Microplastic pollution from cement production: Health risks in tomato fruits (Solanum lycopersicum) cultivated around the sokoto cement plant

Abstract

Microplastics are an emerging class of environmental pollutants that have been widely investigated across various environmental matrices due to their ubiquity and potential toxicity. However, limited studies have explored the contribution of cement production facilities to microplastic pollution. This study evaluated the concentrations, characteristics, and associated health risks of microplastics in tomato fruits ( Solanum lycopersicum ) cultivated around the Sokoto Cement Factory. Tomato samples were collected from the northern, southern, eastern, and western axes surrounding the facility, homogenized, chemically digested, and analyzed using light microscopy and Fourier Transform Infrared (FTIR) spectroscopy. Microplastic concentrations ranged from 120 to 730 items/g, with the highest levels observed in the southern axis and the lowest in the northern axis. Four major microplastic morphotypes, fragments, fibers, foams, and pellets, were identified, with fibers being the dominant form. Most microplastics were transparent/white and blue in color, with size ranges of 100–500 µm and 500–1000 µm predominating. FTIR analysis identified polyethylene (PE), polyvinyl chloride (PVC), polypropylene (PP), and polyethylene terephthalate (PET), indicating inputs from multiple industrial and packaging-related sources. Heavy metal concentrations (Cd, Ni, Pb, Mn, and Cr) were determined, and correlation analysis revealed varying degrees of association between microplastic abundance and metal levels across the sampling locations. Polymer risk assessment revealed that PP posed a low risk (risk level II), PE and PET posed moderate risks (risk level III), while PVC presented a very high risk (risk level V) across all sampling locations. These results demonstrate that emissions and plastic-related activities associated with cement production can contribute to microplastic contamination of adjacent agricultural lands. Continuous environmental monitoring and improved waste management practices are therefore recommended to mitigate potential environmental and public health risks. • Microplastics were detected in tomato fruits cultivated around a cement factory. • Southern axis farms showed the highest microplastic contamination levels. • Fibers dominated, with most particles sized 100–1000 µm and light-colored. • PE, PP, PET, and PVC polymers indicated industrial and packaging sources. • PVC exhibited very high health risk compared with other detected polymers.