Table 2.
Exposure to chlorinated and aromatic hydrocarbons and lymphoma in total (n = 710 matched pairs)
| Cases | Controls | Adj. ORa | 95% CI | |||
| N | % | N | % | |||
| CHLORINATED HYDROCARBONS | ||||||
| Chlorinated hydrocarbons in total [ppm*yrs.] | ||||||
| 0 ppm*yrs. | 567 | 79.9 | 563 | 79.3 | 1.0 | - |
| >0, <= 4.4 ppm*yrs. | 53 | 7.5 | 74 | 10.4 | 0.7 | 0.5–1.0 |
| >4.4, <= 47.3 ppm*yrs. | 54 | 7.6 | 59 | 8.3 | 0.9 | 0.6–1.3 |
| >47.3 ppm*yrs. | 29 | 4.1 | 14 | 2.0 | 2.1 | 1.1–4.3 |
| Trend test* | P = 0.03 | |||||
| Trichloroethene [ppm*yrs.] | ||||||
| 0 ppm*yrs. | 610 | 85.9 | 602 | 84.4 | 1.0 | - |
| >0, <= 4.4 ppm*yrs. | 40 | 5.6 | 55 | 7.7 | 0.7 | 0.4–1.1 |
| >4.4, <= 35 ppm*yrs. | 32 | 4.5 | 44 | 6.2 | 0.7 | 0.5–1.2 |
| >35 ppm*yrs. | 21 | 3.0 | 9 | 1.3 | 2.1 | 1.0–4.8 |
| Trend test* | P = 0.14 | |||||
| Tetrachloroethene [ppm*yrs.] | ||||||
| 0 ppm*yrs. | 667 | 93.9 | 679 | 95.6 | 1.0 | - |
| >0, <= 9.1 ppm*yrs. | 16 | 2.3 | 16 | 2.3 | 1.1 | 0.5–2.3 |
| >9.1, <= 78.8 ppm*yrs. | 14 | 2.0 | 13 | 1.8 | 1.0 | 0.5–2.2 |
| >78.8 ppm*yrs. | 6 | 0.8 | 2 | 0.3 | 3.4 | 0.7–17.3 |
| Trend test* | P = 0.12 | |||||
| Carbon tetrachlorine [ppm*yrs.] | ||||||
| 0 ppm*yrs. | 681 | 95.9 | 696 | 98.0 | 1.0 | - |
| >0, <= 2.3 ppm*yrs. | 13 | 1.8 | 8 | 1.1 | 1.9 | 0.7–5.2 |
| >2.3, <= 48.1 ppm*yrs. | 8 | 1.1 | 5 | 0.7 | 2.0 | 0.6–6.9 |
| >48.1 ppm*yrs. | 1 | 0.1 | 1 | 0.1 | - | - |
| Trend test* | P = 0.48 | |||||
| Dichloromethane [ppm*yrs.] | ||||||
| 0 ppm*yrs. | 681 | 95.9 | 681 | 95.9 | 1.0 | - |
| >0, <= 26.3 ppm*yrs. | 8 | 1.1 | 16 | 2.3 | 0.4 | 0.2–1.0 |
| >26.3, <= 175 ppm*yrs. | 9 | 1.3 | 11 | 1.5 | 0.8 | 0.3–1.9 |
| >175 ppm*yrs. | 5 | 0.7 | 2 | 0.3 | 2.2 | 0.4–11.6 |
| Trend test* | P = 0.40 | |||||
| AROMATIC HYDROCARBONS | ||||||
| Benzene [ppm*yrs.] | ||||||
| 0 ppm*yrs. | 591 | 83.2 | 590 | 83.1 | 1.0 | |
| >0, <= 8.6 ppm*yrs. | 53 | 7.5 | 60 | 8.5 | 0.9 | 0.6–1.3 |
| >8.6, <= 130 ppm*yrs. | 47 | 6.6 | 48 | 6.8 | 1.0 | 0.7–1.5 |
| >130 ppm*yrs. | 12 | 1.7 | 12 | 1.7 | 0.8 | 0.4–1.9 |
| Trend test* | P = 0.87 | |||||
| Toluene [ppm*yrs.] | ||||||
| 0 ppm*yrs. | 538 | 75.8 | 545 | 76.8 | 1.0 | |
| >0, <= 3.5 ppm*yrs. | 81 | 11.4 | 80 | 11.3 | 1.0 | 0.7–1.5 |
| >3.5, <= 207 ppm*yrs. | 70 | 9.9 | 69 | 9.7 | 1.1 | 0.7–1.5 |
| >207 ppm*yrs. | 14 | 2.0 | 16 | 2.3 | 0.8 | 0.4–1.7 |
| Trend test* | P = 0.74 | |||||
| Xylene [ppm*yrs.] | ||||||
| 0 ppm*yrs. | 549 | 77.3 | 552 | 77.7 | 1.0 | |
| >0, <= 4.4 ppm*yrs. | 74 | 10.4 | 80 | 11.3 | 0.9 | 0.7–1.3 |
| >4.4, <= 230 ppm*yrs. | 68 | 9.6 | 63 | 8.9 | 1.1 | 0.7–1.6 |
| >230 ppm*yrs. | 12 | 1.7 | 15 | 2.1 | 0.8 | 0.3–1.6 |
| Trend test* | P = 0.56 | |||||
| Styrene [ppm*yrs.] | ||||||
| 0 ppm*yrs. | 542 | 76.3 | 541 | 76.2 | 1.0 | |
| >0, <= 1.5 ppm*yrs. | 70 | 9.9 | 85 | 12.0 | 0.7 | 0.5–1.0 |
| >1.5, <= 67.1 ppm*yrs. | 79 | 11.1 | 67 | 9.4 | 1.2 | 0.8–1.7 |
| >67.1 ppm*yrs. | 12 | 1.7 | 17 | 2.4 | 0.6 | 0.3–1.4 |
| Trend test* | P = 0.43 | |||||
Missing values were included as a separate category (not shown)
a Odds Ratio (OR) adjusted for smoking [packyears] and alcohol consumption [g per day]
* To calculate tests for trend, the exposure scores were included as continuous variables in the logistic regression model
Abbreviations: OR = odds ratio; CI = confidence interval; yrs. = years