A review of the influences of microplastics on toxicity and transgenerational effects of pharmaceutical and personal care products in aquatic environment

Characterization of the Differences in Dissolved Organic Matter (DOM) Adsorbed on Five Kinds of Microplastics Using Multiple Methods

Microplastics (MPs) are ubiquitous in aquatic environments, soils, and beach sediments, demonstrating a remarkable ability to adsorb dissolved organic matter (DOM). Although there are methods for extracting DOM from water, the approaches for directly extracting DOM from microplastics have not been thoroughly investigated, and the characterization of DOM adsorbed on microplastics is also insufficient. In this study, five different types of microplastic samples were collected from each of five environmental media (water and sediment), and finally 25 samples were obtained. This paper comparatively assessed the extraction efficiency of DOM from MPs with various solvents by using total organic carbon (TOC), culminating in the development of a sodium pyrophosphate-NaOH solution extraction method optimized for DOM. The morphology, material and environmental medium of microplastics were the three primary factors affecting the adsorption of DOM on microplastics, with the highest enrichment ratio of 1.4-1.8 times for extruded polyethylene microplastics (EPE-MPs) characterized by their porous structure in the flowing water environment. The molecular weight of DOM adsorbed on microplastics showed a multi-modal distribution pattern with great dissimilarities among the different environmental media. Gel permeation chromatography (GPC) indicated that the weight-average molecular weight (Mw) of DOM was 2750-4552 Da for river MPs, 2760-5402 Da for Qiantang River MPs, 1233-5228 Da for East China Sea MPs, 440-7302 Da for soil sediment MPs and 438-6178 Da for beach sediment MPs, respectively. Excitation-emission matrix-parallel factor analysis (EEM-PARAFAC) identified that tyrosine-like substances with high excitation in region IV and low excitation in region I were predominantly adsorbed on MPs, followed by tryptophan-like substances with low excitation in region II and protein-like substances in region IV, while humic- and fulvic-like substances in regions V and III, respectively, exhibited the least adsorption affinity. The findings underscored the critical need to comprehensively consider the interactions between MPs and DOM and their environmental impacts in pollution control strategies.

Toxicity and intergenerational accumulation effect of tire wear particles and their leachate on Brachionus plicatilis

Tire wear particles (TWP) are one of the main sources of microplastic (MP) pollution in the marine environment, causing adverse effects on marine life and attracting increasing attention. This study aimed to investigate the chemical composition of TWP (particles and leachate) and their toxic effects on Brachionus plicatilis. The results showed that Zn and acenaphthene were the most frequently detected compounds in the three TWP treatments. In the single-generation exposure experiment, TWP leachate showed the highest toxicity potential, followed by nano-TWP (<1 μm) and micro-TWP (1-20 μm). Both nano-TWP and leachate had negative effects on the lifespan and population of rotifers. High-concentration TWP leachate significantly shortened the reproductive period of rotifers, slowed down their swimming speed, and reduced the number of offspring. These negative effects were mainly attributed to the toxic mixture of nano-TWP with additives in the leachate. Furthermore, in multi-generation exposure experiments, the toxicity pattern showed a new trend: the toxicity of nano-TWP exceeded that of the leachate, while micro-TWP continued to maintain the lowest toxicity level. Continuous exposure to TWP exerted a significant negative impact on rotifer lifespan, and this effect increases cumulatively between generations. Notably, TWP was trans-generationally toxic to the lifespan of rotifers, and repeated exposure was more toxic than maternal exposure and continuous exposure. In addition, rotifers can ingest and accumulate TWP, and maternal transfer was another uptake pathway of TWP in rotifer offspring. This finding provided a new perspective for understanding the transmission mechanism of TWP in the marine food chain.

Microplastics in seawater and fish acquired from the corresponding fishing zones of the Baltic Sea

Microplastics in seawater and fish from the Baltic Sea were analyzed. The significant contribution of the study is due to extensive collection of fish and surface water samples from corresponding fishing zones. Microplastics were detected in 100 % of seawater and 61 % of fish samples. The abundances of microplastics were 19,984 ± 8858 items/m3 (seawater) and 3.3 items/fish in the fish organs. The average dimension was 1.08 ± 1.19 mm (seawater), and 0.77 ± 0.84 mm (fish). In 106 out of 178 specimens (61 %), MPs were found in the gills (46 %), digestive tract (38 %), or liver (16 %). Fiber was the most dominant shape found in seawater (91.7 %) and fish (68.3 %), while the dominant color of items was blue. Items were mostly composed of polyethylene (21 %), polypropylene (20 %), cellophane (16 %), polyamide (9 %), and polyacrylate (8 %).

Acanthocephalans as pollutant sinks? Higher pollutant accumulation in parasites may relieve their crustacean host

Increasing chemical pollution calls for a closer look at ecologically highly relevant host-parasite interactions to understand the persistence of organisms and populations in a polluted environment. The impact of chemical exposure within the host-parasite interactions - particularly the distinctive bioaccumulation behavior of organic micropollutants - can substantially influence the persistence of a species. This significance has been emphasized by previous research showing a higher tolerance of Gammarus roeselii (Amphipoda, Crustacea) infected with acanthocephalans during acute exposure to a pyrethroid. This suggests the presence of infection-related benefits within polluted environments. The present study addressed this complex relationship by investigating the chemical body burden and internal pollutant concentrations of both G. roeselii and its acanthocephalan parasites across a pollution gradient. Specifically, we analyzed 405 organic micropollutants and identified 123 of these in gammarids and their acanthocephalan parasites. Among the detected compounds, 22 are either banned or are no longer permitted for use in Germany. Remarkably, we discovered that the concentrations of pollutants were up to 35 times higher in the acanthocephalan parasites than in their crustacean intermediate hosts. The log KOW, the most frequently used measure of chemical hydrophobicity, could not explain the accumulation. Instead, the accumulation is likely explained by the unique physiology and high absorption capacity of acanthocephalans, combined with potentially limited biotransformation and excretion ability. This results in a redistribution of micropollutants within the host-parasite system, reducing the burden on the host up to 13.9 % and potentially explaining the observed helpful effects of parasitized G. roeselii in polluted environments. Our study underscores the often overlooked but significant role of host-parasite interactions in human-altered ecosystems, revealing how these relationships can mediate and amplify the impacts of micropollutants within aquatic communities. These insights stress the need to consider the pervasive influence of metazoan parasites in environmental assessments and pollution management strategies.

Multigenerational effects of combined exposure of triphenyltin and micro/nanoplastics on marine medaka (Oryzias melastigma): From molecular levels to behavioral response

In natural environments, micro/nanoplastics (MNP) inevitably coexist with various pollutants, making it essential to examine their combined toxicity and intergenerational effects on marine organisms. This study investigated the combined toxicity and intergenerational effects of exposure to triphenyltin (T), microplastics (M), nanoplastics (N), a combination of microplastics and triphenyltin (MT), and a combination of nanoplastics and triphenyltin (NT) on marine medaka. The results showed that all treatments had adverse and intergenerational effects on marine medaka. Regarding oxidative stress and energy metabolism, smaller sized plastic particles caused more significant damage to the organisms. However, MT inflicted greater gonadal system damage than NT, leading to imbalanced sex hormone levels. Additionally, T induced hyperactivity in fish, whereas MNP tended to induce behavioral depression. Notably, large plastic particles in the F0 generation had a more pronounced impact on depressive behaviors compared to smaller particles. These findings suggest that both individual and combined exposures to TPT and MNP can detrimentally affect marine medaka from the molecular to behavioral levels, posing risks to population sustainability. This study provided a robust theoretical foundation and deeper insights into the ecotoxicological impacts and risk assessments of coexisting pollutants.

