Weaning the world off mercury

Mercury hazard waste disposal on an oil rig. (Credit: Shutterstock/Kengseraph)

Delegates from around the world met in Bali this week to tackle the persistent problem of mercury poisoning.  The Minamata Convention is meeting for the fourth time since it entered into force in 2017, in its first physical meeting outside of Geneva.

High on this session’s agenda is expanding the list of mercury-containing products for phase out, discussing thresholds for mercury waste, and requiring national plans for the reduction – ideally the elimination – of mercury in artisanal and small-scale gold mining (ASGM).  Another priority is gender equality, with around four to five million women and children employed in ASGM.

Updated guidelines on the use of mercury in the ASGM sector are expected on Friday. So is an agreement on a timeline for eliminating dental amalgam and other products. Further talks on improving the indicators for measuring how effectively the convention is being applied are also expected.

Why it matters

In the 1950s and 1960s, people living near the Japanese city of Minamata along the Yatsushiro Sea began experiencing muscle weakness, loss of peripheral vision, and impairment of hearing, speech, and movement. Many children were born with birth defects.

The cause was mercury waste from the acetaldehyde-producing company Chisso. The waste flowed into the sea and contaminated fish and shellfish – staples of coastal cuisine. Mercury is a catalyst for making acetaldehyde, which is used in vinegar, disinfectants, drugs, and perfumes. The exposure lasted from 1932 to 1968 and has harmed more than 2,000 people.

Shinobu Sakamoto, a woman living with fetal Minamata disease, at the Convention's first meeting in 2017. (Credit: IISD/ENB Kiara Worth)

Very little mercury is needed to cause harm. High-levels of mercury poisoning can kill. Increased global awareness around the toxic chemical came with the publication of a 1996 study on Faroe islanders whose diet included whale. The mercury in whales harmed the health of newborns whose mothers ate whale during pregnancy.

“The study shows that most likely, there’s no lower threshold of when Mercury can do damage to us,” explains Jakob Maag, senior expert on mercury at the United Nations Institute for Training and Research’s (UNITAR) Chemicals and Waste Management unit.

Everyone is exposed to mercury. It is found in the earth’s crust and can be released through mining. It is released into the air by metal and cement production and the burning of waste. Many people consume mercury through marine animals that are contaminated or, as in the case of some fish, have naturally high-levels. Mercury is also a component of dental amalgam – the silver teeth fillings that are cheaper than alternatives and still used in developing countries.

Human activity emitted approximately 2,220 metric tons in 2015, according to the latest Global Mercury Assessment published by the United Nations Environment Programme (UNEP) in 2018. Atmospheric levels rose by nearly 20 per cent  between 2010 and 2015.

Mercury is persistent. It is an element, which means it cannot be broken down. A third of current mercury levels in the atmosphere comes from current emissions; a third from natural emissions like volcanic eruptions. The remaining third lingers from past human activities. When consumed, the majority of mercury lingers in the body.

What’s more is that mercury biomagnifies. This means that mercury in organisms lower in the food chain add up higher in the food chain, as organisms consume others, says Maag. This is a disadvantage for humans, who are at the top of the chain.

It also has three ways to travel, explains Pamela Chasek, co-founder and executive editor of the Earth Negotiations Bulletin, which has reported on international mercury discussions since the early days of the UN Environment Programme. At room temperature mercury is liquid. When heated, gas. When frozen, solid.

“When mercury rains down from the atmosphere or settles on surfaces, the mercury deposited on leaves and grass and water can evaporate again and thereby continuously cycle around the globe,” says Maag. “The fact that mercury can jump around the globe means that there’s no strict end to when mercury once emitted stops cycling.”

Mercury can filter out of circulation through natural processes, but only slowly. The main way is through ocean sedimentation, Maag explains. Besides being slow, however, a problem is that sediment can be stirred up again.

What are the solutions?

