40 Years of the IAEA
CHERNOBYL'S CHALLENGE
Lothar Wedekind, based on IAEA documents and reports by John Richards, Abel Gonzalez, Franz-Nikolaus Flakus, Malcolm Crick, and David Kinley

Let there always be sunshine Health affects attributed to radioactive fallout from the tragic Chernobyl nuclear plant accident in April 1986 commanded keen attention over the past decade, among the public and scientific communities alike. Key studies were done to help clarify a controversial picture greatly shaped by public fears and perceptions about the potential dangers of radiation exposure. Radioactive fallout from the accident was mainly concentrated in Belarus, Russia, and Ukraine, but it also came down at low concentrations over much of the Northern Hemisphere. Within weeks of the explosion, scientists working through the IAEA's laboratories at Seibersdorf, Austria, and at its Marine Environment Laboratory in Monaco were collecting and analyzing earth, food, water, and other samples to monitor and assess the health and environmental impact of the fallout beyond the former USSR's borders. Seibersdorf analytical teams proved instrumental in coordinating and supporting campaigns in parts of Austria and neighbouring countries. Monaco's tracking teams found that sinking ocean particles had taken Chernobyl radioactivity rapidly to depths of two hundred meters along the Mediterranean coastline within a month of the accident.
Photo: "Let there always be sunshine", a painting by schoolchildren in Kiev done after the accident.

In the 1990s, the IAEA co-sponsored two projects with the World Health Organization and other global partners that included scientific assessments of Chernobyl's radiological health effects. The health teams of the International Chernobyl Project in mid-1990 included one hundred physicians and scientists from twelve countries that closely looked at only specific groups of people living in affected areas of Belarus, Russia, and Ukraine. Key technical and medical monitoring support came from experts of the Agency's radiation safety and dosimetry services at IAEA headquarters in Vienna and at its Seibersdorf Laboratories. The health teams found significant health disorders, most of them not related to radiation exposure directly but to other social, economic, and environmental factors. Roughly nine of every ten people living in contaminated settlements - and about seven of ten living in uncontaminated villages - thought they had, or might have, an illness due to radiation exposure, even though medical examinations found they did not. The finding focused greater attention on psychological health issues raised by the accident. Teams spent most of their time with children, and found cause for real concern. Their detailed but limited examinations did not rule out the chance that cases of thyroid cancer linked to high radiation exposure would rise in the future.

In 1996, about five years later and ten years after the accident, more than 800 experts from seventy-one countries and twenty organizations reassessed the picture, from health, environmental, and other perspectives. The venue was a major scientific conference in Vienna co-sponsored by six organizations of the UN family, including the IAEA, and two regional agencies. The landmark event served to consolidate an international consensus on the accident's consequences, report proven scientific facts, and clarify technical information and prognoses that could be, and have been, misunderstood. The major health findings addressed both short- and long-term effects.

Regarding radiation-related thyroid cancers, the experts reported a sharp increase among children from the affected areas. By the end of 1995, three children had died of the cancer, and about 800 cases had been diagnosed in children under 15 years of age, living mainly in northern Ukraine and Belarus. These effects have been the only major public health impact from radiation exposure documented to date. In the future, thyroid cancers might arise in several thousand adults who were young children at the time they were exposed to radiation from the accident. Experts recommended continued monitoring of these affected groups to detect early signs. They noted that thyroid cancers generally can be successfully treated surgically and by medication.

Long-term health effects from Chernobyl radiation exposure had not been detected by 1996, although they could not be ruled out for the future. Experts urged close monitoring of cancer registries and further investigations to determine ongoing public health impacts and to confirm predictions. Regarding psychological health disorders and symptoms, the conference confirmed significant cases of anxiety, depression, and other illnesses among affected populations. These health effects, not caused by radiation exposure, were more generally related to other factors, notably the Soviet Union's dissolution and sudden economic and political changes.

The accident's immediate victims were among the emergency workers, who were exposed to high doses of radiation. Altogether 237 workers were admitted to hospitals and 134 were diagnosed with acute radiation syndrome. Of these, 28 died within the first three months, and at least fourteen additional patients have died since 1986, not necessarily due to radiation exposure. Two other people died in the explosion, and one from presumed heart failure.

In affected areas, severe environmental impacts were short term because of rapid radioactive decay, and no sustained impacts on people or ecosystems have been observed. Environmental monitoring continues, and it's expected that low-level radioactive contamination of lands will persist for decades. Over the past decade, much work has been directed through IAEA and other global channels toward protecting people living in these areas and rehabilitating affected lands. They include radiation protection measures; medical monitoring systems; and agricultural countermeasures to lower the radioactive content in milk and other food products to acceptable levels. Through its joint work with the FAO, the IAEA sponsored work by nearly forty scientists in nineteen countries who prepared comprehensive guidelines in 1994 of effective measures that have been demonstrated and put into place. Additionally in 1994, combined efforts of the IAEA, WHO, FAO and other organizations led to international guidelines that clarify the problem of when authorities should intervene and take protective measures for public health and safety in a radiological emergency. The intervention criteria are important, since they help to maintain credibility and confidence in decisions and prevent the kind of problems arising after the Chernobyl accident. Then, neighbouring countries set varying standards for foods that confused the public and disrupted trade.

Broader issues related to radiation health effects, and how the public hears and learns about them, commanded attention in 1994 in France, where four hundred policymakers, journalists, and nuclear experts from over fifty countries met at an IAEA-sponsored conference. Among problems addressed were the public's understanding of radiation's actual and perceived health and environmental risks, a problem linked closely to how well scientists and the media communicate the facts about radiation.