Visualizing Environmental Science

Indoor Air Pollution 209

than the level considered at-risk in the United States.

Lead can retard children’s growth and cause brain

damage.

According to the World Health Organization, the

five cities with the worst air pollution are Beijing, China;

New Delhi, India; Santiago, Chile; Ulaanbator, Mon-

golia; and Cairo, Egypt. Respiratory disease is now the

leading cause of death for children worldwide. More

than 80 percent of these deaths occur in children under

age 5 who live in cities in developing countries.

1. What is the U.S. Clean Air Act, and how has it
   reduced outdoor air pollution?


2. Where is air pollution worse: in highly developed
   nations or in developing countries? Why?

The growing number of automobiles in developing
countries is also contributing to air pollution, particu-
larly in urban areas. Many vehicles in these countries are
10 or more years old and have no pollution-control de-
vices. Motor vehicles produce about 60 to 70 percent of
the air pollutants in urban areas of Central America, and
they produce 50 to 60 percent in urban areas of India.
The most rapid proliferation of motor vehicles world-
wide is currently occurring in Latin America, Asia, and
eastern Europe.
Lead pollution from heavily leaded gasoline is an
especially serious problem in developing nations. The
gasoline refineries in these countries are generally not
equipped to remove lead from gasoline. (The United
States was in the same situation until federal law man-
dated that U.S. refineries upgrade their equipment by
1986.) In Cairo, Egypt, for example, many children
have blood lead levels more than two times higher

1. Summarize at least four sources of indoor air
   pollution and explain their role in sick building
   syndrome.


2. Describe the effects of indoor air pollution in
   developing countries.


3. Explain why radon gas is an indoor health
   hazard.

P

eople around the world spend much of their
time indoors, and contaminated indoor air
can lead to substantial health problems. In
rural areas, and particularly in developing
countries, cooking with solid fuels (wood, coal, peat, and
dung) can have serious health impacts. This has led the
World Health Organization to determine that burning
solid fuels is among the 10 greatest threats to human
health.
The most common contaminants of indoor air in
highly developed countries are radon, cigarette smoke,
carbon monoxide, nitrogen dioxide (from gas stoves),

formaldehyde (from carpet, fabrics, and furniture),

household pesticides, cleaning solvents, ozone (from

photocopiers), and asbestos. In addition, viruses, bacte-

ria, fungi (yeasts, molds, and mildews), dust mites, pol-

len, and other organisms are often found in heating,

air-conditioning, and ventilation ducts. Because illnesses

from indoor air pollution usually resemble common ail-

ments such as colds, influenza, or upset stomachs, they

are often not recognized.

Health officials are paying increasing attention to

sick building syndrome. The Labor Department esti-

mates that more than 20 million employees are exposed

to health risks from indoor air

pollution. The EPA estimates that

annual medical costs for treating

the health effects of indoor air

pollution in the United States ex-

ceed $1 billion. When lost work

time and diminished productivity

are added to health care costs, the

sick building

syndrome Eye

irritations, nausea,

headaches,

respiratory infections,

depression, and

fatigue caused by

indoor air pollution.

Indoor Air Pollution

LEARNING OBJECTIVES