Characteristics of the top five most

frequent injuries in United States 

mining operations, 2003-2007 

P. J. Coleman, J. Brune and L. Martini 

National Institute for Occupational Safety and Health (NIOSH), 

Spokane Research Laboratory (SRL), Spokane, WA
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Introduction 

Research in the field of mining safety and health in the 

United States plays an important part in protecting the lives 

of miners. The National Institute for Occupational Safety and 

Health(NIOSH)MiningProgramconductssurveillance,studies 

and developmental work aimed at improving the safety and 

health of miners. With recent reviews of the Mining Program 

by the National Academy of Sciences and the Mining Program 

response (NIOSH, 2008), the importance of setting goals, 

conducting high quality engineering and scientific research 

and evaluating the outputs, outcomes, relevance and impacts of 

theseprojectshasbeenreemphasized. Surveillanceofreported 

injuries is a first step in deciding on research directions and 

in designing specific projects. Groups of injuries often share 

features and attributes that suggest common causes and may 

respond to similar preventive efforts. Identifying groups of 

injuries also serves to prioritize intervention efforts. 

The Mine Safety and Health Administration (MSHA) Accident and Injury database (MSHA, 2008) provides individual 

case reports of mining injuries, illnesses and certain no-injury 

accidents (events such as roof falls that stop mine production 

or miners’ activities for more than one hour). This database 

is an indispensable resource for researchers and stakeholders 

needing information on the statistics of these events. From an 

epidemiological perspective, research projects target groups 

of miners at risk due to specific patterns of work, equipment, 

mine settings and the management of safety and health in 

their mines. Incidence rates are provided by the MSHA data 

for selected variables, such as surface/underground location, 

standard industrial classification and state. While incidence 

rates are the preferred measure for all variables, denominators 

are not typically available; for example, to more clearly understand the data about injury by occupational type, it would be 

necessary to conduct demographic surveys. A current survey 

of the demographics of the mining industry should be complete 

by 2010, which will allow incidence rates to be developed for 

a number of variables such as age, occupation and experience. 

This survey will provide the first update of its kind since the 

first survey was conducted in 1985.

This report describes an alternative method of analyzing 

and presenting MSHA data for the purpose of identifying 

high-cost, high-severity injuries and illnesses. Researchers at 

the NIOSH Spokane Research Laboratory (SRL) developed 

programs to find the top five most frequent accident classes, 

naturesofinjury,typesof accidents andotherselectedvariables 

from the MSHA database. Studying these variables gives a 

cross-sectionalsnapshot ofthemost frequentgroups of injuries 

within a commodity, regional group or time period, and allows 

researchers to quickly understand developing patterns for new 

research projects. The primary benefit of this approach is to 
facilitate the setting of priorities, although at the expense of 

not listing all levels for every variable. For those variables 

with many levels and “other” levels of 50% or more, the next 

group of five levels are listed in the text. For those wishing to 

see complete lists of injuries by frequency, the MSHAdatabase 

is available for downloading (MSHA, 2008). 

Methods 

Results were tabulated for the period 2003 through 2007. 

Cases included all fatal and nonfatal injuries to mine operator 

employeesthroughdegree6(injurieswithoutdeath,days away, 

or restricted activity). Illness cases (degree 7) will be reported 

ina separatestudy, aswillcasesinvolvingcontractors. Software 

used in producing this report included the Statistical Analysis 

System (SAS, version 9.1) and Microsoft Office Excel 2003. 

Results 

Table 1 shows the top five most frequent accidents/ injuries 

by MSHA classification. 

Table 1 — Top five MSHA accident/injury classifications by mine location, all commodities, 2003-2007. 

Mine location AI class Number Percent 

Underground Handling material 5,216 29.3%

 Machinery 2,674 15.0%

 Slip or fall of person 2,563 14.4%

 Powered haulage 1,943 10.9%

 Fall of roof (underground) 1,919 10.8%

 Other 3,458 19.5%

 Total 17,773 100.0% 

Surface Handling material 12,575 35.6%

 Slip or fall of person 8,032 22.7%

 Hand tools 4,971 14.1%

 Machinery 4,059 11.5%

 Powered haulage 2,903 8.2%

 Other 2,791 7.9%

 Total 35,331 100.0% 

Injuries incurred while handling 

materials far outnumbered other major classes of injury. At 

34% of all underground and surface injuries, this class includes 

injuriesresultingfromoverexertionandmostofteninvolvesthe 

back. This class encompasses tasks related to maintenance and 

machine repair, in addition to materials handling. The “slip or 

fall of person” class ranks in the top 3 both underground and 

on the surface. The notably higher percentage of this injury 

class in surface mining (23% vs. 14% underground) may be 

a reflection of the much larger scale of many surface operations, with larger equipment and powered haulage machinery. 

