Enhanced reproductive toxicities induced by phthalates contaminated microplastics in male mice (Mus musculus)

Unraveling the potential human health risks from used disposable face mask-derived micro/nanoplastics during the COVID-19 pandemic scenario: A critical review

With the global spread of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), disposable face masks (DFMs) have caused negative environmental impacts. DFMs will release microplastics (MPs) and nanoplastics (NPs) during environmental degradation. However, few studies reveal the release process of MPs/NPs from masks in the natural environment. This review presents the current knowledge on the abiotic and biotic degradation of DFMs. Though MPs and NPs have raised serious concerns about their potentially detrimental effects on human health, little attention was paid to their impacts on human health from DFM-derived MPs and NPs. The potential toxicity of mask-derived MPs/NPs, such as gastrointestinal toxicity, pneumotoxicity, neurotoxicity, hepatotoxicity, reproductive and transgenerational toxicity, and the underlying mechanism will be discussed in the present study. MPs/NPs serve as carriers of toxic chemicals and pathogens, leading to their bioaccumulation and adverse effects of biomagnification by food chains. Given human experiments are facing ethical issues and animal studies cannot completely reveal human characteristics, advanced human organoids will provide promising models for MP/NP risk assessment. Moreover, in-depth investigations are required to identify the release of MPs/NPs from discarded face masks and characterize their transportation through the food chains. More importantly, innovative approaches and eco-friendly strategies are urgently demanded to reduce DFM-derived MP/NP pollution.

Health risks of phthalates: A review of immunotoxicity

Phthalates (PAEs) are known environmental endocrine disruptors that have been widely detected in several environments, and many studies have reported the immunotoxic effects of these compounds. Here, we reviewed relevant published studies, summarized the occurrence and major metabolic pathways of six typical PAEs (DMP, DEP, DBP, BBP, DEHP, and DOP) in water, soil, and the atmosphere, degradation and metabolic pathways under aerobic and anaerobic conditions, and explored the molecular mechanisms of the toxic effects of eleven PAEs (DEHP, DPP, DPrP, DHP, DEP, DBP, MBP, MBzP, BBP, DiNP, and DMP) on the immune system of different organisms at the gene, protein, and cellular levels. A comprehensive understanding of the mechanisms by which PAEs affect immune system function through regulation of immune gene expression and enzymes, increased ROS, immune signaling pathways, specific and non-specific immunosuppression, and interference with the complement system. By summarizing the effects of these compounds on typical model organisms, this review provides insights into the mechanisms by which PAEs affect the immune system, thus supplementing human immune experiments. Finally, we discuss the future direction of PAEs immunotoxicity research, thus providing a framework for the analysis of other environmental pollutants, as well as a basis for PAEs management and safe use.

Long-Term Exposure to Environmentally Relevant Doses of Large Polystyrene Microplastics Disturbs Lipid Homeostasis via Bowel Function Interference

The question of whether long-term chronic exposure to microplastics (MPs) could induce dose- and size-dependent adverse effects in mammals remains controversial and poorly understood. Our study explored potential health risks from dietary exposure to environmentally relevant doses of polystyrene (PS) MPs, through a mouse model and integrated analyses of the interruptions of fecal microbial metagenomes and plasma lipidomes. After 21 weeks of exposure to the MPs (40-100 μm), mice mainly exhibited gut microbiota dysbiosis, tissue inflammation, and plasma lipid metabolism disorder, although no notable accumulation of MPs was observed in the gut or liver. The change of the relative abundance of microbiota was strongly associated with the exposure dose and size of MPs while less significant effects were observed in gut damage and abnormal lipid metabolism. Moreover, multiomics data suggested that the host abnormal lipid metabolism was closely related to bowel function disruptions, including gut microbiota dysbiosis, increased gut permeability, and inflammation induced by MPs. We revealed for the first time that even without notable accumulation in mouse tissues, long-term exposure to MPs at environmentally relevant doses could still induce widespread health risks. This raises concern on the health risks from the exposure of humans and other mammals to environmentally relevant dose MPs.

Wide occurrence of seven phthalate plasticizers and two typical microplastics in pig feed

Plastics are widely used as packaging and engineering materials in feed processing, which leads to the potential contamination of plasticizers and microplastics (MPs) in animal feeds. In this study, the concentrations of two typical MPs, i.e., polyethylene terephthalate (PET) and polycarbonate (PC), and seven phthalates (PAEs) as well as their corresponding monoester metabolites (mPAEs) in 45 pig feed samples in China were analyzed by mass spectrometers. Among PAEs, dibutyl phthalate (DBP) and bis(2-ethylhexyl) phthalate (DEHP) were detected in all samples, and DEHP showed the highest concentrations of 8.26-2464 μg/kg, which accounted for 65.6% of the total detected PAEs. PET MPs (<MDL-302 μg/kg) were detected in 97.8% of samples. Meanwhile, mPAEs were also detected in feed samples with high detection rates but of much lower concentrations. A significantly positive correlation was observed between DEHP and PET MPs. This indicates that the sources of DEHP and MPs in feeds are homologous, mainly from processing and packaging. Besides, the significantly positive correlations between DBP/DEHP and mBP/mEHP indicated the degradation of PAEs to mPAEs during feed production and transportation. The estimated daily intake (EDI) of PAEs and PET MPs were 2.40-70.3 and 0.800-7.79 μg/kg-bw-day, respectively. The results of this study provided new insight into the first evidence of the co-occurrence and risk of MPs, PAE, and mPAEs in pig feed.

Investigating associations between urinary phthalate metabolite concentrations and chronic diarrhea: findings from the National Health and Nutrition Examination Survey, 2005-2010

This study aimed to explore the relationship between chronic diarrhea and urinary phthalate metabolite concentrations in US adults from the 2005-2010 NHANES study. After adjusting for potential confounding factors, logistic regression was used to explore the relationship between phthalates (PAEs) concentrations and chronic diarrhea, Bayesian kernel machine regression (BKMR), and quantile g calculation (quantile-based g calculation, qgcomp) which was used to study the combined and independent effects of PAEs on gastrointestinal infections. In the current study, 4260 adult participants over the age of 20 from the NHANES study were included, of whom 542 (12.72%) were assessed as having chronic diarrhea. In multivariate logistic regression analysis, after adjusting for all relevant covariates, the results showed that urinary phthalate metabolite concentrations were significantly associated with the risk of chronic diarrhea (P<0.001). Various PAEs were risk factors for chronic diarrhea, among which MiBP (OR=1.419, 95% CI: 1.416-1.423) and MCPP (OR=1.237, 95% CI: 1.235-1.239) were more significant. The BKME results showed a significant increase in the risk of chronic diarrhea with increasing total levels of the PAEs mixture. Mixed exposure to PAEs can promote the occurrence of chronic diarrhea, and the effect was more pronounced in obese people. Notably, most PAEs showed some degree of protection in overweight people. The risk effect of PAEs was more significant in the middle-aged and older population than in the younger population.

