In parts of Nigeria, signs abound warning residents not to drink, swim or fish in the local waterways. Other signs warn residents to avoid drinking their own well water.
Countless oil spills over decades have destroyed fishing and farmland, and turned the once beautiful Niger Delta into a toxic wasteland.
Nevertheless, the large oil companies that extract the oil rarely, if ever, clean up the spills they leave behind. And in places like Nigeria, where the justice system is corrupt and inefficient, using the courts to force the companies to clean up is next to impossible.