Global microplastic contamination of almost all biological and environmental media is an emerging threat to human health that recently fostered intense research. Here, we review polyethylene terephthalate with focus on microplastics, characteristics, uses, concentration, degradation, toxicity, and remediation. Plastic remediation can be done by landfills, incineration, pyrolysis, and biodegradation. We present microplastic occurrence in food, beverages, dust, wildlife, and human tissues. We observed inconsistencies in measurement techniques, limitations in detection reliability, and gaps in risk assessment.

The expanded uses of bioplastics require understanding the potential health risks associated with their exposure. To address this issue, Drosophila melanogaster as a versatile terrestrial in vivo model was employed, and polylactic acid nanoplastics (PLA-NPLs), as a proxy for bioplastics, were tested as a material model. Effects were determined in larvae exposed for 4 days to different concentrations (25, 100, and 400 μg/mL) of 463.9 ± 129.4 nm PLA-NPLs. Transmission electron microscopy (TEM) and scanning electron microscope (SEM) approaches permitted the detection of PLA-NPLs in the midgut lumen of Drosophila larvae, interacting with symbiotic bacteria. Enzymatic vacuoles were observed as carriers, collecting PLA-NPLs and enabling the crossing of the peritrophic membrane, finally internalizing into enterocytes. Although no toxic effects were observed in egg-to-adult survival, cell uptake of PLA-NPLs causes cytological disturbances and the formation of large vacuoles. The translocation across the intestinal barrier was demonstrated by their presence in the hemolymph. PLA-NPL exposure triggered intestinal damage, oxidative stress, DNA damage, and inflammation responses, as evaluated via a wide set of marker genes. Collectively, these structural and molecular interferences caused by PLA-NPLs generated high levels of oxidative stress and DNA damage in the hemocytes of Drosophila larvae. The observed effects point out the need for further studies aiming to deepen the health risks of bioplastics before adopting their uses as a safe plastic alternative.

Cooking with polytetrafluoroethylene-coated pans releases thousands to millions of microplastic and nanoplastic particles per use, directly contaminating food and the environment. Here we review polytetrafluoroethylene microplastics with emphasis on polytetrafluoroethylene characteristics, environmental occurrence, and detection methods. Polytetrafluoroethylene has high chemical stability and is used in medical devices, clothes and protective suits, aerospace, non-sticking pans, cables and insulation, filtration, irrigation and electronics. We discuss plastic utensils as microplastic sources, and the influence of temperature and aging on microplastic release. The presence of microplastics in humans, wild animals, sediments, water and the atmosphere is described. Limitations of actual analytical methods such as density separation are detailed. Polytetrafluoroethylene accounts for about 60% of the global fluoropolymer market, and is a major contributor to microplastic pollution, accounting for up to 44% of microplastics in sediments, 74% in benthic fish, and 60% in human organs. Our meta-analysis shows that polytetrafluoroethylene microplastic concentrations average 7.3 ± 13.3 particles per L in water, 3,685.7 ± 4,832.0 particles per kg in sediment, 24.9 ± 37.1 particles per individual in fish, and 482.5 ± 554.1 particles per kg in human tissues. Polytetrafluoroethylene microplastics may impair physiological homeostasis by inducing oxidative stress, inflammation, necrosis, and disruption of key cellular signaling pathways.

Reproductive toxicity from micro/nanoplastics (MNPLs) is an emerging concern requiring further investigation to close existing knowledge gaps. This study explores the reproductive toxicity of polystyrene nanoplastics (PSNPLs) using Drosophila as an in vivo model. Males and females were exposed to PSNPLs (100 and 500 µg/mL) for one/two weeks. Confocal and transmission electron microscopy revealed widespread distribution of PSNPLs across various tissues, including ovaries, testes, and gametes (ova and sperm). Structural damage, such as hole formation in the seminiferous tubules and ovarian atrophy, was observed following exposure. The physical presence of PSNPLs in reproductive organs disrupted reproductive outcomes, particularly in matings between exposed males and females. Key impairments included reduced fecundity, lower fertility, and a skewed sex ratio, especially after one week of exposure, with minimal effects after two weeks. Significant disruptions in the expression of reproductive and developmental genes were observed in both sexes, with males exhibiting greater sensitivity to PSNPLs, regardless of exposure concentration or duration. These findings provide critical insights into the reproductive toxicity of PSNPLs, underscoring both physical disruptions in reproductive tissues and molecular alterations. This highlights the potential for MNPLs to cause hidden reproductive damage and emphasizes the sex-dependent nature of these toxic effects.

Reproductive toxicity is of special concern among the harmful effects induced by environmental pollutants; consequently, further studies on such a topic are required. To avoid the use of mammalians, lower eukaryotes like Drosophila are viable alternatives. This study addresses the gap in understanding the link between reproductive adverse outcomes and the presence of pollutants in reproductive organs by using Drosophila. Silver nanoparticles (AgNPs) were selected for their ease of internalization, detection, and widespread environmental presence. Both male and female flies were exposed to AgNPs (28 ± 4 nm, 100 and 400 µg/mL) for one week. Internalization and bioaccumulation of AgNPs in organs were assessed using transmission electron microscopy, confocal microscopy, and inductively coupled plasma mass spectrometry. Substantial accumulation of AgNPs in the gastrointestinal tract, Malpighian tubules, hemolymph, reproductive organs (ovaries and testes), and gametes were observed. The highest AgNP content was observed in testes. Exposure to AgNPs reduced ovary size and fecundity, though fertility and gender ratios of the offspring were unaffected. Significant deregulation of reproductive-related genes was observed, particularly in males. These findings underscore the utility of Drosophila as a model for evaluating reproductive hazards posed by AgNP exposure. The ease of AgNP internalization in Drosophila reproductive targets could be extrapolated to mammalians, raising concerns about the potential impacts of nanoparticle exposure on reproduction toxicity in humans.

Evidence of micro- and nanoplastics (MNPLs) presence in human tissues, cells, and biological fluids raises concerns about their potential role in hazardous