In Canada, scientists say tar sands oil operations in Alberta are releasing mercury that is impacting an area of more than 7,300 square miles. According to Postmedia News, mercury levels in the area are up to 16 times higher than “background” levels for the region. Mercury is a powerful neurotoxin that can cause brain damage. The Alberta tar sands are the origin point for the Keystone XL pipeline, which would bring oil to the Texas Gulf Coast.