This year, plastic pollution is the main theme of International Environment Day, celebrated on June 5.

In Africa, 4.4 million tonnes of plastic are found in oceans and seas every year, according to United Nations figures from 2010.

"Plastic, and waste management in general, is a very big problem in Africa," said Mohamed Atani, regional information officer for the UN environmental agency UNEP.

Discarded plastic is a biohazard that can take decades to degrade. But at this site in Kampala, Uganda, women clean plastic bags which are sold to a factory that recycles them into home utensils such as basins, plates and cups. Photo: AFP

"Most of the plastic disposed in the ocean comes from the daily use of single-use plastics," said Atani.

The European Union this month proposed a ban on items such as plastic straws and cutlery.

While many western nations still dole out plastic bags in supermarkets, several African countries have taken the lead and banned them entirely, such as Morocco, Rwanda and Kenya.