In the heart of Iran’s Mian-Ab Plain, a silent invader is seeping into the soil, threatening both agricultural productivity and human health. Microplastics, tiny fragments of plastic less than five millimeters in size, have been found in alarming concentrations in the region’s topsoil, according to a groundbreaking study led by Faezeh Jahedi, a researcher at the Student Research Committee, Ahvaz Jundishapur University of Medical Sciences. The research, published in Discover Applied Sciences, sheds light on the abundance, distribution, and ecological risks of these microscopic pollutants in an arid agricultural setting, offering crucial insights for the energy and agricultural sectors.
The study, the first of its kind in the Middle East, employed a combination of visual observations, scanning electron microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDS), and Raman micro-spectroscopy to quantify and characterize microplastics in soil samples. The results revealed a total microplastic loading of 11.93 ± 0.9 items per kilogram of surface soil, with distinct contamination hotspots in urbanized regions.
“Urban areas, particularly those with high population densities and industrial activities, tend to have higher microplastic concentrations,” Jahedi explained. “Our GIS-based mapping showed that regions like S9, S6, and S11 had the highest concentrations, while predominantly agricultural zones had lower levels.”
The microplastics identified in the study exhibited various morphologies, colors, and sizes, with black-grey fibers smaller than 100 micrometers being the most dominant. SEM–EDS analysis revealed the presence of trace elements on the microplastic surfaces, indicating potential pollutant adsorption and raising concerns about their impact on soil health and crop uptake.
The study also identified several polymer types, suggesting mixed domestic and agricultural sources. “We found polymers like PET, PS, PP, and Nylon, which are commonly used in packaging, textiles, and agricultural films,” Jahedi said. “This highlights the need for better waste management practices and reduced plastic use in agriculture.”
The ecological risks associated with microplastic contamination were assessed using the Hazard Index (HI) and Pollution Load Index (PLI). The HI was found to be at risk level III (10 ≤ HI < 100), while the PLI indicated moderate pollution. Moreover, the estimated ingestion exposure suggested a higher risk for children than adults, underscoring the potential health implications for vulnerable populations. For the energy sector, this research highlights the importance of sustainable practices in plastic management and waste disposal. As the demand for energy and agricultural products continues to grow, so does the need for innovative solutions to mitigate environmental impacts. This study provides a foundation for developing strategies to reduce microplastic pollution in arid agricultural soils, ultimately promoting sustainable agriculture and protecting human health. The findings also emphasize the need for further research on the long-term effects of microplastics on soil ecosystems and crop productivity. As Jahedi noted, "Understanding the spatial distribution and sources of microplastics is the first step in addressing this environmental challenge. Future studies should focus on developing remediation techniques and policies to minimize microplastic contamination in agricultural soils." The study, published in Discover Applied Sciences, which translates to Discover Applied Sciences in English, marks a significant step forward in our understanding of microplastic pollution in arid regions. As the global community continues to grapple with the impacts of plastic waste, this research offers valuable insights for developing effective mitigation strategies and promoting sustainable practices in the energy and agricultural sectors.