91av

The village of Satlykovo, just east of the Ural mountains in Russia, is no more. The main street is knee-high in nettles, its houses bulldozed. All around, the land is blooming. Nearby forests harbour elk and wild boar. The lake is home to radioactive carp.

One morning 59 years ago, soldiers came and ordered the villagers to leave. “Their cattle were destroyed and buried, and they could not even take with them the clothes they stood up in,” says Islam Bagautdinov, who has driven me here through military checkpoints.

There were no explanations. The troops didn’t say that there had been an explosion at a factory a few kilometres away; or that the blast had propelled radioactive dust into the air, forming a deadly plume that rained out across Satlykovo and the surrounding countryside. The very existence of the Mayak complex, where weapons-grade plutonium was made, was a military secret.

Over the next 600 days, thousands of bemused people from Satlykovo and 22 nearby villages were evacuated, 20,000 hectares of farmland was put out of use and a permanent exclusion zone was created. Barring a few in the CIA, nobody in the outside world would know of it for two decades.

Through this long period of secrecy, Soviet researchers surreptitiously collected data on the villagers and their children. Now under analysis by Western and Russian researchers, this data is offering new insights into the ways chronic exposure to radiation affects health.

“Waste was just thrown in [the river]. We were in a race to make bombs”

In November 1976, Soviet dissident Zhores Medvedev wrote about the Mayak disaster in 91av and the secret was out, to the Western world at least. The Soviet public was not told until the era of glasnost, or openness, in the late 1980s. Only then did the evacuees, by now spread across the Soviet Union, learn about their radiation exposure.

This summer, I became the first Western journalist to visit the Mayak evacuation zone, a fenced-off 100-square-kilometre area known as the East Ural State Reserve. These days, radiation in the air is barely above background levels in most areas, but higher concentrations lurk in the soil and vegetation. “The only way to get a significant dose here now would be to eat large amounts of berries and mushrooms,” says Oleg Tarasov, chief wildlife researcher in the reserve.

The ban on people living in the exclusion zone is likely to remain for at least another hundred years, says Yuri Mokrov, ecology chief at the state-owned Mayak Production Association, which still runs the complex. Mayak remains a central part of the Russian nuclear industry, these days focused on waste management and reprocessing.

Nature has prospered in the absence of humans, much as it has in the exclusion zone around the Chernobyl disaster site in Ukraine. The reserve contains more than 200 species of birds and 455 species of plants, including locally rare species like lady’s slipper orchids.

“The biodiversity is better than in other reserves in the Urals,” Tarasov told me as we drove down bumpy tracks. “There are lots of elk, boars, foxes and hares. They understand they won’t be hunted, so they come and they reproduce much better than elsewhere. Small mammals like moles and voles that are closely connected to the ground get much higher radiation doses and are more affected. We find some genetic abnormalities.”

“Waste was just thrown in”

The 1957 accident was just one of a series of major radioactive releases from Mayak at the height of the cold war (see “A catalogue of calamities”, below). The most damaging of these wasn’t even an accident. For years after the plant opened in 1949, waste water was poured into the Techa river, which became easily the most radioactive in the world. “Waste was just thrown in. We were in a race to build bombs – there was no time to do anything else,” says Sergey Romanov of the Southern Urals Biophysics Institute, based in the closed town of Ozersk a few kilometres from the plant.

Official estimates put the total release into the river between 1949 and 1956 at 100 petabecquerels, making it the third largest nuclear disaster after Chernobyl and Fukushima. About a quarter of this was strontium-90 and caesium-137, isotopes with half-lives of around 30 years. William Standring of the Norwegian Radiation Protection Authority, who has reviewed the data, says it caused severe contamination down the entire length of the Techa river, including its extensive floodplain.

“The health of 52,000 people was tracked for decades, secretly at first”

Thousands of villagers downstream drank the river’s water, ate its fish and wildfowl, swam in its waters and let their cattle graze its meadows. In 1951, restrictions were introduced. Given no explanation, local people mostly ignored them. Fences went up along the floodplain in 1956, and little by little some 10,000 people living in 19 riverside villages – some of them 100 kilometres downstream of the plant – were evacuated. Homes were bulldozed to prevent anyone returning, and the villages were removed from official maps. These removals would later become a model for emptying villages hit by the 1957 explosion.

The village that remained

Not everyone was moved. One of the most contaminated riverside villages, Muslyumovo, remained inhabited until a decade ago. We visited the its new location, out of harm’s way on higher ground above the river. Many say they and their children suffer diseases caused by radiation exposure. Nazhiya Akhmadeyeva was born in old Muslyumovo in 1961. She has two sons. One was born with a twisted spine and epilepsy attributed by a government expert committee to radiation; the other with hydrocephalus, an excess of brain cerebrospinal fluid which has left him with severe intellectual disability.

