Indoor Air Pollution - Air Pollution and Global Warming: History, Science, and Solutions - page 213

contains brittle fibers that easily fracture. Asbestos is
chemically inert, does not conduct heat or electricity,
and is fire resistant. As a result, it is has been widely
used as an insulator and fire retardant.
Inhabitants of east Finland used asbestos as far back
as 4,500 years ago to strengthen earthenware pots
and cooking utensils. The Egyptians were aware of
asbestos' fire-resistant properties and used asbestos
in burial cloth. Around 300 BC, the Greek author
Theophrastus described asbestos in detail in his book,
On Stones .Thename asbestos derives from asbesti-
non (“unquenchable”), a term used in the Roman Pliny
the Elder's manuscript, Natural History .The French
emperor Charlemagne (742-814) amused his guests
at dinner parties by wiping his mouth with a napkin
made of asbestos, throwing the napkin into the fire-
place, and then retrieving the unburned napkin to their
surprise.
The adverse health effects of asbestos were suggested
as early as 1898, when the Chief Inspector of Factories
in the UK stated that asbestos had “easily demonstrated”
health risks. A London doctor testified that the 1899
death of a young asbestos worker was due in part to
asbestos dust. Asbestos-related illnesses were reported
among UK textile workers in the 1920s and U.S. ship
workers during World War II. Nevertheless, asbestos
use grew throughout the construction industry as an
electrical and thermal insulator, particularly in pipe and
boiler insulation, cement board, floor and ceiling tiles,
paint, and wallpaper (Maroni et al., 1995; Jones, 1999).
Asbestos has also been used in sheetrock tape, mud and
texture coats, plasters and stuccos, tars, felts, shingles,
putty, caulk, brake pads, lamp wicks, stage curtains,
electric ovens, fire blankets and doors, firefighter cloth-
ing, and fireproofing. More than 3,000 products con-
tained asbestos at one time or another. The early lack of
concern about asbestos health effects is evidenced by
the use of asbestos as a filter in Kent cigarettes between
1952 and 1956.
Between 1920 and 2006, the five leading asbestos-
using countries worldwide were the United States, the
UK, Germany, Japan, and France, with the United States
consuming 42.6 percent of all asbestos among 56 coun-
tries (Park et al., 2011). The United States first banned
the production of asbestos for new fireproofing and insu-
lation in 1973 and for decorative use in 1978, although
existing stock could be used until 1986. Asbestos is also
defined as a hazardous air pollutant under CAAA90.
However, asbestos can still be used in the construc-
tion of, for example, cement asbestos pipes in the
United States. Although most new asbestos production

is banned in the United States and all new produc-
tion is banned in the EU, Australia, Hong Kong, Japan,
and New Zealand, much of the asbestos installed in
buildings before the bans occurred still exists. Further-
more, many countries, particularly developing coun-
tries, still allow construction with asbestos, particu-
larly for roofing and side walls in homes, factories,
and schools. In 2006, the five leading asbestos-mining
countries were Russia, China, Kazakhstan, Canada, and
Brazil.
People who were most likely to be exposed to
asbestos in the past were miners and insulation man-
ufacturers and installers. From 1913 to 1990, a mine in
Libby, Montana, became the world's largest producer
of vermiculite, supplying 80 percent of the world's
supply. Vermiculite is a clay mineral intertwined with
asbestos. Upon heating, vermiculite expands to feather-
weight pieces used in wall insulation, wallboard, nurs-
ery products, and wood products. Unknown to the min-
ers, the vermiculite was contaminated with asbestos.
Between the early 1980s and 2000, 192 people from
the town of 2,700 died, and 375 others were diagnosed
with asbestos-related lung problems. Some miners inad-
vertently exposed their families to asbestos when they
brought their clothes, carrying asbestos-laden dust, into
their homes. Today, the Libby, Montana mine, owned
from 1963 to 1990 by the W. R. Grace Company, is an
U.S. EPA Superfund site.

9.1.11.1. Sources and Sinks
Once insulation containing asbestos has been installed,
the asbestos is not expected to cause damage to humans
unless the insulation is disturbed. At that time, fibers
can be scattered into the air, where they can remain for
minutes to days until they deposit to the ground or are
inhaled. Thus, the only source of asbestos in indoor air
is turbulent uplift, and the only sink is deposition.

9.1.11.2. Concentrations
Indoor concentrations of asbestos vary from building
to building. Lee et al. (1992) found an average of 0.02
structures per cubic centimeters of air in 315 public,
commercial, residential, school, and university build-
ings in the United States. The concentration of fibers
longer than 5 mwas only 0.00013 structures per cubic

centimeter.

9.1.11.3. Health Effects
The primary health effects of asbestos exposure are lung
cancer, mesothelioma, and asbestosis. In 2007, about