Plastic pollution is pervasive in our environment, with impacts seen across ecosystems and taxa. While plastic has become an integral part of our daily lives, not all of it is readily apparent, making it challenging to effectively reduce plastic pollution. A hidden source of plastic pollution is plastic-based printing, which is used on a wide range of items including single-use products like plastic food containers and multi-use plastic items like credit cards. This also includes items that we would not consider to be sources of plastic pollution such as glass bottles with surface printing. The widespread use of this printing, therefore, results in even non-plastic items contributing to plastic pollution, potentially contaminating recycling streams and exacerbating nano- and microplastic (NMP) dispersion. Given the challenges of remediating NMP plastic pollution once it has entered the environment, prevention becomes paramount. With significant efforts underway to reduce plastic production, it is important to take a holistic approach to redesigning objects and materials to avoid false solutions, which will continue to contribute to ecosystem degradation and planetary boundary transgressions. To make meaningful progress and avoid ineffective solutions, it is imperative to consider all sources of plastic pollution, including those concealed within apparently non-plastic objects.

Mitochondria are unique organelles to perform critical functions such as energy production, lipid oxidation, calcium homeostasis, and steroid hormone synthesis in eukaryotic cells. The proper functioning of mitochondria is crucial for cellular survival, homeostasis, and bioenergetics. Mitochondrial structure and function are maintained by the mitochondrial quality control system, which consists of the processes of mitochondrial biogenesis, mitochondrial dynamics (fusion/fission), mitophagy, and mitochondrial unfolded protein response UPRMT. Mitochondrial dysfunction and/or damage is associated with the initiation and progression of several human diseases, including neurodegenerative, cardiovascular, age-related diseases, diabetes, and cancer. Environmental stress and contaminants may exacerbate the sensitivity of mitochondria to damage which causes mitochondrial dysfunction. There is growing evidence about the impact of nanoplastics (NPs) and microplastics (MPs) on mitochondrial health and function. MPs/NPs were reported to trigger oxidative stress and reactive oxygen species production, which eventually change mitochondrial membrane potential. MPs/NPs can cross through the biological barriers in the human body and be internalized by the cells, potentially altering mitochondrial dynamics, bioenergetics, and signaling pathways, thus impacting cellular metabolism and function. This review states the effects of MPs/NPs on mitochondrial homeostasis and function as well as on mitochondrial membrane dynamics, mitophagy, and mitochondrial apoptosis are discussed.

Over the past decade, there have been increasing recognition and concern of the toxicological impacts of microplastics (MPs) in the environment, which have been widely found in various marine environments from estuary to deep oceans. Numerous toxicological studies have been conducted on the impacts of MPs on various marine organisms, especially phytoplankton, zooplankton, bivalves, and fish of different trophic levels. These studies mainly focused on the measurements of MPs bioaccumulation and their resulting biological impacts at molecular, metabolic, biochemical, physiological, and organismic levels. This review examines the various studies conducted over the recent years on the toxicology of MPs in different marine organisms, particularly on the bioaccumulation and toxicity of MPs. The impacts of MPs on marine organisms are diverse, and the complexity of organism physiology as well as MPs physical and chemical properties need to be considered. Future studies should consider the environmental relevance of toxicological research and the development of quantitative tools to model the transport, bioaccumulation, and toxicity of MPs. These are important for the real environmental risk assessments of MPs in the marine environments.