In July, a 47-year-old woman presented to the emergency department at her local hospital in Sacramento, California. His speech was slurred, he couldn't walk, and he couldn't feel his hands or face. The woman soon fell into a coma, where she remained for several weeks. The cause of the woman's desperate condition, health officials discovered, was a skin-lightening ingredient, mercury, that had been illegally mixed into her bottle of face cream.
"Mercury poisoning has dangerous and sometimes irreversible effects, and while unborn babies are more vulnerable, anyone can suffer," said Claudia ten Have, Senior Policy Coordination Officer at the Minamata Convention Secretariat. As the case of the Sacramento woman makes clear, toxic heavy metal can pose serious health threats in both developing and developed countries.
In fact, everyone on the planet is exposed to mercury at some level, whether it's through the food we eat, the air we breathe, or the cosmetics we use. And while there are a number of steps that individuals, businesses, and governments can take to protect themselves against this metal poisoning, the toxic heavy metal will continue to endanger human and environmental health until we manage to comprehensively address mercury. throughout its life cycle.
Achieving that goal is the primary goal of the Minamata Convention on Mercury, a multilateral environmental agreement that entered into force in August 2017. To date, 114 countries have ratified the convention, the youngest environmental treaty in the world. The parties to the convention will meet in Geneva for their third Conference of the Parties on November 25-29. The health impacts of this metal are one of the important points on the meeting's agenda.
Mercury and our health
When we inhale, ingest, or are exposed to mercury, the element can attack our central and peripheral nervous systems, as well as our digestive tracts, immune systems, lungs, and kidneys. Specific symptoms can include tremors, insomnia, memory loss, headaches, muscle weakness and, in extreme cases, death. Unborn babies whose mothers have high levels of mercury in their blood can be born with brain damage and hearing and vision problems. Levels of the toxic element can be measured in blood, hair, or urine samples.
But how are we exposed to mercury in the first place? Despite a growing global awareness of how this metal threatens our health, the element continues to appear in various places. Here are some:
For more than a hundred years, mercury has been one of the main ingredients in dental amalgam, the mixture that dentists use to fill the cavities of their patients' teeth. And although amalgam probably poses a minimal threat to the health of those who walk with it in their mouth, the use of this metal in amalgam also contributes to a gradual accumulation of the toxic element in our environment. To meet this challenge, the Minamata Convention proposes nine specific measures to “reduce the use of dental amalgam” around the world. Steps include setting national targets to reduce amalgam use, promoting the use of mercury-free alternatives, and supporting best practices in managing mercury waste.
Seafood is the main source of protein for approximately one billion people around the world. Because mercury "bioaccumulates" in the food chain, larger fish like shark, swordfish, tuna, and marlin tend to be especially rich in mercury. People who consume very high amounts of shellfish can be exposed to high levels of methylmercury, an organic compound that accumulates in the bodies of fish.
Mercury poisoning from the consumption of marine animals has been seen among indigenous groups in many parts of the world, especially in the Arctic. Per capita seafood consumption in these communities can be up to 15 times higher than in non-indigenous groups.
A study published in 2018 found elevated levels of mercury in women of childbearing age in the island states of the Pacific, Caribbean and Indian oceans, where fish consumption is high. Clearly, mercury pollution has accumulated in the world's major oceans, contaminating the marine food chain and threatening human health.
Mercury can also be found in beauty products, particularly skin lightening creams, but also in makeup and eye cleansers. While many countries have imposed laws banning mercury from cosmetics, a few others have yet to do so, and mercury-contaminated products have been found at major online retailers. Consumers looking to avoid the toxic element should purchase products from reputable suppliers and make sure their products are properly sealed and labeled. The World Health Organization has more information on the subject.
Artisanal and small-scale gold miners regularly use mercury to help them separate gold from other materials, and most of that mercury ends up in the environment.
In 2015, according to the 2018 Global Mercury Assessment of the United Nations Environment Program (UNEP), artisanal and small-scale mining emitted about 800 tons of mercury into the air, approximately 38 percent of the global total, and it also released some 1,200 tons of mercury onto land and water.
Mercury poisoning also poses a serious and direct threat to the health of the 12 to 15 million people who work in the sector worldwide. Reducing emissions and releases of mercury from mining is a key objective of the Minamata Convention, which requires countries with small-scale gold mining to produce national action plans to reduce or eliminate mercury from the sector.
The other major source of anthropogenic mercury emissions is also a major driver of air pollution and climate change: burning coal. The latest UNEP Global Mercury Assessment found that the burning of coal and other forms of fossil fuels and the burning of biomass were responsible for about 24 percent of global mercury emissions.
Although coal contains only small concentrations of mercury, people tend to burn it in very large volumes. And as the global economy grows, so does the burning of coal for power generation. The good news is that up to 95 percent of mercury releases from power plants can be reduced by improving coal and plant performance, and improving control systems for other pollutants.