Maternal exposure to nanopolystyrene induces neurotoxicity in offspring through P53-mediated ferritinophagy and ferroptosis in the rat hippocampus

There are increasing concerns regarding the rapid expansion of polystyrene nanoplastics (PS-NPs), which could impact human health. Previous studies have shown that nanoplastics can be transferred from mothers to offspring through the placenta and breast milk, resulting in cognitive deficits in offspring. However, the neurotoxic effects of maternal exposure on offspring and its mechanisms remain unclear. In this study, PS-NPs (50 nm) were gavaged to female rats throughout gestation and lactation to establish an offspring exposure model to study the neurotoxicity and behavioral changes caused by PS-NPs on offspring. Neonatal rat hippocampal neuronal cells were used to investigate the pathways through which NPs induce neurodevelopmental toxicity in offspring rats, using iron inhibitors, autophagy inhibitors, reactive oxygen species (ROS) scroungers, P53 inhibitors, and NCOA4 inhibitors. We found that low PS-NPs dosages can cause ferroptosis in the hippocampus of the offspring, resulting in a decline in the cognitive, learning, and memory abilities of the offspring. PS-NPs induced NOCA4-mediated ferritinophagy and promoted ferroptosis by inciting ROS production to activate P53-mediated ferritinophagy. Furthermore, the levels of the antioxidant factors glutathione peroxidase 4 (GPX4) and glutathione (GSH), responsible for ferroptosis, were reduced. In summary, this study revealed that consumption of PS-NPs during gestation and lactation can cause ferroptosis and damage the hippocampus of offspring. Our results can serve as a basis for further research into the neurodevelopmental effects of nanoplastics in offspring.

Pharmaceuticals in avian scavengers and other birds of prey: A toxicological perspective to improve risk assessments

Pharmaceuticals are emerging contaminants given their increasing use worldwide due to intensive food production and population growth. These compounds reach the environment through different pathways with potential negative consequences for wildlife. One dramatic example occurred in Asia, where three native vulture populations collapsed almost to extinction due to acute intoxication with diclofenac, a veterinary use non-steroidal anti-inflammatory drug (NSAID). As seen with diclofenac, avian scavengers are useful sentinels to monitor for the presence of pharmaceuticals in the environment given their position at the top of the trophic chain, and in the case of obligate avian scavengers (vultures), their intimate link to domestic animal carcasses. Unfortunately, little is known about the wider exposure and potential health and population risks of pharmaceuticals to birds of prey. Here we compile literature data regarding relevant toxicological aspects of the most important pharmaceutical groups for birds of prey in terms of toxicity: NSAIDs, antibiotics, external antiparasitics and barbiturates. This work also includes critical information for future risk assessments, including concentrations of drug residues that can remain in animal tissues after treatment, or specific pharmaceutical features that might influence their toxicity in avian scavengers and other birds of prey. We also consider future research needs in this field and provide management recommendations to prevent potential intoxication events with pharmaceuticals in these species. This review highlights the need to consider specific risk assessments regarding exposure to pharmaceuticals, especially those used in veterinary medicine, for birds of prey.

Hydrogen bonding-mediated interaction underlies the enhanced membrane toxicity of chemically transformed polystyrene microplastics by cadmium

The global attention on microplastic pollution and its implications for human health has grown in recent years. Additionally, the co-existence of heavy metals may significantly alter microplastics' physicochemical characteristics, potentially amplifying their overall toxicity-a facet that remains less understood. In this study, we focused the membrane toxicity of modified polystyrene microplastics (PS-MPs) following cadmium (Cd) pretreatment. Our findings revealed that Cd-pretreated PS-MPs exacerbated their toxic effects, including diminished membrane integrity and altered phase fluidity in simulated lipid membrane giant unilamellar vesicles (GUVs), as well as heightened membrane permeability, protein damage, and lipid peroxidation in red blood cells and macrophages. Mechanistically, these augmented membrane toxicities can be partially ascribed to modifications in the surface roughness and hydrophilicity of Cd-pretreated PS-MPs, as well as to interactions between PS-MPs and lipid bilayers. Notably, hydrogen bonds emerged as a crucial mechanism underlying the enhanced interaction of PS-MPs with lipid bilayers.

Combined effects of microplastics and pharmaceutical and personal care products on algae: A critical review

Microplastics (MPs) and pharmaceuticals and personal care products (PPCPs) are ubiquitous in aquatic environments. Algae play an important role in aquatic environments. Thus, it is important to study the response of algae to combined exposure of MPs and PPCPs. Here, we review the effects of MPs and PPCPs on algae. First, the individual effects of MPs and PPCPs on algae were summarized. Second, the combined effects of MPs and PPCPs on algae were systematically analyzed. (1) Antagonism: ① when the MPs are too large to enter the algal cells, the adsorption of PPCPs onto MPs results in decreased the contact of MPs and PPCPs with algae; ② PPCPs and MPs have opposing actions on the same biological target; ③ MPs increase the activity of metabolic enzymes in algae, thus promoting the PPCP degradation. (2) Synergy: ① when the MPs are small enough to enter algal cells, the adsorption of PPCPs on MPs promotes the entry of PPCPs; ② when MPs are negatively charged, the adsorption of positively charged PPCPs by MPs decreases the electrostatic repulsion, increasing the interaction between algae and MPs; ③ complementary modes of action between MPs and PPCPs show combined effects on the same biological target. Third, the relative importance of the factors that impact the combined effects are evaluated using the random forest model decreased in the following order: PPCP types > algal species > MP size > MP concentration > MP types > exposure time. Finally, future directions for the combined effects of MPs and PPCPs are proposed, which will facilitate a better understanding of the environmental fate and risks of both MPs and PPCPs.

A review of the neurobehavioural, physiological, and reproductive toxicity of microplastics in fishes

Microplastics (MPs) have emerged as widespread environmental pollutants, causing significant threats to aquatic ecosystems and organisms. This review examines the toxic effects of MPs on fishes, with a focus on neurobehavioural, physiological, and reproductive impacts, as well as the underlying mechanisms of toxicity. Evidence indicates that MPs induce a range of neurobehavioural abnormalities in fishes, affecting social interactions and cognitive functions. Altered neurotransmitter levels are identified as a key mechanism driving behavioural alterations following MP exposure. Physiological abnormalities in fishes exposed to MPs are also reported, including neurotoxicity, immunotoxicity, and oxidative stress. These physiological disruptions can compromise the individual health of aquatic organisms. Furthermore, reproductive abnormalities linked to MP exposure are discussed, with a particular emphasis on disruptions in endocrine signaling pathways. These disruptions can impair reproductive success in fish species, impacting population numbers. Here we explore the critical role of endocrine disruptions in mediating reproductive effects after exposure to MPs, focusing primarily on the hypothalamic-pituitary-gonadal axis. Our review highlights the urgent need for interdisciplinary research efforts aimed at elucidating the full extent of MP toxicity and its implications for aquatic ecosystems. Lastly, we identify knowledge gaps for future research, including investigations into the transgenerational impacts, if any, of MP exposure and quantifying synergetic/antagonistic effects of MPs with other environmental pollutants. This expanded knowledge regarding the potential risks of MPs to aquatic wildlife is expected to aid policymakers in developing mitigation strategies to protect aquatic species.

Bibliometrics analysis of hotspots research on infertility syndromes and polystyrene

Polystyrene plastic pollution poses a pressing environmental concern and represents a significant risk factor for infertility. Despite this, a comprehensive overview of the field remains scarce, with future trends largely unknown. Bibliometrics, an applied mathematical and statistical method, offers a means to analyze textual information across various levels, facilitating quantitative assessments of all knowledge carriers and unveiling the nature and developmental trajectories of a discipline. This study aimed to employ bibliometric methods to scrutinize the current status and research hotspots within the realm of polystyrene and infertility. Literature spanning from 1980 to 2023 pertaining to polystyrene and infertility was retrieved from the core database of Web of Science. Quantitative analyses were conducted utilizing CiteSpace (version 5.7.R7), VOSviewer (version 1.6.18.0), and an online literature analysis website (https://bibliometric.com/). The analysis visually represented countries, institutions, authors, journals, and keywords within the field. This study delved into the development history, knowledge structure, research hotspots, and potential trends in the field, furnishing a macro perspective for researchers. The investigation encompassed 267 articles published across 120 journals by 1,352 authors affiliated with 417 institutions in 51 countries, with these articles garnering 10,310 citations across 2,811 journals. The top three countries contributing the most articles were China, the United States, and Germany. In essence, the research hotspots primarily revolved around metabolism, endocrinology, and immunity. Despite China's relatively recent entry into this field, its rapid development is evident. However, the low citation frequency suggests a need for improved article quality.

