Incidence rate ratios (IRR) of hypersensitivity pneumonitis (HP), other interstitial lung diseases (ILDs) and all ILDs following exposure to organic dust, endotoxin and wood dust among 2 955 863 workers born in 1956 or later, in Denmark
| Exposure | HP | Other ILDs | All ILDs | |||
| Cases | IRR (95% CI)* | Cases | IRR (95% CI)* | Cases | IRR (95% CI)* | |
| Organic dust | ||||||
| Cumulative exposure (unit-years) | ||||||
| 0 | 115 | 1 | 2080 | 1 | 2195 | 1 |
| 1–2 | 54 | 1.17 (0.84 to 1.63) | 953 | 1.09 (1.01 to 1.18) | 1007 | 1.09 (1.01 to 1.18) |
| 3–8 | 91 | 1.32 (1.00 to 1.75) | 1631 | 1.18 (1.10 to 1.26) | 1722 | 1.18 (1.11 to 1.26) |
| 9–156 | 151 | 1.82 (1.39 to 2.38) | 2060 | 1.18 (1.10 to 1.26) | 2211 | 1.21 (1.14 to 1.29) |
| Per 10 unit-years | 1.19 (1.12 to 1.27) | 1.04 (1.02 to 1.06) | 1.05 (1.03 to 1.07) | |||
| Duration (years) | ||||||
| 0 | 115 | 1 | 2080 | 1 | 2195 | 1 |
| 1–2 | 60 | 1.18 (0.86 to 1.63) | 1036 | 1.09 (1.01 to 1.17) | 1096 | 1.09 (1.01 to 1.18) |
| 3–6 | 79 | 1.32 (0.98 to 1.77) | 1354 | 1.16 (1.08 to 1.25) | 1433 | 1.17 (1.09 to 1.25) |
| 7–39 | 157 | 1.78 (1.37 to 2.32) | 2254 | 1.20 (1.12 to 1.28) | 2411 | 1.22 (1.15 to 1.30) |
| Per 5 years | 1.12 (1.04 to 1.21) | 1.02 (1.00 to 1.04) | 1.03 (1.01 to 1.05) | |||
| Endotoxin | ||||||
| Cumulative exposure (EU/m3-years) | ||||||
| 0 | 340 | 1 | 6245 | 1 | 6585 | 1 |
| 15–810 | 13 | 2.73 (1.45 to 5.13) | 139 | 1.10 (0.92 to 1.32) | 152 | 1.16 (0.98 to 1.38) |
| 811–2520 | 19 | 3.43 (2.02 to 5.83) | 151 | 1.19 (1.00 to 1.41) | 170 | 1.28 (1.09 to 1.51) |
| 2521–79 400 | 39 | 6.53 (4.10 to 10.42) | 189 | 1.26 (1.07 to 1.48) | 228 | 1.46 (1.26 to 1.70) |
| Per 5000 EU/m3-years | 1.55 (1.38 to 1.73) | 1.09 (1.00 to 1.19) | 1.16 (1.08 to 1.25) | |||
| Duration (years) | ||||||
| 0 | 340 | 1 | 6245 | 1 | 6585 | 1 |
| 1 | 11 | 3.66 (1.89 to 7.11) | 76 | 0.99 (0.79 to 1.26) | 87 | 1.10 (0.88 to 1.37) |
| 2–5 | 15 | 2.38 (1.33 to 4.26) | 189 | 1.21 (1.04 to 1.42) | 204 | 1.26 (1.08 to 1.46) |
| 6–39 | 45 | 6.84 (4.30 to 10.88) | 214 | 1.26 (1.08 to 1.48) | 259 | 1.47 (1.27 to 1.71) |
| Per 5 years | 1.68 (1.45 to 1.95) | 1.10 (1.04 to 1.16) | 1.15 (1.09 to 1.20) | |||
| Wood dust | ||||||
| Cumulative exposure (mg/m3-years) | ||||||
| 0 | 362 | 1 | 5896 | 1 | 6258 | 1 |
| 0.2–2.3 | 12 | 0.78 (0.43 to 1.43) | 270 | 1.17 (1.02 to 1.33) | 282 | 1.14 (1.00 to 1.30) |
| 2.4–6.9 | 16 | 0.95 (0.56 to 1.63) | 277 | 1.24 (1.09 to 1.42) | 293 | 1.22 (1.08 to 1.39) |
| 7.0–53.0 | 21 | 0.90 (0.54 to 1.49) | 281 | 1.00 (0.87 to 1.15) | 302 | 0.99 (0.87 to 1.13) |
| Per 5 mg/m3-years | 0.91 (0.76 to 1.08) | 1.00 (0.95 to 1.04) | 0.99 (0.95 to 1.03) | |||
| Duration (years) | ||||||
| 0 | 362 | 1 | 5896 | 1 | 6258 | 1 |
| 1 | 5 | 0.57 (0.23 to 1.41) | 148 | 1.14 (0.96 to 1.35) | 153 | 1.10 (0.93 to 1.30) |
| 2–5 | 25 | 1.15 (0.73 to 1.79) | 341 | 1.19 (1.05 to 1.34) | 366 | 1.18 (1.06 to 1.33) |
| 6–39 | 19 | 0.75 (0.45 to 1.26) | 339 | 1.08 (0.95 to 1.22) | 358 | 1.05 (0.93 to 1.19) |
| Per 5 years | 0.90 (0.73 to 1.11) | 1.02 (0.98 to 1.07) | 1.02 (0.97 to 1.06) | |||
IRRs were derived using a discrete-time hazard model with person-years as a unit of analysis.
*Adjusted for age, sex, calendar year, education, probability of smoking, connective tissue disease, fibrogenic medications and cumulative exposure to asbestos and respirable crystalline silica.
EU, endotoxin units.