Lagos, Nigeria; and Nairobi, Kenya – Once a month, John Ebiwari drags an iron rake through the open sewer that runs in front of his house in Nigeria’s sprawling commercial capital of Lagos and scoops out the discarded plastic bags that block the flow of bubbling black filth.

On the last Saturday of each month Lagos police officers armed with big sticks make sure residents fulfill their legal duty and clean up their neighborhoods for ‘Sanitation Day.’

The clean up provides a minimum of order in Lagos. But, in a move more drastic than seen in most Western countries, several African nations are tackling the scourge by banning or restricting use of plastic bags.