Table 9

Relative risk of bladder cancer (all notifications of malignant neoplasms8-151) by potential exposure to various chemicals: employment histories are unlagged

Variable with levels n RR (95% CI) separate analysis8-152 RR (95% CI) simultaneous analysis8-153
Cumulative exposure to MBT (mg.μ-3y):
 None211.01.0
 0.01–21.2452.968-150 (1.11 to 7.86)2.24(0.76 to 6.60)
 21.25–63.7432.50(0.74 to 8.38)1.46(0.38 to 5.63)
 ⩾63.7511.72(0.23 to 12.82)1.21(0.15 to 9.54)
 p Value for trend8-154 p=0.06p=0.48
Duration of employment in PBN department (y):
 None251.01.0
 1–411.26(0.17 to 9.32)0.58(0.06 to 5.46)
 ⩾547.488-160 (2.60 to 21.52)4.358-150 (1.30 to 14.57)
 p Value for trend8-154 p<0.001p=0.03
Duration of employment in aniline department (y):
 None231.01.0
 1–420.85(0.20 to 3.61)0.61(0.14 to 2.76)
 ⩾552.20(0.84 to 5.79)1.50(0.52 to 4.35)
 p Value for trend8-154 p=0.17p>0.50
Duration of employment in o-toluidine department (y):
 None271.01.0
 1–426.738-150 (1.59 to 28.41)5.188-150 (1.04 to 25.80)
 ⩾517.658-150 (1.03 to 56.87)2.73(0.29 to 25.45)
 p Value for trend8-154 p=0.002p=0.31

  • ↵8-150 p<0.05;

  • ↵8-160 p<0.01;

  • 8-165 p<0.001.

  • ↵8-151 See table 3, second column.

  • ↵8-152 Column summarises four analyses, only adjusting for age.

  • ↵8-153 Column summarises a single analysis in which the four chemical exposure variables are analysed simultaneously with age.

  • ↵8-154 See text.