Lack of access to clean water is a factor in the spread of cholera.
Tony Karumba/AFP via Getty Images
Nigeria is prone to a variety of factors that lead to recurring cholera outbreaks.
Sewage spills highlight the urgent need to upgrade the UK’s ageing sewer network.
Jory Mundy/Alamy
The UK’s Victorian-era sewer network is at breaking point.
A sewer overflow maintained by United Utilities that flows into the River Tame in Greater Manchester.
Jamie Woodward
Thames Water has mapped its discharges in near real time. But we still need data on the volume of sewage dumped in rivers.
Surfers Against Sewage
These maps have gone viral – here’s what they owe to 19th century cholera campaigns.
The River Thames is one of the cleanest major world rivers.
Pxfuel
Cleaning and reoxygenating the river Thames has helped its biodiversity surge, but there’s still more to be done to make it healthy.