Table 3

Mesothelioma risk estimates (RR) for cumulative EMP* exposure as a continuous, categorical and geological zone specific

ExposureCasesControlsRR†95% CI
(EMP/cc)×years571841.100.97 to 1.24
High vs low‡ 
 Low: <0.40 (EMP/cc)×years17921.00
 High: ≥0.40 (EMP/cc)×years)40922.251.13 to 4.50
Cumulative exposure tertiles§ 
 0 to <0.16 (EMP/cc)×years (REF)15611.00
 ≥0.16 to <1.15 (EMP/cc)×years11620.690.28 to 1.68
 ≥1.15 (EMP/cc)×years31611.970.89 to 4.32
Exposure by geological zone¶ 
 Zone 1 (EMP/cc)×years)18741.961.15 to 3.34
 Zone 2 (EMP/cc)×years)31581.311.12 to 1.54
 Zone 3 (EMP/cc)×years)12660.880.71 to 1.09
  • *Measured by NIOSH 7400 method (NIOSH EMP definition: >5 µm length, aspect ratio >3).

  • †Results adjusted for age, employment in haematite, and potential for commercial asbestos exposure.

  • ‡High group represents workers with cumulative exposure greater than the control median exposure.

  • §Based on the lower, middle and upper third of the control exposure distribution.

  • ¶Results adjusted for age, employment in haematite, potential for commercial asbestos and exposures in other zones. Cases and controls may have worked in more than one zone.

  • EMP, elongate mineral particles; NIOSH, National Institute for Occupational Safety and Health.