By Jolyon Jenkins
BBC producer, The Clothes Line
Salaula stals at a Soweto market
Only a small proportion of the clothes that go to charity shops will be put on sale in this country. Most of them are bought by rag traders, sent to Africa and where they are resold. So who wins from the arrangement?
In a dusty warehouse off the sprawling Soweto market in Lusaka, Zambia's capital, Christine Mwinge is trying to come to a decision.
She's a market trader, specialising in women's jackets, and she needs to restock. A warehouse assistant has dragged two tightly wrapped 45 kilogram bales of jackets from the stores for her to inspect.
She's allowed to choose between these two, no more. But she's not allowed to open more than a tiny corner of the bales to see exactly what's inside them.
"It's a gamble, but sometimes I make jackpot," she says. Suddenly she spots something inside one of the bales. "This one I get," she announces firmly.
The bales Christine is pursuing do not contain new jackets. They are second hand, the cast-offs from the people of Mansfield. A few weeks earlier I was in Mansfield where I saw similar clothes being sorted, in a factory owned by textile exporters Savannah Rags.
The British are no longer very keen on wearing second hand clothes and so most of the garments we donate to charity shops never get put on sale in the UK. Instead, they are sold on to rag traders like Savannah Rags.
Sometimes the charities never even see the clothes, they simply sell the rag traders the right to put the charity's name and logo on the clothes recycling bins in supermarket car parks - but the bins actually belong to the traders.
Savannah Rags is owned by a Zambian businessman. "It is for the needy of Africa. We look at ourselves as Africans and the local Africans' needs are our needs," says one of his UK managers, also a Zambian.
It may be true, but the accounts for 2004 show the business was healthy enough for the three directors to receive £100,000 each.
Salaula stals at a Soweto market
Back at Soweto market, Christine's son carries the heavy bale on his head half a mile to her stall, where she opens it.
Quickly she sorts through the goods, putting them into a first class and second class pile. It's the moment of truth, when she knows whether her £40 investment will pay off, whether she has hit the jackpot, or bought a load of tat.
She tries to explain her accounting system, a complicated system of profit, stock, cash flow and the balance between the first and second class piles. But soon she spots the garment that made her buy it: a red, cotton jacket.
"I like the quality of this," she says. "I can put on a black skirt and put this one on top and match it, and I look nice."
The pile of second class jackets is bigger than the first class, but if Christine is dismayed, she doesn't show it. A crowd of women falls on Christine's pile of jackets. In Zambia, the second hand clothes are known as "salaula", a Bemba word meaning "to rummage through a pile", and a lot of rummaging goes on now.
Within moments Christine has sold a little black number to journalist Freda Mkuka Phiri for 70p. "I like it because black can mix with anything," she says.
Freda agrees to take us back to her house where she allows us to rummage, in turn, through the wardrobe of herself and her husband Cephas. Virtually everything they own is salaula. "In this house we depend on salaula, without it we would be walking naked," she says.
With the rise in Aids in Africa, there are many orphans in Zambia, and Freda and Cephas are responsible for an extended family of 17, besides their own children. Only with salaula do the household sums begin to add up.
Traders pay around £40 for bales
There is much to be said for salaula. It's affordable yet durable. It clothes everyone from cabinet ministers to street dwellers. The trade provides employment for the vast majority of Zambians who have no hope of a "proper" job in the collapsed Zambian economy. It provides an outlet for Zambian sartorial creativity.
And yet there are criticisms too. Some feel that by wearing western cast-offs, Zambians are demeaning themselves. And many believe that the flood of second hand clothes has helped destroy Zambia's own garment industry - an argument is hotly contested.
The Zambian government has looked at the profits being made by the importers and has slapped a heavy, and highly unpopular, duty on salaula. Perhaps most surprising is the fact that, just as most British people have little idea what happens to their old clothes, Zambians themselves have no real conception of where salaula comes from.
Freda reassured us that, as a Christian, she had no fears that the clothes were haunted by spirits. She was reflecting a common misconception that garments this good must have belonged to dead people - nothing else would explain why they had been discarded.
Her husband, Cephas, says he is grateful to the British. "You brothers on the other side, you also have families, but you sacrifice sending these things to Africa".
This idea, that we are giving up our own clothes to help Africans, is widespread. When we tell a seller of second hand shoes, Valerio Kamlaoewe, the truth - that the shoes are thrown out as rubbish - he is visibly shocked.
He thought a minute, then rallies and says: "Pile them up and give them to us in Africa and we will be surviving on them."
The Clothes Line will be broadcast on Tuesday 21 March at 1100 GMT on BBC Radio 4.
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