Bases de données TCHERNOBYL
Documents consacrés aux anniversaires de l'accident

ADIT, juillet 2011
Tour d'horizon de magazines internationaux

Op-Ed Columnist

Chernobyl’s Lingering Scars
Published: July 11, 2011

Oddly enough, the 25th anniversary of the worst nuclear accident in history has been marked by journalism about animals. Two magazines, Wired and Harper’s, have published lengthy articles about the rebirth of animal life in the so-called exclusion zone around the Chernobyl nuclear plant in Ukraine.

Times Topic: Chernobyl Nuclear Accident (1986)

     All well and good, but given the recent Japanese nuclear accident, wouldn’t you rather know what has happened to the, er, people who were affected by Chernobyl?
     I know such a person. Her name is Maria Gawronska. Thirty years old, smart and attractive, Maria is a native of Poland who moved to New York in 2004. I met her through my fiancée maybe four years ago. She always wore a turtleneck, even on the hottest of days.
     Maria’s hometown, Olsztyn, in northern Poland, is more than 400 miles from Chernobyl. She was 5 years old in April 1986 when the reactor melted down, spewing immense amounts of radioactivity upwind, where it spread across Ukraine, Belarus and, yes, northern Poland.
     “At first,” Maria said, “they said it was an explosion but it wasn’t dangerous.” But within a few days, the Soviet Union grudgingly acknowledged the accident. Maria recalls that everyone was given iodine tablets, and told to remain indoors. She stayed in the house for the next two weeks.
     She also remembers hearing people say that it would be years before Poles knew the health consequences of the accident. Among other things, radiation can wreak havoc on the thyroid gland; that is why people take iodine tablets, to minimize the amount of radioactive iodine that their thyroids absorb.
     Sure enough, over the course of the last quarter-century, there has been an explosion of thyroid problems in Olsztyn. Maria told me that entire hospital wings are now devoted to thyroid disease. This is no exaggeration. Dr. Artur Zalewski, an Olsztyn thyroid surgeon, confirmed that his practice had seen a huge increase in thyroid operations since the early 1990s. Some people have cancerous thyroids, but many more have enlarged thyroids, or thyroids that have stopped functioning properly.
     Dr. Zalewski also cautioned me, though, that there was no scientific proof connecting thyroid disease to Chernobyl. Partly because of Soviet intransigence, and partly because of what The Lancet would describe as “considerable logistical challenges,” epidemiological studies were never begun that might have helped link the disaster to Poland’s thyroid problems.
     The studies that have been done have focused on cancer. According to The Lancet, it is possible that increases in childhood leukemia and breast cancer in Belarus and Ukraine can be attributed to Chernobyl. But because of “flawed study design,” these studies are not definitive.
     When I e-mailed Maria’s mother, Barbara Gawronska-Kozak, however, she was adamant: “I am convinced that Chernobyl increased thyroid problems.” Barbara, a scientist herself (though not an epidemiologist), told me that this was what the “average citizen of Poland” believed. She herself required a thyroid operation a decade after the accident. Her mother had two thyroid operations. Her best friend had a thyroid operation. An old high school friend recently had a goiter removed. Maria told me that her father was the only family member who had not had a thyroid problem.
     Around five years ago, it was Maria’s turn. Gradually, her thyroid become so enlarged that it impinged on her trachea, making it hard to breathe in certain positions. The unsightly growth, of course, was why she always wore a turtleneck. A specialist in New York told her that he had never seen anything quite like it, and that the operation to correct it was high risk and could possibly damage her vocal cords. So Maria decided to return to Poland and have the operation in her hometown. She did so earlier this year.
     Just as in Chernobyl’s case, it will be years before we know how the accident at the Fukushima Daiichi Nuclear Power Station will affect the health of those who lived nearby. Although much less radiation escaped, it did leak into the water, and traces have been found in the food supply. It makes one wonder how to deal with nuclear power, which offers the tantalizing prospect of clean energy — along with the ever-present risk of disaster should something go wrong. These are not simple questions — as we are reminded whenever there is an accident like Fukushima Daiichi. Or Chernobyl.
     For Maria, at least, the story ends happily. Dr. Zalewski, who operated on her, didn’t flinch when he saw the size of her thyroid. The operation was a success. Her vocal cords are just fine. She has more energy than she has had in years.
     Maria told me that while she was in Olsztyn, she sought out old friends. As soon as they heard why she had returned, she said, “They all laughed and pointed to their own scars.”
     When I saw her not long after she returned to New York, I couldn’t help noticing her own small scar. She wasn’t wearing a turtleneck.
     A version of this op-ed appeared in print on July 12, 2011, on page A23 of the New York edition with the headline: Chernobyl’s Lingering Scars.

A voir :

Is Chernobyl a Wild Kingdom or a Radioactive Den of Decay?

