DELVING INTO
MINING RESEARCH
Studies at NIOSH’s Office of Mine Safety and Health
BY JOEL M. HAIGHT
CDC-NIOSH’s Office of Mine Safety and Health Research (OMSHR) is the premier mining health and safety research
establishment in the country. Its
mission is to protect mine workers from injury and illness through
research and prevention. Its two
main divisions, the Division of
Mining Research Operations and
the Division of Mining Science
and Technology, comprise seven
branches covering ground control;
human factors; electrical and mechanical systems safety; hearing
loss prevention; dust, ventilation
and toxic substances; fire and
explosion prevention; and health
communications, surveillance and
research support.
OMSHR’s unique research facilities
include a reverberation chamber and
hemi-anechoic chamber for hearing loss
prevention research; a mine roof simulator for ground control research; dust
laboratories and galleries for respiratory
protection research; and motion analysis
and cognitive engineering laboratories
for ergonomics and human factors research. OMSHR research includes work
in underground and surface mining, and
in the coal and metal/nonmetal mining
industries.
Hearing Loss Prevention
Noise-induced hearing loss (NIHL) is the
most common occupational illness in
the United States, as 30 million workers are exposed to excessive noise levels.
NIHL occurs in all industries but is of
particular concern in construction and
mining, where over 3. 3 million work-
ers are exposed to potentially damaging
noise levels. Approximately 50 percent of
construction workers, 90 percent of coal
miners and 49 percent of metal/nonmetal
miners exhibit hearing loss by age 50. In
contrast, only 10 percent of the non-oc-
cupational noise-exposed population has
a hearing impairment at that age. Opera-
tors of haul trucks and load haul dumps
(LHDs) are particularly at risk: greater
than 90 percent are over-exposed to noise
(see Figure 1). The Bureau of Labor Sta-
tistics (BLS) estimated that during 2010,
314,260 welders were engaged in weld-
ing, cutting, soldering and brazing; one
of these techniques, air carbon arc goug-
ing and cutting, can involve significant
overexposure to noise.1
Current hearing loss prevention
research, with input from mechanical engineering scientists, audiologists
and electrical engineers, focuses on
three main projects to reduce NIHL by
abating noise produced by longwall
mining systems, air carbon arc cutting
and gouging, haul trucks and LHDs.
To reduce these NIHL cases, engineering noise controls are developed and
implemented. For haul trucks, NIOSH
is currently constructing a fan test
apparatus for laboratory noise level
testing that will allow researchers to
determine configurations of fan and
cooling packages that will maintain
the required airflow for cooling while
generating less noise. Promising packages will be installed on equipment at
a cooperating mine and field evaluated
for noise and cooling performance.
Recent results from hearing loss prevention research include a collapsible
drill steel enclosure and drill bit isolator
to reduce the sound pressure level from
Figure 1. Underground metal/nonmetal haul truck (left) and underground metal/
nonmetal LHD.
of kneepad or a personal dust monitor).
This way, OMSHR interventions are more
likely to achieve their intended purposes.
And, with surveillance experts evaluating injury surveillance data, engineering researchers know where the greatest
numbers of injuries occur and are better
able to focus on the greatest prevention
intervention needs. This diversity of expertise and multidisciplinary approach
provides greater assurance that miners
are protected.
The Research Portfolio
OMSHR’s branch structure supports
a discipline-based organizational approach. As engineering interventions
are developed, behavioral research is
performed to determine whether miners
like, agree with or will use a particular
intervention device (such as a new style
