Mercury is a chemical element, a heavy, silvery d-block metal. It is the only metal that is liquid at standard conditions for temperature and pressure.
Small scale gold miners and small scale mining operations most often use great amounts of mercury as a processing reagent. In this amalgamation process an amalgam is formed by alloying mercury with the gold in ore sludge. The amalgam is then separated, by boiling or burning, into gold nuggets and mercury vapor. Ideally mercury vapors can be captured and condensed for reuse.
Unfortunately the vast majority of the small scale miners are unaware of safe amalgamation techniques. Through amalgamation and burning, the miners lose as much as up to 40 times the amount of mercury to the environment in relation to the extracted gold weight. It penetrates ecosystems through the air, soil and water with hazardous results.
Mercury vapors in the air have no odor but they are extremely toxic. Mercury can cause serious and permanent damage in the central and peripheral nervous systems, lungs, kidneys, skin and eyes in humans. It is also mutagenic and affects the immune system. Just one drop of mercury on a person’s skin can be fatal. A drop in a lake can make the fish poisonous to the birds, animals, and people that eat them.
Once mercury has reached surface waters or soils the microorganisms convert it to methyl mercury, a substance that can be absorbed quickly by most organisms and is known to cause nerve damage. Fish are organisms that absorb great amounts of methyl mercury from surface waters every day. As a consequence, methyl mercury can accumulate in fish and in the food chains that they are part of. The effects that mercury has on animals that consume mercury are kidney damage, stomach disruption, damage to intestines, reproductive failure and DNA alteration.
For further information on mercury and its harmful effects on health and the environment please visit the Environment Canada website.
