Microplastics: A major source of phthalate esters in aquatic environments

Occurrence of phthalate esters in the yellow and Yangtze rivers of china: Risk assessment and source apportionment

Phthalate esters (PAEs), recognized as endocrine disruptors, are released into the environment during usage, thereby exerting adverse ecological effects. This study investigates the occurrence, sources, and risk assessment of PAEs in surface water obtained from 36 sampling points within the Yellow River and Yangtze River basins. The total concentration of PAEs in the Yellow River spans from 124.5 to 836.5 ng/L, with Dimethyl phthalate (DMP) (75.4 ± 102.7 ng/L) and Diisobutyl phthalate (DiBP) (263.4 ± 103.1 ng/L) emerging as the predominant types. Concentrations exhibit a pattern of upstream (512.9 ± 202.1 ng/L) > midstream (344.5 ± 135.3 ng/L) > downstream (177.8 ± 46.7 ng/L). In the Yangtze River, the total concentration ranges from 81.9 to 441.6 ng/L, with DMP (46.1 ± 23.4 ng/L), Diethyl phthalate (DEP) (93.3 ± 45.2 ng/L), and DiBP (174.2 ± 67.6 ng/L) as the primary components. Concentration levels follow a midstream (324.8 ± 107.3 ng/L) > upstream (200.8 ± 51.8 ng/L) > downstream (165.8 ± 71.6 ng/L) pattern. Attention should be directed towards the moderate ecological risks of DiBP in the upstream of HH, and both the upstream and midstream of CJ need consideration for the moderate ecological risks associated with Di-n-octyl phthalate (DNOP). Conversely, in other regions, the associated risk with PAEs is either low or negligible. The main source of PAEs in Yellow River is attributed to the release of construction land, while in the Yangtze River Basin, it stems from the accumulation of pollutants in lakes and forests discharged into the river. These findings are instrumental for pinpointing sources of PAEs pollution and formulating control strategies in the Yellow and Yangtze Rivers, providing valuable insights for global PAEs research in other major rivers.

The combined effects of microplastics and their additives on mangrove system: From the sinks to the sources of carbon

Mangrove ecosystems, a type of blue carbon ecosystems (BCEs), are vital to the global carbon cycle. However, the combined effects of microplastics (MPs) and plastic additives on carbon sequestration (CS) in mangroves remain unclear. Here, we comprehensively review the sources, occurrence, and environmental behaviors of MPs and representative plastic additives in mangrove ecosystems, including flame retardants, such as polybrominated diphenyl ethers (PBDEs), and plasticizers, such as phthalate esters (PAEs). Mangrove ecosystems have a complex influence on the behaviors of MPs and additives. Under the action of natural and unnatural factors, these pollutants exhibit complex behaviors including migration, interception, deposition and transformation, that are closely linked to those of particulate carbon, particularly carbon sequestration processes. MPs and additives hinder the CS function of mangroves by harming the growth of flora and fauna, influencing microbial nitrogen and sulfur cycles, and enhancing the degradation of organic matter in the sediment. The increasing accumulation and widespread occurrence of MPs and additives will greatly influence the carbon cycle. Future work is encouraged on systematic investigation of new alternatives to plastics and additives, and research methods to uncover the impact mechanisms of MPs and additives on BCEs. The developments of management measures and engineering technologies are also required to enhance pollutant control and mangrove CS.

Phthalates esters disrupt demersal fish behavior: Unveiling the brain-gut axis impact

The widespread use of plasticizers like phthalate esters (PAEs) has led to environmental and health concerns. The neurobehavioral toxicity of these compounds in marine environments, particularly regulated by the "brain-gut" axis, remains unclear, especially concerning wild demersal fish of high ecological value. Our investigation into the behavioral effects of three common PAEs, i.e., dimethyl phthalate (DMP), di-n-butyl phthalate (DBP), and di(2-ethylhexyl) phthalate (DEHP), and their molecular mechanisms on juvenile Sebastes schlegelii, revealed alarming results from molecular to population levels. After a 20-day foodborne exposure at a low marine environmental concentration (1.0 μg g-1), we observed that all three PAEs significantly increased the thigmotaxis (behavioral tendency to stay close to physical boundaries) and mobility of juvenile fish by 28.2-59.4 % and 23.3-74.5 %, respectively, indicating anxiety-like behavior of fish. DEHP exhibited the most pronounced effects, followed by DBP and DMP. PAEs accumulated in the juvenile fish in the order of brain > liver > gut > muscle, with DEHP showing the highest brain concentrations (23.2 ± 2.98 μg g-1). This accumulation led to oxidative damage, inflammatory responses, and neurodegenerative changes in the optic tectum, resulting in cholinergic system dysfunction. In the gut, PAEs caused inflammatory lesions, disrupted the gut barrier, and altered the gut microbiome, exacerbating the neurotoxicity via "brain-gut" communication. These findings underscore the significant neurobehavioral toxicity of PAEs, emphasizing their critical impact on fish behavior. We also stress the crucial need for further research on fish and other marine species beyond the laboratory scale to fully understand the broader implications of PAE exposure in marine ecosystems and to guide future conservation efforts.

Coagulation performance and mechanism of different novel covalently bonded organic silicon-aluminum/iron composite coagulant for As(V) removal from water: The role of hydrolysate species and the effect of coexisting microplastics

Arsenate [As(V)] pollution is a challenge for water treatment, and the effect of coexisting microplastics (MPs) on As(V) removal is still not clear. In this study, series novel covalently bonded organic silicon-aluminum/iron composite coagulants (CSA/F) with different Al/Fe molar ratios were prepared for enhancing As(V) removal. The effect mechanism of MPs (PS MPs and PS-COOH MPs) on As(V) removal by using CSAF coagulation was analyzed. CSAF and CSF showed significantly better As(V) removal performance than other coagulants under the same conditions, especially CSF, more than 90 % As(V) removal was achieved at dosage of 20 mg/L and pH of 4.0-8.0. Interestingly, the introduction of silane coupling agent and the increase of Fe content in CSA/F changed the Al/Fe species distribution. Charge neutralization dominant in As(V) removal by using CSA, whereas adsorption and net sweeping contributed to As(V) coagulation by using CSAF and CSF with higher iron proportion at neutral pH. 3 µm MPs were removed by net sweeping of amorphous Al/Fe hydroxides, while 26 µm MPs were charge-neutralized or surface adsorbed by coagulant hydrolysates. The aliphatic C-H and -COOH functional groups of MPs were the main sites of hydrogen bonding adsorption with the hydroxyl groups of coagulant hydrolysates. This study is conducive to mitigating the environmental toxicity of arsenic and provides new insights into the interaction mechanism between composite pollutants and coagulants in waters.

Evaluating physiological responses of microalgae towards environmentally coexisting microplastics: A meta-analysis

Microplastics (MPs) are abundantly present in aquatic environments, where the phytoplankton-microalgae, are now inevitably bound to a long-term coexistence with them. While numerous studies have focused on the toxicological effects of high-concentration MPs exposure, there remains controversy over whether and how MPs affect microalgae at environmentally relevant concentrations. This study aims to draw conclusions that narrow the gap from 52 studies with varying results. Overall, MPs can inhibit growth and photosynthesis, induce oxidative damage, from which microalgae can recover after an appropriate period. Cyanobacteria exhibit greater vulnerability than chlorophyta. The relative size of MPs to algal cells potentially governs their coexistence behavior, thereby altering the mechanisms of impact. Pristine MPs may increase the production of extracellular polymeric substances (EPS) and microcystins (MCs), while aged MPs have the opposite effect. Additionally, relevant factors are systematically discussed, offering insights for future research.

Microplastics in freshwater food chains: Priority list based on identification of oxidative stress response characteristic

Exogenous exposure to high concentrations of microplastics (MPs) cause oxidative damage to freshwater food chains (FFCs). Thus, the patterns and mechanisms of oxidative stress responses (OSRs) induced by MPs in FFC organisms were investigated using theoretical simulation methods. Results showed an increasing (reduced) OSR was found in lower trophic levels (higher trophic levels). Besides, polycarbonate (polyvinyl chloride) causes the most (least) significant OSRs in FFC organisms, respectively. The impacts of MP additives were also analyzed using the full factorial experimental design, revealing flame retardants significantly influence oxidative stress variability. A constructive solution of "restriction-control-focus" is proposed for different types of MPs by the coefficient of variation-corrected CRITIC and the nested mean classification method. The mechanism analysis revealed a positive correlation between protein secondary structure orderliness and OSRs. Proteins in organisms that contain a high proportion of hydrophobic non-polar amino acids are more likely to bind to MP and enhance OSRs. This is the first study assessing the OSR patterns and ecological risks of MPs and their additives in FFCs with a proposed priority list, providing theoretical support for risk assessments and management strategies in freshwater environments.

