[Descriptive analysis of the excess of acute leukemia morbidity among children in Briansh district]

12 cases of ALL, 2 cases of ANLL and 3 cases of NHL have been registered among children aged 0-15 living in 6 Bryansk territory regions exposed to radionuclide contamination after the Chernobyl accident. The study covers the period from 1986 to 1991. There was an excess of acute Leukemia incidence in 1986 as indicated by 7 ALL and 1 ANLL cases. For ALL relative risk was 4.49, p = 0.006. In 2 cases AL was diagnosed before the accident, 2 patients fell ill in June, 2 in July, 1 in August, we have no exact date for 1 patient. Relative risk has never exceeded 1.0 for all the analyzed hemoblastoses within the last 5 years. The Poisson probability of chance occurrence of 8 AL cases in supervision regions during one year is 0.0004. Sex distribution of the cases was atypical either: 7 from 8 patients were boys. Binomial probability is 0.056 under the standard sex ratio 6:5. No evidence was obtained that this high incidence of childhood leukemia extends to neighbour regions of the Gomel, Mogilev and Bryansk territories. The descriptive epidemiological analysis has confirmed the existence of childhood leukemia incidence excess in 1986, but failed to explain its cause. Analysis of incidence rates alone is not enough to confirm connection between leukemia hazard and Chernobyl accident.