The Use of Mercury in Gold Mining

Three countries within the region of the Guiana Shield - Guyana, French Guiana and Suriname - still rely on mercury to extract gold, clearly because such a method is cheaper compared to other alternatives such as hard rock gold mining and sluicing. Mercury contamination in the Guiana Shield can come in various forms. Examples of mercury contamination include surface water pollution as a result of runoffs from mines,[2] urban pollution as a result of amalgam burning in gold shops and transboundary pollution as a result of mercury emissions into the air and runoffs into the water. As a non-biodegradable persistent toxic substance, mercury can end up in the effluents of the Guiana Shield rivers flowing into the Caribbean.
http://efface.eu/use-mercury-gold-mining