Acute myeloid leukaemia and exposure to organic solvents--a case-control study

The objective was to study the relation between exposure to organic solvents and the risk of developing acute myeloid leukaemia (AML) in Caucasians aged 18 years and more. Ninety-eight cases of AML were diagnosed from September 1986 to March 1990 in Novi Sad, Yugoslavia, and in two London hospitals from September 1988 and May 1994 and from July 1992 and July 1994, respectively. Two controls were matched to each case by hospital, year of admission, gender and 5-year age group. Information on solvent exposure was collected by interview. Odds ratios (ORs) were derived with conditional logistic regression. The degree of solvent exposure was determined by three experts blind to the status of the subject with good agreement between them (the kappa coefficient ranged between 0.52 and 0.86). The response rate for cases was 80%. Exposure to solvents was associated with the increased risk of AML (OR: 2.52; 95% CI: 1.45-4.39; p = 0.001) and those with probable exposure to solvents were found to have an odds ratio of AML over three times greater than non-exposed. We also found an elevated OR for exposure to oils (OR: 1.56) but this was not statistically significant. There is no clear pattern of increasing risks with increasing duration of employment but a significant risk was found for exposures of 10 years or less. An induction period of less than 10 years or more than 30 years was associated with a significantly raised OR. There was a significant excess of machinery mechanics and fitters among the cases.