Asbestos and Indoor Air
The main source of asbestos in indoor air is
insulation products. Buildings built in the
last 50 years used a variety of materials
composed of asbestos mixed with other fibers
like paper, fiberglass, or synthetic fibers
and a binder, usually lime or gypsum mortar.
The most commonly reported material in
California homes is the cottage-cheese
ceiling insulation. Other common materials
include vinyl floor tiles, patching
compounds and textured paints, furnace,
stove and pipe insulation, stove door
gaskets, some roofing shingles and siding
material, and parts of some pre-1979
appliances (e.g. toasters, clothes dryers,
hair dryers).
How dangerous is asbestos to
my health?
You
will not be harmed by touching it or being
near asbestos-containing materials. Your
health may be affected by inhaling
asbestos fibers, where the fibers may become
lodged in the microscopic tubules of your
lower lung. Symptoms of lung problems do not
usually appear until 20-30 years of exposure
to high levels of asbestos fibers.
Asbestos
lung
How can
asbestos be identified?
It is not possible to identify asbestos by
just looking at it. Asbestos in suspect
building material is identified using the
Polarized Light Microscopy (PLM) method.
Asbestos fibers found in building materials
look very colorful and quite beautiful under
a microscope. However, when lodged in your
lungs what they cause is anything but
beautiful.
Asbestos
is a mineral fiber. It is mined just like any other
mineral. The fibers are heat resistant, resistant to
chemical attack, have excellent tensile strength and have
high electrical resistance. These properties make asbestos a
useful material for electrical and thermal insulation. It
was often added to building materials for this reason. There
are several types of asbestos; the most common are
chrysotile, amosite, and crocidolite. 
