Assessment of Microplastic Contamination in Urban Vegetable Production Soils of Lagos State: Implications for Horticultural Safety

Microplastic contamination of agricultural soils is an emerging environmental concern with potential implications for soil health, plant physiology, and food safety. In Lagos State, urban vegetable farms frequently receive plastic waste-contaminated irrigation water, atmospheric deposition, and direct littering, creating conditions for significant microplastic accumulation in horticultural production soils. This study assesses the type, concentration, and spatial distribution of microplastics in urban vegetable production soils across three ecological zones of Lagos State, including coastal, floodplain, and upland farms. Soil samples were collected from 45 active vegetable farm sites and analyzed for microplastic content using density separation, visual inspection under stereomicroscopy, and FTIR spectroscopy for polymer identification. Results indicate mean microplastic concentrations ranging from 1,850 to 5,430 particles per kilogram of dry soil, with polyethylene, polypropylene, and polystyrene as the dominant polymer types. Urban fringe farms showed the highest concentrations. Microplastic abundance was negatively correlated with soil microbial activity, suggesting functional soil health implications. The study recommends implementation of urban waste management policies targeting agricultural land protection, improved soil amendment screening, and development of horticultural safety guidelines for microplastic-contaminated production sites in Lagos State. Keywords: microplastics, urban vegetable farms, soil contamination, food safety, Lagos State