They've become as much a symbol of Africa's landscape as the stereotypical lions and plains.

Discarded plastic bags -- in the billions -- flutter from thorn-bushes across the continent, and clog up cities from Cape Town to Casablanca.

South Africa was once producing 7 billion bags a year; Somaliland residents became so used to them they re-named them flowers of Hargeisa after their capital; and Kenya not so long ago churned out about 4,000 tonnes of polythene bags a month.

They're an eyesore across Africa, but there are damaging health and environment ... too, said the U.N. Environment Programme's (UNEP) Africa industry officer Desta Mebratu.

Produced -- and then strewn -- en masse in most countries, the flimsy bags block drains and sewage systems and can kill livestock who nibble and digest them.

They spread malaria by holding mini-pools of warm water for mosquitoes to breed in. They choke soil and plants, and leak color additives into food.

The phenomenon began in the late 1990s when new technology made production cheap and easy. The consequent throw-away culture meant plastic bags quickly became an ugly but integral part of the African landscape.

Now UNEP and other concerned bodies are spearheading a fast-growing campaign to contain the menace.

Their emphasis is not just on curbing production, but also promoting re-use of bags, and recycling of plastic waste.

The plastic problem is now on the agenda of almost every African country, Mebratu, an Ethiopian, said at his office in a U.N. compound in Nairobi. The major focus is to promote rational use and disposal of plastic bags.

Rwanda and Eritrea have already banned the bags outright, the United Nations says. Go to the airport in Kigali and if you have a plastic bag, they will confiscate it, Mebratu said.

Somaliland, an autonomous and self-declared independent region of Somalia, has taken a similarly draconian measure.

Larger countries such as South Africa, Uganda and Kenya have introduced minimum thickness rules, while Ethiopia, Ghana, Lesotho and Tanzania are considering such measures too.

Some nations are also slapping levies on plastic bag production to ensure consumers re-use rather than trash them.

Senegal and Egypt get high marks for their recycling initiatives, Mebratu said.

We are very much encouraged by what is happening, but there is a long way to go still. Anyone can see that.

BINS AND BANANAS

Not surprisingly, African manufacturers do not believe in drastic measures or high taxes on plastic bags, but rather a culture change among consumers.

Instead of punishing producers, they say, users should be better educated on disposal, re-use and recycling to prevent mass dumping of plastic bags.

Manufacturers want to help clean the environment, Bimal Kantaria, a board member of the Kenya Association of Manufacturers, told Reuters.

But we want to do so effectively and target the problem, which is irresponsible disposal. We in the industry understand there is a problem with plastic bags polluting the environment. However an excise tax is hard to collect and easy to evade.

Kantaria proposed a moderate green levy tax on the imported raw materials to raise funds for a new body charged with public awareness campaigns.

Some street-sellers have a simpler idea.

John Kihui, chairman of Kenya's national hawkers' association, said merely providing more litter bins would solve 70 percent of the problem.

That is what has removed plastic and other litter from Nairobi city centre where today bins stand at strategic places and people no longer toss refuse carelessly, he told the local Standard newspaper.

Impact? A positive behavior change without necessarily punishing the people.

Ugandan officials meanwhile have a back-to-basics message for their people -- instead of plastic bags, use banana leaves.

(Additional reporting by Nico Gnecchi in Nairobi)

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