Visualizing Environmental Science

Indoor Air Pollution 211

Figure 8.19 summarizes many possible sources of air

pollution in homes.

1. What are some common indoor air
   contaminants?


2. Why is indoor air pollution such a serious health
   hazard in developing countries?


3. How does radon gas enter buildings?

Ironically, efforts to make our homes more energy

efficient have increased the hazard of indoor air pol-

lutants, including radon. Drafty homes waste energy

but allow radon to escape outdoors so it does not build

up inside. Every home should be tested for radon be-

cause levels vary widely from home to home, even in

the same neighborhood. Generally, testing and correc-

tive actions are reasonably priced. However, some cor-

rective actions can be expensive, costing thousands of

dollars.

Gasoline

From: auto,

lawn mower

Methylene

chloride

From: paint

strippers and

thinners Tobacco smoke

From: cigarettes

and pipes

Formaldehyde

From: furniture and

carpeting made from

synthetic polymers,

particle board, foam

insulation

Tetrachloroethylene

From: dry-cleaning

fluid

Pesticides
From: gardening
products

Radon

From: uranium-

containing rocks

Carbon monoxide

From: faulty

furnace, auto

left running

Fungi and

bacteria

From: dirty

heating and

air conditioning

ducts

Asbestos

From: pipe

insulation,

vinyl tiles

Ammonia

From:

household

cleaners

Para-dichlorobenzene

From: mothball

crystals, air fresheners

Chloroform

From: chlorine-

treated water

in hot showers

Nitrogen

oxides

From:

unvented

gas

stoves,

wood

stoves,

kerosene

heaters

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Homes may contain higher levels of air pollutants than outside air, even near polluted industrial sites.