Informal recycling sector contribution to plastic pollution mitigation: A systematic scoping review and analysis of prevalence and productivity

Abstract

Abstract A large global workforce of informal entrepreneurs has historically dominated circular economy practices in the Global South, collecting many millions of tonnes of waste for recycling, and supplementing insufficiencies in struggling municipal waste management systems. Ongoing negotiations for a ‘Legally Binding Instrument on Plastic Pollution’ implicitly recognise the substantial contribution made by the informal recycling sector (IRS - waste pickers) to plastic pollution mitigation. To this, we carried out a systematic scoping review of IRS prevalence and productivity following the PRISMA-ScR method followed by extensive data analytics. Waste pickers represent median 0.2% (interquartile range – IQR: 0.1-0.5%) of the urban population worldwide, collecting between 20 kg and 80 kg of engineered materials for recycling each day, of which 30% (mean wt. ar) are plastics. We identify substantial shortcomings in most methodologies used to gather data on the IRS, introducing epistemic uncertainty into some previous estimates of the sector’s activity. We recommend development of a standardised resource-efficient method of sampling and data gathering, suitable for implementation at municipal/local scale. Our work offers verifiable quantitative knowledge on the sector’s activities to date, suitable for use in plastic pollution quantification models and local/national action plans required to baseline and monitor progress towards multilateral targets.