Urinary concentrations of polycyclic aromatic hydrocarbon and phthalate metabolite mixtures in relation to semen quality among men attending an infertility clinic

Previous studies have reported that exposure to phthalates and polycyclic aromatic hydrocarbons (PAHs) is individually associated with altered semen quality, but no human studies have evaluated their joint effects of exposure mixtures, a more real-world scenario. We aimed to explore urinary metabolite mixtures of phthalates and PAHs in associations with semen quality. Repeated spot-urine samples gathered from 695 men attending a fertility clinic were analyzed for urinary metabolites of eight phthalates and ten monohydroxylated-PAHs (OH-PAHs). Principal component analysis (PCA)-multivariable linear regression (MLR) model, quantile g-computation (qg-comp), and Bayesian kernel machine regression (BKMR) were applied to estimate the associations of urinary mixtures of phthalate and OH-PAH metabolites with semen quality. The overall effects of urinary mixtures of phthalate and PAH metabolites on semen quality were not statistically significant. However, hydroxynaphthalene (OHNa) factor identified from PCA was monotonically associated with decreased total sperm count and sperm concentration, whereas di(2-ethylhexyl) phthalate (DEHP) factor was non-monotonically related to increased progressive sperm motility and total sperm motility. Qg-comp and BKMR models confirmed these findings and identified 2-OHNa and 2-OHFlu as the primary negative contributors, whereas MEOHP and MEHP as the primary positive contributors. Our findings suggest that exposure to mixtures of naphthalene and DEHP is associated with altered semen quality. The finding is warranted to confirm in further well-designed epidemiological studies.

Polystyrene nanoparticles enhance the adverse effects of di-(2-ethylhexyl) phthalate on male reproductive system in mice

Coexposure of nanoplastics (NPs) with other pollutants adsorbed from the surroundings has received extensive attention. Currently, the combined effects of NPs and plasticizers remain unclear. Di-(2-ethylhexyl) phthalate (DEHP) is a commonly used plasticizer that has raised much concern owing to its ubiquitous pollution and endocrine-disrupting potential. This study aimed to investigate the toxic effects on the male reproductive system upon coexposure to NPs and DEHP. The C57BL/6J mice were orally administrated with polystyrene nanoparticles (PSNPs), DEHP or both for 35 days to evaluate their effects on sperm quality, histology of testes and epididymides, testicular transcriptomic characteristics as well as expression of some important genes in the epididymides. The low-dose PSNPs used here did not induce significant changes in sperm quality, while DEHP alone or cotreatment with DEHP and PSNPs caused notable impairment, mainly manifesting as decreased sperm quality and aberrant structure of the testis and epididymis. Moreover, enhanced toxic effects were found in the cotreatment group when compared with the individual DEHP treatment group, as manifested by more obvious alterations in the sperm parameters as well as histological changes in the testis and epididymis. Testicular transcriptomic analysis revealed differential regulation of genes involved in immune response, cytoplasmic pattern recognition receptor signaling pathways, protein ubiquitination, oxidative stress, necrotic cell death, ATP synthesis and the cellular respiratory chain. RT-qPCR verified that the expression patterns of Cenpb, Crisp1 and Mars were changed in testes, and genes relevant to epididymal function including Aqp9 and Octn2 were downregulated in epididymides, particularly in the cotreatment group. Collectively, our results emphasize that DEHP at an environmentally relevant dose can induce male reproductive toxicity, and PSNPs may aggravate the toxic effects.

Polystyrene microplastics induced male reproductive toxicity and transgenerational effects in freshwater prawn

Microplastics have become pervasive environmental pollutants, especially in freshwater rivers and lakes. However, how freshwater prawns' reproductive system is affected by polystyrene microplastics (PS-MPs) remains incompletely understood. Thus, the present study aimed to determine the effect of PS-MPs on the male reproductive system and offspring larval immunity in oriental river prawn. Acute exposure to PS-MPs decreased the survival rate and heart rate of prawn larvae. After chronic exposure to PS-MPs (2 and 20 mg/L) for four weeks, the oxidative stress generation in testis tissue indicated a negative impact on male prawn testicular function. PS-MPs disrupted testicular germ cell quality and caused sex hormone imbalance, leading to reduced hatching success and survival of F1 larvae, despite not being exposed to PS-MPs. Steroidogenic gene expression was altered and apoptosis-related genes had higher expression in the gonads after parental exposure to PS-MPs. Decreased immunity-related enzyme activities were observed in F1 larvae with/without continued PS-MPs exposure, compared with those in untreated prawns. A concentration-dependent increase in bioaccumulation of PS-MPs in different tissues of larval offspring was observed. Thus, PS-MPs had multiple effects on male reproductive dysfunction and transgenerational toxicity in prawns. Our findings provide a novel insight into the reproductive toxicity mechanism of microplastics in freshwater crustaceans.

Ecotoxic effects of microplastics and contaminated microplastics - Emerging evidence and perspective

The high prevalence and persistence of microplastics (MPs) in pristine habitats along with their accumulation across environmental compartments globally, has become a matter of grave concern. The resilience conferred to MPs using the material engineering approaches for outperforming other materials has become key to the challenge that they now represent. The characteristics that make MPs hazardous are their micro to nano scale dimensions, surface varied wettability and often hydrophobicity, leading to non-biodegradability. In addition, MPs exhibit a strong tendency to bind to other contaminants along with the ability to sustain extreme chemical conditions thus increasing their residence time in the environment. Adsorption of these co-contaminants leads to modification in toxicity varying from additive, synergistic, and sometimes antagonistic, having consequences on flora, fauna, and ultimately the end of the food chain, human health. The resulting environmental fate and associated risks of MPs, therefore greatly depend upon their complex interactions with the co-contaminants and the nature of the environment in which they reside. Net outcomes of such complex interactions vary with core characteristics of MPs, the properties of co-contaminants and the abiotic factors, and are required to be better understood to minimize the inherent risks. Toxicity assays addressing these concerns should be ecologically relevant, assessing the impacts at different levels of biological organization to develop an environmental perspective. This review analyzed and evaluated 171 studies to present research status on MP toxicity. This analysis supported the identification and development of research gaps and recommended priority areas of research, accounting for disproportionate risks faced by different countries. An ecological perspective is also developed on the environmental toxicity of contaminated MPs in the light of multi-variant stressors and directions are provided to conduct an ecologically relevant risk assessment. The presented analyses will also serve as a foundation for developing environmentally appropriate remediation methods and evaluation frameworks.

