Microplastics — tiny plastic fragments that can measure less than one micrometre in size — have now been found in 83 percent of tap water tested around the world, according to a 2024 global study. They have also been detected in human brains, cardiovascular tissue, and reproductive organs. Scientists are still working to understand the full health implications — but identifying effective ways to remove them from drinking water has become increasingly urgent.
A study published in the journal ACS Omega in April 2026 offers a promising direction. Led by Dr Adriano Gonçalves dos Reis, a professor at the Institute of Science and Technology of São Paulo State University (UNESP) in Brazil, working alongside researchers in the United Kingdom, the team tested whether an extract made from the seeds of the Moringa oleifera tree — commonly called the "miracle tree" — could remove microplastics from water.
The moringa tree has been used to purify water for thousands of years, with evidence of its use by ancient Egyptians, Greeks, and Romans. Its seeds contain a natural protein that acts as a coagulant — a substance that causes tiny suspended particles in water to clump together so they can be filtered out. Dr Gonçalves dos Reis and his colleagues have been studying this property for a decade. In this study, they applied a salt-based moringa seed extract to synthetic water containing aged PVC (polyvinyl chloride) microplastics — particles with a mean size of 18.8 micrometres, roughly a quarter of the thickness of a human hair.
The result: 98.5 percent of microplastics were removed, matching the performance of aluminium sulfate — the standard industrial chemical — in most conditions, and outperforming it in alkaline water. Unlike aluminium sulfate, which is a toxic heavy metal linked to neurological disorders and produces hazardous sludge during treatment, moringa seed extract is entirely non-toxic and renewable. One moringa seed can treat approximately 10 litres (2.6 gallons) of water. The research team believes the method is best suited to smaller communities, particularly in regions where industrial chemicals are difficult or expensive to access.