Concern about radiation exposure has been rising in Japan as nuclear experts struggle to contain the cores of at least three nuclear reactors and a spent nuclear fuel facility at the Fukushima Daiichi nuclear plant. Prime Minister Naoto Kan's government is at pains to calm anxiety, not only among the Japanese people, but among the international investment community and observers worldwide.
Japan has special historical causes for collective concern: A country that survived the atomic bombings of Hiroshima and Nagasaki knows what havoc radiation can mete out to the human body. But it's likely that far more Japanese have died, and will, as a result of the 9.0 March 11 earthquake and subsequent tsunamis than from the nuclear incidents at Fukushima.
Details of the Fukushima accidents remain sketchy at this writing, and it will likely be months, perhaps years, before the true scope of radiation release will be known, both in terms of which isotopes have escaped containment and at what levels. According to the International Atomic Energy Agency (IAEA), radiation levels following Monday's reactor explosion reached 100,000 microsieverts per hour, four times the maximum allowed by the IAEA, and more than 100 times the normal radiation exposure per person, per year. Even that worrying fact fails to offer guidance about human health impacts. Details regarding what types of isotopes, emitting which forms of radiation, were present in the fallout are unknown.
The Fukushima plant remains unstable, with the possibility of further radiation releases. To date, authorities have listed 190 Fukushima workers as victims of radiation sickness, the most acute form of radiation exposure that results in damage to multiple organ systems, skin burns, and usually a slow deterioration and death. As the reactors fall like dominoes, however, and if fires remain uncontained, plutonium release, explosions, and extrusion of highly radioactive, mixed-isotope steam, are a possibility, according to some physicists.
Though the fallout levels have been well above normal background radiation for Japan, they have not yet come close to those produced by the April 25, 1986, Chernobyl catastrophe in Ukraine.
How many people were exposed to fallout from Chernobyl following the meltdown? At what levels of radiation? With what sorts of long-term health outcomes?
Much of the immediate data and analysis about Chernobyl were biased by Moscow's need to downplay the incident, which occurred during the final years of Soviet power, and allay panic across the USSR and Eastern Europe. Soviet authorities insisted that fewer than ten thousand people were dangerously exposed. In contrast, authorities in post-Soviet Ukraine claimed that more than thirty-four million people in that country and nearby Belarus, Russia, and Moldova were exposed to radioactive fallout.
The chasm between these estimates has remained enormous for decades. In 2006, a multi-agency panel of UN experts estimated that two hundred thousand square miles of Eastern Europe were blanketed with fallout, five million residents of the area were exposed, and one hundred thousand people continue to receive radiation contamination from their food and environment that is above normal background levels. (See Environmental Consequences of the Chernobyl Accident and Their Remediation: Twenty Years of Experience, published by the IAEA in 2006.)
Following the Chernobyl meltdown, Pripyat City was hastily evacuated. Once the home of 135,000 nuclear workers and their families, Pripyat remains a ghost town, amid the so-called Alienation Zone located within a thirty kilometer periphery of the nuclear power plant. Though some Ukrainians stubbornly continue living in the zone, radiation levels detected in soil samples and local flora and fauna remain high, and food in the form of hunted local animals or mushrooms is still considered dangerous for human consumption. Nearly seven thousand workers still make their way to the plant every day, maintaining safety operations and ensuring that the concrete sarcophagus rapidly erected around the melted reactor core does not fail, allowing far more catastrophic radiation leakage, even explosion.
It's likely that far more Japanese have died, and will, as a result of the 9.0 March 11 earthquake and subsequent tsunamis than from the nuclear incidents at Fukushima.
Inside the Alienation Zone and north for another seventy kilometers into Russia, gamma radiation levels in soil samples exceed normal background levels by fourteen to forty-six times those found in the United States. According to the Center for Russian Environmental Policy in Moscow and its 1996 publication Consequences of the Chernobyl Catastrophe: Environmental Health, levels of plutonium-238 isotope radiation found years after the Ukrainian nuclear accident in the Russian town of St. Bobrovichi (located in the Bryansk Oblast of southwestern Russia) were eighty-nine times greater than the combined impact of all 1960 surface nuclear bomb tests (both Soviet and Western). Local fish and wildlife are heavily contaminated with radioactive cesium-137 and local biologists claim evidence of high levels of mutations in both flora and fauna.
Yet the cancer rates across the region, and in Western European countries that experienced spikes in radiation levels post-Chernobyl, never reached the terrifying proportions predicted by pundits and scientists in 1986. Yes, cancer and disease rates rose, but not to levels that endangered or killed the million or more Europeans forecast to suffer.
