Mercury has a long history of being used in the extraction of gold and silver, but unfortunately, this has resulted in significant contamination issues. This toxic substance not only seeps into the soil and rivers through water used in the process and rain runoff contaminated by mining leftovers, but it is also released into the air when burned to separate gold from rocks or mud.
Illegal mining operations in countries like Peru, where regulations are lacking, make it challenging to address and undo the damage caused by mercury contamination, according to Dave Krabbenhoft, a researcher at the U.S. Geological Survey in Middleton, Wisconsin. It is interesting to note that mercury can remain in the environment for centuries, moving between soil, water, and the atmosphere.
Researchers are particularly interested in oceanic mercury because it is where the element transforms into methylmercury, the harmful form that builds up in fish. Consuming seafood is the primary way humans come into contact with this metal, as stated by scientists. The majority of methylmercury is generated by microorganisms in low-light environments, as demonstrated in a recent publication in Nature Geoscience.
Great news is on the horizon as delegates from various countries are set to gather in Minamata, Japan in October to finalize an agreement aimed at reducing mercury pollution. However, a recent study published in the journal Science suggests that mercury levels in the environment are expected to continue to rise for years to come.
The meeting aims to shut down all mercury mines in participating countries within 15 years of the agreement taking effect. Furthermore, products containing mercury are set to be phased out, including dental amalgams that contain the harmful substance. Efforts will also be made to address artisanal mining issues in countries like South America, Southeast Asia, and Africa.
Minamata’s tragic history with mercury poisoning played a significant role in bringing about the first Convention on mercury. It is crucial to raise awareness and prevent future disasters.
While the convention has been established and its language finalized, some experts believe it does not go far enough, especially in terms of short-term mercury exposure reduction. Because mercury remains in the environment for a long time, it is expected that mercury levels will continue to rise despite efforts to curb them.
To reduce mercury exposure, individuals can opt for fish with lower mercury accumulation, like sardines, instead of larger carnivorous fish. It will take decades to see the full effects of the UN treaty, so it is important to make informed decisions about seafood consumption in the meantime.
Grandjean is optimistic about the efforts to reduce small-scale mining while expressing concern about the construction of new coal plants, especially in China, where fossil fuels contribute significantly to mercury pollution, according to Krabbenhoft. Climate change is also a factor that could exacerbate mercury pollution, with a warmer climate potentially leading to more intense flooding and wildfires that release mercury from the soil and vegetation.
While the convention is a positive first step, Grandjean acknowledges that the persistent nature of mercury pollution means the situation may worsen before it improves. Despite this, he remains hopeful that measures can be taken to curb mercury pollution.
Grandjean pointed out that even though the treaty wasn’t perfect, it doesn’t mean that it was a complete loss. He emphasized that we should view it as a victory, but acknowledged that there is a significant amount of work that still needs to be done.
