Vox: In 2006, Canadian doctor John OConnor made a startling realization. Specialists had diagnosed three of his patients in the northern Alberta village of Fort Chipewyan with cholangiocarcinoma -- a deadly cancer of the bile duct. The same cancer had killed his own father years earlier in Ireland.
Only about one in 100,000 Canadians contracts this type of cancer, so the likelihood of three cases in a town of about 950 was minuscule. OConnor suspected pollution from Albertas tar sands, 100 miles...