A recent study from the U.S. Geological Survey has found toxic levels of mercury and selenium in fish and wildlife that populate the Grand Canyon via the Colorado River. The levels would make such animals unsafe if consumed by humans.
When it comes to toxic pollution, even the Grand Canyon isn't safe.
A recent report from the U.S. Geological Survey found levels of mercury and selenium in the Grand Canyon's food chains far outpace those deemed safe for fish and wildlife.
The levels of mercury in some fish are so high that they would pose health hazards if consumed by humans.
Mercury is a