Opportunities for slips and falls range from mounting and 

dismounting machinery and vehicles to walking and running. 

Table 2 shows the relative rankings of injuries by mine 

subunit. 

Table 2 — Most frequent injuries by mine subunit, separated by mine location, all commodities, 2003-2007. 

Mine Location Subunit Number Percent 

Underground Underground operations 17,773 100.0% 

Surface Strip, quarry 17,505 49.5%

 Mill, preparation plant 14,872 42.1%

 Surface-at-underground 1,449 4.1%

 Dredge 1,101 3.1%

 Independent shops 215 0.6%

 Other 189 0.5%

 Total 35,331 100.0% 

Strip mines and quarries reported almost 50% of the 

total injuries, while mills and preparation plants were nearly 

comparable, with 42%. Mines with underground operations 

mayalsohaveminersworkingatsurface shops andyardsphysically located at the mine site, and these subunits contributed 

about 4% of total injuries.

For the period studied, underground bituminous coal mine 

injuries far outnumbered injuries in other standard industrial 

classifications (SICs) with underground operations (Table 

3). The relative risk of injury for underground bituminous 

coal operations was 2.8 times the injury risk for surface coal 

operations. Coal operations are, therefore, a major reason 
why the overall relative risk of underground mines is double 

that of surface mines (with an injury incidence rate of 7.4 vs. 

3.7—Table 3).

Table 3 — Top five injury rates by standard industrial classifications (SIC), separated by mine location, all commodities, 2003-2007. 

Mine location SIC Number Percent Hours worked Incidence rate* 

Underground Coal, bituminous 15,566 87.6% 392,118,045 7.9 

Gold (lode & 422 2.4% 15,691,669 5.4 

placer) 

Platinum group 318 1.8% 11,354,591 5.6 

Limestone 314 1.8% 16,664,987 3.8 

(crushed & 

broken)

Trona 267 1.5% 7,820,590 6.8 

Other 886 5.0% 36,663,439 4.8 

Total 17,773 100.0% 480,313,321 7.4 

Surface Coal, bituminous 6,283 17.8% 444,976,372 2.8 

Limestone 5,919 16.8% 305,643,310 3.9 

(crushed & 

broken)

Sand & gravel 5,816 16.5% 336,722,659 3.5 

Cement 3,772 10.7% 125,049,504 6.0 

Copper ore 1,297 3.7% 76,617,799 3.4 

Other 12,244 34.7% 618,776,257 4.0 

Total 35,331 100.0% 1,907,785,901 3.7 

*Injuries per 100 full-time equivalent miners per year 

Underground mining in the remaining top five 

SICs, gold (lode and placer), limestone (crushed and broken), 

platinum group and trona, has an average incidence rate of 5.1 

injuries per 100 FTEs per year; compared with the corresponding surface rate of 4.0, this shows that coal mining displays 

the greatest contrast between underground and surface risks.

Parts of body injured are shown in Table 4.

Table 4 — Top five parts of body injured by mine location, all commodities, 2003-2007. 

Mine location Part of body Number Percent 

Underground Finger(s) 2,875 16.2%

 Back 2,533 14.3%

 Knee 1,631 9.2%

 Multiple parts 1,108 6.2%

 Hand 1,054 5.9%

 Other 8,572 48.2%

 Total 17,773 100.0% 

Surface Finger(s) 6,178 17.5% 

Back 5,549 15.7% 

Knee 2,634 7.5% 

Eyes 2,508 7.1% 

Shoulder(s) 2,032 5.8% 

Other 16,430 46.5% 

Total 35,331 100.0% 

 With percentages very similar in both surface and underground settings, 

injuries to fingers, backs and knees account for 40% of all 

injuries. Eye injuries in surface mining may be a reflection 

of wind and dust conditions. 

