Reservoirs are lifelines for drinking water, food production, and economic growth. But a new study warns that these crucial ecosystems are increasingly under threat from toxic heavy metals—and that urgent, innovative action is needed to safeguard both human health and the environment.
Researchers from Northeast Agricultural University, together with international collaborators, have published the most comprehensive review to date of heavy metal pollution in reservoirs, outlining its sources, risks, and promising solutions. The findings, published in Agricultural Ecology and Environment, reveal that heavy metals such as mercury, cadmium, and arsenic are accumulating at dangerous levels in reservoir waters and sediments, where they can persist for decades and move through food chains.
"Reservoirs are not only water storage systems, but also living ecosystems. Once heavy metals enter, they don't just stay in the water—they accumulate in sediments and organisms, creating long-term risks for both ecosystems and people," said lead author Dr. Song Cui.
The review identifies three main pathways of contamination: direct industrial and mining discharges, diffuse runoff from agriculture and other land uses, and internal release from sediments under changing environmental conditions. Once inside reservoirs, metals interact with complex physical and chemical processes, making them difficult to predict or remove. Fish from many reservoirs already exceed World Health Organization safety standards, posing dietary exposure risks for nearby communities.
To tackle this global challenge, the authors highlight recent progress in monitoring and remediation. Intelligent technologies, such as Internet of Things (IoT) sensor networks, artificial intelligence, and machine learning, are transforming heavy metal detection, enabling real-time monitoring and early warnings of pollution events.
On the remediation side, greener and more sustainable methods are emerging, including the use of nanotechnology, agricultural waste-based adsorbents, aquatic plants, and biochar. These eco-friendly approaches could replace traditional chemical methods, which are often costly and generate secondary pollution. However, the authors stress that scaling these technologies to real-world reservoirs remains a major challenge.
"Developing multifunctional, low-cost, and environmentally friendly solutions is essential if we want to prevent reservoirs from becoming long-term pollution traps," said co-author Prof. Rupert Hough of the James Hutton Institute in Scotland.
The review also calls for greater international cooperation and the establishment of global risk management frameworks. With over 58,000 large dams worldwide, and many located in regions already facing water scarcity, the stakes are high. Climate change and growing industrial demand will likely worsen contamination risks unless proactive measures are taken.
"Our study shows that we need integrated strategies that combine advanced monitoring, innovative remediation, and coordinated governance," added Dr. Cui. "Reservoirs are too important to fail—protecting them means protecting our future water security."
The study offers a roadmap for policymakers, engineers, and environmental scientists to advance heavy metal pollution control and ensure the sustainability of reservoir ecosystems.
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Journal Reference: Cui S, Ma C, Zhang F, Jia Z, Pan F, et al. 2025. Heavy metals in reservoirs: pollution characteristics, remediation technologies, and future prospects. Agricultural Ecology and Environment 1: e003 https://www.maxapress.com/article/doi/10.48130/aee-0025-0003
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About Agricultural Ecology and Environment :
Agricultural Ecology and Environment is a multidisciplinary platform for communicating advances in fundamental and applied research on the agroecological environment, focusing on the interactions between agroecosystems and the environment. It is dedicated to advancing the understanding of the complex interactions between agricultural practices and ecological systems. The journal aims to provide a comprehensive and cutting-edge forum for researchers, practitioners, policymakers, and stakeholders from diverse fields such as agronomy, ecology, environmental science, soil science, and sustainable development.
