By John C. Zink, Ph.D., P.E., Contributing Editor
The International Atomic Energy Agency and seven other United Nations’ (UN) agencies convened a conference in Vienna last September to examine the long-term effects of the Chernobyl nuclear power plant accident. Conference participants reviewed the findings presented in a three-volume, 600-page report prepared by experts from the eight organizations after they had studied the medical, psychological, environmental and economic effects of the 1986 accident. The report concluded that the public health consequences of the accident were not as severe as originally feared.
High radiation doses often can induce cancer in people, but there is a latency period of as long as ten years before many cancers show up. The UN study group accounted for this fact by examining, over a nearly 20-year period, the health history of those exposed to elevated levels of radiation by the accident. The study concluded that, as of mid-2005, only 59 people had died as a result of Chernobyl-released radiation. Based on these data, the experts predicted that the accident ultimately may cause as many as 4,000 deaths.
Nine of the reported deaths were from thyroid cancer resulting from exposure to radioactive iodine in milk produced by cows who grazed on contaminated grass near the accident site. There were a total of about 4,000 cases of thyroid cancer, mainly in people who were children and adolescents at the time of the accident, but the ultimate survival rate among them was better than 99 percent.
The other 50 deaths occurred among plant staff and emergency workers. According to the study, approximately 1,000 on-site personnel were exposed to high levels of radiation on the first day of the accident. Subsequently, more than 200,000 emergency workers were exposed to high levels of radiation over the next several months. Medical experts predict that these exposures will ultimately cause an estimated 2,200 radiation-induced deaths. They have already noted a slight elevation in the incidence of certain forms of cancer, particularly leukemia, which would be expected from the high radiation exposures received by this group. However, because nearly 50,000 people in any population of 200,000 would be expected to die of cancers unrelated to radiation exposure, the 2,200 additional deaths will be hard to verify statistically.
With regard to the possibility of other, non-lethal effects of radiation exposure, the report states that, “Most emergency workers and people living in contaminated areas received relatively low whole body radiation doses, comparable to natural background levels. As a consequence, no evidence or likelihood of decreased fertility among the affected population has been found, nor has there been any evidence of increases in congenital malformations that can be attributed to radiation exposure.”
The study contains a particular interesting finding regarding the psychological effects of the accident on those in the vicinity. Either because of a lack of information, or because they don’t believe the information they have received, people in the affected area have an exaggerated sense of the danger to their health from radiation exposure. According to the report, this anxiety shows no signs of diminishing, and even may be growing. Their self-perceptions of being helpless victims, “ … has led either to over cautious behavior and exaggerated health concerns, or to reckless conduct, such as the consumption of mushrooms, berries and game from areas still designated as highly contaminated …”
Regarding ecological damage, the report notes that strontium and cesium contamination remain concerns. Most of these isotopes were deposited within 100 km of the Chernobyl site. Wind and rain have reduced surface contamination on open surfaces to nearly background levels, although much of that contamination was washed into surface waters as well as sewage and sludge systems. Closed lakes, which have no outflowing streams, contain fish with elevated levels of cesium that will remain high for decades, and fishing must be restricted in them. Also, “with the exception of a few areas,” radionuclide contamination of agricultural acreage has fallen to safe levels. In forested areas, high levels of radioactive cesium remain in mushrooms, berries and game, requiring some continuing restrictions on hunting.
The UN report provides certainty that those who predicted tens of thousands of casualties from Chernobyl were way off the mark. As usual, those who made these dire predictions in 1986 got the most publicity. They were wrong, as were those who predicted 10,000 casualties from Hurricane Katrina in 2005. With Katrina, the public learned the actual casualty numbers in a timely manner, and they no longer remember the 10,000 casualties predicted by the alarmists. With the Chernobyl accident it is only now, nearly 20 years after the fact, that authorities finally have an accurate estimate of how many victims there were. But the “tens of thousands victims” idea remains burned into the minds of the public. Unfortunately, the facts are not likely to be widely known because the correct, less-spectacular information is not the stuff that makes headlines – especially not 20 years later.