How can mercury enter rivers, lakes, and oceans from mining and manufacturing?

Mercury enters aquatic environments primarily through the discharge of industrial effluent and waste containing mercury compounds. In the context of mining and manufacturing, these pollutants reach rivers, lakes, and oceans through several pathways:1

• Industrial Effluent: Manufacturing plants—such as those producing chemicals, paints, pesticides, or utilizing mercury as a cathode in the production of chlorine and caustic soda—may release liquid waste directly into water bodies. A historic example is the Minamata disease outbreak, where factory discharge contaminated local seafood with methylmercury.213
• Atmospheric Deposition: Industrial processes, including mining, can release mercury vapours, fumes, and dust into the air. These contaminants can subsequently settle into water bodies.1
• Waste Disposal: Improper management of industrial byproducts or the disposal of consumer goods containing mercury can lead to the leaching of these substances into the water supply.1

Once in the water, mercury can be converted by bacteria into highly toxic methylmercury, which accumulates in aquatic organisms and enters the food chain. It is ethically imperative that industries prioritize rigorous waste management and pollution control to prevent such toxic contamination of our shared ecosystems.31