Table 5

Estimates of relative risk for lung cancer from chrysotile exposure in this incident based on the linear non-threshold model,18 assuming exposure to stated average air concentrations of chrysotile, expressed as number of regulated fibres >5 μm and a duration of exposure of 48 hours

Air concentration fibres/ml Cumulative exposure fibresml/ years Computed relative risk Predicted exposed population needed for one extra lung cancer death (millions)* Exposure
Assuming b = 0.0006 (equation [1])
0.50.0081.00000493I
0.250.0041.00000256II
0.10.0021.000001014
0.040.00031.000000436III
0.0010.000021.000000011450IV
Assuming b = 0.01 (equation [1])
0.50.0081.0000820.17I
0.250.0041.0000410.35II
0.10.0021.0000160.87
0.040.00031.0000072III
0.0010.000021.000000286IV
  • United Kingdom industrial control limit.33 Average exposure level if the United Kingdom industrial control limit is enforced.33 Upper limit of asbestos concentration indoors in a building with friable sprayed asbestos.25 Lower limit of asbestos concentration indoors in a building with friable sprayed asbestos, and a median level for residential air in a large city or a road crossing with heavy traffic.25 *See method above under chrysotile and lung cancer risk model.