After a four-year slog, about 140 countries agreed on a new legally binding treaty on Saturday to control and reduce mercury use and emissions known for over a 100 years to seriously damage human health and the environment.
The treaty called the Minamata Convention on Mercury is named after the Japanese city where mercury pollution caused severe poisoning and health damage from the 1950’s onwards. It was agreed in Geneva and will open for signature at a special meeting in Japan next October.
Achim Steiner, head of the UN Environment Programme said the treaty will benefit everyone in the world, particularly “the workers and families of small-scale gold miners, the peoples of the Arctic, this generation of mothers and babies, and the generations to come.”
The World Health Organization said mercury is of global concern because it can cause many adverse health effects, including “permanent damage to the nervous system, in particular the developing nervous system”. Infants, children and mothers are especially vulnerable because mercury’s effects can be passed from a mother to her unborn child.
The treaty bans the production, export and import after 2020 of many products containing mercury, including some types of batteries, fluorescent lamps, cathodes, soaps and cosmetics, and medical devices. Mercury thermometers, blood pressure measuring devices and dental fillings using mercury amalgam will be phased down.
It also establishes a number of protective measures, including controls on mercury emissions. Almost half of mercury emissions to air are from coal-fired power plants, industrial boilers and household burning of coal. The gold boom of recent years has also caused significant growth in small-scale mining where mercury is used to separate gold from the ore-bearing rock.
Once in the environment, a form of mercury called methyl-mercury accumulates in fish and shellfish, which if eaten by a mother can affect the child in her womb. Adverse impacts happen on a baby’s growing brain and nervous system, affecting cognitive thinking, memory, attention, language, and fine motor and visual spatial skills.
Some anti-mercury activists would like to end the use of thiomersal (ethyl-mercury) as a preservative in human and animal vaccines. But the treaty leaves it untouched because the WHO says its presence in vaccines poses no health risks.
Severe mercury poisoning causes a very damaging neurological syndrome discovered in Minamata in 1956 when methylmercury entered industrial waste water and affected nearby shellfish and fish eaten by the local people and animals. The pollution continued from 1932 to 1968 and human deaths occurred for over 30 years. About 12,600 people have been officially recognized as patients affected by mercury in Japan, including about 1500 deaths.
Mercury poisoning fell off the international radar in the 1980s but was not forgotten, finally resulting in the new treaty. However, it remains to be seen how many countries will sign up formally in October and how many will take concrete actions to meet the 2020 deadline.