Polystyrene microplastics facilitate the chemical journey of phthalates through vegetable and aggravate phytotoxicity

Polystyrene microplastics (PS) and dibutyl phthalate (DBP) are emerging pollutants widely coexisting in agroecosystems. However, the efficacies of PS as carriers for DBP and their interactive mechanisms on crop safety remain scarce. Here, this study investigated the combined exposure effects and the interacting mechanisms of PS laden with DBP on choy sum (Brassica parachinensis L.). Results showed that PS could efficiently adsorb and carry DBP, with a maximum carrying capacity of 9.91 %, facilitating the chemical translocation of DBP in choy sum and exacerbating phytotoxicity. Due to the changes in the properties of PS, DBP loading aggravated the phytotoxicity of choy sum, exhibiting synergistically toxic effects compared with individual exposure. The Trojan-horse-complexes formed by PS+DBP severely delayed the seed germination process and altered spatial growth patterns, causing disruptions in oxidative stress, osmoregulation, photosynthetic function, and elemental reservoirs of choy sum. Combined pollutants enhanced the uptake and translocation of both PS and DBP by 8.90-31.94 % and 136.81-139.37 %, respectively; while the accumulation processes for PS were more complex than for DBP. Visualization indicated that PS was intensively sequestered in roots with a strong fluorescent signal after loading DBP. This study comprehensively investigated the efficacies of PS carrying DBP on phytotoxicity, bioavailability, and their interactive mechanisms, providing significant evidence for food safety assessment of emerging contaminant interactions.

Integrative models for environmental forecasting of phthalate migration from microplastics in aquaculture environments

The pervasive utilization of plastic tools in aquaculture introduces significant volumes of microplastic fibers, presenting a consequential risk through the leaching of additives such as phthalates. This study scrutinizes the leaching dynamics of six prevalent phthalate esters (PAEs) from thirteen plastic aquaculture tools comprising polyethylene terephthalate (PET), polypropylene (PP), and polyethylene (PE), with ΣPAEs ranging from 0.24 to 4.26 mg g-1. Di(2-ethylhexyl) phthalate (DEHP) and dibutyl phthalate (DBP) emerged as predominant, marking significant environmental concern. Over a 30-day period, leaching quantities of Σ6PAEs from PET, PP, and PE fibers reached 36.65 μg g-1, 21.87 μg g-1 and 19.11 μg g-1, respectively, influenced by factors such as time, temperature, turbulence, and salinity. Notably, turbulence exerted the most pronounced effect, followed by temperature, with negligible influence from salinity. The kinetic models aligning with interface diffusion control was developed, predicting PAEs' leaching behavior with activation energies (Ea) indicative of the process's thermodynamic nature. The application of this model to real-world aquaculture waters forecasted significant risks, corroborating with empirical data and underscoring the pressing need for regulatory and mitigation strategies against PAEs contamination from aquaculture practices.

Airborne micro- and nanoplastics: emerging causes of respiratory diseases

Airborne micro- and nanoplastics (AMNPs) are ubiquitously present in human living environments and pose significant threats to respiratory health. Currently, much research has been conducted on the relationship between micro- and nanoplastics (MNPs) and cardiovascular and gastrointestinal diseases, yet there is a clear lack of understanding regarding the link between AMNPs and respiratory diseases. Therefore, it is imperative to explore the relationship between the two. Recent extensive studies by numerous scholars on the characteristics of AMNPs and their relationship with respiratory diseases have robustly demonstrated that AMNPs from various sources significantly influence the onset and progression of respiratory conditions. Thus, investigating the intrinsic mechanisms involved and finding necessary preventive and therapeutic measures are crucial. In this review, we primarily describe the fundamental characteristics of AMNPs, their impact on the respiratory system, and the intrinsic toxic mechanisms that facilitate disease development. It is hoped that this article will provide new insights for further research and contribute to the advancement of human health.

Beyond plastic pollution: Unveiling chemical release from plastic debris in river water and seawater using non-target screening

Oceans and rivers are predominant sinks, reservoirs, and carriers of plastic debris that are proposed to be long term sources of a variety of contaminants in the environments. This research unveiled kinetics of chemical releases from plastic debris in freshwater and marine environment via artificial river water (ARW) and seawater (ASW) in combination of nontarget screening. Chemical leaching from PVC cord particles in the ARW and ASW basically followed the first order kinetics, reaching pseudo-equilibrium in 30d and 14d, respectively, associated with both particle surface - water partitioning and inner-particle diffusion of chemicals. Dissolved organic carbon, finer size, and weathering of plastic particles might enhance whereas metal ions potentially hinder chemical releases from plastic debris in waters, respectively. Salinity and pH showed moderate effects on chemical leaching. In addition, chemicals' physiochemical properties might also affect their leaching behavior. Hundreds to thousands of chemicals would be released from plastic debris in days once entering waters, among which > 80% were unknown with rare or no information about eco-toxicity and environmental fate, posing unpredicted risks to the environment. Furthermore, new chemicals may keep being released with increasing weathering and extending retention time of plastics in waters, leading to increases in both numbers and complexities of released chemicals. Chemical leaching from plastics showed product-dependence and certain differences in freshwater and seawater. Large numbers of unknown chemicals potentially released from plastic debris in rivers, lakes, and oceans and subsequent environmental risks warrant in-depth research.

Effects of polystyrene micro- and nanoplastics on androgen- and estrogen receptor activity and steroidogenesis in vitro

While many plastic additives show endocrine disrupting properties, this has not been studied for micro- and nanoplastics (MNPs) particles despite their ubiquitous presence in humans. The objective of this study was to determine the effects of various sizes and concentrations of polystyrene (PS)-MNPs (50-10,000 nm, 0.01-100 μg/mL) on estrogen- and androgen receptor (ER and AR) activity and steroidogenesis in vitro. Fluorescent (F)PS-MNPs of ≤1000 nm were internalized in VM7 and H295R cells and FPS-MNPs ≤200 nm in AR-ecoscreen cells. H295R cells displayed the highest uptake and particles were closer to the nucleus than other cell types. None of the sizes and concentrations PS-MNPs tested affected ER or AR activity. In H295R cells, PS-MNPs caused some statistically significant changes in hormone levels, though these showed no apparent concentration or size-dependent patterns. Additionally, PS-MNPs caused a decrease in estriol (E3) with a maximum of 37.5 % (100 μg/mL, 50 nm) and an increase in gene expression of oxidative stress markers GPX1 (1.26-fold) and SOD1 (1.23-fold). Taken together, our data show limited endocrine-disrupting properties of PS-MNPs in vitro. Nevertheless the importance of E3 in the placenta warrants further studies in the potential effects of MNPs during pregnancy.

Detection and health implications of phthalates in tea beverages in market: Application of novel solid-phase microextraction fibers

Assessment and control of emerging organic pollutants in food have become critical for global food safety and health. The European Union has set standards for certain emerging organic pollutants, such as phthalic acid esters (PAEs) in food. Because of being endocrine disruptors, PAEs are toxic and carcinogenic to humans. Release of PAEs from packaging materials poses a potential risk to human health and causes environmental pollution. In this study, a highly sensitive analytical method for the detection of PAE contents in tea beverages was established using hydroxyl-functionalized covalent organic frameworks (COFs) as solid-phase microextraction (SPME) coating. Results indicate that functionalization with hydroxyl groups enhances the adsorption of PAEs. The proposed method exhibits a wide linear range (1-20,000 ng L-1), low limits of detection (> 0.048 ng L-1), and satisfactory recovery (72.8 %-127.3 %). To investigate the PAE contamination in beverages, contamination levels of six typical PAEs and their health impacts were surveyed across various brands/types/packaging materials of tea beverages sold in China. Results of the hazard quotient and hazard index approaches suggest no or extremely low health concerns regarding PAE levels. We observe that hydroxyl groups functionalized on COFs enhance the adsorption of PAEs. Moreover, an important outcome of this study is development of an efficient and sensitive direct detection method for PAEs in complex tea matrices, providing a reliable approach for the assessment of PAEs in other complex matrices.