The ages of injured miners (Table 5) display a few differ-
ences with respect to surface or underground locations, but 

the differences are small. The youngest age group shown 

in the top five, 25-29-year-olds, account for 13% of injuries 

underground, but less than 11% of surface injuries. In general, 

percentages by age group are similar. While these findings are 

helpful, true differences in risk for one age group vs. another 

requires a denominator, such as age group-specific employment or hours worked. 

Table 5 — Top five age groups for number of injuries by mine location, all commodities, 2003-2007. 

Mine location Age group Number Percent 

Underground 50-54 2,762 15.5% 

45-49 2,704 15.2% 

30-34 2,451 13.8% 

25-29 2,378 13.4% 

35-39 1,926 10.8% 

Other 5,552 31.2% 

Total 17,773 100.0% 

Surface 45-49 5,090 14.4% 

40-44 4,597 13.0% 

50-54 4,530 12.8% 

35-39 4,337 12.3% 

30-34 4,175 11.8% 

Other 12,602 35.7% 

Total 35,331 100.0% 

Table 6 shows injuries by miner activity-when-injured. 

Table 6 — Top five activities-when-injured by mine location, all commodities, 2003-2007. 

Mine location Activity Number Percent 

Underground Handling supplies or materials 2,729 15.4%

Hand tools (not powered) 1,742 9.8%

Machine maintenance and repair 1,617 9.1%

 Walking/running 1,579 8.9%

 Roof bolter, NEC 1,200 6.8%

Other 8,906 50.1%

 Total 17,773 100.0% 

Surface Machine maintenance and repair 6,877 19.5%

Handling supplies or materials 6,188 17.5%

Hand tools (not powered) 4,683 13.3%

Get on or off equipment 3,316 9.4%

 Walking/running 3,031 8.6%

Other 11,236 31.8%

 Total 35,331 100.0% 

Consistent with the MSHA classification (Table 1), handling 

supplies or materials accounts for nearly 17% of all injuries, 

both underground and on the surface. Injuries while doing 

machine maintenance and repair show potentially the biggest 

difference (9% underground vs. 20% surface). The “other” 

category for underground includes, in descending order of 

frequency, activities such as moving a power cable, operating a 

roofbolter/insertingbolt,gettingonoroff equipment,operating 

a mantrip, and operating a roof bolter/drilling, among others. 

The source of injury (Table 7) is dependent on underground 

or surface location, with metal items not elsewhere classified 

(NEC) (pipe, wire, nails) showing a large difference (14% of 

all surface injuries vs. 8% underground). The injuries resulting 

from falls of roof (Table 1) often involve caving rock, coal or 

ore, as shown in Table 7. In underground mines, the 52.6% of 

sources of injury labeled “other” include broken rock, coal and 

ore;undergroundminingmachines; conductors;belt conveyors 

and knives. In surface mines, the 54.5% of source of injury 

labeled “other” include metal-NEC; ground; metal covers, 

guards;brokenrock, coal andore andsurfaceminingmachines.

The incident rates for the nature of injury received are 

roughly the same for underground vs. surface injuries (Table 

8), but the percentages reveal differences of interest. Fractures, 
in particular, account for 17% of all underground injuries, but 

account for only about 12% of all surface injuries.

Table 7 — Top five sources of injury by mine location, all commodities, 2003-2007. 

Mine location Source Number Percent 

Underground Caving rock, coal, ore 2,926 16.5%

 Mine floor, bottom 2,018 11.4%

Metal-NEC 1,496 8.4%

Mine jeep 1,001 5.6%

Metal covers, guards 988 5.6%

Other 9,344 52.6%

 Total 17,773 100.0% 

Surface Metal-NEC 5,002 14.2%

Ground 3,788 10.7%

Metal covers, guards 2,749 7.8%

Broken rock, coal, ore 2,573 7.3%

Surface mining machines 1,954 5.5%

Other 19,265 54.5%

 Total 35,331 100.0% 

Table 8 — The nature of the top five most frequent injuries by mine location, all commodities, 2003-2007. 

