Before expanding nuclear power to combat climate change, we need answers to the global health effects of radioactivity
In 1986, the Soviet minister of hydrometeorology, Yuri Izrael, had a regrettable decision to make. It was his job to track radioactivity blowing from the smoking Chernobyl reactor in the hours after the 26 April explosion and deal with it. Forty-eight hours after the accident, an assistant handed him a roughly drawn map. On it, an arrow shot north-east from the nuclear power plant, and broadened to become a river of air 10 miles wide that was surging across Belarus toward Russia. If the slow-moving mass of radioactive clouds reached Moscow, where a spring storm front was piling up, millions could be harmed. Izrael’s decision was easy. Make it rain.
So that day, in a Moscow airport, technicians loaded artillery shells with silver iodide. Soviet air force pilots climbed into the cockpits of TU-16 bombers and made the easy one-hour flight to Chernobyl, where the reactor burned. The pilots circled, following the weather. They flew 30, 70, 100, 200km – chasing the inky black billows of radioactive waste. When they caught up with a cloud, they shot jets of silver iodide into it to emancipate the rain.
In the sleepy towns of southern Belarus, villagers looked up to see planes with strange yellow and grey contrails snaking across the sky. Next day, 27 April, powerful winds kicked up, cumulus clouds billowed on the horizon, and rain poured down in a deluge. The raindrops scavenged radioactive dust floating 200 metres in the air and sent it to the ground. The pilots trailed the slow-moving gaseous bulk of nuclear waste north-east beyond Gomel, into Mogilev province. Wherever pilots shot silver iodide, rain fell, along with a toxic brew of a dozen radioactive elements.
The public is often led to believe that the Chernobyl exclusion zone, a depopulated 20-mile circle around the blown plant, safely contains Chernobyl radioactivity. Tourists and journalists exploring the zone rarely realise there is a second Chernobyl zone in southern Belarus. In it, people lived for 15 years in levels of contamination as high as areas within the official zone until the area was finally abandoned, in 1999.
In believing that the Chernobyl zone safely contained the accident, we fall for the proximity trap, which holds that the closer a person is to a nuclear explosion, the more radioactivity they are exposed to. But radioactive gases follow weather patterns, moving around the globe to leave shadows of contamination in shapes that resemble tongues, kidneys, or the sharp tips of arrows.
England, for example, enjoyed clear weather for several days after the Chernobyl accident, but rain started on 2 May, 1986 and fell heavily on the Cumbrian fells – 20mm in 24 hours. On the uneven, upland terrain, radioactive fallout pooled in rivulets and puddles. The needles on radiation detectors at the Sellafield (formerly Windscale) nuclear processing plant went upwards alarmingly, 200 times higher than natural background radiation. From 5 becquerels a square metre, radiation levels in topsoil spiked to 4,000 bq/m2. Kenneth Baker, the then environment secretary, issued assurances that the radioactive isotopes would soon be washed away by rain.
Two months later, however, levels rose yet higher to 10,000 bq/m2 in Cumbria and 20,000 bq/m2 in south-western Scotland, 4,000 times higher than normal. Scientists tested sheep and found their levels of caesium-137 were 1,000 becquerels per kilogram – too high for consumption. In the midst of general anxiety, the Ministry of Agriculture, Fish and Food (MAFF) issued temporary restrictions on the sale of meat for 7,000 farms.
The Chernobyl explosions issued 45m curies of radioactive iodine into the atmosphere. Emissions from Soviet and US bomb tests amounted to 20bn curies of radioactive iodine, 500 times more. Radioactive iodine, a short lived, powerful isotope can cause thyroid disease, thyroid cancer, hormonal imbalances, problems with the GI track and autoimmune disorders.
As engineers detonated over 2,000 nuclear bombs into the atmosphere, scientists lost track of where radioactive isotopes fell and where they came from, but they caught glimpses of how readily radioactivity travelled the globe. In the 1950s, British officials detected harmful levels of radioactive caesium in imported Minnesota wheat. The wheat became radioactive from US bomb tests in Nevada, 2,500km from the Minnesota wheatfields. But over the years, scientists failed to come to an agreement on what the global distribution of radioactivity in the food chain did to human health. When the Chernobyl accident occurred, experts in radiation medicine called for a long-term epidemiological study on Chernobyl-exposed people. That study never occurred. After Fukushima, Japanese scientists said what Soviet scientists asserted after Chernobyl – we need 20 years to see what the health effects from the accident will be.
Currently, policymakers are advocating a massive expansion of nuclear power as a way to combat climate change. Before we enter a new nuclear age, the declassified Chernobyl health records raise questions that have been left unanswered about the impact of chronic low doses of radioactivity on human health. What we do know is that as fallout from bomb tests drifted down mostly in the northern hemisphere, thyroid cancer rates grew exponentially. In Europe and North America, childhood leukaemia, which used to be a medical rarity, increased in incidence year by year after 1950. Australia, hit by the fallout from British and French tests, has one of the highest incidence rates of childhood cancer worldwide. An analysis of almost 43,000 men in North America, Europe, Australia, and New Zealand, showed that sperm counts dropped 52% between 1973 and 2011.
Read more at Chernobyl’s disastrous cover-up is a warning for the next nuclear age