Asbestos Fibers and Other Elongate Mineral Particles: State of the ...

Research is needed to produce information on
• current estimates and, where possible, future
projections of numbers of U.S. workers
exposed to asbestos fibers;
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• levels of current exposures and nature of
the exposures (e.g., continuous, short-term,
or intermittent); and
• the nature of any concomitant dust exposures.
Similar research is needed to produce analogous
information about occupational exposures
to other EMPs. Research is needed to
assess and quantify potential human health
risks associated with occupational exposures
to other EMPs, as well as to better understand
and quantify the epidemiology of asbestosrelated
diseases by using more refined indices
of exposure. Research is also needed to produce
improved methods and clinical guidance
for screening, diagnosis, secondary prevention,
and treatment of diseases caused by asbestos fibers
and other hazardous EMPs.
3.5.1 Assess Available Information
on Occupational Exposures to
Asbestos Fibers and Other EMPs
A fully informed strategy for prioritizing research
on EMPs should be based on preliminary
systematic collection and evaluation of available
information on (1) industries/occupations/job
tasks/processes with exposure to various types
of asbestos fibers and other EMPs; (2) numbers
of workers exposed; (3) characteristics and levels
of exposures; and (4) associated concomitant
particulate exposures. Such information could
enable estimations of
• the overall distribution and levels of occupational
exposures and an estimate of
the total number of workers exposed to
EMPs currently, in the past, and projected
in the future; and
• the specific distributions and levels of exposures
to each particular type of EMP,
as well as numbers of workers exposed to
each type of EMP currently, in the past,
and projected in the future.
To complement readily available information
disseminated by the USGS on annual domestic
production and importation of raw asbestos,
data on the annual amounts of asbestos imported
into the United States in the form of any
asbestos-containing products should be aggregated
and made easily accessible.
Additional efforts should be made to collect, review,
and summarize available occupational exposure
information and to collect and analyze
representative air samples relating to various
types of EMPs. For example, systematic compilation
of exposure data collected by OSHA,
MSHA, NIOSH, state agencies, and private
industry could contribute to an improved understanding
of current occupational exposures
to EMPs, particularly if there are opportunities
to (re)analyze collected samples with use of enhanced
analytical methods to better characterize
the exposures (see Section 3.6). To help limit
potential impact of sampling bias that may be
inherent in the available EMP exposure data,
these initial efforts should be supplemented
with efforts to systematically identify, sample,
and characterize EMP exposures throughout
U.S. industry. These exposure assessments
should include workplaces in which a fraction
of the dust comprises EMPs (i.e., mixed-dust
environments), and occupational environments
in which EMPs may not meet the current regulatory
criteria to be counted (i.e., “short” fibers).
With appropriate planning and resources, such
efforts could be designed and implemented as
ongoing surveillance of occupational exposures
NIOSH CIB 62 • Asbestos