By Adam Higginbotham
April 14, 2011
2:52 am
Wired May 2011

Life in the zone:
What we're still learning from Chernobyl

By Steve Featherstone

BOOSTER SHOTS: Oddities, musings and news from the health world

April 26, 2011 |By Eryn Brown, Los Angeles Times
     Twenty-five years ago Tuesday, a catastrophic explosion at the Chernobyl power plant in Ukraine spewed nuclear fuel into the air.  Over 20 days, radioactive smoke and other products emanated from the plant, spreading out over parts of Russia, Ukraine and Belarus and extending, in lower concentrations, around the world.
The Lancet Oncology, Volume 12, Issue 5, Pages 416 - 418, May 2011
doi:10.1016/S1470-2045(11)70095-XCite or Link Using DOI
Published Online: 26 April 2011

25 years after Chernobyl: lessons for Japan?

Kirsten B Moysich, Philip McCarthy a, Per Hall b

     On April 25, 1986, operators shut down unit 4 of the power plant at Chernobyl, in the former Soviet Union, to test the emergency power system in the event of power loss. The nuclear reactor—a different type than those damaged in the recent tsunami in Japan—was a graphite-moderated light water reactor that is now considered obsolete for use, although it still remains in use in some parts of the former Soviet Union. As with most nuclear power plants, uranium fission led to thermal generation, heating water to provide steam for electricity generation. However, because of the test of the backup system, the water that was used to cool the reactor was lost, resulting in overheating, a power surge and steam explosion, and destruction of the reactor core at 0123 h on April 26, 1986.

     Unlike the reactors in Japan, the Chernobyl reactor was not in a reinforced shell, and the roof of the power plant essentially blew up. This explosion released tonnes of nuclear fuel (about 8—180 metric tonnes) and fission products (3—9 billion Ci) into the air, which were then blown northwest by the winds. The exact quantities of released products might never be known because of insufficient dosimetry calculations within the first several days after the accident. Several workers were immediately killed in the explosion, and 100 firefighters received extensive radiation exposure when putting out the fire. The graphite in the reactor burned for 10 days and substantial radiation was released for about 20 days. 100—200 workers were diagnosed with acute radiation syndrome with about 30 dying early and another 14 dying over the next 10 years.
     The major radionuclides released during the accident were radioactive iodine (131I) and caesium (134Cs and 137Cs), and, to a lesser extent, radioactive strontium (89Sr and 90Sr) and plutonium (234Pu). The half-life of 131I is 8 days, therefore, after contaminating the food chain, dissipated fairly soon. However, radioactive caesium products have half-lives between 2 years and 30 years and continue to contaminate large areas around Chernobyl. Strontium has a half-life ranging between 52 days and 28 years, with the same issues of prolonged contamination as caesium. Plutonium has a half-life of 24 400 years. 400 times more radioactivity was released from the Chernobyl power plant than from the Hiroshima atomic bomb; by contrast, the atomic weapons testing of the 1950s and 1960s released about 100—1000 times more than the Chernobyl accident. The areas most affected by the Chernobyl release were Russia, Ukraine, and Belarus; however, other European countries and the rest of the world received some exposure, albeit at lower levels than the regions surrounding Chernobyl.
     More than 800.000 personnel were involved in the clean up, and more than 200.000 workers received varying degrees of exposure, as did about 100.000 evacuees. 270.000 people in the most contaminated areas received small to moderate doses of radiation (about 5—500 mSv). In comparison, a chest radiograph exposes a person to 0,1 mSv, whereas a CT scan of the chest results in exposure to 6—18 mSv. Direct comparisons of the doses are difficult because the harmful effects from ingested radionuclides that expose a person for several days are different to exposure from split-second external gamma beams.
     After the Chernobyl accident, many scientific papers reported the cancer consequences of the event. We participated in writing the first major UN report[1] about the effects of the accident and, in 2002, summarised the existing published work.[2] We concluded that, with the exception of thyroid cancer in young people, there was no strong evidence to suggest that excess cancer incidence was substantial in the aftermath of the accident. Several investigators have shared this conclusion.[3] In this Comment, we aim to emphasise several studies that show the complexities faced when the health consequences of the Chernobyl accident are studied. Two subsequent studies[4, 5]—which provided evidence associating Chernobyl-related radiation and thyroid cancer in children—used population-based, case—control study designs, collated detailed information for individual dosimetry, and used thoughtful and sophisticated statistical approaches. Combined with past evidence, results from these studies leave little doubt that excess childhood thyroid cancer is a result of the accident. These findings should influence the decision to implement potassium iodine supplementation if similar scenarios should occur in the future.
     Although we published work in 2005[6] that reported a possible increase in childhood leukaemia in Belarus, Ukraine, and Russia, we acknowledged that most of the controls were selected from regions that were largely unaffected by the accident, which led to significant associations that were not biologically plausible. This scenario shows the considerable logistical challenges in doing epidemiological research in countries of the former Soviet Union. Little expertise in chronic epidemiology at the time, language barriers, cultural differences, and the daily challenges in covering a very large study area were probable contributors to the flawed study design. Furthermore, an increase in rates of breast cancer was reported in Belarus and Ukraine.[7] Although this study[7] used a descriptive design, dose estimates were calculated on the basis of local contamination data. Ideally, this study should be followed up with an analytical epidemiological study focusing on women who were in puberty at the time of the accident.
     Data from the Japanese Life Span Study[8] suggested that the highest excess risk was for women who were in puberty at the time of the atomic bombing. Another sensitive time-point is lactation at the time of the accident, when the likelihood of radionuclide absorption to the mammary tissue is high. Despite the scientific interest and biological plausibility, there are several serious threats to the feasibility of such an investigation in the most affected regions. Unless government sponsored, to secure funding for a project of this scope will be a great challenge. Another issue is the collection of valid dosimetry data for dose reconstruction 25 years after the accident—eg, women might be unable to recall personal behaviour and food consumption during the crucial window of time. Another area of investigation would be risk of lung cancer. However, as for a study of breast cancer, substantial logistical challenges threaten the feasibility and validity of such investigations. Additionally, the separation of any radiation effects from the overwhelming influence of tobacco exposure in the development of lung cancer might not be possible.
     Much is still unknown about the extent to which human error was involved into the recent accident at the Fukushima nuclear power plant in Japan. The inability to anticipate and react to the loss of power to cooling systems seems to have resulted in severe damage to the nuclear core, with release of radionuclides as seen in the Chernobyl accident. Aggressive efforts will be needed to limit exposure to radioactive iodine and caesium, and to isolate contaminated areas. In particular, children and young adults are at highest risk because of past data showing that exposure at young ages increases the risk of adverse health effects such as thyroid cancer.
     Sadly, the ongoing events in Japan might offer another opportunity to study the cancer consequences of accidents at nuclear power plants. Although Japan is facing many challenges in the aftermath of three simultaneously occurring disasters, the country's long history in epidemiological research of radiation might place it in a better position to study the consequences of the nuclear power plant accident and to implement research investigations in a shorter timeframe than can other countries with less experience. Unlike the former Soviet Union, Japan is a more open society and did not attempt to hide the radiation release from its citizens. Japan is also a politically and economically stable society. Major challenges in doing valid research after the Chernobyl accident were associated with the political instability after the collapse of the former Soviet Union in 1991 and with the scarcity of funding from the new independent countries that were most affected by the accident.
     However, in Japan, the political, economical, and scientific environment should allow for comprehensive investigations of the health consequences of a major accident at a nuclear power plant. Findings from such studies should be useful in informing the public about expectations of these health effects, and should guide public health officials in implementing an effective medical response.

