DEPARTMENT OF HEALTH AND HUMAN SERVICES 

Centers for Disease Control and Prevention 

National Institute for Occupational Safety and Health 

September 2008 

UNDERGROUND AND SURFACE 

MINING FACTS – 2005 

Mining Operations 

In 2005, data obtained from the Mine Safety and 

Health Administration (MSHA) indicated a total of 

922 underground (6.3%) and 13,744 surface (93.7%) 

mining operations.1 

Employees 

A total of 50,732 employees,2 or 53,041 full-time 

equivalent (FTE)3 employees, were reported to 

MSHA as working at underground mining locations 

in 2005. This compares to 260,395 employees (or 

235,564 FTE employees) that were reported as 

working at surface locations.4

• Surface work location employee hours accounted 

for 81.6% of all hours reported to MSHA, while 

18.4% of employee hours were reported for 

underground work locations. 

0

100

200

300

400

500

600

700

Number of Employee Hours

1996 1997 1998 1999 2000 2001 2002 2003 2004 2005

(millions)

Underground Work Locations

Surface Work Locations

All Work Locations

• The majority of surface employee hours were for 

mine operator employees (82.2%), compared to 

independent contractor employees (17.8%). 

• Coal operators were the mining sector5 reporting 

the most underground worker employee hours to 

MSHA (n=80,877,874; 76.2%). 

Fatalities 

Of the 57 occupational mining fatalities reported to 

MSHA in 2005, 20 occurred at underground work 

locations and 37 occurred at surface locations. 

• The fatality rate of 37.7 per 100,000 FTE 

employees was higher at underground work 

locations, compared to the rate of 15.7 for 

surface work locations. 

Nonfatal Lost-time Injuries 

Within underground work locations, 2,772 nonfatal 

lost-time injuries were reported, resulting in 181,107 

lost workdays.6 This compares to 5,538 nonfatal 

lost-time injuries attributed to surface workers (total 

days lost=278,664). 

• The overall underground nonfatal lost-time 

injury rate was greater than the surface injury 

rate (5.2 vs. 2.4 per 100 FTE workers). 

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

both underground (n=793; 28.6%) and surface 

(n=1,921; 34.7%) work locations. 

0

2,000

4,000

6,000

8,000

10,000

1996 1997 1998 1999 2000 2001 2002 2003 2004 2005

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 back was the most frequently reported body 

part injured at both underground (n=498; 18.0%) 

and surface (n=1,093; 19.7%) work locations. 

These back injuries accounted for 38,597 days 

lost from work at underground work locations 

and 48,579 days lost at surface locations in 2005. 

Mining Characteristics, 2005 

Commodity and 

Type of Employer No. of Mines1 

No. of 

Employees2

No. of FTE

Employees3 Fatality Rate 

Nonfatal 

Lost-time 

Injury Rate 

UG Surf UG Surf UG Surf UG Surf UG Surf 

Coal Operator 674 1,389 36,693 41,588 40,439 46,745 34.6 6.4 5.5 1.8 

Metal Operator 77 186 4,128 22,314 4,181 23,592 23.9 17.0 3.7 2.2 

Nonmetal Operator 45 694 2,330 17,348 2,390 17,624 83.7 11.3 3.3 2.4 

Stone Operator 126 4,364 1,889 67,870 2,140 71,510 140.2 16.8 2.8 3.1 

Sand & Gravel Operator -- 7,111 -- 37,705 -- 34,258 -- 26.3 -- 2.5 

Operator Total 922 13,744 45,040 186,825 49,150 193,729 40.7 15.5 5.1 2.5 

Coal Contractor -- -- 4,247 28,392 2,829 17,307 -- 28.9 7.5 1.9 

Noncoal Contractor -- -- 1,445 45,178 1,061 24,528 -- 8.2 2.9 1.6 

Contractor Total -- -- 5,692 73,570 3,890 41,835 -- 16.7 6.3 1.7

TOTAL 922 13,744 50,732 260,395 53,041 235,564 37.7 15.7 5.2 2.4 

Fatality rates were computed per 100,000 FTE employees. Nonfatal lost-time injury rates were computed 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 exclude office employees, except for the total number of mining operations. Analyses of fatalities exclude all 

individuals under 17 years of age and all individuals who were not classified as employees of a mining operator or mining contractor. 

Further statistical methodology is available on the NIOSH Internet [http://www.cdc.gov/niosh/mining/statistics/method.htm]. 1

When classifying mining operations as either underground or surface, the mines reporting employment for the subunit "Surface 

 Operations at Underground Mines" were counted as underground mines. Mining operations reporting only office employees were 

 determined to be underground or surface based on the reported mine type. Mines at which only independent contractors were working 

 did not show any employment and were not counted. 

2

Number of employees is the average number of persons working at individual establishments during calendar quarters of active 

 operations. 

3

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

4

Surface work locations include surface operations at underground mines (surface shops and yards, tipple physically located at the mine 

 site), surface operations (strip or open pit mines including associated shops and yards), auger mining operations, culm banks 

 (reworking of mine dumps or refuse pile), dredge (mining operations conducted from a platform floating on water), other surface 

 operations (brine pumping, etc.), independent shops and yards not associated with a specific mine, and mill or preparation plant. 5

Mining sectors: 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. 

To receive NIOSH documents or for more information about 

occupational safety and health topics, contact NIOSH at 

1–800–CDC–INFO (1–800–232–4636) 

1–888–232–6348 (TTY) 

e-mail: cdcinfo@cdc.gov

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

DHHS (NIOSH) Publication No. 2008-157