Villagers say that some of Muslyumovo’s men were employed in the 1950s to stand guard on the riverbank and stop people going too close. Many died young. Others tell how the radioactive village briefly became a news story in the early 1990s after a visit by Boris Yeltsin, Russia’s president, and how local youths would charge journalists $20 to photograph them swimming in the river.

Some residents have their own theory as to why they were left in the floodplain for five decades. They are Bashkir people of Asiatic ancestry, and say that many fellow Russians of European descent look down on them. They think they were used as guinea pigs. Mokrov dismisses this idea, but has nothing more certain to offer. “Maybe the scientists testing the water came on a day when levels were low,” he suggests.

Later, there was a third major release of radioactivity. Starting in the late 1950s, engineers had begun building a cascade of dams on the Techa. Radioactive waste was dumped into swampy reservoirs upstream of the dams and allowed to settle out into the sediment instead of flowing downstream. In 1967, one of the reservoirs, Lake Karachay, briefly dried out. The radioactive sediments on its exposed bed were whipped up by strong winds and fell to earth downwind.

The lake remained the most radioactive body of water in the world until late last year, when it was finally emptied and concreted over. Now an underground plume of radioactive water extends for 10 square kilometres.

A chilling ‘experiment’

The catalogue of disasters at Mayak is testimony to the sacrifice of human life as Soviet bomb-makers sought to keep up with the US in the cold war arms race. But the story also reveals the remarkable and chilling ability of Soviet medical researchers to secretly monitor the tens of thousands of people who had unwittingly been exposed to very high doses of radioactivity. Starting in 1951, teams headed out to villages to find signs of radiation-related sickness. Later, they tracked down evacuees to log their illnesses and deaths.

Alexander Akleyev is director of the Urals Research Centre for Radiation Medicine (URCRM) in Chelyabinsk, the regional capital. His organisation has been monitoring the people affected by the events at Mayak since the early 1950s. He says that initially, even scientists only dimly appreciated the dangers posed by the contamination of the Techa river. “In the 1950s, humanity did not know about possible effects of chronic radiation exposure,” he told me. “No emergency programmes were developed that could allow quick decisions to protect the population.”

Over the decades, researchers at the URCRM have followed two main groups of villagers: 30,000 people exposed to radioactivity in the Techa river, and 22,000 exposed to the fallout from the 1957 explosion. Around 1500 people fall into both groups: evacuated from the river in 1956, they once again came into harm’s way beneath the 1957 fallout.

If children drank milk from cows grazed on the river floodplain, the URCRM knew about it. If villages hunted waterfowl, that too was recorded. At the URCRM’s Chelyabinsk headquarters, I spoke to Ludmila Krestinina, who leads its epidemiologists. She said the villagers’ exposure has been calculated in detail and correlated with their health data.

According to Krestinina’s colleague Dmitriy Burmistrov, one hour wandering near the river was at times enough to provide a radiation dose comparable with the maximum annual allowable dose for radiation workers. This kind of sustained exposure was unprecedented, and has had severe consequences. The villagers downstream of Mayak are the only people in the world outside nuclear plants ever to be diagnosed with chronic radiation sickness. Like everything else, that diagnosis was kept hidden from them until the 1990s.

Chronic radiation sickness

The condition is less severe than acute radiation sickness, which affects people immediately after exposure to a massive burst of radiation, but can cause long-term illness. It is characterised by extremely low haemoglobin levels in the blood, a range of neurological and immune-system disorders, fatigue, sleep disorders, loss of muscle control, disturbances to the digestive system and bone pain. The long-term data show that cases peaked in 1955 and 1956. By 1960, some 940 people had been diagnosed, some in villages 100 kilometres downstream. They included almost two-thirds of Metlino villagers, who lived on the Techa before their village was moved to a new location within the 1957 fallout zone.

People began to recover from many, if not all, of their symptoms between three months and a year after they moved out of the zone. But the data also suggest that chronic exposure to higher doses of radioactivity can lead to some irreversible damage. Bone disease, particularly of the spine, was a common long-term symptom.

Typically, chronic radiation sickness declared itself around five years after first exposure. Other consequences emerged later: during the 1970s, an excess of leukaemia and cancer started to show up among the evacuated villagers. In 2013, a team of epidemiologists led by Krestinina and Faith Davis at the University of Alberta in Canada concluded that radiation had nearly doubled the risk of leukaemia among Techa riverside residents. Perhaps unsurprisingly perhaps, the people of Muslyumovo, who lived on the polluted Techa floodplain for almost 60 years, have both the highest levels of strontium in their bodies and the highest levels of chromosomal damage.

