In the heart of the Amazon basin, the illegal gold mining has become one of the main threats to both the environment and the health of hundreds of thousands of people. The use of mercury in extraction processes has generated an unprecedented situation of contamination in rivers, fish, and in the indigenous and riverside communities that depend on these resources.
Mercury used in mining not only remains in waterways, but also progressively accumulates in fish., especially in larger and carnivorous ones. In this way, the consumption of fish, a fundamental part of the Amazonian diet, has become a major health risk.
Alarm over high mercury levels in fish and people
Various studies and scientific reports have put figures on this crisis. In regions such as Mother of God and Loreto, research by entities such as the Amazon Scientific Innovation Center (CINCIA), the Foundation for Conservation and Sustainable Development and the Frankfurt Zoological Society have identified the massive presence of mercury both in the air, in the water, in food and in the organism of the inhabitants themselves.
In Puerto Maldonado, for example, it was found that 78% of adults Her hair had mercury levels three times higher than the limits established by international organizations. Women of childbearing age and young children are among the most affected groups, which increases the risk of neurological damage in fetuses and cognitive development in younger children.
The case of Nanay River, in Loreto, which supplies water to half a million people in Iquitos, is equally worrying. In nearby communities, nearly 80% of the residents tested showed medium or high exposure to mercury, a result of their dependence on local fish. Fish analyzed in the Nanay and Pintuyacu rivers, used as an essential source of protein, also showed alarming results: 14% of them exceeded the values ​​recommended by the WHO for human consumption.
Bioaccumulation and health consequences
Mercury enters the food chain primarily as methylmercury, the most toxic form of this metal. This substance bioaccumulates in the tissues of fish, especially in carnivorous and large species. When consumed by humans, primarily by indigenous and riverine communities, mercury enters their bodies, where it can accumulate in vital organs such as the brain, liver, heart, and kidneys.
The health effects are not limited to specific damage. According to researchers and WHO reports, exposure to mercury, even in small but prolonged amounts, It affects the central nervous system, the kidneys and can alter child development.Headaches, tremors, memory loss, muscle weakness, and birth defects have been reported in newborns. The consequences for public health could extend for decades.
In areas of intense mining activity, such as Huepetuhe, La Pampa, and Mazuko, high levels of mercury have been detected in both humans and wildlife, with symptoms associated with chronic poisoning and severe neurological damage.
Factors that aggravate exposure and social responses
The expansion of illegal mining, often supported by criminal structures and cross-border mafias, has been facilitated by the weak state presence in vast Amazonian territories. The advance of dredging and the uncontrolled burning of gold amalgams have caused mercury levels in the air to reach levels of up to 5000 ng/m³ in mining areas, well above acceptable levels.
Poverty, neglect, and the lack of economic alternatives have forced many families to become directly or indirectly involved with mining, sometimes even admitting or tolerating the presence of miners in their communities. These circumstances reinforce the dependence on the illegal gold market and make intervention or conservation actions difficult.
Furthermore, the impact of pollution does not stop at aquatic ecosystems. Mercury concentrations three to five times higher have been found in birds and bats in the area, further jeopardizing the regional ecological balance.
Recovering keystone species: the spotted speck as a symbol of hope
The case of the dotted speck (a fish essential to the diet of Madre de Dios) illustrates both the seriousness of the problem and the potential of science to provide solutions. After discovering that this species had critical levels of mercury, authorities banned its consumption and extraction. For years, communities saw a staple food disappear from their tables, which was a severe cultural and nutritional blow.
However, after several years of research and experiments in fish farms, scientists from the Peruvian Amazon Research Institute (IIAP) They managed to reproduce specimens of the spotted speckled catfish completely free of mercury. Using hormonal techniques and a diet based on balanced foods, they not only managed to return the species to human consumption, but also to do so with safety guarantees.
This experience opens the door to the recovery of other species affected by pollution and demonstrates that technology and proper management can help reverse, at least in part, the degradation caused by illegal mining.
Recommendations and challenges for the future
To address this problem, recent research recommends strengthen controls and surveillance against illegal mining, and promote a safer diet for riverine populations, limiting the consumption of carnivorous species and favoring smaller fish or fish raised under controlled conditions.
The importance of implementing environmental and health monitoring systems, conducting awareness campaigns, and offering specialized health services for those suffering from mercury poisoning is also highlighted. International cooperation, decisive public policies, and the search for sustainable economic alternatives are essential to reducing pressure on Amazonian rivers and biodiversity.
Mercury contamination from illegal mining represents a multidimensional threat: it affects the food, health, culture, and future of entire communities. Although initiatives such as the restoration of the dotted mote show that there are ways to improve the situation, the urgency of halting the spread of illegal mining and restoring ecosystems remains essential.