Environmental microplastic and phthalate esters co-contamination, interrelationships, co-toxicity and mechanisms. A review

Plastics have been pervasive in society for decades, causing extensive environmental contamination. The co-occurrence of microplastics (MPs) and phthalate esters (PAEs) in the environment has significant implications for the global population. This review focuses on the simultaneous presence of MPs and PAEs, exploring co-pollution, leaching, adsorption, correlation, and co-toxicity. Both MPs and PAEs are found in various environmental compartments, including water, sediments, aquatic organisms, pig feed, masks, gloves, and liquid waste from garbage infiltration. Factors such as time, temperature, UV light exposure, and the type of MPs can influence the leaching and adsorption of PAEs onto MPs. The correlation between MPs and PAEs allows for the use of PAEs as indicators for the presence of MPs. However, current constraints, like limited data availability and regional coverage, impede the feasibility of comprehensive tracking. Additionally, the combined effects of MPs and PAEs demonstrate synergistic toxicity, leading to adverse health effects such as reproductive toxicity, neurotoxicity, hepatotoxicity, nephrotoxicity, and other toxicities, primarily mediated by oxidative stress processes. Consequently, the findings provide valuable insights for future researchers and regulatory bodies, enabling the development of more effective strategies to address the simultaneous presence of microplastics and PAEs and mitigate their harmful impacts on human health.

Non-dietary exposure to phthalates in primary school children: Risk and correlation with anthropometric indices, cardiovascular and respiratory diseases

Phthalates are endocrine disruptors of increasing concern for human health; however, previous studies have only assessed the association between internal exposure and human health. We aimed to assess the non-carcinogenic and carcinogenic risks of non-dietary exposure to phthalates in indoor environments among primary school children and their correlations with health indicators. A study involving 54 children was conducted in Jinan, Shandong Province, China. Questionnaires and health examinations were conducted, dust in hard-to-clean corners of students' classrooms and homes was collected, and airborne phthalates in the middle of classrooms and family living rooms were sampled. The gas-phase phthalate concentrations, individual exposure, and non-carcinogenic and carcinogenic risks were calculated. Associations were estimated using linear mixed models. The findings revealed that phthalates posed a non-carcinogenic risk to 7.4 % of the children and a moderate carcinogenic risk to 27.8 % of the children, with higher non-carcinogenic and carcinogenic risks to girls than to boys. Five phthalates were negatively correlated with body mass index, dimethyl phthalate and diethyl phthalate (DEP) were significantly correlated with waist circumference, and di-iso-butyl phthalate (DiBP) was negatively correlated with hip circumference. DiBP, di-n-butyl phthalate, and DEP, were significantly correlated with cardiovascular disease, DEP and di (2-n-butoxyethyl) phthalate were correlated with decreased lung function, and di-n-octyl phthalate influenced airway inflammation. The findings indicated that phthalate exposure may negatively impact children's health, thereby warranting further comprehensive research on the health effects of these chemicals.

Phthalates and fatty acid markers in free-ranging cetaceans from an insular oceanic region: Ecological niches as drivers of contamination

Plastic additives, such as phthalates, are ubiquitous contaminants that can have detrimental impacts on marine organisms and overall ecosystems' health. Valuable information about the status and resilience of marine ecosystems can be obtained through the monitoring of key indicator species, such as cetaceans. In this study, fatty acid profiles and phthalates were examined in blubber biopsies of free-ranging individuals from two delphinid species (short-finned pilot whale - Globicephala macrorhynchus, n = 45; common bottlenose dolphin - Tursiops truncatus, n = 39) off Madeira Island (NE Atlantic). This investigation aimed to explore the relations between trophic niches (epipelagic vs. mesopelagic), contamination levels, and the health status of individuals within different ecological and biological groups (defined by species, residency patterns and sex). Multivariate analysis of selected dietary fatty acids revealed a clear niche segregation between the two species. Di-n-butylphthalate (DBP), diethyl phthalate (DEP), and bis(2-ethylhexyl) phthalate (DEHP) were the most prevalent among the seven studied phthalates, with the highest concentration reached by DEHP in a bottlenose dolphin (4697.34 ± 113.45 ng/g). Phthalates esters (PAEs) concentration were higher in bottlenose dolphins (Mean ∑ PAEs: 947.56 ± 1558.34 ng/g) compared to pilot whales (Mean ∑ PAEs: 229.98 ± 158.86 ng/g). In bottlenose dolphins, DEHP was the predominant phthalate, whereas in pilot whales, DEP and DBP were more prevalent. Health markers suggested pilot whales might suffer from poorer physiological conditions than bottlenose dolphins, although high metabolic differences were seen between the two species. Phthalate levels showed no differences by ecological or biological groups, seasons, or years. This study is the first to assess the extent of plastic additive contamination in free-ranging cetaceans from a remote oceanic island system, underscoring the intricate relationship between ecological niches and contaminant exposure. Monitoring these chemicals and their potential impacts is vital to assess wild population health, inform conservation strategies, and protect critical species and habitats.

Typical Tire Additives in River Water: Leaching, Transformation, and Environmental Risk Assessment

Tire wear particles (TWPs) released during vehicle driving can enter water bodies, leading to leaching of tire additives (TAs) in aquatic environments. However, the transformation behavior and related ecological impacts of TAs and their transformation products (TPs) remain unclear. In this study, laboratory-based simulation experiments and field investigations were conducted to explore the transformation mechanisms and ecological risks of TAs. After being placed in river water for 24 h, about 7-95% of 12 investigated TAs in TWPs were leached. Forty-eight TPs from eight TAs were tentatively identified along with different transformation pathways via suspect screening by high-resolution mass spectrometry. Semiquantitative results indicated that TPs derived from N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylene-diamine (6PPD) were predominant in leachates, while aryl hydrolysis and quinone pathways were the main transformation pathways. Field investigations on urban surface water samples from 16 sites in Hong Kong revealed the occurrence of 17 TAs and 1 TP, with concentrations ranging from 13.9 to 2230 ng/L (median ± standard deviation: 226 ± 534 ng/L). Sixteen TPs from six TAs were additionally identified via suspect screening. It is estimated that 6PPD-quinone and seven TAs could pose medium to high ecological risk, while N-(1,3-dimethylbutyl)-N'-phenyl-p-quinonediimine, a frequently detected TP, was identified as a persistent-bioaccumulative-toxic substance.

Microplastic accumulation in a lizard species: Observations from the terrestrial environments

Microplastics are a global environmental problem, polluting both aquatic and terrestrial environments. Terrestrial lizards are suitable model organisms to study human-induced pollution in these areas, as they can live in urbanized areas where microplastics are most abundant. Therefore, we analyzed the prevalence of microplastics (MPs) in a common Lacertid lizard, the snake-eyed lizard, Ophisops elegans. We detected MPs in the gastrointestinal tract (GIT) of 33 of 152 specimens from 18 populations. The detected MPs had six distinct polymer compositions, namely Polyethylene terephthalate, Polyacrylonitrile, Polypropylene, Polyethylene, Poly methyl methacrylate and Polyamide. The majority of these MPs were fiber-type and the dominant color was navy blue. The lengths of MPs varied from 37 to 563 μm, with an average length of 175 μm. MPs were detected in the GITs of 43% of juveniles (n = 7), 30% of males (n = 105), and 18% of females (n = 40), with a mean of 0.27 per specimen. Furthermore, we found that microplastic densities varied with habitat distance from human settlements, supporting the theory that high levels of microplastic contamination are associated with extensive anthropogenic activity.

Soft plastic fishing lures as a potential source of chemical pollution - Chemical analyses, toxicological relevance, and anglers' perspectives

Soft plastic lures (SPLs) are commonly used artificial lures in recreational angling. Anglers regularly lose SPLs while fishing and there is little knowledge about the environmental impacts of lost SPLs. As with other plastic items, SPLs contain phthalates and other persistent additives that may leach into water. In this study, 16 randomly chosen SPLs of common models were analyzed for the leaching of persistent, water-soluble plastic additives, including phthalates. The estrogenicity of sample extracts from a subsample of 10 SPLs was assessed using luciferase reporter gene bioassays. Over a period of 61 days, 10 of the 16 SPLs leached the targeted phthalates dimethyl phthalate (DMP), diethyl phthalate (DEP), benzyl butyl phthalate (BBP) and di-n-butyl phthalate (DnBP) at median detectable concentrations ranging from 10 ng/g sample BBP to a median of 1001 ng/g DMP as well as 45 persistent, mobile, and toxic (PMT) plastic additives. DEP was detected most frequently in 8 SPLs, followed by BBP (2 SPLs), DMP (2 SPLs) and DnBP (1 SPL). The extract from one SPL with comparatively low phthalate and PMT plastic additive levels was active in the bioassay, indicating high endocrine-disruptive potential, presumably due to unknown additives that were not among the target substances of the methodology used in this study. The study was supplemented by a mail survey among anglers, in which attitudes of anglers towards SPLs were investigated. The survey indicated that SPL loss is a common event during angling. Most participants were concerned about potential ecological impacts of SPLs, wanted the ingredients of SPLs to be labelled and supported legal restrictions concerning toxic ingredients of SPLs. The study shows that SPLs are a potential source of environmental pollution, may pose human health risks and need further investigation, considering the frequent use of SPLs in recreational angling.

