E waste governance in Nigeria through exploratory topic modeling and thematic synthesis

Nigeria's waste electrical and electronic equipment system connects informal livelihoods, hazardous processing, producer responsibility, and circular-economy incentives. This study combines a documented exploratory LDA analysis with contextual thematic synthesis. Thirteen supplied files yield eleven unique readable sources; ten full documents published in 2019–2025 form the primary corpus, and one partial 2008 article is used in sensitivity analysis. A four-topic model separates environmental and material risks, EPR implementation, justice concerns, and hazardous waste trade policy. Their equal-document mean proportions are 44.2%, 33.1%, 12.7%, and 10.0%, respectively. These lexical topics differ from the four interpretive themes used for governance appraisal. The four-topic solution is unstable across seeds and source changes; a two-topic model is substantially more stable. Contamination terms exceed enforcement terms in pooled counts, but the comparison reverses under equal-source weighting. Descriptive period differences are confounded by document type and related project reporting. The synthesis connects practices, exposure, EPR, and economics to transition theory and environmental justice, while distinguishing policy proposals from measured effectiveness. The contribution is a reproducible exploratory analysis with explicit evidence boundaries, rather than a validated national topic taxonomy or a causal evaluation of Nigerian policy.