Informal recovery of recyclable waste in Buenos Aires City

• Innovative transect-based method estimates number and distribution of informal pickers. • 2,400 informal pickers collect 240 tons of cardboard and paper daily in Buenos Aires City. • Informal pickers represent and collect around half as much as the formal workforce. • Population density, accessibility and land use shape pickers distribution. This study analyzes informal recyclable waste recovery in Buenos Aires City (Argentina), a phenomenon poorly quantified despite its key role in urban waste management of many cities. Using an innovative methodology, based on transect sampling and validation with a control population, the number and spatial distribution of informal waste pickers were estimated. The results suggest that, in 2023, approximately 2,400 pickers were active daily, collectively recovering around 240 t of paper and cardboard. Their territorial distribution was concentrated in areas with high population density, intense commercial and administrative activity, and near major transit hubs. This study provides the first robust, spatially explicit estimate of informal waste picking activity in Buenos Aires City, using a replicable methodology that can support planning in other cities.