Indigenous women of childbearing age from Nicaragua’s Waspam municipality have been exposed to toxic levels of mercury, according to a new report by the International Pollutants Elimination Network (IPEN).
The researchers took hair samples from 50 women between 18 and 44 years old. The women live in the Indigenous communities of Li Auhbra and Li Lamn, located along the Wangki River, on the northern Caribbean coast. The area is home to many Indigenous communities and small-scale gold mining operations, which commonly use mercury to amalgamate gold.
While no amount of mercury exposure is considered safe, the U.S. Environmental Protection Agency has set a threshold of 1 part per million (ppm). Beyond that limit, negative impacts can be detected in the fetuses of pregnant women. Of the 50 participants, 80% had mercury levels above 1 ppm, and 98% had levels above the more health-protective proposed level of 0.58 ppm.
Mercury exposure can impact a developing fetus months after the mother’s exposure and cause lifelong health problems, including neurological impairment, IQ loss, and kidney and cardiovascular damage, the report said.
The report links mercury pollution in these women to small-scale gold mining. While most of the women of Li Auhbra and Li Lamni depend on agriculture, fishing and hunting for self-subsistence, some participants said they work as gold washers, a process that involves using mercury to extract gold from the surrounding ore. Researchers said participants who don’t engage directly in mining may be exposed through family members who do work with mercury or they may live close to polluted areas. Though the biggest source of exposure is likely food: mercury pollution commonly ends up in rivers, contaminating the fish local people depend on.
“In combination with the dietary surveys we conducted, it is clear that these women are being exposed to mercury via their diet,” Lee Bell, IPEN’s technical and policy adviser, told Mongabay over email. “This means that the food chain is being impacted across the river system, and in turn, many other populations reliant on river fish in this region will likely also be impacted.”
The Minamata Convention on Mercury, a global treaty to protect public health and the environment, has “shortcomings that limit its effectiveness,” say the authors of the report. For example, the convention regards small-scale mining as an allowed use of mercury, meaning the trade in mercury for that use is also allowed. The report authors said amendments to the treaty, which has been in place since August 2017, are needed to dramatically reduce the global mercury supply.
“National and international measures (such as the Minamata Convention on Mercury) to control mercury contamination from gold mining in Nicaragua are not effective in their current form and need to be strengthened,” Bell told Mongabay.
Banner image: Hair sampling team near a sampling location on the Madre de Dios River. Image courtesy of IPEN.
