NicolasWelch7467 NicolasWelch7467 04-06-2020 Biology contestada High levels of mercury contamination have entered the aquatic ecosystem primarily through: a Medications like vaccines which contain mercury and subsequently enter the drainage systems through human waste. b Emissions from coal burning power plants which then rain down on waterways. c Merurcury solutions which are used in plastic production and then disposed of through waste water. d Paper productions which uses mercury in a bleaching process to whiten the paper.