Abstract
Solid waste pollution is a multifaceted global challenge affecting the environment, economy, and human health, yet our
understanding of environmental solid waste dynamics, such as waste type, weight(W), and volume(V), which inform waste
management initiatives and policy frameworks remains limited in Sub-Saharan Africa. In this longitudinal study, we mapped
informal waste disposal sites using transect-walks and drones in urban Malawi. Monthly characterisation of selected individual
waste piles was undertaken for 12 months. Sampling (200L/waste pile) included both surface and compacted sections.
(60 cm depth), which were characterised by weight(kg/m2), volume(m3), and individual counts of plastic items(m2). Three-way ANOVA and a linear mixed-effect model were used to predict percentage recovery for the interactions between month, waste pile depth, and waste type as fixed factors. Fourteen out of 56 waste piles received detailed temporal characterisation. Waste piles were located along rivers(50%), streams(29%), and open-dumping spaces(21%). Soil (W:60%, V:19%), organic material (W:22%, 33%), and plastics (W:8%, V:24%) were the highest components by weight, and volume, making plastics the highest non-organic category of waste. Seven plastic polymer types were identified, with Low-Density Polyethylene being the most common (83% plastic items/m2). Seasonality, waste pile depth, and waste type (F(171, 4284) = 11.44, p < .001, η2 = .31) significantly affected percentage recovery of waste items, indicating their effect on waste pile dynamics. Sustainable waste management initiatives need to account for seasonal changes, material characteristics, and waste pile stratification to effectively improve waste management systems and the public health implications of waste piles.

Keywords: Environmental pollution. Informal settlements · Plastic pollution · Single-use plastic · Solid waste · Urban waste piles · Waste composition