Mine location Nature Number Percent 

Underground Sprain, strain 5,886 33.1%

 Cut, laceration 4,504 25.3%

 Fracture 2,955 16.6%

 Contusion, bruise 1,851 10.4%

 Unclassified 564 3.2%

 Other 2,013 11.3%

 Total 17,773 100.0% 

Surface Sprain, strain 12,381 35.0%

 Cut, laceration 7,856 22.2%

 Fracture 4,388 12.4%

 Contusion, bruise 2,751 7.8%

 Unclassified 1,472 4.2%

 Other 6,483 18.3%

 Total 35,331 100.0% 

As mentioned above, differences in rates of injury between 

occupational groups (job titles) are best studied when denominator data is available, so that occupation-specific rates can 

be compared. The current approach (Table 9) shows several 

differences, such as injuries to laborers underground (18%) vs. 

laborers on the surface (14%), that may be due primarily to 

differences in the numbers employed. Mechanics or repairmen 

also show a large difference, with 7% of all underground injuries vs. 23% of all surface injuries. However, for prioritizing 

research and preventive efforts, this table identifies specific 

occupations that merit attention.

The geographicdistributionof mines inthe U.S.is a familiar 

feature of the industry. Table 10 ranks the states by number 

of injuries by mine location, along with the injury incidence 

rates for those states. The predominance of coal mines likely 

explains the high number of injuries at underground mines in 

the eastern states, as the mostly non-coal mines of western 

states are surface mines. Note that the states are ranked in 

order of the number of injuries; the incidence rates are more 

indicative of the averages risks for that state. Note also that, 

because every state has many sand and gravel operations (the 

most common type of surface mine), the five states most frequently reporting surface mine injuries account for only 28.4% 

of those injuries. The 71.6% of injuries at surface mines in 

“other” states include, in descending order, Kentucky, Nevada, 

Indiana, Alabama and Florida, among others. 

Commodity-specific results

Inthe second phaseofthe analysis,theMSHAdatawerefirst 

stratified into commodity groups (coal and metal- non-metal). 
For each group injuries were rank-ordered by frequency to 

obtain the commodity-specific top fives. Summarized below 

for coal and the remaining non-coal cases are the major highlights of this analysis.

Table 9 — Numbers of injuries by mine occupation, separated by mine location, all commodities, 2003-2007. 

Mine location Occupation Number Percent 

Underground Roof, rock bolter 3,402 19.1% 

Laborer 3,121 17.6% 

Mechanic, repairman 1,231 6.9% 

Shuttle car operator 1,056 5.9% 

Continuous miner operator 1,019 5.7% 

Other 7,944 44.7% 

Total 17,773 100.0% 

Surface Mechanic, repairman 8,191 23.2% 

Cleaning plant or media 5,795 16.4% 

operator 

Laborer 4,839 13.7% 

Bulldozer operator 2,445 6.9% 

Truck driver 2,215 6.3% 

Other 11,846 33.5% 

Total 35,331 100.0% 

Table 10 — Numbers of mining injuries by state, separated by mine location, all commodities, 2003-2007. 

Mine location State Number Percent Hours worked Incidence rate* 

Underground West Virginia 4,467 25.1% 113,369,640 7.9 

Kentucky 4,260 24.0% 103,021,856 8.3 

Pennsylvania 1,647 9.3% 43,876,893 7.5 

Illinois 1,590 8.9% 31,573,614 10.1 

Alabama 1,058 6.0% 23,979,827 8.8 

Other 4,751 26.7% 164,108,981 5.8 

Total 17,773 100.0% 479,930,811 7.4 

Surface Texas 2,291 6.5% 147,067,723 3.1 

Pennsylvania 2,180 6.2% 96,603,002 4.5 

California 2,072 5.9% 84,920,997 4.9 

Arizona 1,850 5.2% 93,556,566 4.0 

West Virginia 1,651 4.7% 102,102,594 3.2 

Other 25,287 71.6% 1,383,327,819 3.7 

Total 35,331 100.0% 1,907,578,701 3.7 

*Injuries per 100 full-time equivalent miners per year 

Coal. “Handling material” injuries top the list of accidentinjuryclassesforbothundergroundandsurfacemines,followed 

by machinery and slip or fall of person classes (Table 11). 

For underground coal, a persistent problem is injuries resulting from falls of roof. For the remaining top five classes of 

injury, very similar percentages were observed for machinery 

(12% to 15%) and for powered haulage (about 11% in both 

underground and surface mines). Controlling very powerful 

machines and vehicles is a challenge in all mines. The combination of machinery and powered haulage classes accounts for 

23% to 26% of all injuries in coal mining. Slip or fall of person 

injuries were not as equally distributed. They accounted for 

14% of underground cases, but almost 28% of surface cases. 

