygen transport in the body

Nitrogen oxides (NOₓ) irritate the respiratory system and contribute to smog formation

Sulfur dioxide (SO₂) can cause lung irritation and acid rain

Particulates are tiny particles that can damage lung tissue and worsen respiratory conditions

Tobacco smoke contains carcinogens and contributes to respiratory diseases