Microplastics as vectors of antibiotics, heavy metals, and PFAS from agricultural soils to the food chain: Sources, transport pathways, and human health implications

Plastics are integral to modern agriculture and food systems, serving functions from soil covering and crop storage to food packaging. However, their widespread use contributes to the introduction of micro- and nano-plastics into food and the environment. These particles can adsorb pollutants such as antibiotics, heavy metals, and per- and polyfluoroalkyl substances (PFAS) from contaminated soil, water, and packaging materials, enabling their transfer through food systems. To evaluate the role of microplastics as pollutant carriers, we synthesized adsorption data from 87 studies and examined how polymer type, surface properties, and pollutant thermodynamics influence adsorption capacity. Results showed a strong variability across plastic types and pollutants. Polyethylene (PE) and polyvinyl chloride (PVC) exhibited a strong affinity towards antibiotics, while polyethylene terephthalate (PET) and PVC showed a strong affinity to heavy metals. Non-essential metals exhibited greater affinity for microplastics than essential ones. PFAS adsorption was also highest on PET, but data on other plastics were scarce. Thermodynamic indicators such as contact angle and solubility did not reliably predict adsorption behavior, likely due to differing environmental conditions among studies. Our analysis reveals that the risks posed by microplastics depend more on their environmental prevalence, transport, and pollutant release dynamics than on adsorption capacity alone. Major research gaps remain, including inconsistent study protocols, limited pollutant coverage, and insufficient field-scale data-issues that should be resolved to better assess pollutant transfer and exposure risks in agricultural and food systems.