Table 12 shows the numbers and percentages of injury for 

subunits within overall coal mining operations. In surface coal 

mines,the strip/quarrysubunitsreportedalmost58%ofinjuries 

for the period. Mills and preparation plants were next, with 

24%, while the surface-at-underground accounted for 14%.

Occupation differentiates coal and metal-nonmetal mines, 

in that roof and rock bolters rank highest in number of injuries 
Table 11 — Top five MSHA accident/injury classifications by mine location, coal mines, 2003-2007. 

Mine location AI class Number Percent 

Underground Handling material 4,568 29.3%

 Machinery 2,361 15.2%

 Slip or fall of person 2,181 14.0%

 Fall of roof (underground only) 1,774 11.4%

 Powered haulage 1,682 10.8%

 Other 3,017 19.4%

 Total 15,583 100.0% 

Surface Handling material 1,945 29.8%

 Slip or fall of person 1,815 27.8%

 Machinery 789 12.1%

 Hand tools 771 11.8%

 Powered haulage 714 10.9%

 Other 499 7.6%

 Total 6,533 100.0% 

Table 12 — Subunits most frequently reporting injuries, separated by mine location, coal mines, 2003-2007. 

Mine location Subunit Number Percent 

Underground Underground operations 15,583 100.0% 

Surface Strip, quarry 3,761 57.6%

 Mill, preparation plant 1,576 24.1%

 Surface-at-underground 943 14.4%

 Auger (coal) 130 2.0%

 Independent shops 86 1.3%

 Other 37 0.6%

 Total 6,533 100.0% 

Table 13 — Top five occupations reporting injury, separated by mine location, coal mines, 2003-2007. 

Mine location Occupation Number Percent 

Underground Roof, rock bolter 3,361 21.6% 

Laborer 2,757 17.7% 

Shuttle car operator 1,040 6.7% 

Continuous miner operator 987 6.3% 

Belt, conveyor man 930 6.0% 

Other 6,508 41.8% 

Total 15,583 100.0% 

Surface Mechanic, repairman 1,508 23.1% 

Laborer 873 13.4% 

Bulldozer operator 808 12.4% 

Truck driver 540 8.3% 

Cleaning plant or media 410 6.3% 

operator 

Other 2,394 36.6% 

Total 6,533 100.0% 
in underground coal mines (22%, Table 13), but rank much 

lower in number of injuries in underground metal-nonmetal 

mines (less than 3%, data not shown). In surface coal mines, 

mechanics and repairmen top the list of occupations reporting 

injuries, consistent with the activity table (Table 14), where 

machine maintenance and repair is the most frequent activity 

resulting in injury.

Table 14 shows the top five activities-when-injured for coal 

mines. 

Table 14 — Top five activities-when-injured by mine location, coal mines, 2003-2007. 

Mine location Activity Number Percent 

Underground Handling supplies or materials 2,391 15.3% 

Using hand tools (not powered) 1,532 9.8% 

Walking/running 1,414 9.1% 

Performing machine mainte- 1,380 8.9% 

nance and repair 

Roof bolter, NEC 1,148 7.4% 

Other 7,718 49.5% 

Total 15,583 100.0% 

Surface Performing machine mainte- 1,190 18.2% 

nance and repair 

Handling supplies or materials 1,009 15.4% 

Getting on or off equipment 969 14.8% 

Using hand tools (not powered) 711 10.9% 

Walking/running 513 7.9% 

Other 2,141 32.8% 

Total 6,533 100.0% 

Handling supplies or materials are a significant contributor to injury totals, both underground and on the surface. 

Machine maintenance and repair injuries are twice as frequent 

onthe surface asunderground,primarilyowingtothe increased 

role of maintenance in large-scale surface operations.

Table 15 shows the numbers and rates for the bituminous 

vs. anthracite segments of the coal industry. 

Table 15 — Most frequent standard industrial classifications (SIC) by mine location, coal mines, 2003-2007. 

