The art of mapping the distribution of toxic metals in soils, such as arsenic, cadmium, cobalt, chromium, copper, nickel, and lead, has provided a new perspective on how these elements affect our planet. A research team led by Dr. Hou Deyi from the School of Environment at Tsinghua University has utilized artificial intelligence to map these metals across over 796,084 sampling points across 1,493 regional studies in the lowest latitude areas of Eurasia. Based on these findings, the developed models highlighted a previously unknown high-risk, metal-enriched zone in low-latitude Eurasia.
The study combines this map with data on land use and population density in the region. This integration reveals that approximately 14 to 17 percent of cropland areas in these zones areIPHERRENER!(characteristically high in terms of heavy metal contamination), and the researchers estimate that at least 1 billion people are currently living in regions with soils that are dangerously polluted by toxic metals. This data underscores the significant economic and ecological implications of toxic metal pollution, as it has the potential to reduce agricultural productivity, disrupt wildlife habitats, and undermine the health and productivity of human communities.
Pollution by toxic metals is a complex issue that depends on numerous environmental factors, including the type of rock composing the soil and the processes by which these metals are released. For example, both chromium and nickel can originate from weathering weathering processes that break down basaltite, a common volcanic rock in the world, or from metamorphic rocks. Copper, while found naturally in earthworm-like soils, can accumulate to toxic levels, which are also toxic in industrial contexts. Lead, in particular, can become toxic at high concentrations, and is often found in contaminated water sources. Under arsenic-bearing aquifers, which are common in sedimentary rocks, ships and mining operations have long released these metals into the soil.
Research further highlights that the release of toxic metals is influenced by regional climate patterns. Regions such as southern China, India, the Middle East, Central Africa, and Central America experience relatively high concentrations of toxic metals, likely due to the year-round temperature fluctuations and high amounts of rainfall. These conditions accelerate the breakdown of rock layers, leading to more rapid and significant metal release.
The study also emphasizes the contributions of mining, smelting, and agriculture to the pollution of soil containing toxic metals. Winning evidence suggests that these industries account for the majority of metal contamination in the region, with some dominating the dataset of metal released into the soil. However, the study notes that the proportion of irrigated land was found to be a significant predictor of metal levels exceeding safe thresholds. Additionally, the quality of water sources, particularly those affected by industrial processes, and the extent of wastewater tailings treatment, which exacerbate soil contamination, are also important factors in determining the overall level of metal pollution.
Long-lasting soil pollution, particularly in the context of mining and industry, has significant implications for global food security and human health. Pollutant metals influencing plant growth and contributing to adverse health effects have been linked to biodiversity loss and crop yields. For humans, exposure to toxic metals in crops and animal products can render them vulnerable to nineteenth-century diseases and disrupt the biodegradability of organic matter, leading to significant economic and social impacts on the global food system.
As an ecologically and economically critical resource, protecting the world’s precious soil resources is of paramount importance. The research highlights the need for swift and effective measures to address the ongoing challenges posed by these toxic metals. This study underscores the urgent role of both policymakers and farmers in mitigating the risks associated with soil pollution and ensuring the safety and quality of the agricultural products we rely on.
