邻苯二甲酸二丁酯对蚤状溞的毒理影响

Toxicological Effects of Di-N-Butyl Phthalate on Daphnia pulex

摘要: 浮游动物作为浮游生态系统的重要组成部分，其种群增长和群落结构对环境变化较为敏感，常被用作水环境变化的重要指示物。而邻苯二甲酸二丁酯(DBP)作为污染物中的重要组成成分，对浮游动物生长和群落结构有重要影响，并间接影响水生生态系统稳定性。因此，本研究选取蚤状溞为模式生物，探究邻苯二甲酸二丁酯(DBP)的生态毒理效应。结果表明，DBP对蚤状溞生长、行为及种群动态均具有剂量依赖性影响。长期暴露(14 d~21 d)下，100 μg·L⁻¹~250 μg·L⁻¹浓度范围内生长抑制最显著；行为方面，500 μg·L⁻¹暴露组的心跳频率较对照组下降约55%，游泳能力降低45.2%；种群层面，低浓度(5 μg·L⁻¹)可促进内禀增长率，而浓度 ≥ 250 μg·L⁻¹则抑制繁殖与种群增长。以上结果说明，即使在较低浓度下，长期DBP暴露仍对溞类生存与繁殖具有潜在威胁表明其生态风险具有明显的剂量依赖性，并在安全浓度范围内仍可能通过长期作用影响种群可持续性。

Abstract: Zooplankton, as an important component of the planktonic ecosystem, exhibits high sensitivity in population growth and community structure to environmental changes, and is thus commonly used as a key indicator of aquatic environmental changes. Di-N-butyl phthalate (DBP), as a significant constituent of pollutants, exerts considerable influence on the growth and community structure of zooplankton, thereby indirectly affecting the stability of aquatic ecosystems. Therefore, this study selected Daphnia pulex as a model organism to investigate the ecotoxicological effects of DBP. The results demonstrated that DBP had dose-dependent effects on the growth, behavior, and population dynamics of Daphnia pulex. Under long-term exposure (14 d~21 d), the most significant growth inhibition was observed within the concentration range of 100 μg/L ~250 μg/L. In terms of behavior, the heart rate of the 500 μg/L exposure group decreased by approximately 55% compared to the control group, and swimming ability was reduced by 45.2%. At the population level, a low concentration (5 μg/L) promoted the intrinsic rate of increase, whereas concentrations ≥ 250 μg/L inhibited reproduction and population growth. These findings indicate that long-term exposure to DBP, even at relatively low concentrations, poses a potential threat to the survival and reproduction of Daphnia species. This suggests that the ecological risk of DBP exhibits clear dose dependency, and long-term exposure within safe concentration ranges may still affect population sustainability.