Parabens and triclosan in red swamp crayfish (Procambarus clarkii) from China: Concentrations, tissue distribution and related human dietary intake risk

Parabens (PBs) and triclosan (TCS) are commonly found in pharmaceuticals and personal care products (PPCPs). As a result, they have been extensively found in the environment, particularly in aquaculture operations. Red swamp crayfish (Procambarus clarkii) consumption has significantly risen in China. Nevertheless, the levels of PBs and TCS in this species and the associated risk to human dietary intake remain undisclosed. This study assessed the amounts of five PBs, i.e., methyl-paraben (MeP), ethyl-paraben (EtP), propyl-paraben (PrP), butyl-paraben (BuP) and benzyl-paraben (BzP), as well as TCS in crayfish taken from five provinces of the middle-lower Yangtze River. MeP, PrP and TCS showed the highest detection rates (hepatopancreas: 46-86 %; muscle: 63-77 %) since they are commonly used in PPCPs. Significantly higher levels of ∑5PBs (median: 3.69 ng/g) and TCS (median: 7.27 ng/g) were significantly found in the hepatopancreas compared to the muscle (median: 0.39 ng/g for ∑5PBs and 0.16 ng/g for TCS) (p < 0.05), indicating bioaccumulation of these chemicals in the hepatopancreas. The estimated daily intake values of ∑5PBs and TCS calculated from the median concentrations of crayfish were 6.44-7.94 ng/kg bw/day and 11.4-14.0 ng/kg bw/day, respectively. Although no health risk was predicted from consuming crayfish (HQ <1), consumption of the hepatopancreas is not recommended.

Emerging pollutant in surface water bodies: a review on monitoring, analysis, mitigation measures and removal technologies of micro-plastics

Water bodies play a crucial role in supporting life, maintaining the environment, and preserving the ecology for the people of India. However, in recent decades, human activities have led to various alterations in aquatic environments, resulting in environmental degradation through pollution. The safety of utilizing surface water sources for drinking and other purposes has come under intense scrutiny due to rapid population growth and industrial expansion. Surface water pollution due to micro-plastics (MPs) (plastics < 5 mm in size) is one of the emerging pollutants in metropolitan cities of developing countries because of its utmost resilience and synthetic nature. Recent studies on the surface water bodies (river, pond, Lake etc.) portrait the correlation between the MPs level with different parameters of pollution such as specific conductivity, total phosphate, and biological oxygen demand. Fibers represent the predominant form of MPs discovered in surface water bodies, exhibiting fluctuations across seasons. Consequently, present study prioritizes understanding the adaptation, prevalence, attributes, fluctuations, and spatial dispersion of MPs in both sediment and surface water environments. Furthermore, the study aims to identify existing gaps in the current understanding and underscore opportunities for future investigation. From the present study, it has been reported that, the concentration of MPs in the range of 0.2-45.2 items/L at the Xisha Islands in the south China sea, whereas in India it was found in the range of 96 items/L in water samples and 259 items/kg in sediment samples. This would certainly assist the urban planners in achieving sustainable development goals to mitigate the increasing amount of emergent pollutant load.

Acute exposure and biomarkers assessment in rainbow trout exposed to selected pharmaceuticals

Pharmaceuticals released from municipal effluents discharges pose a risk to aquatic organisms. The toxicity of 5 pharmaceuticals with distinct therapeutic actions were assessed in rainbow trout: olanzapine (antipsychotic), erythromycin (antibiotic), mycophenoate (immunosuppression), pinaverium (anti-inflammatory) and trazodone (sedative). Juveniles were exposed to these drugs for 96 h at concentrations between 64 µg/L up to 40 mg/L to reach lethality. Survival was determined and a suite of biomarkers was analyzed for drug biotransformation, oxidative stress/damage and metabolic activity at sublethal concentrations. The data revealed the following toxicity: olanzapine >trazodone>mycophenolate>pinaverium∼erythromycin based on mortality. The data also revealed that toxicity was associated to mass, pKa and hydrophobicity and the following sublethal effects: GST, LPO and DNA strand breaks. Pharmaceuticals with lower molecular weight, physiological pKa, moderate hydrophobicity, low biotransformation and DNA strand breaks were generally more toxic to fish. However, this should be considered as a general guide in identifying toxic pharmaceuticals in non-target organisms.

Nanoplastics aggravated TDCIPP-induced transgenerational developmental neurotoxicity in zebrafish depending on the involvement of the dopamine signaling pathway

Plastics pose a hazard to the environment. Although plastics have toxicity, microplastics (MPs) and nanoplastics (NPs) are capable of interacting with the rest pollutants in the environment, so they serve as the carriers and interact with organic pollutants to modulate their toxicity, thus resulting in unpredictable ecological risks. PS-NPs and TDCIPP were used expose from 2 h post-fertilization (hpf) to 150 days post-fertilization (dpf) to determine the bioaccumulation of tris(1,3-dichloro-2-propyl) phosphate (TDCIPP) and its potential effects on neurodevelopment in F1 zebrafish (Danio rerio) offspring under the action of polystyrene nano plastics (PS-NPs). The exposure groups were assigned to TDCIPP (0, 0.4, 2 or 10 µg/L) alone group and the PS-NPs (100 µg/L) and TDCIPP co-exposed group. F1 embryos were collected and grown in clean water to 5 dpf post-fertilization. PS-NPs facilitated the bioaccumulation of TDCIPP in the gut, gill, head，gonad and liver of zebrafish in a sex-dependent manner and promoted the transfer of TDCIPP to their offspring, thus contributing to PS-NPs aggravated the inhibition of offspring development and neurobehavior of TDCIPP-induced. In comparison with TDCIPP exposure alone, the combination could notably down-regulate the levels of the dopamine neurotransmitter, whereas the levels of serotonin or acetylcholine were not notably different. This result was achieved probably because PS-NPs interfered with the TDCIPP neurotoxic response of zebrafish F1 offspring not through the serotonin or acetylcholine neurotransmitter pathway. The increased transfer of TDCIPP to the offspring under the action of PS-NPs increased TDCIPP-induced transgenerational developmental neurotoxicity, which was proven by a further up-regulation/down-regulation the key gene and protein expression related to dopamine synthesis, transport, and metabolism in F1 larvae, in contrast to TDCIPP exposure alone. The above findings suggested that dopaminergic signaling involvement could be conducive to the transgenerational neurodevelopmental toxicity of F1 larval upon parental early co-exposure to PS-NPs and TDCIPP.

Photo-electrochemical activation of persulfate for the simultaneous degradation of microplastics and personal care products

The recent widespread use of microplastics (MPs), especially in pharmaceuticals and personal care products (PPCPs), has caused significant water pollution. This study presents a UV/electrically co-facilitated activated persulfate (PS) system to co-degrade a typical microplastic polyvinyl chloride (PVC) and an organic sunscreen p-aminobenzoic acid (PABA). We investigated the effect of various reaction conditions on the degradation. PVC and PABA degradation was 37% and 99.22%, respectively. Furthermore, we observed alterations in the surface topography and chemical characteristics of PVC throughout degradation. The possible degradation pathways of PVC and PABA were proposed by analyzing the intermediate products and the free radicals generated. This study reveals the co-promoting effect of multiple mechanisms in the activation by ultraviolet light and electricity.

A platform for microplastic assessment in aquatic environments based on the protein corona-induced aggregation effect

The environmental hazards of microplastics have received widespread attention. However, the in-situ detection of microplastics, particularly in aquatic environments, has been challenged by the limitations of detection methods, the large-scale instruments, and small size. Herein, a photoelectrochemical sensor based on the protein corona-induced aggregation effect is designed for the detection of polystyrene microplastics. The sensor has advantages of high sensitivity, reproducibility, and detection capability. A linear detection range of 0.5-500 μg mL-1, a method detection limit of 0.06 μg mL-1, and a limit of quantification of 0.14 μg mL-1 are achieved. Furthermore, the relative standard deviations of intra-day and inter-day precision, ranging from 0.56% to 4.63% and 0.84%-3.36% are obtained. A digital multimeter was employed to construct a platform for the real-time detection in real water samples, streamlining the detection process and yielding clear results. We believe this sensor provides new insight for the in-situ real-time detection of microplastics and has broad applications for the analysis of microplastic pollution in aquatic environments.

