Fate of pharmaceuticals in soil: A critical review on detection, distribution, and persistence

The increasing consumption and improper disposal of pharmaceuticals have led to their widespread occurrence in terrestrial environments, particularly in soils. The environmental concern associated with pharmaceuticals arises from their distribution and persistence in soil systems, which are governed by processes such as leaching, groundwater interactions, sorption, and slow degradation rates. Despite their potential ecological risks, the fate of pharmaceuticals in soil remains insufficiently understood. This review synthesizes current knowledge on the detection, distribution, and fate of pharmaceutical compounds in soil, with particular emphasis on adsorption and degradation behavior. Sorption is strongly influenced by the content of soil organic matter and fine fractions, while degradation, commonly represented by half-life values, is controlled by the intrinsic sorption properties of pharmaceuticals. As a result, persistent compounds in organic-rich or fine-textured soils may form long-term reservoirs, pose sustained environmental risks, and highlight the need for effective monitoring strategies. Advances in analytical techniques have improved pharmaceutical detection in soils, with liquid chromatography (LC)-based methods, including high-performance and ultra-performance liquid chromatography, increasingly preferred over gas chromatography. Sample preparation approaches such as Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) and solid-phase extraction further enhance analytical sensitivity, while coupling LC with mass spectrometry (LC-MS) enables reliable identification of pharmaceuticals in complex soil matrices. Overall, this review underscores the importance of continued methodological development, including real-time monitoring approaches, to support early detection, improved risk assessment, and informed mitigation strategies for pharmaceutical contamination in soil environments.