Keywords: 
• microplastics /
• di-(2-ethylhexyl) phthalate /
• combined toxicity /
• ecotoxicology

Abstract: Microplastics (MPs) and di(2-ethylhexyl) phthalate (DEHP) are ubiquitous environmental pollutants. Their individual and combined toxicological effects pose significant threats to the ecological health of terrestrial animals, aquatic organisms, and plants. This study systematically reviews the toxicological impacts of MPs and DEHP on various biological groups, elucidating their mechanisms and revealing both synergistic and antagonistic effects of co-exposure. These findings provide a critical theoretical foundation for ecological risk assessment. Among terrestrial animals, exposure to MPs alone can induce liver inflammation, oxidative stress, and intestinal flora imbalance, and lead to abnormal neurological function. When MPs and DEHP are exposed jointly, the toxic effects are significantly enhanced, manifesting as multi-organ coordinated damage: liver cell death is caused through the ROS-mediated mitochondrial apoptosis and necroptosis pathways. Oxidative stress and inflammatory responses are intensified in the kidneys; intestinal permeability increases, triggering systemic inflammation; and the reproductive system is impaired due to hormonal imbalance and disruption of the blood-testis barrier. Studies on aquatic animals have shown that exposure to MPs alone can lead to gill tissue damage, reproductive dysfunction, and neurotransmitter disorders. When DEHP and MPs are co-exposed, the filtration rate of bivalves significantly decreases, the antioxidant system collapses, and metabolic pathways (such as energy metabolism and lipid metabolism) are severely disrupted. Moreover, combined pollution causes cardiac developmental malformations in zebrafish larvae and destruction of intestinal villi structure in largemouth bass, highlighting the long-term harm to the development and survival of aquatic organisms. Plant experiments have demonstrated that MPs inhibit seed germination (such as in tomatoes), reduce chlorophyll content (such as in tobacco), and induce oxidative stress (such as in peas). The combined effects of MPs and DEHP vary by species: in cucumbers, it shows an antagonistic effect on antioxidant enzyme activity, while in corn, it synergistically inhibits growth and photosynthesis, indicating the complexity of the interaction between pollutants. To sum up, the combined exposure of MPs and DEHP has exerted stronger toxic effects on terrestrial, aquatic animals and plants than single exposure. However, the distinct toxic targets have resulted in the variations of toxic effects. In the future, it is necessary to combine multi-omics technology and ecological simulation experiments to provide more comprehensive theoretical support for the ecological risk prevention and control of combined pollution.