Effects of pharmaceutical and personal care products on pubertal development: Evidence from human and animal studies

Pharmaceutical and personal care products (PPCPs) include a wide range of drugs, personal care products and household chemicals that are produced and used in significant quantities. The safety of PPCPs has become a growing concern in recent decades due to their ubiquitous presence in the environment and potential risks to human health. PPCPs have been detected in various human biological samples, including those from children and adolescents, at concentrations ranging from several ng/L to several thousand μg/L. Epidemiological studies have shown associations between exposure to PPCPs and changes in the timing of puberty in children and adolescents. Animal studies have shown that exposure to PPCPs results in advanced or delayed pubertal onset. Mechanisms by which PPCPs regulate pubertal development include alteration of the hypothalamic kisspeptin and GnRH networks, disruption of steroid hormones, and modulation of metabolic function and epigenetics. Gaps in knowledge and further research needs include the assessment of environmental exposure to pharmaceuticals in children and adolescents, low-dose and long-term effects of exposure to PPCPs, and the modes of action of PPCPs on pubertal development. In summary, this comprehensive review examines the potential effects of exposure to PPCPs on pubertal development based on evidence from human and animal studies.

Occurrence of phthalic acid esters (PAEs) and active pharmaceutical ingredients (APIs) in key species of anthozoans in Mediterranean Sea

The Mediterranean Sea's biodiversity is declining due to climate change and human activities, with plastics and emerging contaminants (ECs) posing significant threats. This study assessed phthalic acid esters (PAEs) and active pharmaceutical ingredients (APIs) occurrence in four anthozoan species (Cladocora caespitosa, Eunicella cavolini, Madracis pharensis, Parazoanthus axinellae) using solid phase microextraction (SPME) and liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). All specimens were contaminated with at least one contaminant, reaching maximum values of 57.3 ng/g for the ∑PAEs and 64.2 ng/g (wet weight) for ∑APIs, with dibutyl phthalate and Ketoprofen being the most abundant. P. axinellae was the most contaminated species, indicating higher susceptibility to bioaccumulation, while the other three species showed two-fold lower concentrations. Moreover, the potential adverse effects of these contaminants on anthozoans have been discussed. Investigating the impact of PAEs and APIs on these species is crucial, given their key role in the Mediterranean benthic communities.

Adsorption behavior and interaction mechanism of microplastics with typical hydrophilic pharmaceuticals and personal care products

Microplastics (MPs) and pharmaceuticals and personal care products (PPCPs) are two types of emerging contaminants widely present in the global aquatic ecosystem. The ecological risks associated with the coexistence of these two contaminants have garnered increasing attention from researchers. In this study, we selected 15 typical hydrophilic PPCPs, including Sulfacetamide (SA), Thiamphenicol, Florfenicol, Chloramphenicol (CHL), Ampicillin, Cephalexin, Ofloxacin, Fluorouracil, Phenytoin, Theophylline, Cimetidine, Methylparaben, Diethyltoluamide, Benzophenone-2 (BP-2), and Benzophenone-4, as adsorbates. We evaluated the adsorption potential of five traditional plastics (TPs), namely Polyamide 6 (PA6), Polystyrene (PS), Polyethylene terephthalate (PET), Polyvinyl chloride (PVC), and Polyurethane (TPU), as well as three biodegradable plastics (BDPs), including Polylactic acid (PLA), Polybutylene succinate (PBS), and Poly (ε-caprolactone) (PCL), for these adsorbates. Out of the 120 combinations of MPs and PPCPs tested, only 24 exhibited significant adsorption behavior. Notably, the adsorption performance of the three BDPs was stronger than that of the three typical TPs (PS, PET, and PVC). Based on their adsorption potential, PA6, BDPs, phenytoin, and BP-2 were identified as potential sources of high ecological risk. To further explore the adsorption mechanism, we investigated the adsorption behaviors of SA, BP-2, and CHL on PA6. The conclusions were as follows: SA, BP-2, and CHL all reached adsorption equilibrium within 24 h, with the partition coefficient (Kd) following this order: BP-2 (8.051) ≫ SA (0.052) > CHL (0.018). The primary forces of adsorption were electrostatic interactions, intermolecular hydrogen bonding, and hydrophobic interaction, respectively. Additionally, weak electrostatic effects were observed in the adsorption of CHL and BP-2. The effects of pH, ionic strength, and fulvic acid on adsorption capacity varied. These results highlight a complex adsorption mechanism between MPs and hydrophilic contaminants in the aquatic environment. This study provides a basis for further evaluating the ecological risks of MPs and PPCPs combined pollution.

Long-term tralopyril exposure results in endocrinological and transgenerational toxicity: A two-generation study of marine medaka (Oryzias melastigma)

This study aims to investigate the impact of tralopyril, a newly developed marine antifouling agent, on the reproductive endocrine system and developmental toxicity of offspring in marine medaka. The results revealed that exposure to tralopyril (0, 1, 20 μg/L) for 42 days resulted in decreased reproductive capacity in marine medaka. Moreover, it disrupted the levels of sex hormones E2 and T, as well as the transcription levels of genes related to the HPG axis, such as cyp19b and star. Sex-dependent differences were observed, with females experiencing more pronounced effects. Furthermore, intergenerational toxicity was observed in F1 offspring, including increased heart rate, changes in retinal morphology and cartilage structure, decreased swimming activity, and downregulation of transcription levels of relevant genes (HPT axis, GH/IGF axis, cox, bmp4, bmp2, runx2, etc.). Notably, the disruption of the F1 endocrine system by tralopyril persisted into adulthood, indicating a transgenerational effect. Molecular docking analysis suggested that tralopyril's RA receptor activity might be one of the key factors contributing to the developmental toxicity observed in offspring. Overall, our study highlights the potential threat posed by tralopyril to the sustainability of fish populations, as it can disrupt the endocrine system and negatively impact aquatic organisms for multiple generations.

Microplastics as carriers of toxic pollutants: Source, transport, and toxicological effects

Microplastic pollution has emerged as a new environmental concern due to our reliance on plastic. Recent years have seen an upward trend in scholarly interest in the topic of microplastics carrying contaminants; however, the available review studies have largely focused on specific aspects of this issue, such as sorption, transport, and toxicological effects. Consequently, this review synthesizes the state-of-the-art knowledge on these topics by presenting key findings to guide better policy action toward microplastic management. Microplastics have been reported to absorb pollutants such as persistent organic pollutants, heavy metals, and antibiotics, leading to their bioaccumulation in marine and terrestrial ecosystems. Hydrophobic interactions are found to be the predominant sorption mechanism, especially for organic pollutants, although electrostatic forces, van der Waals forces, hydrogen bonding, and pi-pi interactions are also noteworthy. This review reveals that physicochemical properties of microplastics, such as size, structure, and functional groups, and environmental compartment properties, such as pH, temperature, and salinity, influence the sorption of pollutants by microplastic. It has been found that microplastics influence the growth and metabolism of organisms. Inadequate methods for collection and analysis of environmental samples, lack of replication of real-world settings in laboratories, and a lack of understanding of the sorption mechanism and toxicity of microplastics impede current microplastic research. Therefore, future research should focus on filling in these knowledge gaps.

Independent and synergistic effects of microplastics and endocrine-disrupting chemicals on the reproductive social behavior of fathead minnows (Pimephales promelas)

Microplastics (MPs) have become an environmental concern in recent years, with most research focused on the physiological effects of exposure. Comparatively little consideration has been given to the potential behavioral impacts of exposure, which may also have fitness consequences for individuals. Moreover, MPs can serve as vectors for endocrine-disrupting chemicals and other locally co-occurring contaminants known to impair behavioral responses. This project aimed to determine whether MPs alone or in association with a common environmental EDC (17-alpha ethinyl estradiol; EE2) alter reproductive behavior and decision-making in fish. Male and female fathead minnows (Pimephales promelas) were exposed to MPs associated with either a low (10 ng/L; MPEE2 10) or high (50 ng/L, MPEE2 50) concentration of EE2, or MPs without EE2 (MPvirgin) for 30 days via a dietary feeding protocol. Behavioral trials were conducted on Day 31 to determine the effects of exposure on male-female social interactions. The expression of male sexually selected traits, including courtship, was unaffected by exposure. However, non-exposed females in all treatment groups trended toward discrimination against exposed males, which reached statistical significance for the MPEE2 50 group. Female fish exposed to MPs, alone or in association with EE2, were equally likely to approach and associate with non-exposed and exposed males. The results from this study suggest that MPs may alter social behavior in fishes and that the behavioral impacts of exposure may be more strongly pronounced in females than males. Such individual-level changes in fitness have the potential to impact population size, with downstream effects on the broader aquatic community.

