Scattered Sand: The story of China's rural migrants By Hsiao-Hung Pai

The painstaking journalism here offers remarkable insights into the plight of China's new citizens

"Rulers in China know about the power of those from the countryside," declares an orator close to the start of a book that takes the reader on an odyssey into a very 21st-century heart of darkness. In this meticulously researched portrait of rural migrants, the devastation is in the detail as the Taiwanese journalist Hsiao-Hung Pai tirelessly travels from bleakly beautiful desert landscapes to industrial hellholes to hear the voices of China's great anonymous workforce.

"China's history is all about how the peasantry has been burdened and oppressed," continues the orator, "and how each time they rose up to overthrow those in power. But then those new rulers would oppress the peasant masses again, until our anger could not be contained any longer and boiled over, once more, into a revolution."

The speaker is no powerful young firebrand but a frail white-haired old man called Xue, whom Pai has met with his son close to the labour market in Chengdu, capital of Sichuan. Xue has survived the murderously broken promises of the Great Leap Forward and the Cultural Revolution, only to experience disenfranchisement in old age both through his son's unemployment and the constantly looming threat of land seizure.

Though it's almost a game among economists to predict the year when China will leapfrog the US to become the world's largest economy, this year's slowing of growth has sharpened the focus on a wealth gap that has become a chasm. As Beijing prepares for its once-in-a-decade transfer of power this autumn, the Communist elite should be deeply concerned about how the multi-pronged exploitation of rural migrants could spark fresh social unrest.

It's tempting to think of Dickens's Hard Times as Pai goes from belching brick kilns to mining communities, from production-line workers' living quarters to derelict rural backwaters. But as Gerard Lemos, author of The End of the Chinese Dream, has commented, to compare China's industrial revolution with 19th-century Britain is banal – it's the uniqueness of what's happening here that should be the starting point for analysis.

Through painstaking journalism, Pai breaks down the largest human migration in history – with an estimated 200 million peasants involved –into a multiplicity of personal stories. Each is put into context with different episodes in Chinese politics. It's not just the wide range of people she accesses, but the depth of the conversations that marks this out from other works – and she puts herself in danger on more than one occasion.

For instance, when she visits a brick kiln in the Shandong province, she is accompanied by "Mr Qi", a maintenance worker who suddenly reveals he's going to demand the factory pays him six months' worth of owed wages. "Would the boss yield to our collective pressure and release the money?" she asks herself. "Or would he turn nasty and hire thugs to get rid of us – as in the stories I had heard so many times before?" In the event they are not beaten up, but nor does Qi get his money.

China's rural workers are skewered on so many levels, it's depressingly easy to understand those who urge their children to get into other countries by posing as orphans. Yet as Pai has already proved – with her first book, about Chinese labour in Britain, Chinese Whispers – life is unlikely to be easier elsewhere. Neither communism nor Deng-pioneered capitalism has helped them, and with Western companies complicit in squeezing the minimally-paid minions, the future – despite a few successful protests – looks forlorn. By far the worst story is of the peasants who contracted Aids through selling blood for money, but sadly this is just one example of their ruthless exploitation by a vampiric world.