Krestinina is now following more than 30,000 children born to villagers who were exposed to radiation. She is looking for genetic effects cascading down the generations, and the impact of radiation received while still in the womb. Reassuringly, similar studies have so far found no sign of such effects, but Krestinina says it is too soon to say for certain. “Within 10 or 15 years, we should know if we can see an effect in causes of death among this next generation,” she told me.

Recently, Western epidemiologists have begun studying the data too. Information from Chernobyl victims is much less complete, and survivors of the 1945 atomic bombs at Hiroshima and Nagasaki reveal the effects of a single blast of radiation, not lower doses over years.

Findings are feeding into the rules for running nuclear facilities. is a US-based biostatistician who has studied radiation and health data for over three decades. He says nuclear industry researchers have begun arguing that low doses of radiation received over long periods may cause much less illness than equivalent doses in a short burst. As a result, the industry has called for occupational exposure limits to be relaxed. The Mayak records undermine that theory, says Preston. There is, he says, “no evidence of a reduction in effect at low doses”. On the contrary, he argues that the findings unequivocally show for the first time that being exposed to low doses of radioactivity increases your risk of a variety of cancers, including leukaemia. Moreover, the increased risk of cancer doesn’t go away if chronic exposure is reduced or eliminated.

Other researchers are re-examining the data on thyroid cancers resulting from releases of radioactive iodine at Mayak. This work could help resolve a huge debate in Japan over whether an apparent surge in thyroid cancers around the Fukushima nuclear plant is a result of radiation from the 2011 accident, or whether doctors have simply documented cases that would otherwise have gone unnoticed.

Plutonium risk

The villagers along the Techa are not the only victims of the local nuclear industry. Epidemiologists at the Southern Urals Biophysics Institute have monitored two further groups: workers at the Mayak plutonium factories, including those exposed to the 1957 explosion, and the population of neighbouring Ozersk, where 100,000 people live close to the nuclear plants and 15,000 continue to work in them.

The Southern Urals Biophysics Institute was set up in 1952 after an epidemic of diseases was linked to radiation at the Mayak plant. Its current director, Sergey Romanov, told me that in those days, health and safety concerns were minimal. “Until 1955, even pregnant women worked on plutonium production,” he says.

Between 1948 and 1972, breathing in mists of plutonium was an occupational hazard. “Nowhere in the world had exposure like this,” says Romanov. The 18,000 people who were working there at the time, says Romanov, are “the only adequate human data for evaluating cancer risks from exposure to plutonium”. It is blamed for 239 deaths from lung, liver and bone cancers up to 2003, representing a tenth of lung cancers and almost half of bone-cancer deaths among the workforce.

Where do things stand today?

About 4000 people still live along the Techa. Many of the fences erected to keep them away from the river are down, and warning signs have disappeared. There have been further radioactive discharges. In 2006, Mayak’s chief executive Vitaly Sadovnikov left the company after a local court learned that he had allowed strontium-90 into the river in the early 2000s. He wasn’t convicted, , but a court document reveals that the discharges raised radioactivity in the river beyond legal limits at several villages downstream. One of them was Muslyumovo, where people were still drinking the river water.

Some of the radioactivity that flowed down the Techa in the 1950s still remains on its bed, smeared across its extensive floodplain and secreted in marshes, ready to be washed back into the river by floods and carried downstream. “The contamination is redistributing all the time,” says Svetlana Kostina, the deputy-head of environmental matters for the Chelyabinsk region. She says the restrictions on access to the floodplain are being reassessed but many will have to remain for generations to come.

“People do now understand that they are inhabiting a contaminated area, but still fish and swim in the river and have ducks and geese for food,” wrote Galina Tryapitsyna of the URCRM in a report to an international workshop last year. Some communities drink contaminated water and milk from cattle that eat hay mowed from the floodplain. Even far downstream, anglers may be hooking contaminated fish that have migrated from near the plant.

Just a few hundred metres from the gates to the exclusion zone, one house remains occupied. It belongs to the family of Tarasov, and our party picnicked there before heading into the forbidden area. “This place is quite safe in terms of radiation, despite its closeness to the exclusion zone,” insists Tarasov. “The fruit and vegetables that we grow in the garden do not contain an increased number of radionuclides. Nor do the mushrooms and berries in the forest around the house. They can be eaten without any limitations. This has been verified by our laboratory.”

He has no fears for his family as a result of the radiation next door. Provided they remain outside the exclusion zone itself, they are safe, he says. “The main actual danger here is not radiation but the ticks. They carry encephalitis and their bite can cause severe illness. But the radiation we don’t worry about.”