Swimming in urban waterways across the world should be a right, say campaigners

Swimmable Cities summit in Rotterdam wants to change cleanliness of waterways and people's relationship to them

Swimming in urban waterways should be a right, activists have said, as an international alliance aims to persuade politicians to clean up rivers so they can be used safely by their citizens.

At the world's first Swimmable Cities summit in Rotterdam, more than 200 representatives from more than 20 countries gathered and plunged into the water.