Plastic Leachates Disproportionately Impair Aquatic Animals: A Multifactor, Multieffect, and Multilevel Meta-analytic Model

While the toxicity of microplastics (MPs) and nanoplastics (NPs) has been demonstrated, studies focusing on plastic leachates (PLs) in isolation remain limited. Herein, we developed a multifactor, multieffect, and multilevel meta-analytic model (3M) to systematically evaluate the toxicity of PLs to aquatic animals and examine the impacts of multiple influencing factors. Six biochemical functions (survival, growth, development, reproduction, behavior, and physiology) of aquatic animals and impacts of 20 influencing factors (plastic characteristics, environmental conditions, and animal traits) were analyzed. The results revealed that PLs significantly impaired aquatic animals, with an overall effect of -28% (-40, -16%) on survival, 10% (-18, -2%) on growth, 30% (-44, -16%) on development, and 13% (-25, -2%) on reproduction. PL toxicity was positively correlated with plastic size and concentration and influenced by polymer type, biodegradability, aging conditions, and leaching conditions. Notably, marine species showed greater sensitivity than freshwater species, and primary consumers were more vulnerable than secondary consumers. Future research should prioritize environmentally relevant PL concentrations, standardized leaching procedures, and transparent reporting of environmental conditions. By identifying the key drivers of toxicity, our findings provide a valuable foundation for future efforts to develop effective strategies for mitigating PL toxicity.