Effects of polyvinyl chloride and low-density polyethylene microplastics on oxidative stress and mitochondria function of earthworm (Eisenia fetida)

Plastics are widely used worldwide due to their convenience. However, microplastics (MPs) accumulation poses a serious threat to ecosystem health. Therefore, understanding the effects of MPs on living organisms within their native ecosystem is crucial. Previous studies have primarily focused on the impacts of MPs in aquatic environments, whereas the effects of MPs on terrestrial ecosystems have remained largely understudied. Therefore, our study assessed the impacts of MPs on soil ecosystems by characterizing their toxic effects on earthworms (Eisenia fetida). Here, we exposed earthworms to two representative plastics within soil environments: polyvinyl chloride (PVC) and low-density polyethylene (LDPE). Given the known link between MPs and oxidative stress, we next quantified oxidative stress markers and mitochondrial function to assess the effects of MPs on the redox metabolism of earthworms. Mitochondria are crucial metabolic organelles that generate reactive oxygen species via uncontrolled ATP production. Our findings demonstrated that MPs exert different effects depending on their type. Neither the PVC-exposed groups nor the LDPE-exposed groups exhibited changes in oxidative stress, as worked by the action of superoxide dismutase (SOD) and glutathione (GSH). While treatment of the two types of MP did not significantly affect the amount of reactive oxygen species/reactive nitrogen species (ROS/RNS) generated, PVC exhibited a more pronounced effect on antioxidant system compared to LDPE. However, mitochondrial function was markedly decreased in the group exposed to high LDPE concentrations, suggesting that the examined LDPE concentrations were too low to activate compensatory mechanisms. Collectively, our findings demonstrated that exposure of MPs not only influences the antioxidant defense mechanisms of earthworms but also alters their mitochondrial function depending on their types.

Screening the release of chemicals and microplastic particles from diverse plastic consumer products into water under accelerated UV weathering conditions

Photodegradation of plastic consumer products is known to accelerate weathering and facilitate the release of chemicals and plastic particles into the aquatic environment. However, these processes are complex. In our presented pilot study, eight plastic consumer products were leached in distilled water under strong ultraviolet (UV) light simulating eight months of Central European climate and compared to their respective dark controls (DCs). The leachates and formed plastic particles were exploratorily characterized using a range of chemical analytical tools to describe degradation and leaching processes. These techniques covered (a) microplastic analysis, showing substantial liberation of plastic particles further increased under UV exposure, (b) non-targeted mass spectrometric characterization of the leachates, revealing several hundreds of chemical features with typically only minor agreement between the UV exposure and the corresponding DCs, (c) target analysis of 71 organic analytes, of which 15 could be detected in at least one sample, and (d) metal(loid) analysis, which revealed substantial release of toxic metal(loid)s further enhanced under UV exposure. A data comparison with the US-EPA's ToxVal and ToxCast databases showed that the detected metals and organic additives might pose substantial health and environmental concerns, requiring further study and comprehensive impact assessments.

Gas-phase and air-solid interface behavior of phthalate plasticizer and ozone: The influence of indoor mineral dust

Indoor environments serve as reservoirs for a variety of emerging pollutants (EPs), such as phthalates (PAE), with intricate interactions occurring between these compounds and indoor oxidants alongside dust particles. However, the precise mechanisms governing these interactions and their resulting environmental implications remain unclear. By theoretical simulations, this work uncovers multi-functional compounds and high oxygen molecules as important products arising from the interaction between DEP/DEHP and O3, which are closely linked to SOA formation. Further analysis reveals a strong affinity of DEP/DEHP for mineral dust surfaces, with an adsorption energy of 22.11/30.91 kcal mol-1, consistent with a higher concentration of DEHP on the dust surface. Importantly, mineral particles are found to inhibit every step of the reaction process, albeit resulting in lower product toxicity compared to the parent compounds. Thus, timely removal of dust in an indoor environment may reduce the accumulation and residue of PAEs indoors, and further reduce the combined exposure risk produced by PAEs-dust. This study aims to enhance our understanding of the interaction between PAEs and SOA formation, and to develop a fundamental reaction model at the air-solid surface, thereby shedding light on the microscopic behaviors and pollution mechanisms of phthalates on indoor dust surfaces.

Occurrence, migration and health risks of fluorescent whitening agents and phthalates in bottled water

The occurrence and health risks of fluorescent whitening agents (FWAs) in bottled water were reported for the first time. FWA184 and FWA393 were the most frequently detected FWAs, with mean concentrations of 3.99-17.00 ng L-1. Phthalates (PAEs) such as dibutyl phthalate (DBP), di-iso-butyl phthalate (DiBP), and diethylhexyl phthalate (DEHP) were prevalent in bottled water, with mean levels of 40.89-716.66 ng L-1, and their concentrations in bottled water were much higher than those of FWAs. FWAs and PAEs in bottles and caps were extracted using organic solvent, and the correlation analysis showed that FWA393 and DEHP most likely originated from bottles, while bottle caps were the main sources of DBP and DiBP. The calculated risk quotients (RQs) of target substances and all age groups were considerably lower than the threshold of 0.1, indicating that consuming bottled water containing these plastic additives was unlikely to pose health risks for people of all ages. However, RQ values for underage people were several times higher than those for adults and hence cannot be neglected; therefore, special attention should be paid to understand the potential risks posed by the exposure to these plastic additives during early life stages, especially the infant stage.

Microplastics and phthalate esters contamination in top oceanic predators: A study on multiple shark species in the Pacific Ocean

Marine organisms, especially top predators such as sharks, are susceptible to environmental pollutants like microplastics (MPs) and phthalate esters (PAEs), leading to ecosystem risks. Research on contamination in these apex species is, however, still limited. This study investigated MPs and PAEs in multiple shark species (Isurus oxyrinchus, Alopias superciliosus, Alopias pelagicus, Carcharhinus brevipinna, and Sphyrna zygaena) off Taiwan's eastern coast. Gastric tissue analyses revealed ubiquitous microplastics (2-31 particles), which positively correlated with body lengths and weights for Isurus oxyrinchus. Blue, fiber-shaped (1-2 mm), and rayon-based MPs are likely associated with textile fiber pollution. The PAEs concentration mean was 7035 ± 6829 ng/g, ww, having DEHP and DiNP as primary compounds. This study highlights pervasive contamination in Pacific Ocean sharks, emphasizing anthropogenic impact on top oceanic predators and providing essential insights for food safety and MP accumulation.

Microplastics footprint in nature reserves-a case study on the microplastics in the guano from Yancheng Wetland Rare Birds National Nature Reserve, China

Bio-ingestion of microplastics poses a global threat to ecosystems, yet studies within nature reserves, crucial habitats for birds, remain scarce despite the well-documented ingestion of microplastics by avian species. Located in Jiangsu Province, China, the Yancheng Wetland Rare Birds Nature Reserve is home to diverse bird species, including many rare ones. This study aimed to assess the abundance and characteristics of microplastics in common bird species within the reserve, investigate microplastic enrichment across different species, and establish links between birds' habitat types and microplastic ingestion. Microplastics were extracted from the feces of 110 birds, with 84 particles identified from 37.27% of samples. Among 8 species studied, the average microplastic abundance ranged from 0.97 ± 0.47 to 43.43 ± 61.98 items per gram of feces, or 1.5 ± 0.87 to 3.4 ± 1.50 items per individual. The Swan goose (Anser cygnoides) exhibited the highest microplastic abundance per gram of feces, while the black-billed gull (Larus saundersi) had the highest abundance per individual. The predominant form of ingested microplastics among birds in the reserve was fibers, with polyethylene being the most common polymer type. Significant variations in plastic exposure were observed among species and between aquatic and terrestrial birds. This study represents the first quantitative assessment of microplastic concentrations in birds within the reserve, filling a crucial gap in research and providing insights for assessing microplastic pollution and guiding bird conservation efforts in aquatic and terrestrial environments.

