Genetic effects of radiation.

Fig. 24: The effects of radioactive fallout on genetic material and on the health of future generations cannot yet be estimated. Photo: Martina Buchholz Sources (46.1)  Kovalchuk, Igor; Kovalchuk, Olga; Arkhipov, Andrey; Hohn, Barbara: Transgenetic plants are sensitive bioindicators of nuclear pollution caused by the Chernobyl accident, Nature Biotechnology, Vol. 16, 16.11.1998, pp. 1054 ff. (47.1)  United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR): Hereditary Effects of Radiation, New York, 2001, p. 84 (49.1)  Focus, University Of Haifa, Israel, http://research.haifa.ac.il (50.1)  National Radiological Protection Board, UK: www.nrpb.org (39.1)  European Commission, OCHA et. al., International Conference: Fifteen Years after the Chernobyl Accident. Lesson Learned. Executive Summary, Kiev, April 2001, p. 10 (138.1)  Yuri E. Dubrova: Monitoring of radiation-induced germline mutation in humans, Swiss Medical Weekly, 2003, 133:474-478 www.smw.ch PDF-File for Download (176KB) (154.1)  Chernobyl Forum Report: Chernobyl’s Legacy: Health, Environmental and Socio-Economic Impacts, 2005, published by: IAEA - International Atomic Energy Agency Further literature (48)  Lazjuk, G.I. et. al.: Study of possible genetic impact of Chernobyl accident using Belarus national registry of congenital malformations, Belarus Institute for Hereditary Diseases, Minsk, (113)  Ellegren H., Lindgren G. et al.: Fitness loss and germline mutations in barn swallows breeding in Chernobyl, Nature, Vol. 389, 9.10.1997, S. 539-596, (114)  Goncharova R.I., Slukvin A.M.: Study on mutation and modification variability in young fishes of Cyprinus carpio from regions contaminated by the Chernobyl fallout, Russian-Norvegian Satellite Symposium on Nuclear Accidents, Radioecology and Health, Abstract Part 1, Moscow, 1994 (139)  Simon Bouffler and David Lloyd: Nuclear weapons tests and human germline mutation rate: A commentary, Radiological Protection Bulletin, June 2002 Documents Scientific seminar: Ionizing radiation, genetic and embryonic risk 21.04.06 Glossary Equivalent dose Caesium/Caesium-137 Curie (Ci) Absorbed Dose Sievert Somatic effects Radiation and radioactivity Further information Effects on plants and animals Overview of health consequences

What are the implications of the nuclear accident for future generations' genes?
There is an international consensus that radiation can induce genetic effects. This has been shown in a wide range of studies on plants and animals from the contaminated territories (46.1).

However, the consequences of radiation for human genes and the risk of abnormalities are hotly debated. A study by the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) in 2001 concluded that "No radiation-induced genetic (= hereditary) diseases have so far been demonstrated in human populations exposed to ionizing radiation". The Chernobyl Forum Report (2005) comes to a similar conclusion: Because of the relatively low dose levels to which the population of the Chernobyl-affected regions was exposed, there is no evidence nor any likelihood of observing decreased fertility among males or females in the general population as a direct result of radiation exposure. These doses are also unlikely to have any effect on the number of stillbirths, adverse pregnancy outcomes, delivery complications or the overall health of the children (154.1). This conclusion is however contradicted by a number of studies that indicate an increase in abnormalities, or at least in genetic mutations, as a result of the accident.

A statistical record of the ten most common hereditary defects observed among newborns in Belarus since 1982 has been prepared by the Belorussian geneticist Gennady Lazjuk. He compared the number of birth defects before (1983 to 1985) and after (1987 to 2000) the nuclear accident. According to his data, the incidence of defects rose in proportion to the radioactive contamination of the areas (48.1).

In two papers published in "Nature", scientists presented evidence that even the children of parents who were exposed to Chernobyl radiation exhibit significantly more mutations in the human minisatellite genome than would be expected. A correlation was found with the level of soil contamination in the areas in which the parents had lived. The rise in the mutation rate among the children of parents exposed to radiation was found to be dose-dependent (138.1 and 139).

Another study suggests that genetic defects should be expected not only after high doses of radiation (above 0.5 Sv), but at lower doses as well.

Researchers from Israel and Ukraine examined the children of liquidators, conceived after the accident and now living in Ukraine or Israel. The number of genetic mutations was seven times higher in these children than in siblings who were conceived before the accident (49.1).

A similar conclusion was reached by researchers from the UK, Kazakhstan and Finland who examined three generations from 40 families that had lived close to a Russian nuclear test site. A DNA mutation rate that was 50 per cent higher than normal was passed on to the subsequent generation in these families. However, the experts emphasise that no conclusions can yet be drawn about the impact of these germline mutations on the health of those affected (50.1).

In the Conclusions of the Conference entitled "Fifteen Years after the Chernobyl Accident. Lessons Learned", which took place in Kiev in April 2001, scientists from the three affected countries and representatives of various international organisations therefore designated the genetic effects of radiation as a priority area for research (39.1).

Attendees at the fourth international conference, "Chernobyl Children - Health Consequences and Psychosocial Rehabilitation", which was held in June 2003, also stressed the need for further research into the genetic effects of exposure to radiation.