aRR and 95% CI calculated by the committee with standard methods from the observed and expected numbers presented in the original study.
b95% CI calculated by the committee with standard methods from the observed and expected numbers presented in the original study.
Epidemiologic Studies of Exposure to Organic Solvents and Chronic Leukemia
An association between exposure to benzene and risk of chronic leukemia was reported in several studies (Ireland et al., 1997: SMR=2.3, 95% CI=0.7–5.3; Rushton and Romaniuk, 1997: SMR=1.22, 95% CI=0.38–3.89 for 4.5–44.9 ppm-years; Yin et al., 1996a,b: SMR=2.6, 95% CI=0.7–16.9). No excess risks (OR=1.1, 95% CI=0.6–2.0) were observed for self-reported exposure to aromatic hydrocarbons (the class of solvents that includes benzene, toluene, and xylene) in a population-based case-control study of CLL (Malone et al., 1989). Except for one exposure level, the case-control study by Rushton and Romaniuk (1997) showed relative risks close to unity.
A case-control study of leukemia and preleukemia conducted in Italy found that shoemakers and painters were at high risk for CML (OR=4.5, 95% CI=1.6–13.0 for shoemakers; OR=7.6, 95% CI=1.5–39.8 for painters) (Mele et al., 1994). Positive associations between exposure to mixed solvents and CLL were found in a US study reporting previous exposures to paints (OR=1.4, 95% CI=0.8–2.2) and hobby painting (OR=1.4, 95% CI=0.9-