The authors declared no conflicts of interest.

References below

1. UN Scientific Committee on the Effects of Atomic Radiation. UNSCEAR 2000 report, vol 1: sources and effects of ionizing radiation. (accessed April 13, 2011).
2. Moysich KB, Menezes RJ, Michalek AM. Chernobyl-related ionising radiation exposure and cancer risk: an epidemiological review. Lancet Oncol 2002; 3: 269-279. Summary | Full Text | PDF(471KB) | CrossRef | PubMed
3. Cardis E, Howe G, Ron E, et al. Cancer consequences of the Chernobyl accident: 20 years on. J Radiol Prot 2006; 26: 127-140. CrossRef | PubMed
4. Cardis E, Kesminiene A, Ivanov V, et al. Risk of thyroid cancer after exposure to 131I in childhood. J Natl Cancer Inst 2005; 97: 724-732. CrossRef | PubMed
5. Kopecky KJ, Stepanenko V, Rivkind N, et al. Childhood thyroid cancer, radiation dose from Chernobyl, and dose uncertainties in Bryansk Oblast, Russia: a population-based case-control study. Radiat Res 2006; 166: 367-374. CrossRef | PubMed
6. Davis S, Day RW, Kopecky KJ, et alfor the International Consortium for Research on the Health Effects of Radiation Writing Committee and Study Team. Childhood leukaemia in Belarus, Russia, and Ukraine following the Chernobyl power station accident: results from an international collaborative population-based case-control study. Int J Epidemiol 2006; 35: 386-396. CrossRef | PubMed
7. Pukkala E, Kesminiene A, Poliakov S, et al. Breast cancer in Belarus and Ukraine after the Chernobyl accident. Int J Cancer 2006; 119: 651-658. CrossRef | PubMed
8. Radiation Effects Research Foundation. (accessed April 13, 2011).
a Roswell Park Cancer Institute, Buffalo, NY 14263, USA
b Karolinska Institute, Stockholm, Sweden