Mine location SIC Number Percent Hours worked Incidence rate* 

Underground Coal, bituminous 15,566 99.9% 392,118,045 7.9 

Coal, anthracite 17 0.1% 726,829 4.7 

 Total 15,583 100.0% 392,844,874 7.9 

Surface Coal, bituminous 6,283 96.2% 444,976,372 2.8 

Coal, anthracite 250 3.8% 8,676,254 5.8 

 Total 6,533 100.0% 453,652,626 2.9 

*Injuries per 100 full-time equivalent miners per year 

These results 

confirm the results of earlier surveillance reports (NIOSH, 

2004) in showing that the incidence rate for underground 

coal mining (7.9 injuries per 100 miners per year) is more 

than double the rate for surface coal mining (2.9 injuries per 

100 miners per year). The anthracite coal segment is small 

compared to bituminous, accounting about 1% of employees 

in the coal mining industry.

Numbers and rates of injury occurrence in coal mines 

by state is shown in Table 16. West Virginia, Kentucky and 

Pennsylvania account for 66% of all underground coal mining injuries, in keeping with the large number of coal mines 

in these states. However, while Illinois ranks 4th for number 

of underground coal mining injuries, it has the highest injury 

incidence rate, with 10.3 injuries per 100 miners per year. In 

surface coal mining, the same three states top the list (Table 

16). Wyoming appears in the list of top five states reporting 

injuries at surface coal mines, but it has the lowest incidence 

rate, 1.5 injuries per 100 miners per year. 

Metal-nonmetal. As in coal mines, metal-nonmetal mines 

also have a significant problem with machinery and powered 

haulage. Nineteen percent of all injuries in surface mines, 

and 26% in underground mines, involved either machinery 

or powered haulage.

Table 17 shows the top five accident-injury classes for 

metal-nonmetal mines. Injuries in these mines fall into many 

of the same classes as the injuries occurring in coal mines 

(Table 11), with an exception for handling material injuries. 

While underground metal-nonmetal mines report about 30% 

as handling material injuries, metal-nonmetal surface mines 

report 37% (Table 17). 

Table 18 shows most frequent subunits reporting injuries. 

Compared to coal mines, with 71% of all injuries occurring 
underground(Table12),93%ofmetal-nonmetalmininginjuries 

are reported by surface mines.

Table 16 — Top five states for numbers injured, by mine location, coal mines, 2003-2007. 

Mine location State Number Percent Hours worked Incidence rate* 

Underground West Virginia 4,443 28.5% 112,573,212 7.9 

Kentucky 4,189 26.9% 98,144,200 8.5 

Pennsylvania 1,591 10.2% 41,510,274 7.7 

Illinois 1,547 9.9% 29,941,173 10.3 

Alabama 1,054 6.8% 23,865,773 8.8 

Other 2,759 17.7% 86,810,242 6.4 

 Total 15,583 100.0% 392,844,874 7.9 

Surface West Virginia 1,499 22.9% 94,289,137 3.2 

Kentucky 1,229 18.8% 83,185,928 3.0 

Pennsylvania 737 11.3% 36,577,135 4.0 

 Virginia 466 7.1% 25,954,166 3.6 

Wyoming 414 6.3% 54,638,756 1.5 

Other 2,188 33.5% 159,007,504 2.8 

 Total 6,533 100.0% 453,652,626 2.9 

*Injuries per 100 full-time equivalent miners per year 

Table 17 — Top five MSHA accident/injury classifications by mine location, metal-nonmetal mines, 2003-2007. 

Mine location AI class Number Percent 

Underground Handling material 648 29.6% 

Slip or fall of person 382 17.4% 

Machinery 313 14.3% 

Powered haulage 261 11.9% 

Hand tools 251 11.5% 

Other 335 15.3% 

 Total 2,190 100.0% 

Surface Handling material 10,630 36.9% 

Slip or fall of person 6,217 21.6% 

Hand tools 4,200 14.6% 

Machinery 3,270 11.4% 

Powered haulage 2,189 7.6% 

Other 2,292 8.0% 

 Total 28,798 100.0% 

Metal-nonmetal mines share many of the characteristics of 

injuries occurring in coal mines, including very similar patterns of parts of body injured, natures and sources of injury 

and activities-when-injured (data not shown). Table 19 shows 

the top five states reporting metal-nonmetal mining injuries. 

