Table 2 Odds ratios and 95% confidence intervals for chronic lymphoid leukaemias and specific benzene exposure metrics for the Australian study ever employed at a refinery and ever not employed at a refinery

From: Acute myeloid and chronic lymphoid leukaemias and exposure to low-level benzene among petroleum workers

 

Ever employed at refinery

Not ever employed at a refinery

 

Cases/controls

Odds ratios (95% CI)

Cases/controls

Odds ratios (95% CI)

Cumulative benzene exposure beyond zero (p.p.m.-years)

0.348–2.93

3/15

1

7/20

1

>2.93

9/11

3.75 (0.76, 18.55)

4/13

0.71 (0.16, 3.27)

Maximum benzene exposure intensity (p.p.m.) beyond 0.016 p.p.m.

0.016–0.118

2/13

1

4/17

1

>0.118–0.413

7/8

5.65 (0.87, 36.83)

3/8

1.74 (0.27, 11.19)

>0.413

3/5

2.33 (0.34, 15.91)

4/8

1.83 (0.32, 10.53)

Average benzene exposure intensity (p.p.m.) beyond 0.016 p.p.m.

0.016–0.081

2/10

1

5/17

1

>0.081–0.259

7/11

2.98 (0.53, 16.71)

2/10

0.66 (0.10, 4.61)

>0.259

3/5

2.07 (0.27, 15.87)

4/6

1.67 (0.32, 8.70)

Duration of employment beyond zero (years)

15.6–28

6/13

1

9/28

1

>28

6/13

1.14 (0.10, 12.66)

2/5

0.63 (0.05, 7.49)

  1. Abbreviations: CI=confidence interval; p.p.m.=parts per million.