The hidden threat of plastic leachates: A critical review on their impacts on aquatic organisms

Abstract

Plastic products are made from the essential polymer mixed with a complex blend of substances including catalyst remnants, polymerization solvents, and a wide range of other additives deliberately added to enhance the desirable characteristics of the final product. Additives include bisphenols, phthalates, flame retardants, and further emerging and legacy contaminants. With a few exceptions, additives are not chemically bound to the polymer, and potentially migrate within the material reaching its surface, then possibly leach out to the environment. Leachates are mixtures of additives, some of which belong to the list of emerging contaminants, i.e. substances that show the potential to pose risks to the environment and human health, while are not yet regulated. The review discusses the state of the art and gaps concerning the hidden threat of plastic leachates. The focus is on reports addressing the biological impacts of plastic leachates as a whole mixture. Degradation of plastics, including the weathering-driven fragmentation, and the release of additives, are analysed together with the techniques currently employed for chemically screening leachates. Because marine plastic litter is a major concern, the review mainly focuses on the effects of plastic leachates on marine flora and fauna. Moreover, it also addresses impacts on freshwater organisms. Finally, research needs and perspectives are examined, to promote better focused investigations, that may support developing different plastic materials and new regulations.

Plastic additives: challenges in ecotox hazard assessment

“…The risk characterization of MNPs is a nuanced, multifaceted issue. Much of the research on MNP toxicity has primarily focused on the toxicity of the particles themselves but there is a recognized need to investigate and characterize the potential associated environmental risks of the varied additives inherently present in plastic (Gunaalan, Fabbri & Capolupo, 2020). The concentration of additives in plastic polymers is dependent on function but up to 70% of weight has been previously reported, making plastic additives a potentially underrepresented hazard (Hahladakis et al, 2018).…”

Impacts of Plastic Pollution on Ecosystem Services, Sustainable Development Goals, and Need to Focus on Circular Economy and Policy Interventions

“…Due to improper management, plastic wastes reach the aquatic ecosystems in both fresh and marine water by getting loaded with all kinds of plastics [259,260]. Plastics in micro and nano sizes are affecting the aquatic organisms severely [47,261,262].…”

Microplastics in freshwater fishes: Occurrence, impacts and future perspectives

“…These in vitro studies suggest that a variety of chemical and physiological cues in different species and sections of the GIT may change the absorption profile of MPs to leach out chemicals internalized within the particle as well as those bound to the external surface of the particle. Chemicals within MPs often include additives such as flame retardants and bisphenols which are added to plastics to achieve certain properties (Chen, Allgeier, et al, 2019; Gunaalan et al, 2020; Sun, Nan, et al, 2019), while externally bound chemicals may include a variety of pharmaceuticals, fertilizers, pesticides and heavy metals encountered and bound in the freshwater environment (Atugoda et al, 2020; Bradney et al, 2019; Caruso, 2019; Guan et al, 2020). MPs may therefore vector or leach a range of different chemicals into fish and other biota that then produce effects according to factors such as the type of chemical, concentration, where the chemical is released within the GIT and whether the chemicals are taken up across the intestinal barrier (Bradney et al, 2019; Gunaalan et al, 2020).…”