Occurrence and dynamics of organic contaminants in Tanzanian biota: legacies of the past and emerging concerns

Abstract

Research on persistent organic pollutants (POPs) in tropical regions is scarce, with most efforts concentrated in the Global North. This disparity is concerning as new contaminants are being synthesized and old contaminants find new ways of entering the environment. Of particular worry is the transportation of contaminants within modern consumer goods, such as electronics, from industrialized countries to less industrialized ones. These goods often end up in dumpsites where lack of proper disposal and recycling can lead to environmental contamination. This thesis seeks to expand our understanding of the occurrence and behavior of both legacy and emerging contaminants in Tanzania. The study involves the examination of marine fish, chicken eggs and soil around dumpsites and sites differing in degree of human activity. The main findings of this thesis include bioaccumulation of POPs in marine biota, seasonal variation of POPs, and their association with human activity. We found no definitive evidence linking e-waste to emerging contaminants in the Tanzanian environment. Instead, these contaminants appear to be widespread, even in areas with no production or extensive use. The presence of both legacy and emerging contaminants in Tanzanian biota necessitates continued research and monitoring efforts, building on the insights this study provides.