DEPARTMENT OF HEALTH AND HUMAN SERVICES

Centers for Disease Control and Prevention

National Institute for Occupational Safety and Health

August 2009

UNDERGROUND AND SURFACE 

MINING FACTS – 2007

Mining Operations

Data obtained from the Mine Safety and Health 

Administration (MSHA) indicated a total of 889

underground (6.0%) and 13,982 surface (94.0%) 

mining operations.

1

Employees

A total of 55,617 employees,

2

or 57,222 full-time 

equivalent (FTE)3employees, were reported to 

MSHA as working at underground mining locations 

in 2007. This is in contrast to 322,506 employees (or 

279,541 FTE employees) that were reported as 

working at surface locations.4

Surface work location employee hours accounted 

for 83.0% of all hours reported to MSHA, while 

17.0% of employee hours were reported for 

underground work locations.

0

100

200

300

400

500

600

700

1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 Number of Employee Hours (millions)

All Work Locations

Surface Work Locations

Underground Work Locations

The majority of surface employee hours were for 

mine operator employees (80.0%) as opposed to 

independent contractor employees (20.0%).

Coal operators were the mining sector5reporting 

the most underground worker employee hours to 

MSHA (n=84,475,287; 73.8%).

Fatalities

Of the 67 occupational mining fatalities reported to 

MSHA in 2007, 27 occurred at underground work 

locations, while 40 occurred at surface locations.

The fatality rate of 47.2 per 100,000 FTE 

employees was higher at underground work locations, compared to the rate of 16.1 for surface 

work locations.

Coal Operator Metal Operator

Nonmetal Operator Stone Operator

Sand & Gravel Operator Coal Contractor

Noncoal Contractor

Surf UG 60%

40%

Underground Surface

Distribution of Mining Fatalities

Nonfatal Lost-time Injuries

Within underground work locations, 2,645 nonfatal 

lost-time injuries were reported, resulting in 170,584

lost workdays.

6

This compares to 5,097 nonfatal

lost-time injuries attributed to surface workers (total 

days lost = 255,635).

The overall underground nonfatal lost-time 

injury rate was greater than the surface injury

rate (4.6 vs. 2.0 per 100 FTE workers).

0

2,000

4,000

6,000

8,000

10,000

1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 Number of Nonfatal Lost-time Injuries

0

2

4

6

8

10 Nonfatal Lost-time Injury Rate (per 100 Full-time Equivalent Employees)

Underground Surface UG Rate Surf Rate

The most frequent classification of nonfatal losttime injuries involved handling materials for 

both underground (n=719; 27.2%) and surface 

(n=1,773; 34.8%) work locations. 

The back was the most frequently reported body 

part injured at both underground (n=414; 15.7%) 

and surface (n=957; 18.8%) work locations.
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1–800–CDC–INFO (1–800–232–4636)

TTY: 1–888–232–6348 

e-mail: cdcinfo@cdc.gov

or visit the NIOSH Web site at http://www.cdc.gov/niosh

DHHS (NIOSH) Publication No. 2009–158

Commodity and 

Type of Employer Surface Total Surface Total Surface Total 

Coal Operator 631 1,399 2,030 37,829 46,242 84,071 42,238 51,027 93,265

Metal Operator 97 181 278 5,333 30,667 36,000 5,437 32,309 37,746

Nonmetal Operator 48 677 725 2,411 20,453 22,864 2,478 20,788 23,265

Stone Operator 113 4,526 4,639 1,845 80,873 82,718 2,063 81,191 83,254

Sand and Gravel Operator NA 7,199 7,199 NA 45,761 45,761 NA 38,340 38,340

Operator Total 889 13,982 14,871 47,418 223,996 271,414 52,216 223,655 275,871

Coal Contractor NA NA 2,999 5,160 33,705 38,865 3,071 19,670 22,741

Noncoal Contractor NA NA 5,400 3,039 64,805 67,844 1,935 36,216 38,151

Contractor Total NA NA 8,399 8,199 98,510 106,709 5,006 55,886 60,892

TOTAL 55,617 322,506 378,123 57,222 279,541 336,763

Number of Companies

Mine and Employment Characteristics, 2007

Underground Underground Underground

Number of Mining Operations1 Number of Employees2 Number of FTE Employees3

Commodity and 

Type of Employer

Coal Operator 18 42.6 10 21.1 28 31.2 2,120 5.0 822 1.7 2,942 3.3

Metal Operator 3 55.2 4 14.4 7 21.1 178 3.3 620 2.2 798 2.4

Nonmetal Operator 1 40.4 0 0.0 1 5.0 91 3.7 417 2.4 508 2.5

Stone Operator 0 0.0 8 11.4 8 11.1 36 1.7 1,844 2.6 1,880 2.6

Sand and Gravel Operator NA NA 5 15.0 5 15.0 NA NA 657 2.0 657 2.0

Operator Total 22 42.1 27 13.8 49 19.7 2,425 4.6 4,360 2.2 6,785 2.7

Coal Contractor 3 97.7 3 16.3 6 28.0 177 5.8 283 1.5 460 2.1

Noncoal Contractor 2 103.4 10 29.3 12 33.3 43 2.2 454 1.3 497 1.4

Contractor Total 5 99.9 13 24.8 18 31.3 220 4.4 737 1.4 957 1.7

TOTAL 27 47.2 40 16.1 67 21.9 2,645 4.6 5,097 2.0 7,742 2.5

NA Not applicable.

Rate

Occupational Fatalities (per 100,000 FTE employees)

Underground Surface

 No. No. Rate No. Rate No. Rate No. Rate No. Rate 

Mining Occupational Fatalities and Injuries, 2007

Total Underground Surface Total

Nonfatal Lost-time Injuries (per 100 FTE employees)

Data source: Publicly released data files of employment and accident/injury/illness collected by MSHA under 30 CFR 50.

Notes: All analyses of accident data exclude office employees. Occupational fatalities exclude all cases under 17 years of age. Further 

statistical methodology is available on the NIOSH Internet [http://www.cdc.gov/niosh/mining/statistics/method.htm]. Data in the above 

tables may not add to totals shown because of independent rounding. Caution should be used when interpreting rates based on a small 

number of events.

1Mines at which only independent contractors were working did not show any employment and were not counted.

2Average number of employees working at individual mines during calendar quarters of active operations (includes office workers).

3

Full-time equivalent employees computed using reported employee hours (2,000 hours = 1 FTE).

4

Surface work locations include surface operations at underground mines, surface operations (strip or open pit), auger, culm banks,

 dredge, other surface operations, independent shops and yards, and mills or preparation plants.

5Mining sectors include coal operators, metal operators, nonmetal operators, stone operators, sand and gravel operators, coal contractors,

 and noncoal contractors.

6

Includes actual days away from work and/or days of restricted work activity. For permanently disabling injuries only, statutory days

charged by MSHA were used if they exceeded the total lost workdays.