Characteristics of injured workers in mining by time of accident since shift began
| N | During first 2 hours | Between hours 2 and 6 | Between hours 7 and 8 | Long working hour cases 9 or more hours | |
| All cases | 545 537 | 73 284 | 327 822 | 92 225 | 52 206 |
| Gender | |||||
| Male | 534 311 | 71 603 (97.7%) | 3 21 227 (98.0%) | 90 433 (98.1%) | 51 048 (97.8%) |
| Female | 11 219 | 1680 (2.3%) | 6590 (2.0%) | 1791 (1.9%) | 1158 (2.2%) |
| Unspecified | 7 | 1 (0.0%) | 5 (0.0%) | 1 (0.0%) | 0 (0.0%) |
| Mean age (SD) | ~ | 39.5 (10.80) | 39.0 (10.70) | 38.9 (11.00) | 38.6 (11.30) |
| Mean total mine years experience (SD) | ~ | 11.8 (9.30) | 11.5 (9.30) | 11.0 (9.40) | 10.0 (9.50) |
| Mean total mine years experience in this mine (SD) | ~ | 8.0 (8.30) | 7.5 (8.00) | 6.9 (8.00) | 6.1 (7.80) |
| Mean total mine years experience in this job title (SD) | ~ | 6.6 (7.40) | 6.3 (7.20) | 6.5 (7.40) | 6.4 (7.60) |
| Time shift began | |||||
| 07:00–14:59 | 263 232 | 34 532 (47.1%) | 1 56 623 (47.8%) | 49 161 (53.3%) | 22 916 (43.9%) |
| 15:00 to 22:59 | 127 088 | 17 085 (23.3%) | 80 287 (24.5%) | 18 661 (20.2%) | 11 055 (21.2%) |
| 23:00 to 06:59 | 155 217 | 21 667 (29.6%) | 90 912 (27.7%) | 24 403 (26.5%) | 18 235 (34.9%) |
| Irregular shift start* | 46 841 | 6840 (9.3%) | 22 642 (6.9%) | 6603 (7.2%) | 10 756 (20.6%) |
| Employed by contractor | 39 687 | 4110 (5.6%) | 21 526 (6.6%) | 7576 (8.2%) | 6475 (12.4%) |
| Not working in primary occupation/job/role at time of injury† | 21 846 | 2557 (3.5%) | 12 576 (3.8%) | 3777 (4.1%) | 2936 (5.6%) |
| Apprentice/trainee | 1514 | 182 (0.2%) | 897 (0.3%) | 276 (0.3%) | 159 (0.3%) |
| Canvass or general product class | |||||
| Anthracite coal | 4109 | 654 (0.9%) | 2612 (0.8%) | 608 (0.7%) | 235 (0.5%) |
| Bituminous coal | 268 266 | 35 305 (48.2%) | 171 413 (52.3%) | 41 963 (45.5%) | 19 585 (37.5%) |
| Metal | 73 991 | 9655 (13.2%) | 43 312 (13.2%) | 12 353 (13.4%) | 8671 (16.6%) |
| Non-metal | 37 487 | 5300 (7.2%) | 22 110 (6.7%) | 6704 (7.3%) | 3373 (6.5%) |
| Sand and Gravel | 39 762 | 5185 (7.1%) | 21 116 (6.4%) | 7749 (8.4%) | 5712 (10.9%) |
| Stone | 121 922 | 17 185 (23.4%) | 67 259 (20.5%) | 22 848 (24.8%) | 14 630 (28.0%) |
| Number of injuries reported for accident/incident categories | |||||
| 1 | 541 820 | 72 734 (99.2%) | 325 916 (99.4%) | 91 559 (99.3%) | 51 611 (98.9%) |
| 2 | 2379 | 308 (0.4%) | 1301 (0.4%) | 423 (0.5%) | 347 (0.7%) |
| 3 | 425 | 57 (0.1%) | 198 (0.1%) | 97 (0.1%) | 73 (0.1%) |
| 4 | 242 | 55 (0.1%) | 93 (0.0%) | 53 (0.1%) | 41 (0.1%) |
| 5 or more | 671 | 130 (0.2%) | 314 (0.1%) | 93 (0.1%) | 134 (0.3%) |
| Fatal injury | 2662 | 316 (0.4%) | 1438 (0.4%) | 549 (0.6%) | 359 (0.7%) |
| Permanent disability, partial or total | 7505 | 953 (1.3%) | 4560 (1.4%) | 1303 (1.4%) | 689 (1.3%) |
| Median total lost work days (restricted and lost work) (IQR) | 370 997 | 5.0 (0, 31) | 5.0 (0, 30) | 4.0 (0, 28) | 4.0 (0, 26) |
All reported injuries to MSHA Part 50 Program in USA: 1983–2015.
IQR (25%, 75%).
*Based on MSHA data, most shifts start in specific windows of time in the morning, afternoon and evening shifts (92.2%). We accounted for irregular start times for each shift including shifts beginning between 00:31–05:29, 08:31–13:29 and 16:31–21:29, allowing for workers to arrive 30 min early or late for shifts in the morning (06:00–08:00), afternoon shifts (14:00–16:00) and night (22:00–00:00).
†These are workers whose regular job title was different from the job title they were working at the time of injury.
MSHA, Mine Safety and Health Administration.