Aflatoxins and Fumonisins: Assessment Methods, Biomarkers of Exposure, Modified Forms, Co-Exposure, and Impact on Human Health

Aflatoxins and fumonisins are two of the most prevalent and toxicologically significant mycotoxins contaminating global food supplies, particularly maize and groundnuts. Although several regulated mycotoxins contribute to food safety concerns, this review focuses on aflatoxins and fumonisins because they frequently co-occur in maize and maize products. Their widespread prevalence, distinct toxicological mechanisms, and combined health effects necessitate an integrated exposure and risk assessment. This review critically evaluates the current state of exposure assessment and its implications for human health. We examine the evolution of sample preparation techniques, highlighting the transition from traditional liquid–liquid extraction to advanced approaches such as QuEChERS and green extraction technologies that can handle the divergent physicochemical properties of lipophilic aflatoxins and hydrophilic fumonisins. Analytical methods are compared, from the robust but limited HPLC-FLD to the multi-analyte capabilities of LC-MS/MS and the emerging potential of aptamer-based biosensors. Furthermore, the review addresses the critical challenge of modified mycotoxins that evade routine detection yet may contribute to total toxicity. By synthesizing data on biomarkers of exposure and the mechanisms of co-exposure, we discuss the complex interplay between these toxins in the etiology of hepatocellular carcinoma and neural tube defects. The review concludes that mitigating the public health burden of mycotoxins requires a holistic strategy that integrates HRMS for non-targeted analysis with human biomonitoring to capture the accurate individual-level exposure.