[...] Three hundred million migrant workers have passed through the Pearl River Delta in the past twenty years and 30 million currently work there. For most of them, their factory lives are brief: after five years, factory owners are reluctant to employ someone who is judged, by then, to be worn out. Their remittances have helped to raise their distant villages out of poverty, but many have paid a terrible price for their willingness to labour. There are some sights in China I shall always remember: the young women from a battery factory, poisoned by cadmium, who pushed forward their thin haired, yellow faced little children for me to look at (they had passed on the contamination, unwittingly, to the next generation); the men who gasped for breath as they contemplated an early death from silicosis; the workers hideously mutilated by a factory fire for which they received no compensation. For the last two decades men and women like them have provided the labour that has given us cheap goods (on the shelves of Wal-Mart and elsewhere) and put fortunes into the pockets of local officials and factory owners.