3.2, 95% CI=1.0–10.3); estimates of risk of astroglial tumors were also increased for “high” levels of exposure to solvents (OR=2.3, 95% CI=0.9–5.8) and other glial tumors were not (OR =0.8, 95% CI=0.1–6.6) (Cordier et al., 1997). Like maternal exposure, high paternal exposure to solvents was associated with increased risk of brain cancer (OR=1.2, 95% CI=0.7–1.9) and astroglial tumors (OR=1.3, 95% CI=0.7–2.3), but not other glial tumors (OR=0.4, 95% CI 0.1–1.4). A second case-control study of childhood brain cancer and paternal occupational exposure showed no association with exposure to benzene (OR=0.7, 95% CI=0.1–3.1) (Feingold et al., 1992). However, an association was found with exposure to solvents (OR=1.2, 95% CI=0.2–8.5) and diethylene glycol (OR=1.3, 95% CI=0.3–5.2).

Summary and Conclusion

On the basis of those two case-control studies, the committee decided that the body of evidence was too small and inconsistent in outcome (brain cancer broadly vs PNET vs astroglial tumors). Table 6.50 identifies the studies reviewed by the committee in drawing its conclusion.

The committee concludes, from its assessment of the epidemiologic literature, that there is inadequate/insufficient evidence to determine whether an association exists between either maternal or paternal preconception exposure to solvents under review and childhood brain cancers.

TABLE 6.50 Selected Epidemiologic Studies—Childhood Brain Cancers and Exposure to Organic Solvents

Reference

Study Population

Exposed Cases

Estimated Relative Risk (95% CI)

Brain Cancer

Case-Control Studies

Cordier et al., 1997

Children in Milan, Paris, and Valencia

 

 

Occupational exposure in the 5 years before birth

 

 

Maternal exposure to solvents

 

 

Medium level, brain cancer

30

1.0 (0.6–1.7)

 

High level, brain cancer

19

2.4 (1.2–4.9)

 

Medium level, PNET

7

1.3 (0.5–3.3)

 

High level, PNET

5

3.2 (1.0–10.3)

 

Medium level, astroglial tumors

15

1.1 (0.6–2.1)

 

High level, astroglial tumors

9

2.3 (0.9–5.8)

 

Medium level, other glial tumors

6

0.9 (0.3–2.6)

 

High level, other glial tumors

1

0.8 (0.1–6.6)

 

Paternal exposure to solvents

 

 

Medium level, brain cancer

40

0.9 (0.6–1.5)

 

High level, brain cancer

37

1.2 (0.7–1.9)

 

Medium level, PNET

16

2.3 (1.1–4.9)

 

High level, PNET

9

1.7 (0.7–4.1)

 

Medium level, astroglial tumors

23

1.1 (0.6–2.0)

 

High level, astroglial tumors

24

1.3 (0.7–2.3)

 

Medium level, other glial tumors

10

1.3 (0.6–3.0)

 

High level, other glial tumors

3

0.4 (0.1–1.4)

Feingold et al., 1992

Children in the Denver, CO, area

 

 

Paternal occupational exposure year before birth

 

 

Benzene

4

0.7 (0.1–3.1)

 

Solvents

2

1.2 (0.2–8.5)

 

Diethylene glycol

7

1.3 (0.3–5.2)

NOTE: PNET=primitive neuroectodermal tumors



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