Toxicity assessment of di(2-ethylhexyl) phthalate using zebrafish embryos: Cardiotoxic potential

Plasticizers are considered as newly emerged contaminants. They are added to plastics to increase their flexibility and softness. Phthalate plasticizers including the Di-2-ethylhexyl phthalates (DEHP) are toxic and induce adverse effects on the different organization levels of the environment. In the current study, we investigated the potential toxicity of DEHP using Zebrafish as a biological model. Five ascending concentrations of DEHP were tested in embryos throughout 96 hpf: 0.0086, 0.086, 0.86, 8.6, and 86 mg/L. Embryotoxicity assessments revealed limited lethal effects on DEHP-exposed embryos, yet notable anticipation of the hatching process was observed at 48 hpf. Although DEHP showed negligible influence on the length and pericardial area of exposed embryos, it led to multiple bodily deformities. Gene expression analyses of key cardiogenic and inflammatory genes evidenced alterations in tbx20, bcl2, and il1b expression in Zebrafish embryos at 96 h post-fertilization. Results from the cardiac function analysis displayed that DEHP significantly affected the arterial pulse and linear velocity within the Posterior Cardinal Vein (PCV) of exposed fish. These findings strongly advance that even at low concentrations, DEHP can be considered as potential toxic agent, capable of inducing cardiotoxic effects.

Exploring polystyrene weathering behavior: From surface traits to micro(nano)plastics and additives release

Plastic weathering in the natural environment is a dynamic and complex process, where the release of microplastics, nanoplastics and additives poses potential threats to ecosystems. Understanding the release of different weathering products from plastics is crucial for predicting and assessing the environmental hazards of plastics. This study systematically explored these phenomena by exposing polystyrene (PS) to UV irradiation and mechanical agitation for different durations (1 day, 5 days, 10 days, 20 days). The degree of aging, yellowing, brittleness, and the abundance of carbonyl (CO) functional groups in PS were all gradually increasing over time. The weathering pattern of PS surfaces manifested as initial particle oxidation followed by later cracks or flakes formation. The release of products was positively correlated with the aging degree of plastics, as well as among the various released products. Laser infrared and Raman tests indicated that, for microplastics, the size range of 10-20 μm consistently dominated over time, while the primary size range of nanoplastics shifted towards smaller sizes. Additives and other soluble products were prone to release from weathering plastics, with 20 different chemicals detected after 20 d. The release of plastic additives was closely related to aging time, additive type, and quantity. This study contributes to our understanding of the weathering process of plastics, clarifies the release patterns of products over time, and the relationships among different products. It helps predict and assess the environmental pollution caused by plastics.

Detection of microplastics in human tissues and organs: A scoping review

Background

Research on microplastics has largely focused on the environment and marine organisms until recently. A growing body of evidence has detected microplastics in human organs and tissues, with their exact entry routes being unclear and their potential health effects remain unknown. This scoping review aimed to characterise microplastics in human tissues and organs, examine their entry routes and addressing gaps in research analytical techniques.

Methods

Eligibility criteria included English language full text articles, in-vivo human studies only, and searching the databases using pre-defined terms. We based our analysis and reporting on the PRISMA guideline and examined the quality of evidence using the risk of bias assessment tool.

Results

Of 3616 articles screened, 223 evaluated and 26 were eventually included in this review. Nine were high risk for bias, three were unclear risk and the rest low risk for bias. Microplastics were detected in 8/12 human organ systems including cardiovascular, digestive, endocrine, integumentary, lymphatic, respiratory, reproductive and urinary. Microplastics were also observed in other human biological samples such as breastmilk, meconium, semen, stool, sputum and urine. Microplastics can be characterised based on shape, colours, and polymer type. Potential entry routes into human included atmospheric inhalation and ingestion through food and water. The extraction techniques for analysis of microplastics in human tissues vary significantly, each offering distinct advantages and limitations.

Conclusions

Microplastics are commonly detected in human tissues and organs, with distinct characteristics and entry routes, and variable analytical techniques exist.

Microplastics emerge as a hotspot for dibutyl phthalate sources in rivers and oceans: Leaching behavior and potential risks

Dibutyl phthalate (DBP) as a plasticizer has been widely used in the processing of plastic products. Nevertheless, these DBP additives have the potential to be released into the environment throughout the entire life cycle of plastic products. Herein, the leaching behavior of DBP from PVC microplastics (MPs) in freshwater and seawater and its potential risks were investigated. The results show that the plasticizer content, UV irradiation, and hydrochemical conditions have a great influence on the leaching of DBP from the MPs. The release of DBP into the environment increases proportionally with higher concentrations of additive DBP in MPs, particularly when it exceeds 15 %. The surface of MPs undergoes accelerated oxidation and increased hydrophilicity under UV radiation, thereby facilitating the leaching of DBP. Through 30 continuous leaching experiments, the leaching of DBP from MPs in freshwater and seawater can reach up to 12.28 and 5.42 mg g-1, respectively, indicating that MPs are a continuous source of DBP pollution in the aquatic environment. Moreover, phthalate pollution index (PPI) indicates that MPs can significantly increase DBP pollution in marine environment through land and sea transport processes. Therefore, we advocate that the management of MPs waste containing DBP be prioritized in coastal sustainable development.

Occurrence of specific pollutants in a mixture of sewage and rainwater from an urbanized area

Urban runoff appears to be a pathway for transferring new emerging pollutants from land-based sources to the aquatic environment. This paper aimed to identify and describe the groups of pollutants present in rainwater surface runoff as well as their mixture with wastewater in the combined sewer system from urbanized catchments and to determine the correlations between these pollutants. Four leading groups of new emerging pollutants have been identified that may be present in rainwater and municipal wastewater mixtures. The samples were tested for microplastics, phthalic acid esters, pesticides, and polycyclic aromatic hydrocarbons as well as basic parameters. The pilot site was Słupsk (northwestern Poland). We conducted nine sampling campaigns at three points. The results of the present study revealed that (i) polycyclic aromatic hydrocarbons were not present in the tested samples; (ii) the selected organochlorine pesticides were detected during one campaign in the dry season and therefore were not of critical importance; (iii) out of the 11 analyzed phthalic acid esters, five selected substances released from commonly used plastic products were present; and (iv) the number of microplastics contained in the tested samples ranged from 1,400 to 14,036 pcs/L and even occurred during pure rainfall.

Antioxidant defenses and metabolic responses of Mytilus coruscus exposed to various concentrations of PAEs (phthalate esters)

Phthalate esters (PAEs), as a major plasticizer with multi-biotoxicity, are frequently detected in marine environments, and potentially affecting the survival of aquatic organisms. In the study, three typical PAEs (dimethyl phthalate [DMP], dibutyl phthalate [DBP] and di(2-ethylhexyl) phthalate [DEHP]) were selected to investigate the accumulation patterns and ecotoxicological effects on Mytilus coruscus (M. coruscus). In M. coruscus, the accumulation was DEHP>DBP>DMP, and the bioaccumulation in tissues was digestive glands>gills>gonads>muscles. Meanwhile, the activities of superoxide dismutase (SOD) and catalase (CAT) showed an activation-decrease-activation trend of stress, with more pronounced concentration effects. Glutathione reductase (GSH) activity was significantly increased, and its expression was more sensitive to be induced at an early stage. The metabolic profiles of the gonads, digestive glands and muscle tissues were significantly altered, and DEHP had a greater effect on the metabolic profiles of M. coruscus, with the strongest interference. PAEs stress for 7 d significantly altered the volatile components of M. coruscus, with potential implications for their nutritional value. This study provides a biochemical, metabolomic, and nutritional analysis of DMP, DBP, and DEHP toxic effects on M. coruscus from a multidimensional perspective, which provides support for ecotoxicological studies of PAEs on marine organisms. ENVIRONMENTAL IMPLICATION: Phthalate esters (PAEs), synthetic compounds from phthalic acid, are widespread in the environment, household products, aquatic plants, animals, and crops, posing a significant threat to human health. However, the majority of toxicological studies examining the effects of PAEs on aquatic organisms primarily focus on non-economic model organisms like algae and zebrafish. Relatively fewer studies have been conducted on marine organisms, particularly economically important shellfish. So, this study is innovative and necessary. This study provides a biochemical, metabolomic, and nutritional analysis of DMP, DBP, and DEHP toxic effects on mussels, and supports the ecotoxicology of PAEs on marine organisms.