The invisible Threat: Assessing the reproductive and transgenerational impacts of micro- and nanoplastics on fish

Micro- and nanoplastics (MNPs), emerging as pervasive environmental pollutants, present multifaceted threats to diverse ecosystems. This review critically examines the ability of MNPs to traverse biological barriers in fish, leading to their accumulation in gonadal tissues and subsequent reproductive toxicity. A focal concern is the potential transgenerational harm, where offspring not directly exposed to MNPs exhibit toxic effects. Characterized by extensive specific surface areas and marked surface hydrophobicity, MNPs readily adsorb and concentrate other environmental contaminants, potentially intensifying reproductive and transgenerational toxicity. This comprehensive analysis aims to provide profound insights into the repercussions of MNPs on fish reproductive health and progeny, highlighting the intricate interplay between MNPs and other pollutants. We delve into the mechanisms of MNPs-induced reproductive toxicity, including gonadal histopathologic alterations, oxidative stress, and disruptions in the hypothalamic-pituitary-gonadal axis. The review also underscores the urgency for future research to explore the size-specific toxic dynamics of MNPs and the long-term implications of chronic exposure. Understanding these aspects is crucial for assessing the ecological risks posed by MNPs and formulating strategies to safeguard aquatic life.

Chromium (IV) transfer to Amusium pleuronectes by LDPE microplastics: An experimental study

An experiment was carried out to investigate the potential of virgin LDPE microplastics to transfer heavy metals. Desired shapes (fibres, fragments, and films) and sizes (< 5 mm) of virgin LDPE microplastics were immersed in a known concentration (30 µg/l) of chromium (IV). These Cr-coated microplastics were introduced into a culture tank containing edible scallops (Amusium pleuronectes). After the completion of the experiment (5 days), the sediments in the culture tank and edible tissues of A. pleuronectes were tested for the presence of Cr. In the sediments, a maximum concentration of 1.934 µg/g of Cr was accumulated at a rate of R2 = 0.979, while in the tissues, the maximum accumulation concentration was 0.733 µg/g of Cr at a rate of R2 = 0.807. Energy Dispersive X-ray Spectroscopy analysis also confirmed the presence of Cr (2.61 ± 0.44 mass % and 1.80 ± 0.30 atom%) in the tissues of A. pleuronectes, which was absent in the control tissues. The study showed that when exposed to contaminants such as heavy metals, LDPE microplastics can adhere and transfer them to biotic tissues. LDPE showed the potential to transfer adhered contaminants; however, the effects caused by these transferred contaminants on biota must be studied further. Risk assessment study showed that potential ecological risk of Cr is < 40 indicating low risk however, the combined effect of Cr and LDPE can compound its toxicity which needs to be studied further.

Chronic Paternal/Maternal Exposure to Environmental Concentrations of Imidacloprid and Thiamethoxam Causes Intergenerational Toxicity in Zebrafish Offspring

Imidacloprid (IMI) and thiamethoxam (THM) are ubiquitous in aquatic ecosystems. Their negative effects on parental fish are investigated while intergenerational effects at environmentally relevant concentrations remain unclear. In this study, F0 zebrafish exposed to IMI and THM (0, 50, and 500 ng L-1) for 144 days post-fertilization (dpf) was allowed to spawn with two modes (internal mating and cross-mating), resulting in four types of F1 generations to investigate the intergenerational effects. IMI and THM affected F0 zebrafish fecundity, gonadal development, sex hormone and VTG levels, with accumulations found in F0 muscles and ovaries. In F1 generation, paternal or maternal exposure to IMI and THM also influenced sex hormones levels and elevated the heart rate and spontaneous movement rate. LncRNA-mRNA network analysis revealed that cell cycle and oocyte meiosis-related pathways in IMI groups and steroid biosynthesis related pathways in THM groups were significantly enriched in F1 offspring. Similar transcriptional alterations of dmrt1, insl3, cdc20, ccnb1, dnd1, ddx4, cox4i1l, and cox5b2 were observed in gonads of F0 and F1 generations. The findings indicated that prolonged paternal or maternal exposure to IMI and THM could severely cause intergenerational toxicity, resulting in developmental toxicity and endocrine-disrupting effects in zebrafish offspring.

Microplastics as vectors of chemical contaminants and biological agents in freshwater ecosystems: Current knowledge status and future perspectives

Microplastics (MPs) are becoming ubiquitous, and their environmental fate is becoming an issue of concern. Our review aims to synthesize current knowledge status and provide future perspectives regarding the vector effect of MPs for chemical contaminants and biological agents. The evidence in the literature indicates that MPs are a vector for persistent organic pollutants (POPs), metals and pharmaceuticals. Concentrations of chemical contaminant in orders of six-fold higher on MPs surfaces than in the surrounding environmental waters have been reported. Chemical pollutants such as perfluoroalkyl substances (PAFSs), hexachlorocyclohexane (HCHs) and polycyclic aromatic hydrocarbons (PAHs), exhibiting polarities in the range of 3.3-9 are the commonest chemicals reported on MP surfaces. Regarding metals on MPs including chromium (Cr), lead (Pb), cobalt (Co), the presence of C-O and N-H in MPs promote a relatively high adsorption of these metals onto MP surfaces. Regarding pharmaceuticals, not much has been done, but a few studies indicate that commonly used drugs such as ibuprofen, ibuprofen, diclofenac, and naproxen have been associated with MPs. There is sufficient evidence supporting the claim that MPs can act as vectors for viruses, bacterial and antibiotic-resistant bacteria and genes, and MPs act to accelerate horizontal and vertical gene transfer. An area that deserves urgent attention is whether MPs can act as vectors for invertebrates and vertebrates, mainly non-native, invasive freshwater species. Despite the ecological significance of invasive biology, little research has been done in this regard. Overall, our review summarises the state of the current knowledge, identifies critical research gaps and provides perspectives for future research.

Fate and environmental behaviors of microplastics through the lens of free radical

Microplastics (MPs), as plastics with a size of less than 5 mm, are ubiquitously present in the environment and become an increasing environmental concern. The fate and environmental behavior of MPs are significantly influenced by the presence of free radicals. Free radicals can cause surface breakage, chemical release, change in crystallinity and hydrophilicity, and aggregation of MPs. On the other hand, the generation of free radicals with a high concentration and oxidation potential can effectively degrade MPs. There is a limited review article to bridge the fate and environmental behaviors of MP with free radicals and their reactions. This paper reviews the sources, types, detection methods, generation mechanisms, and influencing factors of free radicals affecting the environmental processes of MPs, the environmental effects of MPs controlled by free radicals, and the degradation strategies of MPs based on free radical-associated technologies. Moreover, this review elaborates on the limitations of the current research and provides ideas for future research on the interactions between MPs and free radicals to better explain their environmental impacts and control their risks. This article aims to keep the reader abreast of the latest development in the fate and environmental behaviors of MP with free radicals and their reactions and to bridge free radical chemistry with MP control methodology.

Rainbow trout (Oncorhynchus mykiss) physiological response to microplastics and enrofloxacin: Novel pathways to investigate microplastic synergistic effects on pharmaceuticals

Enrofloxacin (ENR) is a broad-spectrum antibiotic widely used due to its efficacy against pathogens. Microplastics (MPs) may bind to ENR and reduce its efficiency, whereas there would be an increase in its toxicity, bioavailability, and bio-accumulation rates. Therefore, the hypothesis is that the interaction between MPs and ENR can alter their toxicity and bioavailability. The subjective of this study is to examine the toxicity of various concentrations of ENR (0, 1.35, and 2.7 ml Kg^-1 diet) and MPs (0, 1000, and 2000 mg Kg^-1 diet) alone and in combination for 21 days. The rainbow trout (Oncorhynchus mykiss) is an economic aquaculture species used as an experimental model in ecotoxicology studies. Blood biochemical analytes indicated that ENR and MPs combination led to increasing enzymatic activity of each biomarker, except for gamma-glutamyl-transferase (GGT). Alterations related to triglycerides, cholesterol, glucose, urea, creatinine, total protein, and albumin blood contents were observed. An elevation in the levels of superoxide dismutase (SOD), malondialdehyde (MDA), and glucose 6-phosphate dehydrogenase (G6PDH) was found in the liver. In contrast, catalase (CAT) and glutathione peroxidase (GPx) levels decreased. Furthermore, a decline was observed in the cellular total antioxidant (ANT) levels. These findings suggested that ENR and MPs could affect fish health both independently and together. Consequently, the study determined that when both ENR and MPs were present in high concentrations, the toxicity of ENR was amplified, providing further evidence of the synergistic impact of MPs on ENR toxicity.