Polystyrene nanoparticles aggravate the adverse effects of di-(2-ethylhexyl) phthalate on different segments of intestine in mice

Emerging evidence indicates that nanoplastics (NPs) can transport organic pollutants such as di-(2-ethylhexyl) phthalate (DEHP) into organisms and induce adverse health effects. Nevertheless, the toxic effects of NPs combined with DEHP on mammalian intestine are still unclear. In this study, the C57BL6J mice were exposed to polystyrene nanoparticles (PSNPs), DEHP or them both for 30 days to determine their effects on different segments of intestine and the gut microbiota. As a result, DEHP alone or co-exposure to DEHP and PSNPs induced histological damages in all intestinal parts, mainly manifested as the decreased villus lengths, increased crypt depths in the duodenum, jejunum and ileum and decreased villus counts accompanied with decreased epithelial area in the colon. Moreover, decreased mucus coverage, down-regulated Muc2 expression levels as well as the broken tight junctions were observed in intestinal epithelium of mice, particularly obvious in the co-treatment groups. In general, as manifested by greater alterations in most of the parameters mentioned above, simultaneously exposed to PSNPs and DEHP seemed to induce enhanced toxic effects on intestine of mouse when compared with DEHP alone. Furthermore, the altered community composition of gut microbiota might at least partially contribute to these abnormalities. Overall, our results highlight the aggravated toxicity on different segments of intestine in mammalians due to co-exposure of PSNPs and DEHP, and these findings will provide valuable insights into the health risk of NPs and plastic additives.

Testicular toxicity of bisphenol compounds: Homeostasis disruption of cholesterol/testosterone via PPARα activation

The widespread application of bisphenols (BPs) has made them ubiquitous in the environment. Although the side effects of bisphenol A (BPA) substitutes have received increasing attention, studies on their reproductive toxicity remain lacking. In this research, the effects of BPA and its substitutes, including bisphenol S (BPS), bisphenol F (BPF), and bisphenol AF (BPAF), on the male reproductive system were evaluated. Results proved that these BPs disturbed germ cell proliferation, induced germ cell apoptosis, and perturbed sperm physiologies and spermatogenesis, which resulted from the disruption of testosterone (T) biosynthesis in Leydig cells (LCs). Importantly, in vitro and in vivo studies indicated that the exhausted cholesterol in LCs accounted for the reduced T production. Furthermore, the knockdown of peroxisome proliferator-activated receptor alpha (PPARα) remarkably ameliorated the downregulation of cholesterogenesis-related genes (i.e., Hmgcs1, Hmgcr, and Srebf2), indicating that PPARα played a critical role in BPs-induced testicular dysfunction. Overall, our studies indicated that BPS, BPF, and BPAF could induce testicular toxic effects similar to that of BPA, which were associated with the PPARα pathway.

Ecotoxicological effects of micro- and nanoplastics on terrestrial food web from plants to human beings

Micro- and nanoplastics (MNPs) are present in almost all environmental compartments. Terrestrial soils are major environmental reservoirs for MNPs, but the ecotoxicological effects of MNPs on terrestrial biota remain relatively understudied. In this review, we collated findings of previous research on the uptake and impact of MNPs in terrestrial organisms, including flora, fauna, and human beings. Terrestrial plants can take up MNPs via the roots or leaves and translocate them to other parts. MNPs have been detected in the gastrointestinal tracts or feces of many terrestrial animals, including some high trophic-level predators, indicating the incidence of direct ingestion or trophic transfer of MNPs. The presence of MNPs in food items and human feces combines to verify human intake of MNPs via the dietary pathway. Exposure to MNPs can cause diverse effects on terrestrial organisms, including alterations in growth performance, oxidative stress, metabolic disturbance, cytotoxicity, genotoxicity, and mortality. The biological internalization and impact of MNPs are influenced by the physicochemical properties of MNPs (e.g., particle size, polymer type, surface chemistry, and exposure concentrations) and the physiology of the species. MNPs can also affect the bioavailability of co-occurring intrinsic or extrinsic contaminants to terrestrial biota, but their specific role is under dispute. Finally, we underlined the current research gaps and proposed several priorities for future studies.

Dibutyl phthalate-induced oxidative stress and apoptosis in swine testis cells and therapy of naringenin via PTEN/PI3K/AKT signaling pathway

Dibutyl phthalate (DBP) is a phthalic acid ester (PAE) that has posed a health hazard to the organisms. Naringenin (NRG) is a flavanone compound that has shown protection against several environmental chemicals through suppression of oxidative stress and activation of phosphatidylinositol 3-kinase/threonine kinase (PI3K/AKT) signaling pathway. Herein, swine testis (ST) cells were treated with 1.8 μM of DBP or/and 25.39 nM of NRG for 24 h, we described the discovery path of NRG inhibition on apoptosis in DBP-exposed ST cells through targeting phosphatase and tensin homologue deleted on chromosome 10 (PTEN). We first found that the anti-apoptosis effect of NRG is dependent on mitochondrial pathway through flow cytometry and related gene/protein expression, and then we detected PI3K/AKT pathway-related gene/protein expression, and established a computational docking assay between NRG and PTEN. We found that NRG specifically binds to three basic residues (His93, Lys125, Lys128) of P loop in PTEN, as well as phosphatase domains (Asp92, His93, Cys124, Lys125, Ala126, Lys128, and Arg130) in active dephosphorylation pockets, thereby reducing PTEN level and activating PI3K/AKT signaling pathway, and further inhibiting oxidative stress and mitochondrial pathway apoptosis. Taken together, our results push forward that NRG deserves further attention as a potential antagonistic therapy against DBP through targeting PTEN to inhibit oxidative stress and activate PI3K/AKT signaling pathway.

Microplastics in the Gulf of Mexico: A Bird’s Eye View

Microplastic debris is a persistent, ubiquitous global pollutant in oceans, estuaries, and freshwater systems. Some of the highest reported concentrations of microplastics, globally, are in the Gulf of Mexico (GoM), which is home to the majority of plastic manufacturers in the United States. A comprehensive understanding of the risk microplastics pose to wildlife is critical to the development of scientifically sound mitigation and policy initiatives. In this review, we synthesize existing knowledge of microplastic debris in the Gulf of Mexico and its effects on birds and make recommendations for further research. The current state of knowledge suggests that microplastics are widespread in the marine environment, come from known sources, and have the potential to be a major ecotoxicological concern for wild birds, especially in areas of high concentration such as the GoM. However, data for GoM birds are currently lacking regarding typical microplastic ingestion rates uptake of chemicals associated with plastics by avian tissues; and physiological, behavioral, and fitness consequences of microplastic ingestion. Filling these knowledge gaps is essential to understand the hazard microplastics pose to wild birds, and to the creation of effective policy actions and widespread mitigation measures to curb this emerging threat to wildlife.

