Table 2

Incidence rate ratios (IRR) of idiopathic interstitial pneumonias (IIPs), pulmonary sarcoidosis and silicosis following exposure to respirable crystalline silica (RCS) as assessed by a job exposure matrix, Denmark

IIPs*Pulmonary sarcoidosis*Silicosis†
Exposure to RCS Cases IRR (95% CI)‡ Cases IRR (95% CI)‡ Cases IRR (95% CI)‡
Cumulative exposure (μg/m3-years)
 014 9721552713691
 <43.66121.04 (0.96 to 1.13)3971.30 (1.17 to 1.44)291.45 (0.99 to 2.13)
 43.6–153.18311.15 (1.07 to 1.23)3321.58 (1.41 to 1.76)791.86 (1.45 to 2.39)
 153.2–130014541.14 (1.08 to 1.21)4141.61 (1.45 to 1.78)962.95 (2.31 to 3.76)
 Per 50 µg/m3-years, including non-exposed1.03 (1.02 to 1.03)1.06 (1.04 to 1.07)1.20 (1.17 to 1.23)
 Per 50 µg/m3-years, excluding non-exposed§1.03 (1.01 to 1.04)1.03 (1.01 to 1.05)1.16 (1.12 to 1.20)
Highest attained exposure (μg/m3
 014 9721552713691
 <13.87261.11 (1.03 to 1.20)4861.34 (1.22 to 1.47)272.31 (1.55 to 3.45)
 13.8–22.44911.13 (1.03 to 1.23)1991.65 (1.43 to 1.90)402.45 (1.76 to 3.40)
 22.5–105.416801.12 (1.06 to 1.18)4581.57 (1.42 to 1.74)1372.34 (1.91 to 2.86)
 Per 5 µg/m3, including non-exposed1.03 (1.02 to 1.03)1.05 (1.04 to 1.07)1.18 (1.16 to 1.21)
 Per 5 µg/m3, excluding non-exposed§1.04 (1.02 to 1.05)1.02 (1.00 to 1.04)1.23 (1.19 to 1.27)
Duration (years)¶
 014 9721552713691
 1–24281.06 (0.96 to 1.17)2411.23 (1.08 to 1.41)432.24 (1.63 to 3.07)
 3–89291.15 (1.08 to 1.23)3831.43 (1.29 to 1.59)892.29 (1.81 to 2.90)
 9–3915401.12 (1.06 to 1.18)5191.67 (1.52 to 1.83)722.54 (1.94 to 3.34)
 Per 5 years, including non-exposed1.03 (1.01 to 1.05)1.17 (1.14 to 1.20)1.33 (1.22 to 1.44)
 Per 5 years, excluding non-exposed§1.00 (0.97 to 1.03)1.10 (1.05 to 1.14)1.09 (0.94 to 1.25)
  • *Followed from 1994 to 2015, 5 100 706 workers.

  • †Followed from 1977 to 2015, 5 439 728 workers.

  • ‡Adjusted for age, sex, calendar year, education, probability of smoking, connective tissue disease, cancer and medications.

  • §For silicosis: not adjusted for education.

  • ¶For silicosis: all analyses for this metric are not adjusted for education.