Nano-Enabled Agrochemicals as Ecological Technologies: Ecotoxicity, Non-Target Effects, and a Safe-and-Sustainable-by-Design Framework

Nanofertilizers and nanopesticides provide significant agricultural benefits through enhanced nutrient efficiency and reduced pesticide application; however, their nanoscale properties raise environmental safety concerns. As emerging ecological technologies designed to minimize environmental footprints, these nano-enabled agrochemicals require systematic safety evaluation. However, conventional ecotoxicity tests-designed for soluble chemicals-cannot adequately capture nanoparticle stability, aggregation, or time-dependent exposure, creating a 'measurement gap' in risk assessment. This review summarizes the historical development, primary application areas, and cutting-edge advancements of nanotechnology. A systematic analysis is conducted on the dose-dependent phytotoxicity of metal and metal oxide nanoparticles, including their impacts on chlorophyll content, microbial community structure, carbon and nitrogen cycling enzymes, arbuscular mycorrhizal colonization, soil respiration, and plant metabolic remodeling. Additionally, the review evaluates the effects on soil physicochemical properties, plant-microbe symbioses, and non-target organisms such as invertebrates, pollinators, and nematodes. Finally, we propose a Safe-and-Sustainable-by-Design framework that emphasizes low-hazard materials, predictable degradability, life-cycle thinking, carrier minimization, and AI-assisted risk prediction to guide responsible nano-agrochemical development.