July 28: Researchers are raising concerns that plastic materials used in modern construction are contributing to microplastic pollution in rivers, where the particles are increasingly being detected in freshwater fish.
Concrete and construction materials are used extensively worldwide, with the construction sector consuming an estimated 17–20% of global plastic production. Plastics such as polyethylene terephthalate (PET), polypropylene (PP) and polyvinyl chloride (PVC) are commonly incorporated into waterproof coatings, fiber reinforcement, insulation, pipes and composite building materials to improve durability and performance.
Scientists say these materials gradually break down through weathering, cutting, grinding and other construction activities. During rainfall, stormwater runoff can carry microscopic plastic particles from construction sites into drains, streams and rivers.
Once in freshwater ecosystems, these particles are transported downstream, where they can accumulate in aquatic habitats and be ingested by fish and other organisms.
Studies have reported microplastics in the gills, digestive tracts and internal organs of freshwater fish collected downstream of urban and developed areas. Researchers have found particularly high concentrations in the liver and kidneys of some species, suggesting that the particles can remain in tissues for extended periods and potentially affect fish health.
Experts warn that construction related runoff is becoming an increasingly important source of microplastic pollution alongside urban runoff, industrial discharges and the breakdown of larger plastic waste.
At the same time, researchers are exploring ways to reduce these emissions. New approaches include improved sediment barriers at construction sites, better management of concrete wash water, stormwater filtration systems and engineered porous concrete capable of trapping microplastic particles before they enter waterways.
Scientists emphasize that while research is still evolving, reducing plastic runoff from construction activities could play an important role in protecting freshwater ecosystems and limiting the spread of microplastics through aquatic food chains.