Occurrence and combined exposure of phthalate esters in urban soil, surface dust, atmospheric dustfall, and commercial food in the semi-arid industrial city of Lanzhou, Northwest China

A total of 138 samples including urban soil, surface dust, atmospheric dustfall, and commercial food were collected from the semi-arid industrial city of Lanzhou in Northwest China, and 22 phthalate esters (PAEs) were analyzed in these samples by gas chromatography-mass spectrometry for the pollution characteristics, potential sources, and combined exposure risks of PAEs. The results showed that the total concentration of 22 PAEs (Ʃ22PAEs) presented surface dust (4.94 × 104 ng/g) ≫ dustfall (1.56 × 104 ng/g) ≫ food (2.14 × 103 ng/g) ≫ urban soil (533 ng/g). Di-n-butyl phthalate (DNBP), di-isobutyl phthalate, di(2-ethylhexyl) phthalate (DEHP), and di-isononyl phthalate/di-isodecyl phthalate were predominant in the environmental media and commercial food, being controlled by priority (52.1%-65.5%) and non-priority (62.1%) PAEs, respectively. Elevated Ʃ22PAEs in the urban soil and surface dust was found in the west, middle, and east of Lanzhou. Principal component analysis indicated that PAEs the urban soil and surface dust were related with the emissions of products containing PAEs, atmosphere depositions, and traffic and industrial emissions. PAEs in the foods were associated with the growth and processing environment. The health risk assessment of United States Environmental Protection Agency based on the Chinese population exposure parameters indicated that the total exposure dose of 22 PAEs was from 0.111 to 0.226 mg/kg/day, which were above the reference dose (0.02 mg/kg/day) and tolerable daily intake (TDI, 0.05 mg/kg/day) for DEHP (0.0333-0.0631 mg/kg/day), and TDI (0.01 mg/kg/day) for DNBP (0.0213-0.0405 mg/kg/day), implying that the exposure of PAEs via multi-media should not be ignored; the total non-carcinogenic risk of six priority PAEs was below 1 for the three environmental media (1.21 × 10-5-2.90 × 10-3), while close to 1 for food (4.74 × 10-1-8.76 × 10-1), suggesting a potential non-carcinogenic risk of human exposure to PAEs in food; the total carcinogenic risk of BBP and DEHP was below 1 × 10-6 for the three environmental media (9.13 × 10-10-5.72 × 10-7), while above 1 × 10-4 for DEHP in food (1.02 × 10-4), suggesting a significantly carcinogenic risk of human exposure to DEHP in food. The current research results can provide certain supports for pollution and risk prevention of PAEs.

Alterations in neurotransmitters, steroid hormones, vitellogenin, and antioxidant system induced by di-n-butyl phthalate and di-isopentyl phthalate on catfish Rhamdia quelen

Phthalates, such as di-n-butyl phthalate (DBP) and di-isopentyl phthalate (DiPeP), are pollutants with a high potential for endocrine disruption. This study aimed to evaluate parameters of endocrine disruption in specimens of the Neotropical fish Rhamdia quelen exposed to DBP and DiPeP through their food. After 30 days of exposure, the fish were anesthetized and then euthanized, and blood, hypothalamus, liver, and gonads were collected. DBP caused statistically significant alterations in the serotoninergic system of males (5 and 25 ng/g) and females (5 ng/g) of R. quelen and it increased testosterone levels in females (25 ng/g). DiPeP significantly altered the dopaminergic system in females, reduced plasma estradiol levels (125 ng/g) and hepatic vitellogenin expression (25 ng/g), and changed the antioxidant system in gonads (125 ng/g). The results suggest that DBP and DiPeP may have different response patterns in females, with the former being androgenic and the latter being anti-estrogenic. These findings provide additional evidence regarding the molecular events involving DBP and DiPeP in the endocrine disruption potential in juvenile specimens of Rhamdia quelen.

Regulatory path for soil microbial communities depends on the type and dose of microplastics

To reveal the feedbacks and regulating mechanisms of microplastic types and doses on microbial community, a microcosm experiment was carried out with two non-degradable microplastics [polyethylene (PE) and polyvinyl chloride (PVC)] and four biodegradable microplastics [poly(butylene succinate) (PBS), polyhydroxyalkanoates (PHA), poly(butyleneadipate-co-terephthalate) (PBAT), and polypropylene carbonate (PPC)] at different levels (1 %, 7 %, and 28 %). As a result, the content of total carbon (TC), soil organic carbon (SOC), and microbial biomass carbon (MBC) (expect MBC in PBS soil) increased with increasing doses of microplastics, and increased at the lowest PE dose rate. Biodegradable microplastics created a more active ecological niche while enriching more pathogens than non-degradable microplastics. Structural equation modeling indicated that microbial diversities were in a type-dependent assembly, whereas microbial compositions were more profoundly affected by the microplastic doses, ultimately. The standardized total effect coefficient of microplastic types on bacterial and fungal diversities was - 0.429 and - 0.282, and that of doses on bacterial and fungal compositions was 0.487 and 0.336, respectively. Both microplastic types and doses significantly impacted pH, electrical conductivity, total nitrogen, TC, SOC, and MBC, subsequently inhibiting microbial diversities and stimulating microbial compositions with particular pathways. The results provide a comprehensive understanding for evaluating the potential risk of microplastics.

Oral Exposure to Microplastics Affects the Neurochemical Plasticity of Reactive Neurons in the Porcine Jejunum

Plastics are present in almost every aspect of our lives. Polyethylene terephthalate (PET) is commonly used in the food industry. Microparticles can contaminate food and drinks, posing a threat to consumers. The presented study aims to determine the effect of microparticles of PET on the population of neurons positive for selected neurotransmitters in the enteric nervous system of the jejunum and histological structure. An amount of 15 pigs were divided into three groups (control, receiving 0.1 g, and 1 g/day/animal orally). After 28 days, fragments of the jejunum were collected for immunofluorescence and histological examination. The obtained results show that histological changes (injury of the apical parts of the villi, accumulations of cellular debris and mucus, eosinophil infiltration, and hyperaemia) were more pronounced in pigs receiving a higher dose of microparticles. The effect on neuronal nitric oxide synthase-, and substance P-positive neurons, depends on the examined plexus and the dose of microparticles. An increase in the percentage of galanin-positive neurons and a decrease in cocaine and amphetamine-regulated transcript-, vesicular acetylcholine transporter-, and vasoactive intestinal peptide-positive neurons do not show such relationships. The present study shows that microparticles can potentially have neurotoxic and pro-inflammatory effects, but there is a need for further research to determine the mechanism of this process and possible further effects.

Characterization of the transcriptional effects of the plastic additive dibutyl phthalate alone and in combination with microplastic on the green-lipped mussel Perna canaliculus

The presence and persistence of microplastics (MPs) in diverse aquatic environments are of global concern. Microplastics can impact marine organisms via direct physical interaction and the release of potentially harmful chemical additives incorporated into the plastic. These chemicals are physically bound to the plastic matrix and can leach out. The hazards associated with chemical additives to exposed organisms is not well characterized. We investigated the hazards of plastic additives leaching from plastic. We used the common plasticizer dibutyl phthalate (DBP) as a chemical additive proxy and the New Zealand green-lipped mussel (Perna canaliculus) as a model. We used early-adult P. canaliculus exposed to combinations of virgin and DBP-spiked polyvinyl chloride (PVC), MPs, and DBP alone for 7 days. Whole transcriptome sequencing (RNA-seq) was conducted to assess whether leaching of DBP from MPs poses a hazard. The differences between groups were evaluated using pairwise permutational multivariate analysis of variance (PERMANOVA), and all treatments were significantly different from controls. In addition, a significant difference was seen between DBP and PVC MP treatment. Transcriptome analysis revealed that mussels exposed to DBP alone had the most differentially expressed genes (914), followed by PVC MP + DBP (448), and PVC MP (250). Gene ontology functional analysis revealed that the most enriched pathway types were in cellular metabolism, immune response, and endocrine disruption. Microplastic treatments enriched numerous pathways related to cellular metabolism and immune response. The combined exposure of PVC MP + DBP appears to cause combined effects, suggesting that DBP is bioavailable to the exposed mussels in the PVC MP + DBP treatment. Our results support the hypothesis that chemical additives are potentially an important driver of MP toxicity. Environ Toxicol Chem 2024;43:1604-1614. © 2024 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Insights into pollution characteristics and human health risks of plasticizer phthalate esters in shellfish species

