Solid waste management in informal settlements in Harare, Soweto, Egypt, Accra, Kinshasa, and Lagos: a review of challenges, impacts, and measures for improvement

In many African cities, informal settlements have become a ubiquitous feature, housing approximately 238 million people. Despite their prevalence, these settlements often struggle to access basic services, including solid waste management, with approximately 70% of waste generated in these areas going uncollected. This current review paper investigates the solid waste management challenges in informal settlements in Harare, Soweto, Kinshasa, and Lagos. The study employed a semi-systematic review methodology, utilizing a combination of thematic presentation and narrative format to present the findings. A systematic search of academic databases, including Scopus, Web of Science, and Google Scholar, was conducted using specific keywords such as "informal settlements," "solid waste management," "urban planning," and "environmental health." Studies published in English between 2016 and 2024 were included, yielding a total of 58 studies that met the inclusion criteria. The results of this systematic review confirm that informal settlements face significant challenges in waste management, including insufficient waste collection, inadequate disposal facilities, and lack of proper infrastructure. However, our comparative analysis of 6 cities reveals new insights into the similarities and differences in waste management practices and their impact on environmental and health outcomes. The research further explores the far-reaching environmental and health consequences of inadequate solid waste management in these settlements. Notably, other African cities, such as Accra, Cairo, and Lagos, have also demonstrated strong community leadership and social cohesion, contributing to the success of their community-led initiatives. These examples illustrate that the principles underlying successful community-based waste management initiatives can be applied in different contexts, highlighting the potential for replication and adaptation.