Characteristics of workers in mining occupations and industries (1983–2016) by disease follow-up spanning from 1999 to 2016 in the study cohort
| Follow-up periods by disease | |||
| 2006–2016 Alzheimer’s disease Parkinson’s disease Motor neuron disease | 1999–2016 ‘Alzheimer’s and other dementias’ parkinsonism | 2012–2016 Amyotrophic lateral sclerosis | |
| The industry of Mines (including Milling), Quarries and Oil Wells (SIC 04) | |||
| Number of workers in mining industries at start of follow-up* | 16 657 | 17 892 | 15 353 |
| Year of birth, median (IQR) | 1954 (1945–1962) | 1954 (1944–1962) | 1955 (1947–1963) |
| Years of follow-up, median (IQR) | 11 (11–11) | 18 (12–18) | 5 (5–5) |
| Age at the end of follow-up, median (IQR) | 62 (54–71) | 62 (54–71) | 61 (53–70) |
| Major level industry groups (SIC codes), number ever-employed* (Proportion in each major industry group among total in SIC 04 mining industry, %) | |||
| Metal mines(09) | 9943 (60) | 10 843 (61) | 9025 (59) |
| Non-metal mines(10)† | 810 (5) | 874 (5) | 743 (5) |
| Quarries and sand pits(12) | 3201 (19) | 3337 (19) | 3038 (20) |
| Services incidental to mining(13) | 3058 (18) | 3206 (18) | 2871 (19) |
| Minor level industry groups (SIC codes), no ever-employed* (Proportion in each minor industry group among total in SIC 04 mining industry, %) | |||
| Gold mines (051 and 052) | 1847 (11) | 2050 (11) | 1685 (11) |
| Uranium mines (057) | 1455 (9) | 1572 (9) | 1334 (9) |
| Miscellaneous metal mines (059)‡ | 6848 (41) | 7424 (41) | 6217 (40) |
| Non-SIC 04 industries | |||
| Number of workers in mining industries at start of follow-up* | 1 133 699 | 1 178 576 | 1 079 918 |
| Year of birth, median (IQR) | 1961 (1951–1969) | 1960 (1950–1969) | 1961 (1952–1970) |
| Years of follow-up, median (IQR) | 11 (11–11) | 18 (12–18) | 5 (5–5) |
| Age at the end of follow-up, median (IQR) | 56 (47–65) | 56 (47–65) | 55 (47–65) |
| Occupations of mining and quarrying including oil and gas field (CCDO 77) | |||
| Number of workers mining occupations at start of follow-up* | 9297 | 9967 | 8604 |
| Year of birth, median (IQR) | 1955 (1946–1963) | 1954 (1944–1962) | 1956 (1947–1963) |
| Years of follow-up, median (IQR) | 11 (11–11) | 18 (13–18) | 5 (5–5) |
| Age at the end of follow-up, median (IQR) | 61 (53–70) | 61 (53–70) | 61 (53–69) |
| Minor level occupation groups (CCDO codes), no ever-employed* (Proportion in each minor occupation group among total with CCDO 77 mining occupations, %)* | |||
| Foremen (7710) | 602 (6) | 655 (7) | 544 (6) |
| Rotary well-drilling and related occupations (7711) | 242 (3) | 246 (2) | 235 (3) |
| Rock and soil drilling occupations (7713) | 2269 (24) | 2478 (25) | 2062 (24) |
| Blasting occupations (7715) | 132 (1) | 136 (1) | 121 (1) |
| Cutting, handling and loading occupations (7717) | 3463 (37) | 3729 (37) | 3179 (37) |
| Occupations in labouring and other elemental work (7718) | 1420 (15) | 1520 (15) | 1324 (15) |
| Other occupations (7719) | 3108 (33) | 3251 (33) | 2940 (34) |
| Non-CCDO 77 occupations | |||
| Number of workers in non-mining occupations at start of follow-up* | 1 141 059 | 1 186 502 | 1 086 667 |
| Year of birth, median (IQR) | 1961 (1951–1969) | 1960 (1950–1969) | 1961 (1952–1970) |
| Years of follow-up, median (IQR) | 11 (11–11) | 18 (12–18) | 5 (5–5) |
| Age at the end of follow-up, median (IQR) | 56 (47–65) | 56 (47–66) | 55 (47–65) |
|
Workers in mining industries and held mining occupations (SIC and CCDO codes)* (Proportion in each subgroup among total in each mining industry group, %) | |||
| Industry of Mines and Occupations of Mining and Quarrying (SIC 04 & CCDO 77) | 7710 (46) | 8325 (47) | 7109 (46) |
| Metal Mines and Occupations of Mining and Quarrying (SIC 09 & CCDO 77) | 5861 (59) | 6390 (59) | 5370 (60) |
| Non-metal Mines and Occupations of Mining and Quarrying (SIC 10 & CCDO 77) | 222 (27) | 231 (26) | 205 (28) |
| Gold Mines and Occupations of Mining and Quarrying(SIC (051 and 052) and CCDO 77) | 1295 (70) | 1435 (70) | 1189 (71) |
| Uranium Mines and Occupations of Mining and Quarrying (SIC 057 and CCDO 77) | 913 (63) | 990 (63) | 841 (63) |
| Miscellaneous Metal Mines and Occupations of Mining and Quarrying (SIC 059 and CCDO 77) | 3909 (57) | 4227 (57) | 3586 (58) |
*Number of workers ever employed as workers in mining industries or occupations by the same follow-up period differs slightly by disease; workers may appear in multiple subgroups.
†Workers in non-metal mines include those ever employed in Coal Mines, Crude Petroleum and Natural Gas Industry, Asbestos Mines, Peat Extraction, Gypsum Mines and Miscellaneous Non-metal Mine which consists of 66% of salt mines.
‡Miscellaneous metal mines consist of nickel (78%) and zinc mines (13%), and others (9%) in the ODSS cohort.
CCDO, Canadian Classification Dictionary of Occupations; ; IQR, Interquartile Range; SIC, Standard Industrial Classification.