Overview of PCB Pollution in Africa: E-Waste and Insights from International Pellet Watch

Abstract

In this paper, literature from the last decade concerning the environmental levels of polychlorinated biphenyls (PCBs) in Africa is reviewed. Although data to determine general trends of PCBs across African countries were insufficient, high levels were observed in environmental and biological samples from some urban and industrial areas near electronic waste (e-waste) sites in Ghana, South Africa and Nigeria, in comparison to those in rural settings. Notably, atmospheric PCB concentrations showed a slow rate of decrease, particularly in a 10-year monitoring program (2008–2019), in which PCB levels ranged from 0.5 to 37.7 pg/m³, whereas more rapid decreases were observed in other areas globally. PCB levels in plastic resin pellets, which reflect pollution in coastal waters, in some African countries, namely, Tunisia and Senegal (554–3,384 ng/g-pellet, respectively), were comparable with, or slightly higher than, those in developed countries, i.e., the United States and France (178 and 2,230 ng/g-pellet, respectively). Nevertheless, due to inconsistent monitoring methods and limited data availability, temporal trends were still unclear. Improperly disposed PCB-containing equipment, like electrical transformers and capacitors, informal recycling and open burning of e-waste are significant contributors of PCBs in Africa. Even though there is no known PCB production in the region, the contamination levels mirror those in historically heavy-use areas, largely due to electrical equipment and inadequate e-waste handling practices. The understanding of temporal trends is hindered by the current gaps in data, which highlights that comprehensive monitoring and effective enforcement of global treaties such as the Stockholm Convention and the Basel Convention are urgently needed. To understand better and address the pervasive impact of PCBs in Africa, this review calls for sustained monitoring with follow-up intervals.