Table 5

Incidence RRs of motor neuron disease and amyotrophic lateral sclerosis among workers in mining industries or occupations compared to in non-mining industries or occupations in subcohorts for each outcome

Motor neuron disease (2006–2016)Als (2012–2016)
CasesRR (95% CI)CasesRR (95% CI)
By mining industry classification (SIC code)
Workers in non-mining industries5701.00 (–)2471.00 (–)
Workers in industry of mines (including milling), quarries and oil wells (04)151.32 (0.79 to 2.20)91.94 (1.00 to 3.78)
Major industry groups
 Workers in metal mines (09)131.62 (0.94 to 2.81)72.21 (1.04 to 4.69)
By mining occupation classification (CCDO code)
Workers in mining occupations5761.00 (–)2521.00 (–)
Workers in mining and quarrying, including oil and gas field occupations (77)91.46 (0.75 to 2.82)<5
Both mining industry and occupation classification (SIC and CCDO codes)
Workers in industry of mines and occupations of mining and quarrying (SIC 04 and CCDO 77)91.65 (0.86 to 3.2)<5
Workers in metal mines and occupations of mining and quarrying (SIC 09 and CCDO 77)91.96 (1.01 to 3.79)<5
  • Follow-up was censored at age 100 years old. All models were adjusted by mean age, age,2 and birth year. Results for subgroups of the mining industry and occupation classifications were all suppressed due to small (<5) numbers of case counts. Motor neuron disease: At least one record with one diagnostic code (ICD10: G12.2) in any diagnostic field in DAD or NACRS. Amyotrophic later sclerosis: At least one record with one diagnostic code (ICD10: G12.20) in any diagnostic field in DAD or NACRS.

  • CCDO, Canadian Classification Dictionary of Occupations; DAD, Hospital Discharge Abstract Database; NACRS, National Ambulatory Care Reporting System; OHIP, Ontario Health Insurance Plan Claims Database; ; SIC, Standard Industrial Classification.