Factors Determining the Susceptibility of Fish to Effects of Human Pharmaceuticals

The increasing levels and frequencies at which active pharmaceutical ingredients (APIs) are being detected in the environment are of significant concern, especially considering the potential adverse effects they may have on nontarget species such as fish. With many pharmaceuticals lacking environmental risk assessments, there is a need to better define and understand the potential risks that APIs and their biotransformation products pose to fish, while still minimizing the use of experimental animals. There are both extrinsic (environment- and drug-related) and intrinsic (fish-related) factors that make fish potentially vulnerable to the effects of human drugs, but which are not necessarily captured in nonfish tests. This critical review explores these factors, particularly focusing on the distinctive physiological processes in fish that underlie drug absorption, distribution, metabolism, excretion and toxicity (ADMET). Focal points include the impact of fish life stage and species on drug absorption (A) via multiple routes; the potential implications of fish's unique blood pH and plasma composition on the distribution (D) of drug molecules throughout the body; how fish's endothermic nature and the varied expression and activity of drug-metabolizing enzymes in their tissues may affect drug metabolism (M); and how their distinctive physiologies may impact the relative contribution of different excretory organs to the excretion (E) of APIs and metabolites. These discussions give insight into where existing data on drug properties, pharmacokinetics and pharmacodynamics from mammalian and clinical studies may or may not help to inform on environmental risks of APIs in fish.

Insights into Anthropogenic Micro- and Nanoplastic Accumulation in Drinking Water Sources and Their Potential Effects on Human Health

Anthropogenic microplastics (MPs) and nanoplastics (NPs) are ubiquitous pollutants found in aquatic, food, soil and air environments. Recently, drinking water for human consumption has been considered a significant pathway for ingestion of such plastic pollutants. Most of the analytical methods developed for detection and identification of MPs have been established for particles with sizes > 10 μm, but new analytical approaches are required to identify NPs below 1 μm. This review aims to evaluate the most recent information on the release of MPs and NPs in water sources intended for human consumption, specifically tap water and commercial bottled water. The potential effects on human health of dermal exposure, inhalation, and ingestion of these particles were examined. Emerging technologies used to remove MPs and/or NPs from drinking water sources and their advantages and limitations were also assessed. The main findings showed that the MPs with sizes > 10 μm were completely removed from drinking water treatment plants (DWTPs). The smallest NP identified using pyrolysis-gas chromatography-mass spectrometry (Pyr-GC/MS) had a diameter of 58 nm. Contamination with MPs/NPs can occur during the distribution of tap water to consumers, as well as when opening and closing screw caps of bottled water or when using recycled plastic or glass bottles for drinking water. In conclusion, this comprehensive study emphasizes the importance of a unified approach to detect MPs and NPs in drinking water, as well as raising the awareness of regulators, policymakers and the public about the impact of these pollutants, which pose a human health risk.

Combined exposure of polystyrene microplastics and carbamazepine induced transgenerational effects on the reproduction of Daphnia magna

Polystyrene microplastics (PS MPs) and carbamazepine (CBZ) are frequently detected in freshwater ecosystems. However, the transgenerational effects of PS MPs and CBZ on the reproduction of aquatic organisms and the corresponding mechanisms are still unclear. In the present study, Daphnia magna was used to evaluate the reproductive toxicity in two consecutive generations (F0, F1). The molting and reproduction parameters, the expression of reproduction, and the toxic metabolism genes were examined after 21-day exposure. A significantly enhanced toxicity was observed in the presence of 5 μm PS MPs and CBZ. Chronic exposure results showed that the 5 μm PS MPs alone, CBZ alone, and their mixtures exerted significant reproductive toxicity of D. magna. The results of RT-qPCR showed transcripts of genes related to reproduction (cyp314, ecr-b, cut, vtg1, vtg2, dmrt93b) and toxic metabolism (cyp4, gst) were altered in both the F0 and F1. In addition, for the F0, gene transcriptional changes of reproduction were not fully translated into physiological performance, probably due to the compensatory responses caused by the low dose of PS MPs alone, CBZ alone, and their mixtures. Whereas for the F1, the trade-off between reproduction and toxic metabolism at gene levels was observed, which translated into a significant reduction in the total neonate number of F1. These findings suggest that long-term exposure to MPs and CBZ can cause serious reproduction damage to aquatic animals, which needs to be given sufficient attention.

The generation of environmentally persistent free radicals on photoaged microbeads from cosmetics enhances the toxicity via oxidative stress

Microbeads used in personal care products have been one of the important sources of microplastics (MPs), and little has been reported on their environmental behaviors and health risks. The characteristics of environmentally persistent free radicals (EPFRs) and the toxicity assessment of MPs (environmentally relevant concentrations) from cosmetics during photoaging remains largely unknown. In this study, the formation of EPFRs on polyethylene (PE) microbeads from facial scrubs under light irradiation and their toxicity were investigated using C. elegans as a model organism. The results suggested that light irradiation induced the generation of EPFRs, which accelerates the aging process and alters the physicochemical properties of PE microbeads. Acute exposure to PE (1 mg/L) at photoaged times of 45-60 d significantly decreased the physiological indicators (e.g., head thrashes, body bends, and brood size). The oxidative stress response and stress-related gene expression were also enhanced in nematodes. The addition of N-acetyl-l-cysteine induced significant inhibition of toxicity and oxidative stress in nematodes exposed to 45-60 d of photoaged PE. The Pearson correlation results showed that the concentration of EPFRs was significantly correlated with physiological indicators, oxidative stress, and related-genes expression in nematodes. The data confirmed that the generation of EPFRs combined with heavy metals and organics contributed to toxicity induced by photoaged PE, and oxidative stress might be involved in regulating adverse effects in C. elegans. The study provides new insight into the potential risks of microbeads released into the environment during photoaging. The findings also highlight the necessity for considering the role of EPFRs formation in evaluating the impacts of microbeads.

Understanding the underestimated: Occurrence, distribution, and interactions of microplastics in the sediment and soil of China, India, and Japan

Microplastics (MPs) are non-biodegradable substances that can sustain our environment for up to a century. What is more worrying is the incapability of modern technologies to annihilate MPs from om environment. One ramification of MPs is their impact on every kind of life form on this planet, which has been discussed ahead; that is why these substances are surfacing in everyday discussions of scholars and researchers. This paper discusses the overview of the global occurrence, abundance, analysis, and remediation techniques of MPs in the environment. This paper primarily reviews the event and abundance of MPs in coastal sediments and agricultural soil of three major Asian countries, India, China, and Japan. A significant concentration of MPs has been recorded from these countries, which affirms its strong presence and subsequent environmental impacts. Concentrations such as 73,100 MPs/kg in Indian coastal sediments and 42,960 particles/kg in the agricultural soil of China is a solid testimony to prove their massive outbreak in our environment and require urgent attention towards this issue. Conclusions show that human activities, rivers, and plastic mulching on agricultural fields have majorly acted as carriers of MPs towards coastal and terrestrial soil and sediments. Later, based on recorded concentrations and gaps, future research studies are recommended in the concerned domain; a dearth of studies on MPs influencing Indian agricultural soil make a whole sector and its consumer vulnerable to the adverse effects of this emerging contaminant.

Transgenerational impacts of micro(nano)plastics in the aquatic and terrestrial environment

Plastic particles of diameters ranging from 1 to 1000 nm and > 1 µm to 5 mm are respectively known as nanoplastics and microplastics, and are collectively termed micro(nano)plastics (MNPs). They are ubiquitously present in aquatic and terrestrial environments, posing adverse multifaceted ecological impacts. Recent transgenerational studies have demonstrated that MNPs negatively impact both the exposed parents and their unexposed generations. Therefore, this review summarizes the available research on the transgenerational impacts of MNPs in aquatic and terrestrial organisms, induced by exposure to MNPs alone or in combination with other organic and inorganic chemicals. The most commonly reported transgenerational effects of MNPs include tissue bioaccumulation and transfer, affecting organisms' survival, growth, reproduction, and energy metabolism; inducing oxidative stress; enzyme and genetic responses; and causing tissue damage. Similarly, co-exposure to MNPs and chemicals (organic and inorganic pollutants) significantly impacts survival, growth, and reproduction and induces oxidative stress, thyroid disruption, and genetic toxicity in organisms. The characteristics of MNPs (degree of aging, size, shape, polymer type, and concentration), exposure type and duration (parental exposure vs. multigenerational exposure and acute exposure vs. chronic exposure), and MNP-chemical interactions are the main factors affecting transgenerational impacts. Selecting MNP properties based on their realistic environmental behavior, employing more diverse animal models, and considering chronic exposure and MNP-chemical mixture exposure are salient research prospects for an in-depth understanding of the transgenerational impacts of MNPs.

