National Public Radio: Canadian researchers have used the mud at the bottom of lakes like a time machine to show that tar sands oil production in Alberta, Canada, is polluting remote regional lakes as far as 50 miles from the operations.
An increasingly large share of U.S. oil comes from Canada's tar sands. There are environmental consequences of this development, but until recently, Canadian regional and federal governments left it to the industry to monitor these effects.
A new study follows other recent rigorous...