Minamata COP-4 continues efforts to eliminate mercury poisoning. (Credit: IISD/ENB Kiara Worth)

The Minamata poisoning and the Faroe island study spurred momentum for action. Consensus on the need to tackle the global issue led to the launch of a convention – a legally binding treaty – signed in 2013 in Geneva, named in honour of the victims of the Minamata epidemic. The treaty entered into force in 2017 and now boasts 137 parties and 141 focal points. The treaty requires all parties to report on the nature and effectiveness of their implementation measures and to flag challenges.

“That we have a convention is a success. It is something that is quite rare,” Felix Wertli, head of the Swiss delegation to the Convention, told Geneva Solutions.

A further success is the high national reporting rates, Wertli says, which are at 73 per cent. These reports are crucial for understanding what initiatives work, what challenges remain, and how effectively the convention is implemented.

The young convention is an innovative one. It is the first multilateral environmental agreement to take a lifecycle approach, from phasing out the production of mercury to ensuring good disposal, explains Wertli.

The convention has mandated – in addition to restrictions for the trade of mercury and the phase-down of its use – the phase out of several mercury-added products, and the current conference of the parties is conducting the first review of that annex.

Dental amalgam and lamps with mercury are being considered for the list, says Roger Baro, one of the vice-presidents of the convention and national focal point for Burkina Faso.

The African Group is urging a phase out of international trade in dental amalgam by 2027, and complete phase out by 2029, Baro says. The issue continued to be debated Thursday and a conclusion on the phase out timeline is expected Friday.

“That we are able to expand the annex shows that this is a living convention,” says Wertli.

The convention is also notable for tackling the informal parts of the ASGM sector, Wertli adds. It does so in a way that seeks to balance environmental, health, and livelihood considerations.

While some parties argued in the negotiation process that informal ASGM should be banned, the reality is that the informal sector is a significant employer in many areas of the world, especially in developing countries, and is not easily dismantled.

“Mercury-pollution poses a threat to human health and the environment. In some developing countries, however, the livelihoods of an important number of people depend on the commercial use of mercury for ASGM,” Wertli says.

A challenge posed by the informal nature of significant portions of the ASGM sector – much of which uses mercury to separate gold from sediment – is that data collection and access to operations is difficult, Chasek explains.

Taking a practical approach, the convention has chosen to require countries with small-scale gold mining to develop a plan on how they will reduce and, where possible, completely eliminate the use of mercury in the sector, says Wertli.

The convention’s financing mechanism is the Global Environment Facility (GEF), which supports phase down and phase out efforts across many problematic sectors, including ASGM.

While it is still too early to extensively measure the effects the convention’s implementation is having on mercury levels and exposure, emission reductions, phase-outs, phase-downs, and mercury alternatives put in place by the convention have a track record of success.

Though human-emitted mercury levels grew between 2010 and 2015, the 2018 UNEP report shows that they have declined in some parts of the world since the 1990s. The measures that the Minamata Convention has made legally binding are the same that have contributed to the observed decline – so we know they work, Maag says.

“The key challenge that I see right now is that developing countries need time to get an overview of their mercury situation and implement the convention measures nationally. For this purpose, they have had help in the form of funding and technical assistance for making Minamata initial assessments,” Maag says.

UNITAR helps implement the convention, by raising awareness about mercury, training personnel globally in mechanisms for putting it into force, and helping to develop UNEP’s Mercury Inventory Toolkit. The toolkit offers one of the most comprehensive methods for mercury emissions estimation, which countries can use for developing appropriate policies.

Technologies for phasing out mercury are less of a challenge, for example, than regulation, says Maag. “There are mercury-free alternatives to everything today.”

At the intersection of technology and economic structures, accessibility remains an issue, however. Dental fillings are a case in point. “If low-cost alternatives are not available, it could prove to harm human health if low-income patients are not able to afford the proper dental treatment. This could lead to more infections and tooth extractions, to name a few,” says Chasek.