Table 4

Wood dust exposure concentration, duration and cumulative exposure relative to risk of nasopharyngeal cancer 4-150

Exposure to wood dustControls
(n=244)
n
Cases
(n=142)
n
Adjusted for formaldehyde
No OR4-151
(95% CI)
Yes OR4-152
(95% CI)
Unexposed2201251.0 (reference)1.0 (reference)
Ever exposed 24 171.5 (0.7 to 3.3)1.2 (0.5 to 2.7)
Maximum exposure (mg/m3):
 >0.0–0.55 15 101.7 (0.7 to 4.4)1.3 (0.5 to 3.6)
 >0.55–1.50  4  62.5 (0.6 to 10.2)2.0 (0.5 to 8.1)
 >1.50  5  10.3 (0.0 to 3.2)0.2 (0.0 to 2.1)
 Trend testp=0.76p=0.68
Duration (y):
 1–4 12  81.5 (0.5 to 4.2)1.4 (0.5 to 4.4)
 5–13  6  41.4 (0.3 to 5.6)1.3 (0.3 to 5.4)
 ⩾14  6  51.8 (0.5 to 7.3)0.8 (0.2 to 3.7)
 Trend testp=0.27p=0.74
Cumulative exposure (mg/m3-years):
 >0.0–2.75 13  50.9 (0.3 to 3.0)0.7 (0.2 to 2.5)
 >2.75–15.70  5 103.9 (1.2 to 12.5)3.0 (0.9 to 9.8)
 >15.70  6  20.6 (0.1 to 3.7)0.4 (0.1 to 2.3)
 Trend testp=0.42p=0.99
  • 4-150 Excluding undifferentiated and non-keratinising histologies.

  • 4-151 OR adjusted for age, sex, race, SEER site, cigarette use, proxy status, and education.

  • 4-152 OR also adjusted for cumulative exposure to formaldehyde with the log transformed continuous measure and including jobs with possible or higher probabilities of exposure.