Results from logistic regression analysis of respiratory symptoms relative to exposure to cumulative respirable fibres
| Symptom | Cumulative exposure OR (95% CI) | Recent exposure (1987–1996) OR (95% CI) |
| Chronic bronchitis | 1.28 (0.94 to 1.74) | 1.62 (0.74 to 3.56) |
| Usual cough or phlegm | 1.10 (0.92 to 1.31) | 1.50 (0.99 to 2.25) |
| Breathlessness | 1.18 (0.88 to 1.56) | 1.82 (0.92 to 3.62) |
| Recurrent chest illness | 1.48 (1.11 to 1.96) | 1.42 (0.57 to 3.58) |
| Pleuritic chest pain | 1.43 (0.99 to 2.07) | 1.93 (0.72 to 5.20) |
OR (95% CI) are/5 f.ml−1.y