25 years after the chernobyl disaster, fukushima may unravel health consequences of nuclear accidents in the past, present and future

On the 25th anniversary of the Chernobyl nuclear disaster, a Comment and Editorial published by Lancet Oncology describes the known health consequences of this event. The authors point out that there were many obstacles in studying the aftermath of the Chernobyl accident and that the Fukushima incident might offer a new, albeit sad, opportunity to more accurately study the health consequences of a major nuclear power plant accident. The authors attribute this to the greater scientific expertise in Japan, as well as the greater economic and political stability. The Comment is by Dr Kirsten B Moysich and Dr Philip McCarthy, Roswell Park Cancer Institute, Buffalo, NY, USA, and Dr Per Hall, Karolinska Institute, Stockholm, Sweden— who have contributed to numerous scholarly articles on this topic, including the first major United Nations Report into the effects of the Chernobyl accident in 2000.

Radioactive elements with a long half-life (the time it takes for half the sample to decay), especially Caesium and Strontium, will be prevalent in the environment for decades to come. Radioactive iodine, despite having a half-life of just 8 days, can cause damage by being absorbed into the body through food, where it is stored in the thyroid gland. An increased risk of childhood thyroid cancer of 3 to 8 times among those with the highest exposures was seen post-Chernobyl in affected areas. This has lead to recommendations to distribute potassium iodine tablets to children and adolescents in the most contaminated areas following a nuclear power plant accident. Unfortunately, no chemoprotective interventions are available for radiation exposure from caesium or strontium. The authors say: "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."

They also discuss the potential harmful effect of radiation for girls in puberty. Evidence from Japanese Life Span Study (that looked at radiation related risk factors following the atomic bombs in world war II) suggested that the highest excess risk for breast cancer was for women who were in puberty at the time of the atomic bombing. The authors say: "Another sensitive time-point is lactation at the time of the accident, when the likelihood of radionuclide absorption to the mammary tissue is high."

Dr. Moysich and colleagues conclude that the documented cancer consequences of the Chernobyl accident were restricted to thyroid cancer in children and were much lower than first expected. Due to the many issues associated with studying Chernobyl health effects, results from new studies focusing on the Fukushima incident might uncover more accurate estimates of the aftermath of nuclear power plant accidents in the past and present, as well as provide useful information for the public health management of future events.

A linked Lancet Oncology Editorial concludes: "An often overlooked aspect of nuclear disaster is the psychological burden on those affected. In 1991, an International Atomic Energy Agency study concluded that the psychological effects of the Chernobyl disaster were disproportionately large by comparison with the biological risk. According to the UN Chernobyl Forum report, the accident's largest public health effect was on mental health—an effect worsened by poor information about health risks associated with radiation exposure. The long-term consequences of events at Fukushima remain to be seen, but as Japan moves forward, clear and accessible dissemination of information is essential to ensure that adequate safeguards, monitoring, and support are provided in the years ahead."


Source: Lancet Oncology