“DO YOU have a radiation meter?” asks Emilkhan Osekeeva, a family doctor, as she walks up a dirt lane called Engels Street. “The woman here died of stomach cancer,” she says, nodding at a mud-brick home on the right. “Her youngest son died of leukaemia before his 30th birthday. On the left, the mother also died of stomach cancer. Up there the woman died of uterine cancer.”

Dr Osekeeva’s 38 years practising family medicine in this idyllic-looking valley in southern Kyrgyzstan make her a cataloguer of death. Cancer rates are rising, she says, and she thinks she knows the culprit. Buried along the river in and around Mailuu-Suu, a town of some 20,000 people, lurks the poisonous legacy of the Soviet Union’s first atom bombs: 2m cubic metres of radioactive waste leaching into the water supply.

Mailuu-Suu was once closed to outsiders. Its well-paid workers were treated as members of the elite: they received perks such as handouts of beer and beach vacations in Crimea. Over the years, they mined and milled 10,000 tonnes of uranium ore into yellowcake, ready for conversion into bomb material. Uranium was also sent from as far as East Germany and Czechoslovakia to be processed here.

With the collapse of the Soviet Union and local industry in 1991, the specialists left. Supervision of the town’s 23 tailings sites—dumps containing the hazardous leftovers—became sporadic. Fences and warning signs have been looted for scrap metal (a surviving sign is pictured). Today, cows graze atop the invisible menace. Goats sleep inside an abandoned uranium mineshaft. Local dairy products and meat are often unsafe; kitchen taps spew silty river water laced with heavy metals.

The local health effects are anecdotally heartbreaking, if poorly studied. Neighbouring countries worry. The river through Mailuu-Suu is prone to earthquakes and floods. It is only about 15 miles (25km) upstream from Central Asia’s breadbasket, the Fergana Valley, which is home to over 10m people. Every few years landslides block the flow, threatening to flood the dumps and wash radionuclides over the melon patches and cornfields downstream. A European aid official warns of a “creeping environmental disaster”.

Mailuu-Suu is only a small part of the picture. Dotting hills above the Fergana—straddling the post-Soviet republics of Kyrgyzstan, Tajikistan and Uzbekistan—lie dozens of other tailings dumps (see map). Many also contain other heavy metals such as lead, arsenic and cadmium, which can be more dangerous to the body than radiation. Few are secured or monitored.

The three countries are hardly on speaking terms, so cross-border co-operation is non-existent. Secretive Tajikistan and Uzbekistan have done little to develop legislation on how to handle the waste. An official at Kyrgyzstan’s Ministry of Emergency Situations says his budget allows him to do little more than fill in holes where people have scavenged for metals. Kyrgyzstan, however, has made a little progress. Between 2010 and 2012, an $8.4m World Bank-led project moved 150,000 cubic metres of waste from one of the most accident-prone tailings dumps in Mailuu-Suu to a safer spot up the hill. But locals complain they were not briefed properly about this. They say workers stirred up radioactive dust; many claim cancers have grown more frequent since the transfer. The government is appealing to the European Union for $50m to deal with ten sites at Mailuu-Suu it says are in need of “urgent” relocation. Others estimate that even this relatively small project would cost hundreds of millions. Kyrgyz officials grumble that donors are slow to make decisions, spending millions on assessments that take years. The International Atomic Energy Agency says the landslides and flooding make Mailuu-Suu “high risk” and a top priority. But donors can be forgiven for hesitating. Corruption and inertia have eroded many government institutions in Kyrgyzstan and its neighbours.

Mailuu-Suu’s deputy mayor, Zamirbek Rasoluv, says that his town educates the community about the tailings’ dangers, in schools and through public-awareness campaigns. But awareness is little in evidence. Questioned about the government’s efforts, over a dozen residents ranging in age from 12 to 63 say they have never heard officials mention the danger. Five high-school boys say their teachers have not spoken of it either.

What little is known circulates by word of mouth. Inaccurate rumour sometimes serves only to make the threat greater. A pharmacist suggests drinking vodka to prevent getting sick from radiation—advice, no doubt, that many relish taking. Such beliefs may explain why 60-year-old Svetlana Kazaeva, born and raised in Mailuu-Suu, thinks there is no danger at all. The mines closed decades ago, she argues, so “now there is no effect”.