Advanced microplastic monitoring using Raman spectroscopy with a combination of nanostructure-based substrates

Micro(nano)plastic (MNP) pollutants have not only impacted human health directly, but are also associated with numerous chemical contaminants that increase toxicity in the natural environment. Most recent research about increasing plastic pollutants in natural environments have focused on the toxic effects of MNPs in water, the atmosphere, and soil. The methodologies of MNP identification have been extensively developed for actual applications, but they still require further study, including on-site detection. This review article provides a comprehensive update on the facile detection of MNPs by Raman spectroscopy, which aims at early diagnosis of potential risks and human health impacts. In particular, Raman imaging and nanostructure-enhanced Raman scattering have emerged as effective analytical technologies for identifying MNPs in an environment. Here, the authors give an update on the latest advances in plasmonic nanostructured materials-assisted SERS substrates utilized for the detection of MNP particles present in environmental samples. Moreover, this work describes different plasmonic materials-including pure noble metal nanostructured materials and hybrid nanomaterials-that have been used to fabricate and develop SERS platforms to obtain the identifying MNP particles at low concentrations. Plasmonic nanostructure-enhanced materials consisting of pure noble metals and hybrid nanomaterials can significantly enhance the surface-enhanced Raman scattering (SERS) spectra signals of pollutant analytes due to their localized hot spots. This concise topical review also provides updates on recent developments and trends in MNP detection by means of SERS using a variety of unique materials, along with three-dimensional (3D) SERS substrates, nanopipettes, and microfluidic chips. A novel material-assisted spectral Raman technique and its effective application are also introduced for selective monitoring and trace detection of MNPs in indoor and outdoor environments.

Harmful effects of the microplastic pollution on animal health: a literature review

Background

The environmental pollution by microplastics is a global problem arising from the extensive production and use of plastics. Small particles of different plastics, measured less than 5 mm in diameter, are found in water, air, soil, and various living organisms around the globe. Humans constantly inhale and ingest these particles. The associated health risks raise major concerns and require dedicated evaluation.

Objectives

In this review we systematize and summarize the effects of microplastics on the health of different animals. The article would be of interest to ecologists, experimental biologists, environmental physicians, and all those concerned with anthropogenic environmental changes.

Methodology

We searched PubMed and Scopus from the period of 01/2010 to 09/2021 for peer-reviewed scientific publications focused on (1) environmental pollution with microplastics; (2) uptake of microplastics by humans; and (3) the impact of microplastics on animal health.

Results

The number of published studies considering the effects of microplastic particles on aquatic organisms is considerable. In aquatic invertebrates, microplastics cause a decline in feeding behavior and fertility, slow down larval growth and development, increase oxygen consumption, and stimulate the production of reactive oxygen species. In fish, the microplastics may cause structural damage to the intestine, liver, gills, and brain, while affecting metabolic balance, behavior, and fertility; the degree of these harmful effects depends on the particle sizes and doses, as well as the exposure parameters. The corresponding data for terrestrial mammals are less abundant: only 30 papers found in PubMed and Scopus deal with the effects of microplastics in laboratory mice and rats; remarkably, about half of these papers were published in 2021, indicating the growing interest of the scientific community in this issue. The studies demonstrate that in mice and rats microplastics may also cause biochemical and structural damage with noticeable dysfunctions of the intestine, liver, and excretory and reproductive systems.

Conclusions

Microplastics pollute the seas and negatively affect the health of aquatic organisms. The data obtained in laboratory mice and rats suggest a profound negative influence of microplastics on human health. However, given significant variation in plastic types, particle sizes, doses, models, and modes of administration, the available experimental data are still fragmentary and controversial.

Recent advances in toxicological research and potential health impact of microplastics and nanoplastics in vivo

As emerging pollutants, direct and indirect adverse impacts of micro(nano)plastics (MPs/NPs) are raising an increasing environmental concern in recent years due to their poor biodegradability and difficulty in recycling. MPs/NPs can act as carriers of bacteria, viruses, or pollutants (such as heavy metals and toxic organic compounds), and may potentially change the toxicity and bioavailability of pollutants. Ingested or attached MPs/NPs can also be transferred from low-trophic level organisms to high-nutrient organisms or even the human body through the food chain transfer process. This article reviews the emerging field of micro- and nanoplastics on organisms, including the separate toxicity and toxicity of compound after the adsorption of organic pollutants or heavy metals, as well as possible mechanism of toxicological effects and evaluate the nano- and microplastics potential adverse effects on human health. The inherent toxic effects MPs/NPs mainly include the following: physical injury, growth performance decrease and behavioral alteration, lipid metabolic disorder, induced gut microbiota dysbiosis and disruption of the gut's epithelial permeability, neurotoxicity, damage of reproductive system and offspring, oxidative stress, immunotoxicity, etc. Additionally, MPs/NPs may release harmful plastic additives and toxic monomers such as bisphenol A, phthalates, and toluene diisocyanate. The vectors' effect also points out the potential interaction of MPs/NPs with pollutants such as heavy metals, polycyclic aromatic hydrocarbons, organochlorine pesticides, polychlorinated biphenyls, perfluorinated compounds, pharmaceuticals, and polybrominated diphenyl ethers. Nevertheless, these potential consequences of MPs/NPs being vectors for contaminants are controversial.

Accumulation of polystyrene microplastics induces liver fibrosis by activating cGAS/STING pathway

The environmental pollution from microplastics has caused concern from the whole society due to its harm to organisms. However, the effect of microplastics on liver damage and fibrosis remains unclear in the case of long-term accumulation. The present study demonstrated that the 0.1 μm microplastic could enter hepatocytes from circulation and result liver damage even at a low concentration. Microplastic exposure could induce DNA damage in both nucleus and mitochondria, by which the dsDNA fragment was translocated into cytoplasm and triggered the DNA sensing adaptor STING. The activation of cGAS/STING pathway initiated the downstream cascade reaction, the NFκB translocated into nucleus and upregulated pro-inflammatory cytokines expression, and thus facilitating liver fibrosis eventually. Furthermore, inhibition of STING could alleviate the liver fibrosis via blocking the NFκB translocation and fibronectin expression. This study provided a valuable insight to elucidate the potential risk and mechanism of hepatic toxicity and fibrosis induced by microplastics.

