Indoor Air Pollution - Air Pollution and Global Warming: History, Science, and Solutions - page 214

4,800 people in the United States died of asbestos-
induced lung cancer (U.S. EPA, 2009b). Mesothe-
lioma is a cancer of the mesothelial membrane lining
the lungs and chest cavity. Between 1994 and 2008,
about 174,300 people in fifty-six countries contracted
mesothelioma, causing more than 92,100 deaths (Park
et al., 2011). Asbestosis is a slow, debilitating disease
of the lungs, whereby bodily produced acids scar the
lungs as they try to dissolve asbestos fibers in lung tis-
sue. Significant scarring causes crackling of the lungs
and inhibits oxygen from transferring from the airway
to the blood, making it difficult to breathe. The most
dangerous asbestos fibers are those longer than 5 to 10

to other flowers for fertilization. Emitted pollen grains
are generally large, ranging from 10 to 125

mindiam-
eter. A typical corn plant emits 14 to 50 million pollen
grains/yr, all within a short period (Miller, 1985). Pollen
grains are released more during spring than in any other
season (Pasken and Pietrowicz, 2005).
Some diseases associated with fungi, bacteria, and
viruses include rhinitis (a respiratory illness), asthma,
humidifier fever, extrinsic allergic alveolitis, and atopic
dermatitis. Most human illnesses due to viral and bacte-
rial infection are due to human-to-human transmission
of microorganisms rather than to building-to-human
transmission (Ayars, 1997).

m. Exposure to
0.0004 structures per cubic centimeter of air is expected
to cause a lifetime cancer risk of 160 cases of mesothe-
lioma per 1 million people (Turco, 1997). People with
lung cancer attributable to asbestos typically have more
than 100 fibers per gram of lung tissue (Wright et al.,
2008). The time between first exposure to asbestos and
the appearance of tumors is estimated to be 20 to 50
years (Jones, 1999). Cigarette smoking and exposure
to asbestos are believed to amplify the rates of lung
cancer in comparison with the rates of cancer associ-
ated with just smoking or just exposure to asbestos.
Short-term acute exposure to asbestos can lead to skin
irritation and itching (Spengler and Sexton, 1983).
Today, miners and those who remove asbestos from
buildings are the people most likely to be exposed to
asbestos in concentrations high enough to cause health
problems.

mbutwith a diameter of 0.01 to 1

9.1.13. Environmental Tobacco Smoke
When a person smokes a cigarette, some of the smoke
is inhaled and swallowed, some is inhaled and exhaled
( mainstream smoke ), and the rest is emitted from the
burning cigarette between puffs ( sidestream smoke )
(Figure 9.6). The mainstream plus sidestream smoke is
called environmental tobacco smoke (ETS), a mix-
ture of more than 4,000 aerosol particle components
and gases, at least 50 of which are known carcinogens.
However, because of the different conditions result-
ing in mainstream versus sidestream smoke, the rela-
tive gas and particle composition of the two types of
smoke differ somewhat, with sidestream smoke possi-
bly being more dangerous (Schick and Glantz, 2005).
Also called second-hand smoke , ETS builds up in
enclosed spaces, increasing danger to others in the
vicinity. Even in well-ventilated indoor areas, particle
and gas concentrations associated with ETS increase.
Although the cumulative effect of ETS on outdoor air
pollution is relatively small compared with the effects
of other sources of pollution, such as automobiles, ETS
concentrations can build up outdoors in the vicinity of
smokers.
Outdoor ETS emission rates are not regulated in the
United States, although regulations prohibiting smok-
ing in many public and private indoor facilities exist
at the local, state, and federal levels. Many chemical
constituents of ETS are classified as hazardous air
pollutants under CAAA90, and ETS itself has been
classified by the U.S. EPA as a carcinogen. However,
CAAA90 controls only sources emitting more than 9.1
tonnes of a hazardous substance per year, and indi-
vidual cigarettes emit less than 1 g of all pollutants
combined. The product of the number of cigarettes
smoked per year in the United States multiplied by
the emission rate per cigarette is much larger than

9.1.12. Fungal Spores, Bacteria, Viruses,
and Pollen
Fungal spores, bacteria, viruses, and pollen are com-
mon indoor air contaminants. They can infiltrate indoors
from outdoor air or grow indoors. Fungal spores are
reproductive or resting organisms released by fungi and
algae growing on leaf surfaces, soils, animals, and food-
stuffs. They are generally 2 to 3.5

mindiameter.
Fungi grow well on damp surfaces. Common fungi
in buildings include Penicillium , Cladosporium , and
Aspergillus (Jones, 1999).
Bacteria and viruses live in water, soil, plants, ani-
mals, and foodstuffs, and they can be picked up read-
ily by wind or turbulence. Common bacteria include
Bacillus , Staphylococcus , and Micrococcus .Bacteria
are generally 0.5 to 10 mindiameter.

Pollens are large granules containing male genetic
material released from flowers and blown by the wind