Consequences of the Chernobyl Accident in Russia: Search for effects of radiation exposure in utero using psychometric tests

The probability of the existence of significant differences between pshychometric indicators for mental development of children in towns distinguished by radioactive contamination resulting from the Chernobyl accident is investigated. A database for psychometric tests ('Draw-a-Man', 'Raven Coloured Matrices' test, 'British Picture Vocabulary Scale' test) is analyzed. These tests are passed by 700 children (at the age off) exposed in utero to radiation in Novozybkov and Klintsy and born within 38 weeks after the accident, as well as by 300 children born within the same time interval in Obninsk that had not been contaminated with radionuclides. Comparing the results of examinations in Novozybkov, Klintsy and Obninsk, no confident evidence has been obtained that radiation exposure of the developing brain exerts influence on indicators for mental development. At the same time some rare cases of appreciable mental retardation are probable, however, under the condition of exclusively high doses to the developing brain. However, it is more likely that a greater contribution to the differences observed was made by non-radiation factors.