Microplastics May Be a Significant Cause of Male Infertility

Due to the problematic degradation properties of plastics, the decomposition of plastic results in the formation of numerous microplastics (MPs), less than 5 mm in diameter. These MPs enter the soil and the ocean, eventually passing through the air, water, or food chain back to the human body and harming human health. In the last 80 years, male semen analysis parameters have shown a significant decline for unknown reasons, speculated to be caused by pollutants. No studies examined the relationship between human MP exposure and male infertility. In this article, we reviewed the relevant animal experimental research literature in recent years and calculated that the minimum human equivalent dose of MPs leading to abnormal male semen quality is 0.016 mg/kg/d. The literature comparison found that MP exposure in Japan and South Korea was close to this value. These results suggest that MPs can affect male semen quality and that MPs may significantly impact male fertility.

Exposure to microplastics leads to a defective ovarian function and change in cytoskeleton protein expression in rat

Microplastics (MPs) are ubiquitous environmental contaminants; through their physicochemical properties, they can have potentially negative effects on the environment as well as on animal and human health. Studies addressing the toxicity of MPs on mammalian female reproduction are almost absent. Thus, the main objective of the present study was to assess the impact of oral exposure, during four estrous cycles, of 5 µm polystyrene-type microplastics (PS-MPs) on ovarian function in rats. Particles of PS-MPs were detected in the duodenum and, for the first time, in the different compartments of the ovarian tissue. The toxicity of accumulated PS-MPs was manifested by the reduced relative ovarian weights, by the alteration in the folliculogenesis and in the estrous cycle duration, and by the reduced serum concentration of estradiol. The defective ovarian function following PS-MP treatment might be due to the induction of oxidative stress, which has been proved by an increased malondialdehyde (MDA) concentration and an increased superoxide dismutase (SOD) and catalase (CAT) activities as well as a decreased protein sulfhydryl (PSH) level in the rat ovary. Importantly, by immunofluorescence and RT-PCR, we demonstrated a significant decrease in the expression of cytoskeletal proteins: α-tubulin and disheveled-associated activator of morphogenesis (DAAM-1) in the ovary of rats exposed to PS-MPs at proteomic and transcriptomic levels. Our results uncovered, for the first time, the distribution and accumulation of PS-MPs across rat ovary, revealed a significant alteration in some biomarkers of the ovarian function, and highlighted the possible involvement of MP-induced disturbance of cytoskeleton in these adverse effects.

Consequences of nano and microplastic exposure in rodent models: the known and unknown

The ubiquitous nature of micro- (MP) and nanoplastics (NP) is a growing environmental concern. However, their potential impact on human health remains unknown. Research increasingly focused on using rodent models to understand the effects of exposure to individual plastic polymers. In vivo data showed critical exposure effects depending on particle size, polymer, shape, charge, concentration, and exposure routes. Those effects included local inflammation, oxidative stress, and metabolic disruption, leading to gastrointestinal toxicity, hepatotoxicity, reproduction disorders, and neurotoxic effects. This review distillates the current knowledge regarding rodent models exposed to MP and NP with different experimental designs assessing biodistribution, bioaccumulation, and biological responses. Rodents exposed to MP and NP showed particle accumulation in several tissues. Critical responses included local inflammation and oxidative stress, leading to microbiota dysbiosis, metabolic, hepatic, and reproductive disorders, and diseases exacerbation. Most studies used MP and NP commercially provided and doses higher than found in environmental exposure. Hence, standardized sampling techniques and improved characterization of environmental MP and NP are needed and may help in toxicity assessments of relevant particle mixtures, filling knowledge gaps in the literature.

The emerging risk of microplastics and nanoplastics on the microstructure and function of reproductive organs in mammals: A systematic review of preclinical evidence

AIMS

Plastic particles (PP) pollution is a global environmental concern. Although the reproductive toxicity of PP is primarily understood for invertebrates, the evidence for mammals is still fragmented. We used a systematic review framework to investigate the reproductive impact of microplastics and nanoplastics (MNP) on mammals.

MATERIALS AND METHODS

Research records were screened from Embase, Medline, Scopus and Web of Science. Twelve original papers were identified and reviewed. Immunological, oxidative and morphofunctional outcomes, and the risk of bias in all studies reviewed were analyzed.

KEY FINDINGS

These studies indicated that PP can accumulate in the gonads, triggering seminiferous degeneration, Sertoli cells death, blood-testis barrier disruption, sperm degeneration, malformation, reduced number and mobility, ovarian cysts, reduced follicular growth and granulosa cells death. Gonadal damage was associated with upregulation of prooxidant mediators (oxygen reactive species, lipid and DNA oxidation), cell death, proinflammatory molecular pathways and cytokines, as well as inhibition of enzymatic and non-enzymatic antioxidant defense mechanisms. Spermatogenesis, folliculogenesis, testosterone, progesterone and estrogen levels were also impaired in PP-treated animals, which were potentially associated with down-regulation of molecules involved in germ cells microstructural organization (occludin, N-cadherin, β-catenin and connexin 43) and steroidogenesis, such as hydroxysteroid dehydrogenases, steroidogenic acute regulatory proteins, follicle stimulating and luteinizing hormones. Selection, performance and detection bias were the main limitations identified.

SIGNIFICANCE

Current evidence indicates that PP can induce dose-dependent microstructural and functional gonadal damage, which is orchestrated by pro-oxidant and pro-inflammatory mechanisms that disrupt genes, molecular effectors, and hormones that control spermatogenesis and folliculogenesis.

Microplastics and Their Impact on Reproduction—Can we Learn From the C. elegans Model?

Biologically active environmental pollutants have significant impact on ecosystems, wildlife, and human health. Microplastic (MP) and nanoplastic (NP) particles are pollutants that are present in the terrestrial and aquatic ecosystems at virtually every level of the food chain. Moreover, recently, airborne microplastic particles have been shown to reach and potentially damage respiratory systems. Microplastics and nanoplastics have been shown to cause increased oxidative stress, inflammation, altered metabolism leading to cellular damage, which ultimately affects tissue and organismal homeostasis in numerous animal species and human cells. However, the full impact of these plastic particles on living organisms is not completely understood. The ability of MPs/NPs to carry contaminants, toxic chemicals, pesticides, and bioactive compounds, such as endocrine disrupting chemicals, present an additional risk to animal and human health. This review will discusses the current knowledge on pathways by which microplastic and nanoplastic particles impact reproduction and reproductive behaviors from the level of the whole organism down to plastics-induced cellular defects, while also identifying gaps in current knowledge regarding mechanisms of action. Furthermore, we suggest that the nematode Caenorhabditis elegans provides an advantageous high-throughput model system for determining the effect of plastic particles on animal reproduction, using reproductive behavioral end points and cellular readouts.