When I visited the region and spent time in the Alienation Zone in 1997, I found the local Ukrainian and Russian populations in the grips of two extremes: “radiophobia” and denial. The “radiophobia”--a Russian term--was a syndrome in which thousands of people across the region feared every morsel they ate, every drop they drank, and the very air their breathed, regardless of how far away from Chernobyl they resided. This level of extreme fearfulness persisted more than a decade after the accident, and was rarely connected to any real evidence for concern. By contrast, the denialists claimed all radiation concerns were mere hysteria, and continued living and working in or near the Alienation Zone, drinking the water and eating locally harvested (highly radioactive) mushrooms. Each successive administration in Kyev and Moscow has struggled to move these extremes toward a more scientifically supported middle ground.
Overall cancer rates did rise in Ukraine after 1986--including in areas that never received Chernobyl fallout--from 300 diagnosed cases per 100,000 people in 1988 to 410 per 100,000 in 1994. But these numbers are hard to interpret, as all health indicators across the region deteriorated after the 1991 fall of the Soviet Union for a host of reasons. (See “Bourgeois Physiology” in my book, Betrayal of Trust: The Collapse of Global Public Health, Hyperion 2000.)
The clearest evidence of Chernobyl impact on human health was damage to the thyroid gland, a crucial hormone-producing organ located by the esophagus, which absorbs iodine. Radioactive iodine was a key component of Chernobyl fallout, and along the path of that grim extrusion are today thousands of deaths as well as ailing adults who were children in 1986. Distribution of prophylactic iodine--which saturate the organ's receptors, blocking attachment by radioactive forms of the element--was slow under the Soviets after the Chernobyl incident. The 2006 IAEA analysis found this mistake fatal for many, because thyroid uptake of radioactive iodides was very rapid, saturating the organ within days.
Thirteen years after the Chernobyl disaster, the incidence of pediatric thyroid cancer is fifty-two times the region's pre-1986 level. In Belarus, where the fallout blew, it was 113 times higher than the country's pre-1986 diagnosed incidence of thyroid cancer. In the immediate area surrounding Chernobyl, the incidence of pediatric and adult thyroid cancer remains the highest found anywhere in the world, more than 500 times the pre-1986 levels for the region and an order of magnitude higher than anything ever seen in any other location on earth, including Hiroshima and Nagasaki. The rate of thyroid diseases--including non-cancer conditions such as Graves and Hashimoto's dysfunctions--is extraordinary. Fourteen years after the accident, thyroid diseases of various kinds were diagnosed in these Ukrainians at a rate of about one per three thousand local residents annually.
Researchers at the Institute of Experimental Physiology in Ukraine's capital, Kyev, have diagnosed a range of immune system and blood disorders among most of the estimated seven hundred thousand people who were children in 1986, exposed to significant fallout. Harvard scientists estimate the leukemia rates in this population are about 50 percent higher than what has been diagnosed among comparable Ukrainians not exposed to the fallout.
What Do These Chernobyl Lessons Teach Us About Japan 2011?
Unlike 1986 Soviet authorities, the Kan government in Japan has responded swiftly to each stage of the Fukushima disaster, has evacuated citizens rapidly from the area, and has been relatively transparent about radiation evidence as it has been collected. Aware of the dangers of both “radiophobia” public hysteria, and cavalier denialism, the government has tried to convey information that directs the Japanese people to a rational, middle ground response. Given the Fukushima catastrophe is a sideline to the earthquake and tsunami horrors, this is a remarkable feat.
Still, the human health dangers remain, not only for the workers remaining inside the Fukushima plant, but all people remaining in a roughly twenty to thirty mile periphery of the area. Until details regarding the radionuclide types and doses that have already been emitted are known, most health claims regarding the general Japanese population are pure speculation. Certainly further breaches, fires, explosions, or meltdowns in the Fukushima facility increase the probability of health problems among those directly exposed to fallout.
The Chernobyl experience teaches us that the thyroid gland is among the most vulnerable parts of the human body, but it can be protected through ingestion of iodine pills. Chernobyl also illustrates the special vulnerabilities of children, whose bodies are more likely to absorb radioactive substances into their growing tissues and bones. And Chernobyl demonstrates the wisdom of evacuation, moving tens of thousands of people away from likely fallout. Finally, Chernobyl shows that the environmental absorption of fallout results in persistent radiation that will affect plants, wildlife, soils, and water for thousands of years.