In a remarkable breakthrough, scientists from the University of Bristol have uncovered a way to neutralize toxic arsenic in water without oxygen, promising safer drinking water across the Globe.
A study by the University of Bristol has unveiled new methods to neutralize toxic arsenic in water, potentially transforming water and food safety, particularly in vulnerable regions of the Global South. The discovery, spearheaded by Jagannath Biswakarma, addresses a critical environmental and public health issue, particularly relevant to areas reliant on groundwater for drinking and farming.
For Biswakarma, this study is deeply personal. Growing up in India, he experienced the daily challenge of finding clean, arsenic-free water. Now, as a senior research associate at the university’s School of Earth Sciences, his mission is to improve water safety for millions facing similar struggles.
“There are millions of people living in regions affected by arsenic, like I was growing up,” Biswakarma said in a news release. “This breakthrough could pave the way for safer drinking water and a healthier future.”
Arsenic pollution is particularly problematic in southern and central Asia and South America. The toxic, mobile form of arsenic, known as arsenite, easily leaches into water supplies, posing severe health risks, including cancers and heart disease.
Traditional understanding suggested that arsenite could only transform into the less harmful arsenate in the presence of oxygen. However, this new research has demonstrated that arsenite can still be oxidized in oxygen-scarce environments, using iron as a catalyst.
“I’ve seen the daily battle for safe drinking water in my hometown Assam,” Biswakarma added. “It’s very hard to find groundwater sources that aren’t contaminated with arsenic, so for me this research hits close to home. It’s an opportunity to not only advance science, but also better understand the extent of a problem which has affected so many people in my own community and across the world for many decades.”
Green rust sulfate, an iron source prevalent in low-oxygen conditions such as groundwater, was found to oxidize arsenite. This process can be further enhanced by organic ligands, such as citrate from plant roots, which are common in soils and groundwater.
“This study presents a new approach to addressing one of the world’s most persistent environmental health crises by showing that naturally occurring iron minerals can help oxidize, lowering the mobility of arsenic, even in low-oxygen conditions,” added Biswakarma.
The implications are especially significant for regions like the Ganges-Brahmaputra-Meghna Delta in India and Bangladesh, where high arsenic levels have jeopardized drinking water for decades. Economically disadvantaged households frequently rely on tube wells and hand pumps that often do not guarantee safe water, exacerbating financial and health burdens.
Additionally, regions like the Mekong and Red River Deltas in Vietnam have also battled with arsenic pollution affecting water supplies and agricultural productivity. The toxic chemical can accumulate in soils and rice plants, posing further health risks through food consumption.
Molly Matthews, who contributed to the paper during her master’s degree in environmental geoscience at the University of Bristol, shared her excitement about the discovery.
“The research opens the door for developing new strategies to mitigate arsenic pollution. Understanding the role of iron minerals in arsenic oxidation could lead to innovative approaches to water treatment or soil remediation,” she said in the news release.
The study utilized the advanced capabilities of the European Synchrotron Radiation Facility in Grenoble, France, to conduct complex experiments, crucial for confirming the oxidation state of arsenic.
James Byrne, associate professor of earth sciences, noted the importance of this high-level analysis, adding, “Determining arsenic formation at the atomic level using X-ray absorption spectroscopy was crucial for confirming changes to the arsenic oxidation state.”
Support for this groundbreaking research came through a UK Research & Innovation Future Leaders Fellowship awarded to Byrne. Further research is needed to explore how these findings can be implemented in real-world scenarios.
“The whole research team worked tirelessly on this project,” Dr. Biswakarma added. “I genuinely believe, with more work, we can find effective possible solutions. We’re already making great inroads to overcoming this big global issue. We’re excited to investigate how this process might work in different types of soils and groundwater systems, especially in areas where arsenic contamination is most severe.”
This study, published in the journal Environmental Science & Technology Letters, significantly contributing to advancing equitable and sustainable health and driving forward social justice.