[A leukemia cluster in the Pinneberg district. Results of an incidence study by the epidemiologic task force of the Schleswig-Holstein Medical Association].

After regional media had reported in early 1995 of multiple leukaemia cases in a small community in the state of Schleswig-Holstein, an "Epidemiological Task Force" was asked to review the existing evidence for a possible cluster. The Task Force is a small group appointed in 1994 by the regional Medical Association and the state's ministry of social affairs. It includes five professionals from the fields of environmental toxicology and hygiene, Public Health, epidemiology and cancer pathology. In agreement with the local Public Health administration and the ministry the Task Force organized a retrospective screening of all incident leukaemia, lymphoma and myeloma cases (ICD-9 codes 200-208) within a (5-10 km) around the small community (population on December 31st 1993: 72000) that had occurred after January 1st 1990. Any practising physician (response rate 78%), hospital (100 %), oncological centre (100%), and tumour registry (100%) serving the region were asked to notify all relevant cases to the Task Force. Additionally spontaneous case reports were elicited, and all death certificates from the a.m. time period were screened for by two Public Health administrations. We identified 202 single cases for further analysis. Comparative data for the entire region and single communities came from two cancer registries, the Danish and that of the state of Saarland/FRG, and allowed for calculating the expected number of cases by indirect standardisation. While Hodgkin's lymphomas and myelomas were (insignificantly) less frequent than expected, an excess of non-Hodgkin's lymphomas and leukaemias (all types combined) was observed. Standardised incidence ratios for the whole region varied between 1.54 and 1.68 with significant and consistent increases only for the group of leukaemias among adults (aged 15+). All results were reported to both the public and administrative/professional bodies together with specific recommendations. The reactions showed a good acceptance of the Task Force and its work.