Mercury Rising
Mercury accumulates high up the food chain in animals that humans consume. What is being done to safeguard our health?
Almost 60 years ago, two sisters from an idyllic stretch of Japanese coastline became the first people to be diagnosed with a painful, irreversible and stigmatized illness that became known as Minamata disease. They were two and five years old.
Minamata disease was later discovered to be a consequence of mercury poisoning. The disease was devastating, affecting the central nervous
system and causing a variety of dreadful symptoms. Loss of hearing, speech , vision and muscular coordination were common. Some victims went insane, and died within months.
The two girls, and the many who would be diagnosed after had been poisoned by methylmercury, which had been discharged into Minamata Bay by a local chemical plant. Toxic concentrations had bioaccumulated in fish and shellfish, which were then consumed by the local population. Some 20,000 people have been diagnosed with Minimata disease since the first cases were detected in the 1950s.
Unfortunately, the tragedy in Minamata was not the last of its kind. Similar events occurred in Japan, in Canada, in Iraq, and elsewhere that resulted in many more cases of Minamata disease.
Countless more around the world have suffered from other varieties of mercury poisoning.
Mercury is a naturally occurring, ubiquitous metal that has broad uses in everyday objects. It is released to the atmosphere, soil and water from a variety of sources. But it took decades for us to understand how mercury poisoning was related to what we eat, drink and breathe. How does mercury enter our environment? How does it accumulate in humans?
According to estimates, anthropogenic mercury emissions to air range anywhere from 1,000 to 4,000 tonnes per year.
Small scale and artisanal gold miners account for over a third of mercury emissions. Activities such as coal burning, cement and metals production, waste incineration, and coal burning release mercury into communities often oblivious to either its presence or its potent effects.
Those potent effects can be devastating, as described earlier. However, in addition to the impacts on individual persons, in pregnant mothers, mercury poisoning can cause irreversible health effects to fetuses.
The events in Minamata, Japan were critical to drawing public attention to impacts of mercury on our environment and human health. Part of the legacy of the tragedy is the UNEP Minamata Convention on Mercury, a global treaty that is designed to protect human health and the environment from the adverse effects of mercury and mercury compounds. 24 countries have ratified the Convention so far. When 26 more ratify, it will come into force.
Governments are meeting this week at the Dead Sea in Jordan to discuss the Convention’s implementation. Controlling the anthropogenic release of mercury throughout its lifecycle has been a key factor in shaping the obligations under the convention. The major highlights include a ban on new mercury mines, the phase-out of existing ones, the phase out of mercury in a number of products and processes, control measures on air emissions, and the international regulation of the informal sector for artisanal and small-scale gold mining.
UNEP’s Global Mercury Partnership is also working toward effective implementation of the Convention, by bringing together expertise from IGOs, NGOs and the private sector.
With this convention, governments are targeting reductions in mercury pollution to ensure the health of the environment and that of current and future generations. The engagement on this issue from all sectors of society is important to the treaty’s success. It is critical that we are all invested in ensuring another tragedy like Minamata cannot happen.
