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.
In the immediate aftermath of the disaster, about 30 people -- mostly firefighters -- died from acute radiation poisoning. A few more died of radiation poisoning over the next decade, and in 2008, a United Nations report concluded that 6,000 thyroid cancers in young people were linked to the accident, too. (Exposure to iodine-131, which was released into the atmosphere during the accident, is known to cause thyroid cancer.)
But even after decades of study, experts are still debating the long-term health effects of the disaster. While the U.N. and other investigators have determined that there is no evidence of excess cancers resulting from the accident, others -- for instance, this blogpost from the Union of Concerned Scientists -- suggest that excess cancers and cancer deaths worldwide will number in the tens of thousands, or even higher.
Co-authors Kirsten Moysich, Philip McCarthy and Per Hall, who participated in the U.N. study that found no evidence of excess cancers, noted that there are "considerable logistical challenges in doing epidemiological research in the countries of the former Soviet Union." Researchers have little access to good health records. Potential study subjects speak a number of languages, are culturally diverse and are spread out over a large area. Today, many don't remember details of their whereabouts clearly enough to solidly assess their exposure to radiation. What's more, sufficient funding to put together a well-crafted study would be hard to secure, the authors wrote.
There's a silver lining, of sorts: the recent accident at the Fukushima Daiichi nuclear plant, the authors added, "sadly...offer[s] another opportunity to study the cancer consequences of accidents at nuclear power plants." Unlike countries of the former Soviet Union, Japan has studied the epidemiology of radiation for decades and should be able to put together new, scientifically sound investigations relative quickly, they wrote.