Occurrence and Characteristics of Microplastics in Food and Drinking Water in Nigeria: A Systematic Review and Meta-Analysis

Microplastic pollution has emerged as a growing environmental and public health concern globally, yet evidence synthesis from developing regions such as Nigeria remains limited. This systematic review aims to consolidate and critically appraise published data on the occurrence, concentration, and characteristics of microplastics in food and drinking water in Nigeria. The review will follow the PRISMA 2020 guidelines and be registered on the Open Science Framework (OSF) to enhance transparency and reproducibility. Electronic databases including Scopus, Web of Science, PubMed, ScienceDirect, Google Scholar, and African Journals Online will be searched for studies published between 2015 and 2025. Eligible studies will include peer-reviewed articles reporting the detection, quantification, or characterization of microplastics in food or water samples consumed in Nigeria. Data will be extracted on sample type, concentration, polymer composition, morphology, and analytical methods. Risk of bias will be assessed using the Joanna Briggs Institute (JBI) critical appraisal checklist for prevalence studies. Quantitative data will be synthesized using random-effects meta-analysis, while qualitative data will be narratively summarized. The findings will provide a baseline for microplastic exposure estimation, highlight research gaps, and inform policy directions on environmental monitoring and food safety in Nigeria.