The impact of nano/micro-plastics toxicity on seafood quality and human health: facts and gaps

Contamination of the food and especially marine environment with nano/micro-plastic particles has raised serious concern in recent years. Environmental pollution and the resulting seafood contamination with microplastic (MP) pose a potential threat to consumers. The absorption rate of the MP by fish is generally considered low, although the bioavailability depends on the physical and chemical properties of the consumed MP. The available safety studies are inconclusive, although there is an indication that prolonged exposure to high levels of orally administered MP can be hazardous for consumers. This review details novel findings about the occurrence of MP, along with its physical and chemical properties, in the marine environment and seafood. The effect of processing on the content of MP in the final product is also reviewed. Additionally, recent findings regarding the impact of exposure of MP on human health are discussed. Finally, gaps in current knowledge are underlined, and the possibilities for future research are indicated in the review. There is an urgent need for further research on the absorption and bioavailability of consumed MP and in vivo studies on chronic exposure. Policymakers should also consider the implementation of novel legislation related to MP presence in food.

The Pressing Issue of Micro- and Nanoplastic Contamination: Profiling the Reproductive Alterations Mediated by Oxidative Stress

Micro- and nanoplastics (MPs/NPs) are among the most widely distributed pollutants in the environment. It has been suggested that exposure to MPs/NPs can trigger toxicity pathways among which inflammation and oxidative stress (OS) play a pivotal role. Once absorbed, MPs/NPs may act locally or access the bloodstream and, following the translocation process, reach several organs and tissues, including the gonads. Notably, MPs/NPs can bioaccumulate in human and murine placenta, opening new scenarios for toxicological evaluations. We review recent studies on the effects of MPs/NPs on the reproductive health in aquatic and terrestrial organisms of both sexes, focusing on the role of OS and the antioxidant defence system failure as the main underlying mechanisms. Alterations in gametogenesis, embryonic and offspring development, and survival have been shown in most studies and often related to a broken redox balance. All these detrimental effects are inversely related to particle size, whereas they are closely linked to shape, plastic polymer type, superficial functionalization, concentration, and time of exposure. To date, the studies provide insights into the health impacts, but no conclusions can be drawn for reproduction toxicity. The main implication of the few studies on antioxidant substances reveals their potential role in mitigating MP-induced toxic effects.

Efficacy and cytotoxicity of engineered ferromanganese-bearing sludge-derived biochar for percarbonate-induced phthalate ester degradation

Phthalate esters (PAEs) are a group of ubiquitous organic environmental contaminants. Engineered ferromanganese-bearing sludge-derived biochar (SDB), synthesized using one-step pyrolysis in the temperature range between 300 and 900 °C, was used to enable Fenton-like processes that decontaminated PAE-laden sediments. SDB was thoroughly characterized using scanning electron microscopyenergy-dispersive spectroscopy, transmission electron microscopy, Brunauer-Emmett-Teller surface area, thermogravimetric analysis, Raman spectroscopy, Fourier-transform infrared spectroscopy, electron paramagnetic resonance, X-ray photoelectron spectroscopy, and fluorescence excitation-emission matrix spectroscopy coupled with parallel factor analysis. The maximum PAE degradation was remarkable at 90% in 12 h at pH 6.0 in the presence of 1.7 g L^-1 of SDB 900. The highly-effective PAE degradation was mainly attributed to the synergism between FeO_x and MnO_x, which strengthened the activation of percarbonate (PC) via electron transfer, hydroxy addition, and hydrogen abstraction through radical (HO•) and nonradical (¹O₂) oxidation mechanisms, thereby facilitating PAE catalytic degradation over SDB in real sediments, which clearly proved the efficacy of ferromanganese-bearing SDB and PC for the remediation of contaminated sediments. The cytotoxicity exhibited by human skin keratinocyte cells exposure to high SDB concentration (100-400 µg mL^-1) for 24-48 h was low indicating insignificant cellular toxicity and oxidative damages. This study provides a new strategy for freshwater sludge treatment and reutilization, which enables a water-cycle-based circular economy and waste-to-resource recycling.

Analysis of Microplastics in Human Feces Reveals a Correlation between Fecal Microplastics and Inflammatory Bowel Disease Status

Human ingestion of microplastics (MPs) is inevitable due to the ubiquity of MPs in various foods and drinking water. Whether the ingestion of MPs poses a substantial risk to human health is far from understood. Here, by analyzing the characteristics of MPs in the feces of patients with inflammatory bowel disease (IBD) and healthy people, for the first time, we found that the fecal MP concentration in IBD patients (41.8 items/g dm) was significantly higher than that in healthy people (28.0 items/g dm). In total, 15 types of MPs were detected in feces, with poly(ethylene terephthalate) (22.3-34.0%) and polyamide (8.9-12.4%) being dominant, and their primary shapes were sheets and fibers, respectively. We present evidence indicating that a positive correlation exists between the concentration of fecal MPs and the severity of IBD. Combining a questionnaire survey and the characteristics of fecal MPs, we conclude that the plastic packaging of drinking water and food and dust exposure are important sources of human exposure to MPs. Furthermore, the positive correlation between fecal MPs and IBD status suggests that MP exposure may be related to the disease process or that IBD exacerbates the retention of MPs. The relative mechanisms deserve further studies. Our results also highlight that fecal MPs are useful for assessing human MP exposure and potential health risks.

Maternal exposure to polystyrene nanoplastics during gestation and lactation induces hepatic and testicular toxicity in male mouse offspring

Nanoplastics have raised considerable concerns since their ubiquity in the environment and potential hazard to health. It has been proven that polystyrene nanoparticles (PS-NPs) can be maternally transferred to the offspring. In this study, mice were exposed gestationally and lactationally to PS-NPs (size 100 nm) at different doses (0.1, 1 and 10 mg/L) to investigate the trans-generational poisonousness. Our data illustrated that maternal PS-NPs exposure in pregnancy and lactation resulted in a decline in birth and postnatal body weight in offspring mice. Furthermore, high-dose PS-NPs reduced liver weight, triggered oxidative stress, caused inflammatory cell infiltration, up-regulated proinflammatory cytokine expression, and disturbed glycometabolism in the liver of male offspring mice. In addition, pre- and postnatal PS-NPs exposure diminished testis weight, disrupted seminiferous epithelium and decreased sperm count in mouse offspring. Moreover, PS-NPs induced testicular oxidative injury, as presented by increased malondialdehyde generation and altered superoxide dismutase and catalase activities in the testis of offspring mice. These findings declared that maternal exposure to PS-NPs in pregnancy and lactation can cause hepatic and testicular toxicity in male mouse pups, which put forward new understanding into the detrimental effects of nanoplastics on mammalian offspring.

