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

Figure 3. Number of asbestosis deaths, U.S. residents aged ≥15 years, 1968–2004. Source of data:
NIOSH [2007b].
data, representing all deaths among U.S. residents,
show that asbestosis deaths increased almost
20-fold from the late 1960s to the late 1990s
(Figure 3) [NIOSH 2007b]. Asbestosis mortality
trends are expected to substantially trail trends
in asbestos exposures (see Section 2.4.2) for two
primary reasons: (1) the latency period between
asbestos exposure and asbestosis onset is typically
long, commonly one or two decades or
more; and (2) asbestosis is a chronic disease, so
affected individuals can live for many years with
the disease before succumbing. In fact, asbestosis
deaths have apparently plateaued (at nearly
1,500 per year) since 2000 (Figure 3) [NIOSH
2007b]. Ultimately, it is anticipated that the annual
number of asbestosis deaths in the United
States will decrease substantially as a result of
documented reductions in exposure. However,
asbestos use has not been completely eliminated,
and because asbestos-containing materials
remain in structural materials and machinery,
the potential for exposure continues. Thus,
NIOSH CIB 62 • Asbestos
asbestosis deaths in the United States are anticipated
to continue for several decades.
2.4.3.2 Malignant Mesothelioma
Malignant mesothelioma, an aggressive disease
that is nearly always fatal, is known to be caused
by exposure to asbestos and some other mineral
fibers [IOM 2006]. The occurrence of
mesothelioma has been strongly linked with
occupational exposures to asbestos [Bang et
al. 2006]. There had been no discrete International
Classification of Disease (ICD) code for
mesothelioma until its most recent 10 th revision.
Thus, only seven years of NORMS data are available
with a specific ICD code for mesothelioma
(Figure 4); during this period, there was a 9%
increase in annual mesothelioma deaths, from
2,484 in 1999 to 2,704 in 2005 [NIOSH 2007b].
A later peak for mesothelioma deaths than
for asbestosis deaths would be entirely expected,
given the longer latency for mesothelioma
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