Kalman Mizsei, from the United Nations Development Program (UNDP), told the UN-sponsored Chernobyl Forum that met in Vienna Tuesday: "For the vast majority of people, the fears associated with exposure to radiation from Chernobyl have been exaggerated.
"The damage, both to human health and natural environment has been much smaller than commonly assumed," he said.
"People in the affected communities can, with very few exceptions, pursue normal lives," Mizsei told the forum, which brings together experts from eight UN agencies, as well as the governments of the main affected countries Belarus, Russia and Ukraine.
A report by the forum said that the total number of people expected to die over time from cancers from the disaster was likely to be around 4,000 out of some 600,000 people who were subjected to radiation in the most affected regions, far lower than the tens of thousands expected to die according to other predictions.
It also said a total of 56 deaths could be attributed to the disaster to date, of whom 47 were rescue workers who received whole-body high doses of radiation and nine children who had died from thyroid cancer.
The forum's conclusions are "ridiculous," Greenpeace environmental group researcher William Peden told AFP.
"It is way too early to make such bold assertions when so many questions remain unanswered and many thousands more may die in decades to come," Peden said.
Oleksiy Pasyuk, of the Ukraine National Ecology Center, said in Kiev: "We are worried that they are suggesting allowing people to once again live in the affected areas... Their goal is to push for development of nuclear energy."
In Belarus, physicist Georgi Lepnin, who himself received massive doses of radiation as a rescue worker at Chernobyl, said: "The figure of 4,000 dead is a huge under-estimate."
He said that some 10,000 of the 200,000 rescue workers, the so-called liquidators, had died even if authorities tried to pass this off by saying they had perished from heart attacks and other non-cancer causes.
The explosion on April 26, 1986, of the number four reactor at the Chernobyl power plant in the what was then the Soviet republic of Ukraine, sent a radioactive cloud across Europe in what was the worst nuclear accident in history.
Jan Van de Putte, a Greenpeace nuclear campaigner, said in a statement that "denying the real implications (of the accident) is not only insulting the thousands of victims -- who are told (they are) sick because of stress and irrational fears -- but it also leads to dangerous recommendations, to relocating people in contaminated areas."
Burton Bennett, an expert on radiation effects who is chairing the meeting, said the 4,000 figure should be taken as a sign of the extent to which authorities have "overplayed the health consequences" of the accident.
He said misinformation was responsible for a range of psychological problems as people in the region of Chernobyl thought they were doomed to get cancer, when in fact their exposure to radiation had been relatively low.
Mohamed ElBaradei, head of the UN's watchdog atomic agency, said in a speech read out to the opening session, as he was not present, that "poverty, mental health problems and 'lifestyle' diseases have come to pose a far greater threat to affected communities than radiation exposure."
He said that people bombarded with dire predictions "came to regard themselves not as 'survivors' but as helpless, weak and lacking control over their futures."
Mizsei said an "industry has been built on this unfortunate event," with 22 percent of the 1991 national budget of neighbouring Belarus being dedicated to Chernobyl relief, a figure that has since dropped to six percent.
Russian Nadezda Gerasimova said "that the most grave results of the Chernobyl accident were in the social area rather than in the radiological area" and that the time had come to cut down on some benefits to people, although many resisted this.