A recent study has revealed new methods to reduce the dangers of arsenic for humans. This breakthrough could significantly enhance the safety of water and food, particularly in developing countries.
A recent study led by the University of Bristol has uncovered new ways to minimize the risks posed by arsenic to human health, which could greatly enhance food and water safety, especially in the Global South.
The lead researcher has a personal connection to this issue, having experienced the challenge of accessing clean, arsenic-free water while growing up in India.
Dr. Jagannath Biswakarma, Senior Research Associate at the University’s School of Earth Sciences, stated: “Millions of people live in arsenic-affected regions, similar to my childhood experiences. This discovery could lead to safer drinking water and a healthier future.”
Exposure to arsenic pollution poses serious environmental and public health risks in central and southern Asia, as well as South America, where many rely on groundwater for drinking and agricultural activities. Arsenite, a more toxic and mobile form of arsenic, easily contaminates water supplies and can result in cancers, heart disease, and other severe health issues.
Dr. Biswakarma remarked: “I have witnessed the struggle for safe drinking water in Assam, my hometown. It’s extremely difficult to find groundwater that isn’t tainted with arsenic, so this research resonates deeply with me. It’s a chance not only to advance our scientific understanding but also to gain insight into an issue that has affected countless individuals in my community and around the globe for decades.”
Earlier, scientists thought that arsenite could be converted into the less harmful arsenate form only in the presence of oxygen. However, this new research indicates that it can also be oxidized in low-oxygen environments with the help of small amounts of iron that act as a catalyst.
Dr. Biswakarma explained: “This research offers a new strategy for tackling one of the most enduring environmental health challenges by demonstrating that naturally occurring iron minerals can facilitate oxidation, thereby reducing arsenic mobility, even in low-oxygen conditions.”
The study showed that arsenite can be oxidized by green rust sulfate, an iron source commonly found in low-oxygen water supplies. Additionally, this oxidation process can be improved by organic compounds released from plants, which are prevalent in soils and groundwater.
“These organic ligands, such as citrate from plant roots, may significantly influence the control of arsenic mobility and toxicity in natural environments,” Dr. Biswakarma added.
This finding holds great significance for regions in the Global South that grapple with severe arsenic pollution. In nations like India and Bangladesh, the geology is rich in iron, and groundwater systems often experience reducing conditions that lead to high arsenic levels. Many people in the Ganges-Brahmaputra-Meghna Delta have been exposed to arsenic-contaminated groundwater for decades due to natural contamination processes.
Dr. Biswakarma noted: “Many families depend on tube wells and hand pumps for water, but these sources don’t always provide clean water. The water can be toxic, unpleasant in smell, and discolored, preventing its use for drinking and everyday tasks. Additionally, there’s a financial burden linked to installing new tube wells or hand pumps, making it tough for low-income families to secure safe water for daily needs.”
Similar arsenic pollution challenges exist in the Mekong Delta and the Red River Delta in Vietnam, impacting both drinking water supplies and agricultural productivity. Rice paddies can become areas where arsenic gathers, as the toxic element can accumulate in the soil and be taken up by rice plants, further endangering health through food consumption.
“This research opens opportunities for developing new methods to combat arsenic pollution. Understanding how iron minerals facilitate arsenic oxidation could lead to novel approaches for water treatment or soil restoration, utilizing natural processes to convert arsenic into a safer form before it contaminates drinking water,” said co-author Molly Matthews, who contributed to the study during her Master’s in Environmental Geoscience at the University of Bristol.
Identifying the specific type of arsenic in a sample can be complex. Even minimal oxygen exposure can change arsenite to arsenate, underscoring the importance of protecting samples from air. Thanks to support from the European Synchrotron Radiation Facility (ESRF), the research team conducted sophisticated experiments at the XMaS synchrotron facility in Grenoble, France.
Co-author Dr. James Byrne, Associate Professor of Earth Sciences, emphasized: “Using X-ray absorption spectroscopy to analyze arsenic formation at the atomic level was essential for confirming the changes in arsenic’s oxidation state. The synchrotron played a vital role in supporting our findings, which could have widespread implications for understanding water quality.”
This research at the University of Bristol received backing from a UK Research & Innovation (UKRI) Future Leaders Fellowship (FLF) awarded to Dr. James Byrne. Further studies are necessary to see how these results can be applied in practical situations.
Dr. Biswakarma shared: “The entire research team dedicated immense efforts to this project, working around the clock, including during Easter, to carry out experiments in France.”
“I truly believe that, with additional work, we can discover effective solutions, and we are already making significant strides in tackling this pressing global issue. We are eager to explore how this process might function in various soils and groundwater systems, particularly in regions with severe arsenic contamination.”
At the core of the University of Bristol’s research is the quest for impactful solutions to major global challenges, focusing on promoting equitable and sustainable health and advancing social justice.
