Malignant lymphomas and leukemias, and exposures in the wood industry: an industry-based case-referent study

Jobs and exposures in woodwork may entail an elevated risk of lymphomas and leukemias. Exposures occurring in woodwork were scrutinized in a small industry-based case-referent study of four cases of Hodgkin's disease, eight cases of non-Hodgkin's lymphoma, 12 cases of leukemia, and 152 matched referents, all from the Finnish wood industry. Past exposures to wood dust, chlorophenols, terpenes, and engine exhaust, individually reconstructed through plant- and period-specific job exposure matrices, were unrelated to lymphoma/leukemia risk. Exposures to various solvents were associated with an odds ratio (OR) of 5.6 (95% confidence interval 1.0-32.0). The OR for formaldehyde was 2.5 (nonsignificant). The results are interpreted as providing limited evidence of the role of exposure to some as yet unidentified organic solvents in increasing the risk of malignant lymphomas. Formaldehyde may be another woodwork-related risk factor for some lymphomas, but the power of the study was too low for empirical confirmation of this possibility. Leukemias did not seem to be associated with any of the exposures studied.