Table 4

 Relative risk of mortality from lung cancer and non-malignant respiratory disease by levels of cumulative respirable crystalline silica exposure in UK industrial silica sand workers

Cumulative RCS exposurenRR*(95% CI)RR†(95% CI)
(mg/m3-years)
*Analysed simultaneously with attained age.
†Analysed simultaneously with attained age, period from first employment, employment status, year of starting employment, and quarry.
‡Any part of the death certificate coded to ICD 162 or C33/C34.
§Underlying cause of death coded to ICD 460–519 or J00–J99.
Lung cancer‡
    <0.13201.01.0
    0.13–<0.40211.24(0.66 to 2.34)1.14(0.60 to 2.18)
    0.40–<1.00221.42(0.76 to 2.67)1.12(0.58 to 2.18)
    ⩾1.00190.88(0.45 to 1.73)0.92(0.44 to 1.92)
p value for trendp = 0.79p = 0.80
Non-malignant respiratory diseases§
    <0.13191.01.0
    0.13–<0.40191.24(0.67 to 2.28)1.33(0.71 to 2.50)
    0.40–<1.00211.22(0.65 to 2.30)0.98(0.51 to 1.88)
    ⩾1.00241.46(0.82 to 2.62)1.12(0.59 to 2.14)
p = 0.48p = 0.98