Key points
- A major global study found that up to 17% of the world’s cropland is contaminated with toxic heavy metals such as arsenic, cadmium, and lead — posing serious risks to public health and food safety, particularly in South and East Asia, the Middle East, and Africa.
- Researchers used machine learning to analyze nearly 800,000 soil samples, revealing that 1.4 billion people live in regions where polluted soil may be affecting crops and ecosystems.
- The contamination is linked to industrialization, mining, and even green energy development. And while long-term solutions are limited, experts recommend better soil management and diets rich in fiber and nutrients to help the body reduce metal absorption.
A new study is sounding the alarm that the land we use to grow food may be contaminated with harmful chemicals.
In April, researchers from the American Association for the Advancement of Science published their findings in the journal Science after analyzing 1,493 regional studies that used machine learning to estimate soil pollution worldwide. They discovered a startling statistic: Up to “17% of cropland exceeds agricultural thresholds for at least one toxic metal.”
As the authors noted, they wanted to gain a better understanding of the distribution of heavy metal pollution. To achieve this, they analyzed a global database of soil pollution, extracting information on contaminants like “arsenic, cadmium, cobalt, chromium, copper, nickel, and lead” from nearly 800,000 sampling points. This analysis revealed that 14 to 17% of cropland worldwide suffers from toxic metal pollution. Additionally, the authors pointed out that up to 1.4 billion people “live in regions of heightened public health and ecological risks.”
They also found that the most polluted regions were in South and East Asia, as well as parts of the Middle East and Africa. Specifically, the researchers noted that levels of nickel, chromium, arsenic, and cobalt exceeded safe thresholds in several areas, likely due to mining.
“We hope that the global soil pollution data presented in this report will serve as a scientific alert for policymakers and farmers to take immediate and necessary measures to better protect the world’s precious soil resources,” the authors shared in a statement.
Although certain heavy metals are naturally occurring, industrial development in the past century has resulted in what some scientists refer to as a “massive increase” in human exposure.
“Bioaccumulation of these heavy metals leads to a diversity of toxic effects on a variety of body tissues and organs,” researchers explained in a 2021 study in the journal Frontiers in Pharmacology. “Heavy metals disrupt cellular events, including growth, proliferation, differentiation, damage-repairing processes, and apoptosis.” This, in turn, can cause gastrointestinal and kidney issues, along with “nervous system disorders, skin lesions, vascular damage, immune system dysfunction, birth defects, and cancer.”
Interestingly, the global shift towards green energy might be worsening the issue.
“Our drive for technology-critical metals to build the green infrastructure required to tackle climate change (wind turbines, electric vehicle batteries and photovoltaic panels) will exacerbate this pollution,” Dr Liz Rylott, a senior lecturer in the department of biology at the University of York, who was not involved in this particular study, shared in a statement.
Since these metals can remain in the soil for many years, our short-term options are limited. Nonetheless, you can exert some influence by selecting foods that aid your body in eliminating heavy metals.
“Insufficient intake of other key nutrients, like fiber, folate, and vitamin C, can also increase the likelihood of absorbing undesirable heavy metals,” the Center for Research on Ingredient Safety at Michigan State University shared.
“Fiber, for instance, helps bind to toxins and toxicants in the digestive system, supporting their elimination, while vitamin C enhances the absorption of beneficial nutrients like iron.” It added that nutrition alone cannot protect against heavy metal poisoning. However, eating whole foods like fruits, veggies, grains, and lean protein can help your body “more effectively protect itself from diseases and environmental contaminants, including trace heavy metals.”
