Sweeteners at the Water–Soil Interface and in Soil Matrices: A Brief Review of Ecotoxicological Impacts

Sweeteners have become emerging contaminants in terrestrial and aquatic environments due to their extensive use in food, pharmaceutical, alternative smoking, and personal care products. They reach terrestrial ecosystems from both atmospheric and aquatic ecosystems, making the water–soil interface a critical zone governing their transport, persistence, and environmental fate, which remains mostly unknown, thus creating a gap that needs to be filled. This review aims to summarize current knowledge on the occurrence, mobility, persistence, and ecotoxicological effects of artificial and natural sweeteners in soils and at the water–soil interface, with emphasis on sucralose, saccharin, acesulfame potassium, aspartame, cyclamate, and steviol glycosides. The review covers seventy-two full papers, published from 2004 to 2026, involving sweetener intake and occurrence and environmental fate in soil and at the water–soil interface. Sweeteners may persist in terrestrial and aquatic ecosystems, inducing, either individually or in combination, oxidative stress and influencing microbial communities and enzymatic activity at the soil–water interface, which affects invertebrates, plant roots, and the overall ecosystem. Their effects on soil biota are still poorly understood. These influences, as well as the effects of long-term persistence and differences in responses across soil types and climatic conditions, are mostly unknown. This review highlights the central role of the soil matrix and water–soil interface in understanding the environmental fate and ecological significance of sweeteners and identifies key gaps requiring further soil-specific research.