Chile river sampling reveals high waste accumulation risks

The IV National River Waste Sampling in Chile has revealed significant pollution levels across the country's waterways. Conducted between July 2025 and January 2026, the study involved 43 volunteer groups monitoring 71 sites across 58 rivers, stretching from the Lluta River in Arica to the Las Minas River in Punta Arenas.

Researchers found that more than half of the monitored sites contained large accumulations of waste, defined as more than 25 objects. The highest concentrations were recorded in the Lluta and Loa rivers in the northern region, an area currently facing a state of catastrophe due to alluvial floods. These accumulations pose a heightened risk as heavy rains and floods can mobilize debris.

The participatory science program, ‘Científicos de la Basura’ (Waste Scientists) from the Universidad Católica del Norte (UCN), reported a total of over 7,000 objects, with an average abundance of 1.7 objects per square meter of riverbank. In addition to surface waste, volunteers used specialized nets to collect microplastics, which are currently undergoing analysis in Germany.