ASBESTOS AND OTHER FIBROUS MATERIALS Mineralogy, Crystal Chemistry, and Health Effects

In 1971 the National Academy of Science published a 40-page report, "Asbestos: The Need for and Feasibility of Air Pollution Controls," (Cooper,
1971) summarizing the illnesses associated with occupational exposure to
asbestos and the risks of developing asbestosis, pleural calcifications, and
cancers of the pulmonary and gastrointestinal tracts and thoracic cavity. Based
on the evidence, the committee recommended control and reduction of dust
containing fibrous inorganic materials in the workplace; it also discussed
nonoccupational exposure to asbestos.
Since this report was published, the government has imposed regulations.
The maximum allowable exposure to asbestos fibers in the ambient air of
the workplace is now mandated. The workers affected include not only the
miners extracting mineral fibers from rock but also the people who manufacture or use products containing asbestos—construction workers, for example. More significant, the emphasis has shifted to the hazards associated
with nonoccupational exposure to asbestos. The public has become acutely
aware that the environment contains a large quantity of asbestos. It is used
as insulation material in homes, schools, other public buildings, and ships,
in the brake linings of cars, in hair driers, and in many other products. All
of us have been, and continue to be, exposed to asbestos. What are the
dangers to the public of this low-level exposure, and what can or should be
done about them?
In spite of the publication of thousands of articles on asbestos, and its
role as a hazard, the ability to assess the risks to low-level exposure is limited. Many basic scientific and medical questions remain unanswered. For
example, we are still a long way from understanding the material known as
asbestos, much less the relationship between it and disease.
Asbestos is a fibrous inorganic material. It is mined and exploited because
of its unique chemical and physical properties, in part the result of its distinctive fibrous form. The hazards, as we understand them, are also attributed to this fibrous character, but asbestos represents only a fraction of the
many inorganic fibers now in use. Furthermore, although it is a readily recognizable form, fiber has no precise scientific or technical definition. Thus,
to address the health effects of asbestos, federal government (OSHA—Oc
cupational Safety and Health Agency) regulators had to define fiber and to
establish the criteria for their regulations.

ASBESTOS AND OTHER FIBROUS MATERIALS Mineralogy, Crystal Chemistry, and Health Effects -

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