Effects of heavy metals on the adsorption of ciprofloxacin on polyethylene microplastics: Mechanism and toxicity evaluation

Microplastics are plastic particles less than 5 mm in diameter and are widely present in water environments. Their unique surface structures can adsorb coexisting pollutants in the surrounding environment, such as antibiotics and metal ions, leading to compound pollution. The adsorption of ciprofloxacin on polyethylene microplastics under different environmental conditions (pH and salinity) was investigated. The Freundlich model fitted well at 25 °C, indicating that the adsorption of ciprofloxacin by polyethylene microplastics was multilayered, and Fourier Transform infrared spectroscopy (FTIR) analysis indicated that the adsorption of ciprofloxacin by polyethylene microplastics was physical. The kinetic adsorption of ciprofloxacin on polyethylene microplastics followed a pseudo-second-order mode. Heavy metals (Cu²⁺, Cr³⁺, Cr⁶⁺, Cd²⁺, and Pb²⁺) affected the adsorption of ciprofloxacin by microplastics, which was related to the type and concentration of metal ions and the valence state of the ions. The acute toxicity of microplastics and the microplastic-ciprofloxacin-Cu²⁺ complex were evaluated using luminescent Photobacterium phosphoreum, demonstrating the polyethylene toxicity microplastic-ciprofloxacin-Cu²⁺ complex was mainly caused by Cu²⁺ and ciprofloxacin rather than microplastics. This study provides theoretical support for the environmental behavior and ecological effects of microplastics in aqueous environments.

Biochar for the Removal of Emerging Pollutants from Aquatic Systems: A Review

Water contaminated with emerging pollutants has become a serious environmental issue globally. Biochar is a porous and carbon-rich material produced from biomass pyrolysis and has the potential to be used as an integrated adsorptive material. Many studies have shown that biochar is capable to adsorb emerging pollutants from aquatic systems and could be used to solve the water pollution problem. Here, we provided a dual perspective on removing emerging pollutants from aquatic systems using biochar and analyzed the emerging pollutant removal efficiency from the aspects of biochar types, pollutant types and coexistence with heavy metals, as well as the associated mechanisms. The potential risks and future research directions of biochar utilization are also presented. This review aims to assist researchers interested in using biochar for emerging pollutants remediation in aquatic systems and facilitate research on emerging pollutants removal, thereby reducing their environmental risk.

Melanin interference toxicity or transgenerational toxicity of organic UV filter ethylhexyl salicylate on zebrafish

With the improvement of human health awareness, the production and usage of sunscreens have increased dramatically, and their active ingredients, organic ultraviolet (UV) filters (OUVFs), have the potential to induce melanin abnormalities in aquatic organisms due to their UV-absorbing properties as they enter the aquatic environment directly with the washing of skin during water activities. In this paper, the melanin interference toxicity or transgenerational toxicity effects of typical OUVFs ethylhexyl salicylate (EHS) on zebrafish (Danio rerio) were investigated based on transcriptomic sequencing technology. Results showed that EHS induced significant enrichment of the melanin-related pathway cAMP signaling pathway in parental skin tissue through UV absorption, with sensitive genes identified as melanocortin 1 receptor, protein kinase A catalytic subunit beta a, calcium/calmodulin-dependent protein kinase II delta 2, adenylate cyclase 1 and G protein subunit alpha I a. qRT-PCR verification results showed that EHS may inhibit the expression of the melanin master regulator microphthalmia-associated transcription factor a (mitfa) and its induced signaling cascade mitf-tyrosinase (tyr)-dopachrome tautomerase (dct)-tyrosinase related protein 1 (tyrp1) by inducing abnormal expression of the above sensitive genes, thereby reducing melanogenesis. After reproduction, the melanin interference effect of EHS on the parents can be carried over to offsprings through maternal inheritance of abnormally expressed mitfa and parental transfer of pollutants, as evidenced by significant enrichment of melanogenesis pathway, abnormal expression of sensitive genes mitfa, tyr, dct and tyrp1b and significant decreases in melanin content and spinal melanin area. These findings revealed the specific melanin interference toxicity of OUVFs with UV-absorbing properties, facilitating a comprehensive ecological risk assessment of OUVFs and providing scientific support for the management of new pollutants.

Developmental Polyethylene Microplastic Fiber Exposure Entails Subtle Reproductive Impacts in Juvenile Japanese Medaka (Oryzias latipes)

Microplastic pollution has been recognized as a potential threat to environmental and human health. Recent studies have shown that microplastics reside in all ecosystems and contaminate human food/water sources. Microplastic exposure has been shown to result in adverse effects related to endocrine disruption; however, data are limited regarding how exposure to current environmental levels of microplastics during development may impact reproductive health. To determine the impact of environmentally relevant, chronic, low-dose microplastic fibers on fish reproductive health, juvenile Japanese medaka were exposed to five concentrations of polyethylene fibers for 21 days, and reproductive maturity was examined to assess the later life consequences. Fecundity, fertility, and hatching rate were evaluated to determine the organismal level impacts. Gonadal tissue integrity and stage were assessed to provide insights into potential tissue level changes. Expression of key reproductive genes in male and female gonads provided a molecular level assessment. A significant delay in hatching was observed, indicating cross-generational and organismal level impacts. A significant decrease in 11-beta-dehydrogenase isozyme 2 (HSD11 β 2) gene expression in male medaka indicated adverse effects at the molecular level. A decrease in male expression of HSD11 β 2 could have an impact on sperm quality because this enzyme is crucial for conversion of testosterone into the androgen 11-ketotestosterone. Our study is one of the first to demonstrate subtle impacts of virgin microplastic exposure during development on later life reproductive health. The results suggest a possible risk of polyethylene fiber exposure for wild fish during reproductive development, and populations should be monitored closely, specifically in spawning and nursery regions. Environ Toxicol Chem 2022;41:2848-2858. © 2022 SETAC.

Single and combined effects of microplastics and cadmium on juvenile grass carp (Ctenopharyngodon idellus)

Microplastics (MPs) have received extensive attention as a new type of environmental pollutants with potential ecological risks. However, there are still few studies on the physiological stress response of aquatic organisms under the interaction of MPs and heavy metals. In this study, grass carp (Ctenopharyngodon idellus) were chosen as experimental fish and were exposed to 5 μm polystyrene microplastics (PS - MPs, 700 μg/L) and cadmium (Cd, 100 μg/L) individually or in combination. The results indicated that the presence of Cd didn't affect the accumulation of MPs in the intestines of grass carp. On the contrary, the concentration of Cd in the intestines of grass carp was higher in the MPs - Cd combined exposure group than in the Cd alone exposure group. Histological analysis revealed multiple abnormalities in the intestines after acute exposure, and the damage in the MPs - Cd combined exposure group was particularly severe. After 24 h of exposure, the expression of pro-inflammatory cytokines was significantly up-regulated in all exposed groups. However, after 48 h of exposure, the expression of inflammatory cytokines was significantly down-regulated, which may be related to intestinal damage. Our results deepen the significance of toxicological studies of MPs exposure, highlight their interaction with heavy metal toxicants, and provide important data for assessing the risk of MPs and heavy metals to grass carp.