The ubiquitous application of phthalate esters (PAEs) as plasticizers contributes to high levels of marine pollution, yet the contamination patterns of PAEs in various shellfish species remain unknown. The objective of this research is to provide the first information on the pollution characteristics of 16 PAEs in different shellfish species from the Pearl River Delta (PRD), South China, and associated health risks. Among the 16 analyzed PAEs, 13 were identified in the shellfish, with total PAE concentrations ranging from 23.07 to 3794.08 ng/g dw (mean = 514.35 ng/g dw). The PAE pollution levels in the five shellfish species were as follows: Ostreidae (mean = 1064.12 ng/g dw) > Mytilus edulis (mean = 509.88 ng/g dw) > Babylonia areolate (mean = 458.14 ng/g dw) > Mactra chinensis (mean = 378.90 ng/g dw) > Haliotis diversicolor (mean = 335.28 ng/g dw). Dimethyl phthalate (DMP, mean = 69.85 ng/g dw), diisobutyl phthalate (DIBP, mean = 41.39 ng/g dw), dibutyl phthalate (DBP, mean = 130.91 ng/g dw), and di(2-ethylhexyl) phthalate (DEHP, mean = 226.23 ng/g dw) were the most abundant congeners. Notably, DEHP constituted the most predominant fraction (43.98 %) of the 13 PAEs detected in all shellfish from the PRD. Principal component analysis indicated that industrial and domestic emissions served as main sources for the PAE pollution in shellfish from the PRD. It was estimated that the daily intake of PAEs via shellfish consumption among adults and children ranged from 0.004 to 1.27 μg/kgbw/day, without obvious non-cancer risks (< 0.034), but the cancer risks raised some alarm (2.0 × 10-9-1.4 × 10-5). These findings highlight the necessity of focusing on marine environmental pollutants and emphasize the importance of ongoing monitoring of PAE contamination in seafood.

Impacts associated with the plastic polymers polycarbonate, polystyrene, polyvinyl chloride, and polybutadiene across their life cycle: A review

Polymers are the main building blocks of plastic, with the annual global production volume of fossil carbon-based polymers reaching over 457 million metric tons in 2019 and this figure is anticipated to triple by 2060. There is potential for environmental harm and adverse human health impacts associated with plastic, its constituent polymers and the chemicals therein, at all stages of the plastic life cycle, from extraction of raw materials, production and manufacturing, consumption, through to ultimate disposal and waste management. While there have been considerable research and policy efforts in identifying and mitigating the impacts associated with problematic plastic products such as single-use plastics and hazardous chemicals in plastics, with national and/or international regulations to phase out their use, plastic polymers are often overlooked. In this review, the polymer dimension of the current knowledge on environmental release, human exposure and health impacts of plastic is discussed across the plastic life cycle, including chemicals used in production and additives commonly used to achieve the properties needed for applications for which the polymers are generally used. This review focuses on polycarbonate, polystyrene, polyvinyl chloride, and polybutadiene, four common plastic polymers made from the hazardous monomers, bisphenol, styrene, vinyl chloride and 1,3-butadiene, respectively. Potential alternative polymers, chemicals, and products are considered. Our findings emphasise the need for a whole system approach to be undertaken for effective regulation of plastics whereby the impacts of plastics are assessed with respect to their constituent polymers, chemicals, and applications and across their entire life cycle.

Ecotoxicity assessment of additives in commercial biodegradable plastic products: Implications for sustainability and environmental risk

Biodegradable plastics have gained popularity as environmentally friendly alternatives to conventional petroleum-based plastics, which face recycling and degradation challenges. Although the biodegradability of these plastics has been established, research on their ecotoxicity remains limited. Biodegradable plastics may still contain conventional additives, including toxic and non-degradable substances, to maintain their functionality during production and processing. Despite degrading the polymer matrix, these additives can persist in the environment and potentially harm ecosystems and humans. Therefore, this study aimed to assess the potential ecotoxicity of biodegradable plastics by analyzing the phthalate esters (PAEs) leaching out from biodegradable plastics through soil leachate. Sixteen commercial biodegradable plastic products were qualitatively and quantitatively analyzed using gas chromatography-mass spectrometry to determine the types and amounts of PAE used in the products and evaluate their ecotoxicity. Among the various PAEs analyzed, non-regulated dioctyl isophthalate (DOIP) was the most frequently detected (ranging from 40 to 212 μg g-1). Although the DOIP is considered one of PAE alternatives, the detected amount of it revealed evident ecotoxicity, especially in the aquatic environment. Other additives, including antioxidants, lubricants, surfactants, slip agents, and adhesives, were also qualitatively detected in commercial products. This is the first study to quantify the amounts of PAEs leached from biodegradable plastics through water mimicking PAE leaching out from biodegradable plastics to soil leachate when landfilled and evaluate their potential ecotoxicity. Despite their potential toxicity, commercial biodegradable plastics are currently marketed and promoted as environmentally friendly materials, which could lead to indiscriminate public consumption. Therefore, in addition to improving biodegradable plastics, developing eco-friendly additives is significant. Future studies should investigate the leaching kinetics in soil leachate over time and toxicity of biodegradable plastics after landfill disposal.

Distribution characteristics and microbial synergistic degradation potential of polyethylene and polypropylene in freshwater estuarine sediments

The microbial degradation of polyethylene (PE) and polypropylene (PP) resins in rivers and lakes has emerged as a crucial issue in the management of microplastics. This study revealed that as the flow rate decreased longitudinally, ammonia nitrogen (NH4+-N), heavy fraction of organic carbon (HFOC), and small-size microplastics (< 1 mm) gradually accumulated in the deep and downstream estuarine sediments. Based on their surface morphology and carbonyl index, these sediments were identified as the potential hot zone for PE/PP degradation. Within the identified hot zone, concentrations of PE/PP-degrading genes, enzymes, and bacteria were significantly elevated compared to other zones, exhibiting strong intercorrelations. Analysis of niche differences revealed that the accumulation of NH4+-N and HFOC in the hot zone facilitated the synergistic coexistence of key bacteria responsible for PE/PP degradation within biofilms. The findings of this study offer a novel insight and comprehensive understanding of the distribution characteristics and synergistic degradation potential of PE/PP in natural freshwater environments.

Basin scale monitoring of microplastics and phthalates in sediments from the Persian Gulf and the Gulf of Makran using GIS-based algorithms: Insights towards spatial variation and potential risk assessment

Information on sedimentary microplastics and phthalates has been restricted to the coastal regions of the Persian Gulf and the Gulf of Makran. Our basin-wide study monitored their levels, spatial behaviors, and potential risks using GIS-based techniques. Microplastics and phthalates ranged from 5 to 75 particles/kg d.w and 0.004-1.219 μg g-1 d.w, respectively. Microplastics were in the size category of 100 μm to 3 mm, and black microfibers (< 1 mm) and high-density polymers were dominant. The total number of microplastics was between 356.333 × 1012 and 469.075 × 1012 particles in the surface sediments of the studied regions (confidence interval = 99 %). Diethylhexyl phthalate (DEHP) and Di-isobutyl phthalate contributed 88 % of detected phthalates. Significant correlations among microplastic abundance, total phthalates, and DEHP were distinguished (p < 0.05). Overall, the findings reiterated the widespread presence of microplastics and a potential link between phthalates and microplastics. Semi-variogram, cluster Voronoi polygons, and Trend analysis identified spatial outliers and major deposition sites of microplastics and phthalates and consequently outlined the localities where upcoming studies should be concentrated. A hotspot of potential risks was marked using Fuzzy logic and GIS-based algorithms in the Sea of Makran, covering an area equal to 342. 99 km2.

Application of organoid technology in the human health risk assessment of microplastics: A review of progresses and challenges

Microplastic (MP) pollution has become a global environmental issue, and increasing concern has been raised about its impact on human health. Current studies on the toxic effects and mechanisms of MPs have mostly been conducted in animal models or in vitro cell cultures, which have limitations regarding inter-species differences or stimulation of cellular functions. Organoid technology derived from human pluripotent or adult stem cells has broader prospects for predicting the potential health risks of MPs to humans. Herein, we reviewed the current application advancements and opportunities for different organoids, including brain, retinal, intestinal, liver, and lung organoids, to assess the human health risks of MPs. Organoid techniques accurately simulate the complex processes of MPs and reflect phenotypes related to diseases caused by MPs such as liver fibrosis, neurodegeneration, impaired intestinal barrier and cardiac hypertrophy. Future perspectives were also proposed for technological innovation in human risk assessment of MPs using organoids, including extending the lifespan of organoids to assess the chronic toxicity of MPs, and reconstructing multi-organ interactions to explore their potential in studying the microbiome-gut-brainaxis effect of MPs.

