Environmental Engineering Reference
In-Depth Information
Epithelial cell
Cilia
Nasal cavity
Oral cavity
Goblet cell
(secreting
mucus)
Pharynx (throat)
Mucus
Trachea (windpipe)
Bronchioles
Bronchus
Alveolar duct
Right lung
Bronchioles
Alveolar sac
(sectioned)
Alveoli
Figure 15-14
Science:
major components of the human respiratory system.
breath. Damage deeper in the lung can cause
emphy-
sema,
in which irreversible damage to air sacs or alve-
oli leads to abnormal dilation of air spaces, loss of lung
elasticity, and acute shortness of breath (Figure 15-15).
People with respiratory diseases are especially
vulnerable to air pollution, as are older adults, infants,
pregnant women, and people with heart disease.
tants. According to the WHO, worldwide at least 3
million people (most of them in Asia) die prematurely
each year from the effects of air pollution—an average
of 8,200 deaths per day. About 2.8 million of these
deaths (93%) result from indoor air pollution, typically
from heart attacks, respiratory diseases, and lung can-
cer related to prolonged breathing of polluted air.
The
WHO and the World Bank consider indoor air pollution to
be one of the world's most serious environmental problems.
In the United States, the EPA estimates that annual
deaths related to indoor and outdoor air pollution
range from 150,000 to 350,000 people—equivalent to
one to two fully loaded 400-passenger jumbo jets
crashing
each day
with no survivors. Millions more be-
come ill and lose work time. Most of these deaths are
related to inhalation of fine and ultrafine particulates
Science: Harmful Health Effects of Key
Air Pollutants
Air pollutants damage materials and human lungs
and worldwide prematurely kill at least 3 million
people each year.
Table 15-1 lists some of the harmful health effects of
prolonged or chronic exposure to six major air pollu-
Figure 15-15
Science:
normal
human lungs (left) and the lungs
|of a person who died of emphy-
sema (right). Prolonged smoking
and exposure to air pollutants can
cause emphysema in anyone, but
about 2% of emphysema cases
result from a defective gene that
reduces the elasticity of the air
sacs in the lungs. Anyone with this
hereditary condition, for which
testing is available, should not
smoke and should not live or work
in a highly polluted area.