Particles as carriers of matter in the aquatic environment: Challenges and ways ahead for transdisciplinary research

A diverse array of natural and anthropogenic particles found in the aquatic environment, can act as carriers of co-transported matter (CTM), such as nutrients, genetic material and contaminants. Thus, understanding carrier particle transport will increase our understanding of local and global fluxes of exogenous CTM (affiliated with the particle) and endogenous CTM (an inherent part of the particle). In the present contribution, researchers from multiple disciplines collaborated to provide perspectives on the interactions between carrier particles and CTM, and the fundamentals of transport of particles found in the aquatic environment and the generic spherical smooth particles, often used to make predictions about particle behavior in suspension. Evidently, the particles in the aquatic environment show a great variety of characteristics and vary greatly from each other as well as from the generic particle. However, in spite of these differences, many fundamental concepts apply to particles in general. We emphasize the importance of understanding the basic concepts of transport of particle-associated CTM, and the main assumptions in the generic-founded models, which are challenged by the diverging characteristics of particles found in the aquatic environment, as paramount moving forward. Additionally, we identified the need for a conceptual and semantic link between different scientific fields of particle research and initiated the formation of a consistent terminology. Disciplinary and organizational (academic and funding) barriers need to be overcome to enable individual researchers to move beyond their knowledge sphere, to stimulate future interdisciplinary collaborations and to avoid research silos. Hereby, we can foster faster and better progress of evolving research fields on new and emerging anthropogenic carrier particles, and stimulate the development of solutions to the technological and environmental challenges.

The distinct toxicity effects between commercial and realistic polystyrene microplastics on microbiome and histopathology of gut in zebrafish

As a ubiquitous emerging pollutant, microplastics (MPs) have attracted widespread attention. At this stage, researchers mainly employed commercial MPs (CMPs) as the model particles to explore the toxic effects of MPs. But whether CMPs can reflect the effects of realistic MPs (RMPs) still remains unknown. Herein, the effects of commercial and realistic polystyrene MPs on gut microbiota of zebrafish were compared. Considering MPs co-exist with antibiotics in real environment, we further distinguished the effects of CMPs and RMPs when they co-existed with enrofloxacin (ENR). The results revealed that while both CMPs and RMPs significantly shifted the gut microbiota, CMPs exhibited stronger toxic effects and more severe damage to gut. Furthermore, ENR exhibited a distinct effect with both CMPs and RMPs on gut microbiota, while the addition of CMPs and RMPs significantly alleviated the toxicity of ENR. In addition, analysis via Kyoto Encyclopedia of Genes and Genomes pathway database revealed that seven major level 1 pathways associated with metabolism, information processing and diseases in the microbial community were affected. Taken together, this work is the first to report that CMPs could not represent RMPs in terms of toxicity and other behaviors, reminding people the limits of using CMPs in ecotoxicology studies.

Exploring the discharge characteristics of personal care behaviors for high precision estimation of microplastic emission

Microplastics (MPs) from personal care and cosmetic products (PCCPs) pose a threat to aquatic environment due to the small size and the complexity of composition. Although the habits of personal care behaviors (PCBs) vary from individuals affecting MPs emissions, quantitative research is not sufficient to support high-precision emission estimates and targeted management decisions. Based on a questionnaire survey about PCBs and laboratory experiments on corresponding PCCPs utilization, this study proposed a bottom-up micro-simulation method to quantify MPs emissions combining multinomial logit model and categorized emission coefficients, and identified the impact of individual attributes on the emissions. The results show that the annual PCBs-derived MPs emissions amounted to 2931.8 trillion particles in China, of which teeth brushing, face washing, and bathing behavior accounted for 29%, 36% and 35%, respectively. The residents discharged an average of 2.18 million particles per capita per year with 95% confidence interval of 0.58-4.34 million particles. Gender, age and living region had greater impacts on PCBs-derived MPs emissions. The effect of living region was significantly related to local temperature and humidity. The estimation based on the MPs discharge characteristics of PCBs provides high-precision method regarding the MPs emission from people's daily life and contributes to further understanding the source of MPs and initiating environmental control strategies.

Extraction, identification, and environmental risk assessment of microplastics in commercial toothpaste

Microplastics in personal care and food products are given much importance globally due to the adverse impact of microplastics on living beings. In the present study, microplastics from ten different commercially sold toothpaste in India were extracted by vacuum filtration and characterized with microscopic and Fourier-transform infrared spectroscopic analyses. Results revealed that colorless fragments and fibers were the microparticle types of common occurrence which ranged from 0.2 to 0.9% weight in the toothpaste with an abundance range of 32.7-83.2%. Fifty percent of the toothpaste samples showed more than 50% microplastic particle abundance indicating that the microplastic plastic particles were added by the manufacturers. The minimum size of microplastics recorded in the present study was 3.5 μm with a maximum size exceeding 400 μm. The maximum number of microplastics in the toothpaste was 167, 508 and 193 respectively, distributed in the size range of <100 μm, 100-400 μm, and >400 μm. The present study recorded four major polymer types, viz., cellophane, polypropylene, polyvinyl chloride, and polyamide in the toothpaste samples. Surprisingly, polyethylene-a common polymer reported in toothpaste was not traced in the present samples. Regarding the Indian context, the current study is a new addition to the knowledge of the occurrence of microplastics in toothpaste. The average annual addition of microplastics into the environment through toothpaste was calculated as 1.4 billion g/year for India, posing a significant threat to the environment.

Epigenetic mechanisms of DNA methylation in the transgenerational effect of ethylhexyl salicylate on zebrafish

In this study, a 120-day whole-life cycle exposure and oviposition experiment on zebrafish with maternal and paternal mixed mating strategy was conducted to investigate the epigenetic mechanism of DNA methylation in ethylhexyl salicylate (EHS, 1, 10, 100 μg/L)-induced transgenerational effects. Results showed that EHS could induce the decrease of DNA methyltransferase 1 (DNMT1) activity and average global DNA methylation level in maternal parents and the increase of the above indexes in paternal parents, while the change of glycine N-methyltransferase activity was opposite to DNMT1. The average global DNA methylation levels were significantly increased in the offsprings of both parents exposed and father-only exposed to EHS, suggesting that EHS-induced epigenetic modifications may be stable and heritable. Hierarchical clustering analysis of promoter at different methylation sites showed that the DNA methylation pattern of offsprings were similar to that of the paternal parents, meaning that the offsprings may have inherited paternal DNA methylation pattern with eya2, pcdh2g5 and pcdh2g1 as key genes and lead to high locomotor activity in offsprings. KEGG pathway analysis showed that parental exposure to EHS may interfere with the central nervous system, insulin function system, melanogenesis system and the normal development of somatic axis of offsprings.

A review on per- and polyfluorinated alkyl substances (PFASs) in microplastic and food-contact materials

Plastic, paper and cardboard are widely used as food contact materials (FCMs), due to its numerous favourable characteristics. However, they are usually coated with hazardous substances, such as per- and polyfluorinated alkyl substances (PFASs). PFASs, with its functional properties of oil- and water-repellency, can migrate from FCMs into the food and cause potential risk to human health. There are also increasing concerns about the harm that FCMs can cause to the environment. These concerns include accumulation of non-degradable plastics in the environment, generation of microplastics (MPs) and nanoplastics, and release of PFASs from FCMs. While many reviews have been conducted on PFASs in the environment, including their occurrence, fate, toxicity, biodegradation, migration in ecosystems and remediation technologies, a systematic review of PFASs in FCMs and MPs is currently lacking. In addition, our knowledge of the PFAS sorption processes on MPs is rather limited, and in particular their desorption processes. Thus, this review aims to (1) review the presence of various classes of PFASs in FCMs and their migration into food, (2) review the PFASs in MPs and summarize the sorption mechanisms, and factors that influence their sorption behaviour on MPs in the aquatic environment, and (3) identify the current research gaps and future research directions to predict the risks associated with the presence and sorption of PFASs in FCMs and MPs.

Influence of physicochemical parameters on PPCP occurrences in the wetlands

There have been many global studies on the occurrence and distribution of pharmaceuticals and personal care products (PPCPs) in the aquatic resources, but reports on the effects of physicochemical properties of water on their concentrations are very scarce. The amounts and removal of these contaminants in various environmental media are dependent on these physicochemical properties, which include pH, temperature, electrical conductivity, salinity, turbidity, and dissolved oxygen. Here, we reviewed the influence of these properties on determination of PPCPs. Reports showed that increase in turbidity, electrical conductivity, and salinity gives increase in concentrations of PPCPs. Also, neutral pH gives higher PPCP concentrations, while decrease in temperature and dissolved oxygen gives low concentration of PPCPs. Nevertheless, it is quite challenging to ascertain the influence of water quality parameters on the PPCP concentration, as other factors like climate change, type of water, source of pollution, persistence, and dilution factor may have great influence on the concentration of PPCPs. Therefore, routine monitoring is suggested as most water quality parameters vary because of effects of climate change.

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.