A new scientific study conducted in Peru exposes an alarming reality about the pollution of its highlands.
Apparently, the basin of Lake Junín faces extreme levels of pollution from heavy metals: in particular, arsenic, lead, and cadmium.
Therefore, today the carcinogenic risk is 100% for the adult population and the exposure is critical in children.
The research, published in Science of the Total Environment, analyzed 211 samples of soil around Lake Junín (also known as Chinchaycocha).
This evaluated 14 heavy metals, metalloids, and trace elements and reached compelling results: 99% of the area studied presents levels of pollution from “very high” to “ultra high“.
“These are extremely high levels of arsenic, also of lead and cadmium“, explained to SciDev.Net Samuel Pizarro, researcher of the Directorate of Strategic Agricultural Services of the National Institute of Agrarian Innovation.
And he warned that these are “far above acceptable thresholds” and “the cumulative carcinogenic risk is inadmissible”.
Peru: an emblematic ecosystem in danger due to pollution
Lake Junín is located at 4,100 meters above sea level and is the second largest body of water in the country.
The area is home to approximately 50,000 people between urban and rural areas, and is part of the Junín National Reserve.
However, the impact of this pollution extends far beyond. According to Pizarro, the waters of the lake feed the Mantaro River, which irrigates agricultural valleys downstream.
Therefore, the impact of the heavy metals “reaches 1.3 million people because part of the waters are then used in the valleys and in reservoirs”, noted the researcher.
The concentrations of arsenic, lead, cadmium, and zinc exceed ecological thresholds by more than 100 times in agricultural areas.
The study also highlights the significant presence of chromium, a serious element for human health.
Historical origin of pollution in Peru
Dennis Ccopi, co-author of the work, explained that this emblematic ecosystem became a “sink of metals and metalloids” that accumulate in water, sediments, and grazing soils.
This directly affects food and exposes local communities.
The source of this pollution comes from environmental liabilities of abandoned mines for almost a century.
The mining tradition of the high Andean area exceeds 300 years, in addition to current livestock and urbanization.
“There is a process of bioaccumulation because the animals around the lake consume contaminated forage”, added Pizarro, noting that the heavy metals thus enter the food chain.
Innovative methodology with artificial intelligence
The study was conducted by researchers from the National Institute of Agrarian Innovation of Peru and the National University Toribio Rodríguez de Mendoza. One of its strengths is the use of systematic sampling with grids around the lake.
The researchers used a machine learning model with cross-validation to ensure the robustness of the data.
“This concentration is compared with environmental variables to which is added the calculation of how many days the area is flooded”, detailed Pizarro.
The system could be applied in other similar areas.
Anna Heikkinen, a researcher from the University of Helsinki who did not participate in the study, confirmed that the results match findings in the Mantaro River basin and the Huaraz region.
“Mining-related pollution in the high Andes of Peru poses a serious ecological, socioeconomic, and health risk to the local population”, she noted.
Heikkinen hopes that “the Peruvian authorities seriously consider this study to protect the well-being of the local population, animals, and the environment”.
SOURCE: Martín De Ambrosio, for SciDev.Net
