CASE-CONTROL STUDY ON THE ASSOCIATION BETWEEN A CLUSTER OF CHILDHOOD HEMATOPOIETIC MALIGNANCIES AND LOCAL ENVIRONMENTAL-FACTORS IN AALSMEER, THE NETHERLANDS

Study objective and design - In Aalsmeer, a horticultural community ne ar the main international airport in The Netherlands, a more than four fold increase in the incidence of haematopoietic malignancies in young people was observed between 1980 and 1985. In a population based case -control study, the association with local environmental factors was i nvestigated. Participants - For each patient younger than 40 years of age (n = 14) diagnosed between 1975 and 1989, four age and sex matched controls were selected via local general practitioners. Methods - All parents of patients and controls completed a questionnaire on their l ifestyle, living conditions, and health, for several years preceding e ach individual diagnosis. Odds ratios (ORs) with 95% confidence interv als (CI) were calculated, matched, and, if necessary, stratified for n eighbourhood. Main results - Increased ORs were recorded for intensive use of petroleum products and pesticides by the patients themselves a nd their fathers: OR petroleum products: 8.0 (95% CI.2.2,129.9) and 9. 0 (1.0,66.1) respectively; OR pesticides: 6.0 (0.6,49.3) and 3.2 (1.0, 10.1) respectively. Swimming in a local pond was also significantly as sociated with the disease: OR = 5.3 (1.3,17.4). In the 1970s this pond had been polluted by petroleum products and pesticides. Conclusions - The increased incidence of childhood haematopoietic malignancies in A alsmeer may have been associated with several specific local environme ntal factors. Interpretation of the results, however, should take into account the fact that confidence intervals were wide because of the l imited number of cases.