American researchers estimate that about one-sixth of the world’s arable land is contaminated with toxic heavy metals. By analyzing research data and global population distribution, the team found that roughly 1.4 billion people live in areas at increased risk of poisoning. Between 14 and 17 percent of the Earth’s arable land — about 242 million hectares — is polluted with at least one toxic metal (arsenic, cadmium, cobalt, chromium, copper, nickel, or lead) at concentrations above safety thresholds for agriculture.
The analysis, conducted by the American Association for the Advancement of Science (AAAS) and published in the journal Science, compiled data from more than 1,000 regional studies worldwide and used machine learning. Dr. Liz Rylott, a senior lecturer in the Department of Biology at York University who was not involved in the study, said, “These results highlight how these natural toxins contaminate our soils, enter our food and water, and impact our health and the environment.” She added, “These elements, often referred to as heavy metals, cause a range of serious health problems, including skin damage, impaired nervous system and organ function, and cancer.”
The study found that soil contamination comes from both natural processes and human activities. Contaminated soil poses significant risks to ecosystems and human health, while also reducing crop yields and degrading water quality. Because heavy metals bioaccumulate in farm animals, food products can become contaminated, The Guardian reported. Contamination from toxic metals can persist in arable lands for decades. Scientists predict that as demand for these metals increases, soil pollution is likely to worsen.
“The need for critical metals to build the green infrastructure needed to address climate change — such as wind turbines, electric vehicle batteries, and photovoltaic panels — will worsen this pollution,” Dr. Rylott said. The most prevalent toxic metal found was cadmium, which is especially widespread in South and East Asia and parts of the Middle East and Africa. Dr. Rylott added that low- and middle-income countries suffer the most from heavy metal contamination.
