I think it can be safely said that for the majority of Russians, over the greater part of recorded history, to have been born in that country has not been to draw one of the winning tickets in the lottery of life. A true history of its people need be no more than the howls of despair of millions of voices, punctuated by moments of incredible tenderness, courage and grim humour.

Which is more or less the Belarusian writer Svetlana Alexievich’s technique: her books are collections of hundreds of interviews with people who have been rolled over by the various incarnations of the Russian state. In Chernobyl Prayer each interview is usually a few pages long, and reads as a monologue – which is how they are described in the contents pages. “Monologue on how easy it is to return to dust”; “Monologue on how some completely unknown thing can worm its way into you”, and so on.

On 26 April 1986, reactor number four at the Chernobyl nuclear plant in Ukraine, then part of the Soviet Union, exploded and released 50m curies of radiation into the atmosphere, 70% of it falling on Belarus, but with plenty to spare for other countries not even vaguely adjacent. (Our dose started arriving on 1 May.)

The scale of the devastation and its insidious nature are perhaps beyond the power of the individual mind to imagine, which is one good reason why the polyphonic form Alexievich has made her own (and for which she won the Nobel prize for literature last year) is so appropriate. Only the voice of the witness can do the events justice, and, in Chernobyl Prayer, after some useful facts about the explosion and its aftermath (“travelling through the villages, one is struck by the overspill of the cemeteries”), we launch into the testimony of the widow of one of the firefighters called in to deal with the explosion. The description of his death from radiation poisoning – two weeks of increasing agony – was so harrowing that I wondered if I would be able to proceed. What kept me going was the strength of her love for her husband, and the child she was carrying; the baby seemed to absorb the radiation meant for her as it was born dead.

This is what pulls you through the book: the iterations of wisdom and bravery from its speakers. “Man is crafty only in evil, but he’s so simple and honest in his plain words of love,” says one. Another, quoting the Bolshevik slogan “with an iron fist we shall herd the human race into happiness”, calls it “the psychology of the rapist”.

Chernobyl Prayer, first published in 1997 and then revised in 2013, is part of a project collectively entitled, with some irony, “Voices from Utopia”, which Alexievich has been working on since 1985. Other volumes deal with different aspects of Russian life: from the war in Afghanistan (Zinky Boys – the title refers to the zinc coffins dead soldiers were sent back to the motherland in) to life during and after the collapse of the Soviet Union (Second-Hand Time, to be published by Fitzcarraldo Editions next month).

Alexievich’s documentary approach makes the experiences vivid, sometimes almost unbearably so – but it’s a remarkably democratic way of constructing a book. The authorial presence is invisible, except when she interviews herself on the significance of the disaster: “We cannot go on believing, like characters in a Chekhov play, that in a hundred years’ time mankind will be thriving,” she says, adding, “What lingers most in my memory of Chernobyl is life afterwards: the possessions without owners, the landscapes without people. The roads going nowhere, the cables leading nowhere ... It sometimes felt to me as if I were recording the future.”

At which point, when you consider the extent to which she has been traversing the irradiated landscape, you realise she has put herself on the line in a way very few authors ever do.

• To order Chernobyl Prayer for £7.99 (RRP £9.99) go to bookshop.theguardian.com or call 0330 333 6846. Free UK p&p over £10, online orders only. Phone orders min p&p of £1.99.