A Cautionary Tale: Tar Sands Oil and Health. Part 2

Plans to build the Keystone XL pipeline—designed to pump 35 million gallons of tar sands oil a day through the heart of America—are on hold, stalled by legal challenges about its route to Gulf Coast refineries from Canada. Yet there are very few answers to questions about the health risks involved in moving that kind of oil, as pipeline accidents in Michigan and Arkansas are demonstrating. WhoWhatWhy takes a look at those questions in the second part of a series.