A review of the endocrine disrupting effects of micro and nano plastic and their associated chemicals in mammals

Over the years, the vaste expansion of plastic manufacturing has dramatically increased the environmental impact of microplastics [MPs] and nanoplastics [NPs], making them a threat to marine and terrestrial biota because they contain endocrine disrupting chemicals [EDCs] and other harmful compounds. MPs and NPs have deleteriouse impacts on mammalian endocrine components such as hypothalamus, pituitary, thyroid, adrenal, testes, and ovaries. MPs and NPs absorb and act as a transport medium for harmful chemicals such as bisphenols, phthalates, polybrominated diphenyl ether, polychlorinated biphenyl ether, organotin, perfluorinated compounds, dioxins, polycyclic aromatic hydrocarbons, organic contaminants, and heavy metals, which are commonly used as additives in plastic production. As the EDCs are not covalently bonded to plastics, they can easily leach into milk, water, and other liquids affecting the endocrine system of mammals upon exposure. The toxicity induced by MPs and NPs is size-dependent, as smaller particles have better absorption capacity and larger surface area, releasing more EDC and toxic chemicals. Various EDCs contained or carried by MPs and NPs share structural similarities with specific hormone receptors; hence they interfere with normal hormone receptors, altering the hormonal action of the endocrine glands. This review demonstrates size-dependent MPs' bioaccumulation, distribution, and translocation with potential hazards to the endocrine gland. We reviewed that MPs and NPs disrupt hypothalamic-pituitary axes, including the hypothalamic-pituitary-thyroid/adrenal/testicular/ovarian axis leading to oxidative stress, reproductive toxicity, neurotoxicity, cytotoxicity, developmental abnormalities, decreased sperm quality, and immunotoxicity. The direct consequences of MPs and NPs on the thyroid, testis, and ovaries are documented. Still, studies need to be carried out to identify the direct effects of MPs and NPs on the hypothalamus, pituitary, and adrenal glands.

Time to Safeguard the Future Generations from the Omnipresent Microplastics

Microplastics (MPs) as a ubiquitous environmental pollutant have drawn growing attention, and it is concerning that children are more sensitive to MPs than adults. Unfortunately, information about the link between children and MPs is insufficient. Therefore, we review the sources and exposure routes of children to MPs and collect evidence for the potential risks. Children can ingest and/or inhale MPs derived from various foodstuffs and plastic products. Despite the limited knowledge on the toxicity to humans, current studies have proved the accumulation and translocation of MPs in different tissues and organs. Main damages including cytotoxicity, neurotoxicity, and immunotoxicity can be caused by pristine polymers and/or co-contaminants. There is much more to be understood about MPs, especially their health effects, and this study has made it clear that it is time to protect our future generations from the threat of MPs.

Microplastics in the Environment: Intake through the Food Web, Human Exposure and Toxicological Effects

Recently, studies on microplastics (MPs) have increased rapidly due to the growing awareness of the potential health risks related to their occurrence. The first part of this review is devoted to MP occurrence, distribution, and quantification. MPs can be transferred from the environment to humans mainly through inhalation, secondly from ingestion, and, to a lesser extent, through dermal contact. As regards food web contamination, we discuss the microplastic presence not only in the most investigated sources, such as seafood, drinking water, and salts, but also in other foods such as honey, sugar, milk, fruit, and meat (chickens, cows, and pigs). All literature data suggest not-negligible human exposure to MPs through the above-mentioned routes. Consequently, several research efforts have been devoted to assessing potential human health risks. Initially, toxicological studies were conducted with aquatic organisms and then with experimental mammal animal models and human cell cultures. In the latter case, toxicological effects were observed at high concentrations of MPs (polystyrene is the most common MP benchmark) for a short time. Further studies must be performed to assess the real consequences of MP contamination at low concentrations and prolonged exposure.

The effect of microplastics on behaviors of chiral imidazolinone herbicides in the aquatic environment: Residue, degradation and distribution

The pollution of aquatic environments by microplastics and herbicides has become a global concern. This study was focused on imazamox, imazapic, and imazethapyr sorption to polypropylene microplastics in water. And the potential effects of microplastics on herbicide enantiomer degradation and distributions in water, sediment, and water-sediment microcosms were investigated. Adsorption experiment results indicated that herbicide sorption to microplastics involved both chemisorption and physical adsorption. Degradation experiment results indicated that microplastics could markedly increase herbicide persistence in water and sediment. Marked stereoselective degradation was not found for the three herbicides in water and sediment, but stereoselective degradation of imazapic in water containing microplastics was found. The water-sediment microcosms experiment results indicated that microplastics have significant effect on stereoselectivity degradation and distribution in water and water-sediment microcosms for imazapic, and have little effect on stereoselectivity behaviors of imazamox and imazethapyr in water-sediment systems. Furthermore, the microcosm experiment results also indicated that herbicides can partition between water and microplastics and that microplastics could affect herbicide persistence and distributions in aquatic environments. The present study provides new insights into the fate of chiral pollutants in aquatic environments containing microplastics, and contributes to understanding behaviors of herbicides and microplastics in aquatic environments.

Micro- and Nanoplastic-Mediated Pathophysiological Changes in Rodents, Rabbits, and Chickens: A Review

ABSTRACT

Plastics provide tremendous societal benefits and are an indispensable part of our lives. However, fragmented plastics or those intentionally manufactured in small sizes (microplastics and nanoplastics) are of concern because they can infiltrate soils and enter the human food chain through trophic transfer. The pathophysiological impacts of micro- and nanoplastics in humans are not characterized, but their effects in terrestrial mammals may help elucidate their potential effects in humans. Rodent studies have demonstrated that micro- and nanoplastics can breach the intestinal barrier, accumulate in various organs, cause gut dysbosis, decrease mucus secretion, induce metabolic alterations, and cause neurotoxicity, among other pathophysiologic effects. Larger mammals such as rabbits can also absorb microplastics orally. In farm animals such as chickens, microplastics have been detected in the gut, thereby raising food safety concerns. This review mostly focuses on studies conducted to assess effects of micro- and nanoplastic exposure through food and water in terrestrial mammals and farm animals including rodents, rabbits, and chickens; identifies main knowledge gaps; and provides recommendations for further research to understand foodborne micro- and nanoplastic toxicity in humans.