Compared with the eastern locale of many coal mines, western 

states predominate for underground metal-nonmetal injuries, 

with Nevada, Montana, Wyoming and Idaho reporting 52% 

of underground mining injuries in this sector. Also, because 

every state has many sand and gravel operations, the five states 

mostfrequentlyreportingsurfacemine injuries accountforonly 

29.7% of those injuries. The 70.3% labeled “other” include, 

in descending order, Florida, Wisconsin, Missouri, Georgia, 

and Indiana, among others.

While Idaho’s numbers are about one-half those of each of 

the other three states, its incidence rate (11.8 injuries per 100 

miners per year) is more than double the average rate for the 

other three states (5.7). 

Conclusions 

Many injuries common to all mines, mine locations and 

commodities can be identified and their most prominent attributes highlighted through ranked lists by frequency. In the 

absence of more detailed, cause-specific incidence rates, such 

rankings can reveal general trends of mine injuries and classify them by nature, accident type and class. Most frequently 
injured miners by age group, activity, and job title can provide 

valuable indicators not only of hazards and the problems that 

contribute to them, but also potential solutions.

Table 18 — Most frequent subunits reporting injuries by mine location, metal-nonmetal mines, 2003-2007. 

Mine Location Subunit Number Percent 

Underground Underground 2,190 100.0% 

Surface Strip, quarry 13,744 47.7% 

Mill, preparation plant 13,296 46.2% 

Dredge 1,099 3.8% 

Surface @ Underground 506 1.8% 

Independent shops 129 0.4% 

Other 24 0.1% 

 Total 28,798 100.0% 

Table 19 — Top five states reporting injuries by mine location, metal-nonmetal mines, 2003-2007. 

Mine Location State Number Percent Hours worked Incidence rate* 

Underground Nevada 379 17.3% 14,309,581 

Montana 339 15.5% 12,166,091 

Wyoming 271 12.4% 8,022,607 

Idaho 148 6.8% 2,505,767 

Missouri 137 6.3% 7,779,529 

Other 916 41.8% 42,302,362 

 Total 2,190 100.0% 87,085,937 

Surface California 2,072 7.2% 84,920,997 

 Texas 2,026 7.0% 123,606,282 

Arizona 1,810 6.3% 87,060,956 

Pennsylvania 1,443 5.0% 60,025,867 

Nevada 1,188 4.1% 74,284,761 

Other 20,259 70.3% 1,024,027,212 

 Total 28,798 100.0% 1,453,926,075 

*Injuries per 100 full-time equivalent miners per year 

5.3 

5.6 

6.8 

11.8 

3.5 

2.1 

5.0 

4.9 

3.3 

4.2 

4.8 

3.2 

2.8

4.0 

From the miner’s point of view, training, task and mine 

design, job hazard analysis, personal protective equipment 

and a variety of related measures can provide prevention for 

each such group of injuries on a one-by-one basis. For more 

systematic and long-term preventive results, research is often 

valuable in identifying solutions common to large groups of 

injuries. In particular, the patterns highlighted above provide 

a focal point for research, mine planning and safety and health 

and the continued reduction of risk for U.S. miners. In addition, groups of injuries with common causes provide useful 

baselines for evaluating the effectiveness of interventions. 

A general engineering control that facilitates safe operation 

of a mining machine, for example, can be evaluated using a 

pre- and post-intervention design. Such controls can then be 

evaluated using MSHA surveillance data, without developing 

costly reporting systems.

Further work is planned to investigate those groups of injuries displaying the largest differences between underground 

and surface. 

Disclaimer 

The findings and conclusions in this report are those of 

the authors and do not necessarily represent the views of the 

National Institute for Occupational Safety and Health. 

References 

NIOSH, 2007, “Implementation Plan Response to the National Academies Report on the NIOSH Mining Program,” http://www.cdc.gov/niosh/nas/pdfs/ 

MngProgPlanNASRecs.pdf 

NIOSH, 2004, National Institute for Occupational Safety and Health. Worker 

Health Chartbook, 2004. http://www.cdc.gov/niosh/docs/2004-146/ 

MSHA, 2008, Mine Safety and Health Administration (MSHA), Accident, Illness 

and Injury and Employment Self-Extracting Files (Part 50 Data), http://www. 

msha.gov/STATS/PART50/p50y2k/p50y2k.HTM, September, 2008.