Mercury poisoning has been a prominent problem for the world particularly during the second half of the twentieth century. Acetaldehyde production using Mercury sulfate catalysis releases methyl mercury as a bye product. This process used by the chemical plant of the Showa electrical company caused bioaccumulation of methyl mercury in Agano river of Japan. This, in turn, resulted in two outbreaks of a neurological disease caused by mercury poisoning in Kumamoto and Niigata prefectures of Japan during the 1940s and 1950s. This disease known as Niigata Minimata disease, had also affected people who were living far away from the sites of the mercury release in the environment in the Japanese prefectures.

Mercury poisoning can be transmitted across generations. Methyl mercury is transmitted to the newborn baby through the placenta in the mother’s body. The mercury compound has degenerative effects on various systems in the body especially the nervous system. It can have damaging effects on various aspects of brain development like spatio-visual processing, fine motor skills, memory, language, attention among others. Mercury mining and production of chemicals like acetaldehyde and uses in Chlor-alkali industry have been traditional sources of methyl mercury release. With the passing decades in the industrial age, the mercury got deposited and trashed in various soils, wetlands, and aquatic ecosystems. This results in the microbial action on the mercury and its compounds which again releases methyl mercury in the environment as a bye product. Volcanoes form a prominent source of natural mercury in the environment. But the large amounts of human released mercury compounds have more closer and adverse impact on human health. The Japanese outbreaks form a point in the case.

In the landmark UN conference held at Stockholm in 1972, the issue of Minimata disease was one of the centers of attention of the delegates when it was known that a Japanese school student Shinobu Sakamoto was disabled in utero (in the womb) by mercury. In the year 2003, Governing Council of UNEP assessed and found out that there is enough evidence of the impacts of mercury on human health. Six years later, in 2009, the body built a consensus that a legally binding global instrument needs to be developed on mercury. As a result, in 2013 the Minimata convention was signed as a UN treaty for which the Secretary General of the UN became the depositary for the instrument of accession. The treaty became effective in 2017 and has 105 parties to it.

As per the 2019 report of UNEP, atmospheric concentrations of mercury have gone up by 450 % above natural levels due to anthropomorphic activities. Hence, the treaty becomes important to deal with impacts of mercury on human health. Gold extraction especially in the form of Artisanal and small scale Gold Mining also results in substantial mercury release in the environment. ASGM forms a source of multiple problems; gold smuggling through Dubai, illegally processing of gold, and mercury release in the environment as a pollutant with impacts on Human health.

The Minimata convention has set a phase-out year 2020 for various mercury containing products and demands for phase down of mercury containing dental amalgam. As an important parallel development under the Minimata convention, a funding of 45.2 million US$ was provided to eight countries with a substantial gold mining sector, through the global opportunities for long term development programme (GEF GOLD) by the global environment facility. This funding was done to phase out the use of mercury in the gold manufacturing sector in the recipient countries. The convention acts at the complex interface of science policy as the convention incorporates the various social and political aspects related to the impacts of mercury on human health and environment. The implementation of the Minimata convention is crucial with a larger geochemical ramification as the mercury cycle in intertwined with the Selenium Cycle and the Carbon Cycle.

The Article 22 of the Minimata convention incorporates effectiveness evaluation which is needed for the success of this convention. In the context of the convention, evaluation means to identify the trends of mercury pollution in various selected environmental matrices on a temporal scale. The conference of parties of the convention is responsible for deciding on the environmental matrices, which would be used for the effectivity of the Minimata convention. In the effectiveness study model under the convention, the air, seawater, soil and biota have been noted as the indicators. Regional and National biomonitoring programmes are central to collecting data on the biota mercury levels. This would be integrated on a global scale to get a statistically sound data for monitoring under the convention.

The mercury pollution problem is at its core an environmental chemistry issue. But, it is also a seafood and food security problem as well. The year of 2020 is a deadline year as per the convention in terms of ceasing of import, export, production of products which have mercury in them like lamps, pesticides, cosmetics, biocides, antiseptics, thermometers among others. If the conference of parties of the convention chalks out a mechanism of robust involvement of science, then the Minimata convention can be a major success among the UN guided actions like the Montreal protocol. In addition to the scientific rigor, the international communication and coordination are also crucial for the convention’s success, especially in the current global context which is witnessing a certain level of distrust due to the pandemic.