Pesticides effects and sensitivity of enchytraeids and earthworms: A systematic review in Brazilian research and future perspectives

The intensive use of pesticides in Brazilian agriculture may pose significant risks to soil biodiversity and ecological functions in tropical and subtropical conditions. Terrestrial oligochaetes, such as earthworms and enchytraeids, are key bioindicators for assessing pesticide toxicity due to their ecological roles in soil structure, nutrient cycling, and organic matter decomposition. This systematic review compiles 118 toxicity assessments derived from 34 studies conducted in Brazil, using natural soils or Tropical Artificial Soil (TAS), primarily involving Eisenia andrei and Enchytraeus crypticus. Insecticides accounted for the most evaluations (54%), followed by fungicides (31%) and herbicides (15%), with emphasis on substances showing high toxicity: imidacloprid, fipronil, carbendazim, and mancozeb. Soil characteristics such as pH, organic matter, and clay content played a decisive role in modulating pesticide effects, with sandy and acidic soils generally enhancing toxicity. The predominant endpoints assessed were lethality and reproduction, reflecting the reliance on standardized ISO and OECD protocols. However, the scarcity of studies involving native species and representative tropical soil types reveals a significant knowledge gap that could limit ecological realism and regulatory applicability of current data. This review underscores the urgent need for more context-specific approaches in pesticides Environmental Risk Assessment to ensure adequate protection of tropical soil ecosystems.