Data that shows dangerously high levels of mercury found in the heavily forested areas of the Amazon Rainforest was published on Jan. 28, 2022. According to Scientific American, these toxic levels are attributed to small-scale gold mining that is being conducted illegally, specifically in the Madre de Dios region in Peru.
The miners in this area use mercury to separate pieces of gold from the sediment attached to it by burning it off. This then transforms the liquid mercury into particles that are released into the atmosphere, landing on leaves or bird feathers, according to Catrin Einhorn, a writer for The New York Times.
The constant exposure to high amounts of mercury is extremely toxic for birds and can have negative effects on the species’ population. It impairs them so that they are unable to navigate or communicate with others. Birds will also have a harder time reproducing, Jacqueline Gerson, a biogeochemist with a PhD from Duke University said in a study published in Nature Communications.
According to Einhorn, high quantities of mercury have also been found in the soil of the rainforest. This occurs as precipitation brings mercury particles in the air down to the ground, or when rainwater combines with mercury-coated leaves. The runoff of the new mercury-rainwater mixture then ends up in waterways close by, such as rivers and oceans.
Mercury in the same water that humans get their seafood from is dangerous because it increases people’s chances of being exposed through a process called biomagnification. Biomagnification is the buildup of toxins as it travels through the food chain. Smaller aquatic animals that feed on algae and other particles will ingest the mercury, then larger fish feed on the smaller ones, getting a higher dosage that increases as it moves up the food chain, ending with humans. The more mercury in the water, the higher the levels of it in the seafood we consume.
“At remote locations, GEM (mercury) concentrations were below the global southern hemisphere average background concentration of approximately 1 ng m^−326. In contrast, GEM concentrations in all three mining sites were 2−14 times higher than remote sites,”Jacqueline Gerson, a biogeochemist with a PhD from Duke University
Mercury is toxic and can be fatal to humans if exposed to high levels. When subject to and consumed, it can cause neurological damage to the brain. In small doses, symptoms can be anxiety, mood swings or memory problems. Higher exposure can lead to kidney failure or damage to the central nervous system, according to the United States Environmental Protection Agency.
In 2016, a health emergency was declared in the Madre de Dios region because the levels of mercury were found to be extremely high in those living there.
“40 percent of people tested in 97 villages had dangerously high levels of mercury in their systems,” Einhorn wrote.
The buildup of mercury is higher in places that are more heavily canopied or populated by plants and trees when compared to areas that have gone through mass deforestation. This is because areas with increased vegetation have more places for mercury particles to land. With a barren patch of land, the particles can only fall to the ground. In heavily wooded areas, however, they can rest on leaves, branches and any animals living there.