Major Sources of Mercury

• Coal Fired Power Plants The large volume of coal burned every year makes this the largest source of mercury emissions in most countries.
  
• Gold Refining Old methods of refining involved the use of very large amounts of liquid mercury in the separation process and has caused severe contamination of the Amazon River Basin.
  
• Chlor-Alkali Plants Chlor-alkali plants are usually part of pulp and paper mills. Most existing (especially older) plants use mercury as one of the electrodes in the electrolysis of brine to produce chlorine gas and sodium hydroxide, two important chemicals in the paper industry.
  
• Waste Incinerators: These are a significant source, although emissions vary widely depending on the particular type of waste being burned.
  
• Battery Manufacturers: Even the newer "mercury free" batteries still contain considerable amounts of residual mercury.
  
• Fluorescent Lamps: Both the manufacture and the disposal of many types of lighting pose risks due to high mercury levels.
  
• Electrical Industry: Mercury is used in thermostats, lighting switches, relays and a host of other electrical equipment.
  
• Metals Smelting: Depending on the ore, mercury in substantial quantities may be released during initial smelting.
  
• Mercury Mining: Although the primary form of naturally occurring mercury, cinnabar (HgS) is not soluble or volatile, mercury mining generally produces large amounts of the elemental form. The world's largest cinnabar deposits are located in Spain.
  
• Petroleum Refining: Depending on the feed stock, high levels of mercury may be present in crude oil and its finished products. For example, most North American crude is quite low in mercury content, however levels in much of the crude found in Southeast Asia are relatively high. Natural gas levels generally reflect the levels of the input stock.