Meta-analysis of endocrine-disrupting chemical effects on earthworm functional traits

Endocrine-disrupting chemicals (EDCs) are ubiquitous emerging environmental contaminants. However, the comprehensive impact of EDCs on soil ecosystems, particularly on the model organism Eisenia fetida, remains inadequately understood due to disparate experimental and assessment methods. A meta-analysis was conducted to analyze the effects of EDCs on earthworm functional traits, including survival, behavior, growth, reproduction, and cellular responses. The analysis revealed that EDCs significantly impaired earthworm survival (-17.5%, p < 0.05), behavior (-62.2%, p < 0.001), growth (-11.5%, p < 0.001), and reproduction (-36.7%, p < 0.001). EDCs induced substantial oxidative stress, evidenced by a 36.5% (p < 0.001) increase in reactive oxygen species (ROS) production and elevated oxidative damage. The antioxidant defense system showed compensatory activation, with enhanced superoxide dismutase (10.0%) and catalase (8.90%) activities and glutathione levels (23.3%) (p < 0.001). The present study found chemical-specific toxicity patterns with heavy metals causing the most severe effects on behavior and reproduction. Toxicity profiles varied with exposure concentration and duration, revealing complex dose-response and temporal relationships. These findings provide crucial insights for the ecological risk assessment of EDCs and establish a foundation for developing targeted mitigation strategies. Furthermore, the findings highlight the importance of taking multiple endpoints into account when evaluating the toxicity of EDCs and suggest possible directions for future research.