Table 2

Occupational asbestos exposure in cases and controls (n=960)

Exposure*Cases (n=494)%Controls (n=466)%
Ever asbestos exposed3276629363
High-risk non-construction65135111
High-risk construction1382812627
Medium risk industrial1242511625
Low risk industrial94199721
Number of patients who recalled working with asbestos (permitting a Fibre ml⁻¹ year estimate)222510723
Median fibre ml⁻¹ years (IQR)6 (0–63)5 (0–60)
 ≥100 fibre ml⁻¹ years275245
 ≥50 fibre ml⁻¹ years347296
 ≥25 fibre ml⁻¹ years408358
  • *Categories of occupational asbestos exposure risk were defined on the basis of occupational proportional mortality ratios for mesothelioma16 and ever asbestos exposed was defined as ever having had a high or medium asbestos exposure risk job. Fibre ml⁻¹ year asbestos exposure estimates were calculated for participants who recalled working with asbestos using a source-receptor model.17 20