HIGHLIGHTS

Impacts of three glyphosate formulations on gonadal development of Xenopus laevis

The emergence of widespread morphological malformations in the reproductive system of wildlife is generating increasing concerns. This concern is because the observed malformities may be linked to pollution by pesticides and other chemicals. The amphibian declines, for example, have been linked to pesticide pollution among other factors. Using an extended Xenopus Metamorphosis Assay protocol, until the tadpoles metamorphosized, the exposure impacts of three glyphosate formulations, namely, Roundup, Kilo Max and Enviro Glyphosate, were assessed on the reproductive system of Xenopus laevis, vis-a-vis the body mass, sex ratios and morphological malformations as endpoints. The exposure concentrations ranged between 0.2–0.6 mg/L, 0.9–28 mg/L and 90–280 mg/L for Roundup, Enviro Glyphosate, and Kilo Max, respectively. Both Kilo Max and Enviro Glyphosate formulations significantly reduced the body mass of the metamorphs compared to the control. In sex ratios, only Kilo Max altered the percentage sex ratio of the treated frogs at a ratio of 68:32 (F:M) compared to 50:50 ratio in the control. In reproductive malformations, the three formulations showed abnormality index range of 22.3–49%, 17.5–37.5% and 20–30% for the Kilo Max, Enviro Glyphosate and Roundup formulations, respectively, compared to 7.5% in the control. Observed reproductive malformations include mixed sex, translucence, aplasia, segmented hypertrophy and segmented aplasia and translucence. This result indicates that some of the glyphosate formulations have the capacity to cause widespread reproductive malformations in a way that could reduce the reproductive fitness of the amphibian. Care must therefore be taken to reduce the application rate of these formulations, particularly in aquatic environments.

Detrimental effects of microplastic exposure on normal and asthmatic pulmonary physiology

Concerns that airborne microplastics (MP) may be detrimental to human health are rising. However, research on the effects of MP on the respiratory system are limited. We tested the effect of MP exposure on both normal and asthmatic pulmonary physiology in mice. We show that MP exposure caused pulmonary inflammatory cell infiltration, bronchoalveolar macrophage aggregation, increased TNF-α level in bronchoalveolar lavage fluid (BALF), and increased plasma IgG1 production in normal mice. MP exposure also affected asthma symptoms by increasing mucus production and inflammatory cell infiltration with notable macrophage aggregation. Further, we found co-labeling of macrophage markers with MP incorporating fluorescence, which indicates phagocytosis of the MP by macrophages. A comparative transcriptomic analysis showed that MP exposure altered clusters of genes related to immune response, cellular stress response, and programmed cell death. A bioinformatics analysis further uncovered the molecular mechanism whereby MP stimulated production of tumor necrosis factor and immunoglobulins to activate a group of transmembrane B-cell antigens, leading to the modulation of cellular stress and programmed cell death in the asthma model. In summary, we show that MP exposure had detrimental effects on the respiratory system in both healthy and asthmatic mice, which calls for urgent discourse and action to mitigate environmental microplastic pollutants.

Comprehensive insights into the interactions of dicyclohexyl phthalate and its metabolite to human serum albumin

Phthalate esters (PAEs) are a type of persistent organic pollutants and have received widespread concerns due to their adverse effects on human health. Dicyclohexyl phthalate (DCHP) and its metabolite monocyclohexyl phthalate (MCHP) were selected to explore the mechanism for interaction of PAEs with human serum albumin (HSA) through molecular docking and several spectroscopic techniques. The results showed that DCHP/MCHP can spontaneously occupy site I to form a binary complex with HSA, and DCHP exhibited higher binding affinity to HSA than MCHP. At 298 K, the binding constants (K_b) of DCHP and MCHP to HSA were 24.82 × 10⁴ and 1.04 × 10⁴ M^-1, respectively. Hydrogen bonds and van der Waals forces were the major driving forces in DCHP/MCHP-HSA complex. The presence of DCHP/MCHP induced the secondary structure changes in HSA, and the pi electrons of the benzene ring skeleton of DCHP/MCHP played a key role in this binding processes. Exposure of DCHP/MCHP to TM4 cells revealed that interactions between PAEs and serum albumin can affect their cytotoxicity; DCHP showed higher toxicity than MCHP. The binding affinity of PAEs with HSA may be a valuable parameter for rapid assessment of their toxicity to organisms.

Exposure to phthalates DEHP and DINP May lead to oxidative damage and lipidomic disruptions in mouse kidney

Di(2-ethylhexyl) phthalate (DEHP) has been well acknowledged for its endocrine disruption and associated metabolic diseases, leading to the search for safer industrial alternatives including di-isononyl phthalate (DINP). However, safety data for the latter chemical has been relatively scarce particularly regarding potential damage to the kidney at low doses. Five-week-old ICR male mice were exposed to vehicle, DEHP or DINP (0.05 and 4.8 mg/kg bw) daily via gavage for 5 weeks. We observed increased levels of reactive oxygen species and malondialdehyde, decreased levels of reduced glutathione, in the kidney at higher dose for both chemicals suggestive of oxidative damage. Elevated levels of inflammatory cytokines tumor necrosis factor-α and interleukin-6 of the kidney further suggested inflammatory status as a result of phthalate exposure in both high dose groups. Targeted lipidomics demonstrated greatest changes in the kidney induced by high dose of DEHP, although DINP also induced significant changes in phospholipids diacylglycerides that are associated with lipid accumulation in glomerular podocytes and inflammatory responses. Our data suggest that oxidative stress may be involved in both DEHP- and DINP-induced renal lipidomic disruption and continue to question the suitability of DINP as proper DEHP substitute.

Microplastics: A Threat for Male Fertility

Much of the planet is swimming in discarded plastic, which is harming animal and possibly human health. Once at sea, sunlight, wind, and wave action break down plastic waste into small particles: the microplastics (MPs). Currently, particular attention has been drawn to their effects on aquatic environments but the health risks, especially in mammals, are poorly known. These non-biodegradable materials can act as a vector for environmental pollutants, can be ingested by humans in food and water, and can enter and accumulate in human tissues with a possible risk for heath. Recent studies revealed the deleterious effects of MPs exposure in male reproduction and sperm quality, making them a potential hazard to reproductive success. This manuscript summarizes the main changes in sperm quality along the lifespan and the upcoming studies on the effects of MPs in male fertility in mammals.