Chernobyl Forum reports 20-year findings, offers ...

1 Countries mentioned in news stories this month are shadedNEARLY20 YEARS after theApril 26, 1986, accident at theChernobyl-4 reactor in Ukraine,the Chernobyl Forum met as an interna-tional conference, held September 6 7 inVienna, and arrived at a consensus on itsscientific findings, as well as on measuresto alleviate the health and environmentalproblems that remain. The conference, thetheme of which was Chernobyl : LookingBack to Go Forwards,was attended bysome 200 scientists and senior-level gov-ernmental representatives, including somefrom the three most affected countries Belarus, Russia, and Chernobyl Forum was establishedby the International Atomic Energy Agency(IAEA) in 2003 with the aim of developingan authoritative consensus on the impact ofthe accident that would guide future re-search and the rehabilitation of the peopleand the environment.

2 In addition to theIAEA, the other UN bodies involved in theforum are the Office of the Coordinator forHumanitarian Affairs (OCHA), the UN De-velopment Program (UNDP), the Food andAgriculture Organization, the UN Environ-ment Program, the UN Scientific Commit-tee on the Effects of Atomic Radiation, theWorld Health Organization (WHO), andthe World Bank. The governments of Be-larus, Russia, and Ukraine are also mem-bers of the findings discussed at the conferencewere prepared by international experts con-vened as two working groups on environ-mental impacts, under the IAEA, and onhealth impacts, under official consensus summary reportdescribes the accident as explosions ruptur-ing the reactor vessel of Unit 4 and causinga fire that continued for 10 days.

3 The result-ing cloud spread numerous types of ra-dioactive materials, most significantly io-dine and cesium radionuclides, over muchof Europe, with the greatest concentrationsoccurring over large areas of Belarus, Rus-sia, and Ukraine adjacent to the 200 000 emergency and recoveryoperation workers, known as liquidators, were initially involved in containment andcleanup work in 1986 1987 at the strickensite and the nearby area, since designatedthe Exclusion Zone. The number of reg-istered liquidators was later increased to600 000, but only a small fraction of thosewere exposed to dangerous levels of radi-ation.

4 The highest doses were to about1000 liquidators during the first day of 5 million people are living in ar-eas contaminated above 37 kBq/m2of Cs-137, of whom some 400 000 had lived inmore contaminated areas, classified by So-viet authorities as areas of strict control(above 555 kBq/m2of Cs-137). Some116 000 people were evacuated from theExclusion Zone (which is in Belarus andUkraine, adjacent to the power plant) tononcontaminated areas in the spring andsummer of 1986, and another 230 000 insubsequent information about the accidentand the resulting radioactive contaminationwas not initially made available to the af-fected people and remained inadequate for46 NUCLEARNEWSO ctober 2005 InternationalNearly 20 years after the Chernobyl accident, aninternational Forum says a different approach isneeded in addressing the region s FORUMC hernobyl Forum reports 20-yearfindings.

5 offers recommendationsabout two years following the led to widespread distrust of officialinformation and the mistaken attribution ofmany ill health conditions to radiation expo-sure. The Forum s aim was to fill this voidand promote better understanding of thepost-accident situation, and also to recom-mend measures to better deal with the impactThe findings on health effects raised con-troversy and lengthy debate over the num-ber of deaths already caused by the accidentand how many were anticipated as likely tooccur.

6 The report of the WHO-led expertgroup noted the deaths of 30 power plantemployees and firemen within a few daysor weeks, of whom 28 died of acute radi-ation syndrome (ARS). It did not project afigure for future summary report states, Claims havebeen made that tens or even hundreds ofthousands of persons have died as a result ofthe accident. These claims are exagger-ated. It says that total deaths amounted to50 liquidators, who died of ARS in 1986and other causes in later years, and ninechildren, who died of thyroid cancer.

7 It putthe estimated possible deaths from cancercontracted as a result of radiation exposureat 3940 from among the 200 000 1986 87liquidators, 116 000 evacuees, and 270 000residents of the most contaminated seemed to be laced withsome confusion when cancer specialistElisabeth Cardis, of WHO, in a detailedpresentation during the conference sug-gested that another 4000 might die fromamong the 5 million to 6 million in areaswith low-level contamination. So, asked aGreen Party member of the European Par-liament, what is the number now?

8 Anotherparticipant said that after 20 years of hear-ing that this was the world s worst nuclearaccident, nobody would believe a total of4000 deaths that it was unbelievably Repacholi, of WHO, and otherforum officials were put to some pains toexplain that none of the predictions weremeant to be exact, but merely to indicatescope. The estimates, he said, were basedon models of dose-effect relationships,which in turn were based mostly on datafrom the survivors of the Hiroshima andNagasaki bombs. It was noted that the twoevents were very dissimilar: The bomb sur-vivors received a burst of acute exposure,and the accident at Chernobyl caused achronic low-level condition.

9 The samemodels could not be applied to both. Thescientists did not want to include numbersfor predicted deaths, but public relations of-ficials had wanted them in the summary,Repacholi said in answer to other findings on health impacts relating to exposures, diseases caused andlikely to occur, inherited or reproductive ef-fects, trauma, and possible persistent psy-chological or mental health problems were more readily regard to exposures, the report saysthat with the exception of on-site reactorpersonnel and emergency workers.

10 Most ofthe recovery operation workers and peopleliving in the contaminated territories re-ceived relatively low whole-body radiationdoses, comparable to background radiationlevels. Those who worked on site shortlyafter the accident received external gammaradiation of 2 to 20 Gy, and as a result 28died within four months and another 19over the years up to 2004. Doses to recov-ery operation workers, who worked forshort periods during the following fouryears, ranged up to about 500 mSv, with anaverage of about 100 levels of the evacuees from theChernobyl accident area were also of con-cern, the report says, with doses that couldonly be estimated some time after they oc-curred.