Phthalate diester occurrence in marine feed and food (Mediterranean Sea)

Organic contaminants such as diesters of phthalic acid (PAEs) can be conveyed by microplastics in aquatic environment and constitute a relevant risk to marine organisms and humans that consume them. A method was developed for the identification and quantitative detection of 6 dimethyl phthalate (DMP), di-ethyl phthalate (DEP), di-n-butyl phthalate (DNBP), butyl benzyl phthalate (BBP), di-2-ethylesyl phthalate (DHEP), and di-n-octyl phthalate (DnOP). PAEs were then quantified in mesozooplankton, mollusk bivalves, and fish from the north-western Mediterranean Sea. Among all PAEs, DEHP was found in all zooplankton samples, in 30% of fish samples, and in 10% of bivalve samples. DBP was instead recovered in only 4% of samples (plankton and fish).

Effect of Biofilm Forming on the Migration of Di(2-ethylhexyl)phthalate from PVC Plastics

Plastic additives, represented by plasticizers, are important components of plastic pollution. Biofilms inevitably form on plastic surfaces when plastic enters the aqueous environment. However, little is known about the effect of biofilms on plastic surfaces on the release of additives therein. In this study, PVC plastics with different levels of di(2-ethylhexyl)phthalate (DEHP) content were investigated to study the effect of biofilm growth on DEHP release. The presence of biofilms promoted the migration of DEHP from PVC plastics to the external environment. Relative to biofilm-free controls, although the presence of surface biofilm resulted in 0.8 to 11.6 times lower DEHP concentrations in water, the concentrations of the degradation product, monoethylhexyl phthalate (MEHP) in water, were 2.3 to 57.3 times higher. When the total release amounts of DEHP in the biofilm and in the water were combined, they were increased by 0.6-73 times after biofilm growth. However, most of the released DEHP was adsorbed in the biofilms and was subsequently degraded. The results of this study suggest that the biofilm as a new interface between plastics and the surrounding environment can affect the transport and transformation of plastic additives in the environment through barrier, adsorption, and degradation. Future research endeavors should aim to explore the transport dynamics and fate of plastic additives under various biofilm compositions as well as evaluate the ecological risks associated with their enrichment by biofilms.

Mitigating phthalate toxicity: The protective role of humic acid and clay in zebrafish larvae

This research study aimed to explore the mitigating effects of humic acid and clay on the toxicity induced by three different phthalates (DBP, DEP, DEHP) on zebrafish larvae growth. Prolonged exposure to DBP resulted in a concerning 87.33% mortality rate, significantly reduced to 7.3% when co-administered with humic acid. A similar reduction in mortality was observed for the other two phthalates (DEP and DEHP). Additionally, the introduction of phthalates with humic acid, clay, or their combination led to a significant decrease in the malformation rate in larvae. High-Performance Liquid Chromatography (HPLC) analysis of phthalates in treatments revealed a noteworthy decline in their concentration when combined with humic acid and clay. This suggests a reduced bioavailability of phthalates to larvae, aligning with diminished toxicity, lower mortality, fewer malformations, and improved organ development, as well as less oxidative stress. Furthermore, measurements of larval length and morphological scoring affirmed the protective role of humic acid and clay in promoting the normal growth of zebrafish. This study underscores the potential of environment modulators, such as humic acid and clay, as effective bioremediation agents against phthalate toxicity. The generation of reactive oxygen species (ROS), indicative of oxidative stress, was markedly higher in larvae treated solely with phthalates compared to the control. Conversely, larvae treated with a combination of phthalates and humic acid or clay exhibited a significant decrease in ROS generation, signaling a decline in oxidative stress. Histopathological analysis of adult fish subjected to various treatments revealed significant damage to vital organs like the liver and intestine when treated with phthalates alone. However, when phthalates were introduced with humic acid, clay, or both, the morphology closely resembled that of the control, reinforcing the protective role of humic acid and clay in zebrafish development against administered phthalates.

Comparison of phthalate esters (PAEs) in freshwater and marine food webs: Occurrence, bioaccumulation, and trophodynamics

Phthalate esters (PAEs) have received widespread attentions due to their ubiquity in various kinds of matrices and potential biotoxicity. This study systematically compared the concentrations, bioaccumulation, trophodynamics and health risk of PAEs in 25 species (n = 225) collected from a marine (Bohai Bay, BHB) and freshwater environment (Songhua River, SHR), China. Results showed that di-(2-ethylhexyl) phthalate and di-n-butyl phthalate were the predominant PAEs in the organisms from the two aquatic environments. The total concentrations of 6 PAEs in algae and fish from SHR were significantly higher than those from BHB. Two food webs were constructed in BHB and SHR based on the abundance of 15N in the organisms. All the PAEs except dimethyl phthalate exhibited trophic dilution with the trophic magnification factors less than 1. Moreover, an obvious biodilution of PAEs was observed in marine food web compared to freshwater food web. A low health risk of PAEs was found in organisms from both BHB and SHR. However, di-(2-ethylhexyl) phthalate exhibited a potential carcinogenic risk by consumption of some benthos in BHB and fish in SHR. This study provides a valuable perspective for understanding the trophodynamics and health risk of PAEs in marine and freshwater environments.

High-throughput analytical methodology of monoalkyl phthalate esters and the composite risk assessment with their parent phthalate esters in aquatic organisms and seawater

A sensitive, robust, and highly efficient analytical methodology involving solid phase extraction coupled to ultra-high performance liquid chromatography tandem mass spectrometry was successfully established to detect 13 monoalkyl phthalate esters (MPAEs) in aquatic organisms and seawater. After the organisms were preprocessed using enzymatic deconjugation with β-glucuronidase, extraction, purification, and qualitative and quantitative optimization procedures were performed. Under optimal conditions, the limits of detection varied from 0.07 to 0.88 μg/kg (wet weight) and 0.04-1.96 ng/L in organisms and seawater, respectively. Collectively, MPAEs achieved acceptable recovery values (91.0-102.7%) with relative standard deviations less than 10.4% and matrix effects ranging from 0.93 to 1.07 in the above matrix. Furthermore, MPAEs and phthalate esters were detected by the developed methodology and gas chromatography-triple quadrupole tandem mass spectrometer in practical samples, respectively. Mono-n-butyl phthalate and mono-iso-butyl phthalate were the most predominant congeners, accounting for 24.8-35.2% in aquatic organisms and seawater. Comprehensive health and ecological risks were higher after the MPAEs were incorporated than when phthalate esters were considered separately, and greater than their risk threshold. Therefore, the risks caused by substances and their metabolites in multiple media, with analogous structure-activity relationships, should be considered to ensure the safety of aquatic organisms and consumers.

Analysis and identification of degradation products in gas, particle, and liquid phases of polypropylene and polyethyleneterephthalate microplastics aging through non-thermal plasma simulation

Plastic aging can cause alterations in the physical and chemical characteristics of plastics, as well as their behavior in the environment. Due to the extremely slow natural aging process, laboratory simulated aging methods have to be used. In this study, non-thermal plasma (NTP) was adopted to investigate the aging process of polypropylene (PP) and polyethylene terephthalate (PET) microplastics. Various analytical instruments, including proton transfer reaction mass spectrometry and single-particle aerosol mass spectrometry, were employed to examine and identify the organic constituents of the gas, liquid, and particle phase degradation products, as well as to monitor the degradation process. The results showed that after 90 min of aging, both PP and PET surfaces showed yellowing, and the carbonyl index of PP increased while that of PET decreased, with an increase in crystallinity. The organic components of reaction products, such as ketones, esters, acids, and alcohols, increased with longer aging times. Gas products mainly contain aromatic hydrocarbons, while particles from aged PET contain compounds with benzene rings and metal elements. Liquid products from aged PP show a significant presence of branched alkanes. Based on this analysis, degradation mechanisms of PP and PET by NTP were proposed. This investigation represents the initial systematically exploration of the release of organic substances during the degradation of microplastics mediated by NTP. It provides significant insights into the detrimental organic compounds emitted during this process, thereby offering valuable information for understanding the environmental and human health implications of natural microplastic degradation. Furthermore, it addressed the requirements for increased attention to the potential environmental risks associated with these harmful components.

Microplastics and chemical leachates from plastic pipes are associated with increased virulence and antimicrobial resistance potential of drinking water microbial communities

There is increasing recognition of the potential impacts of microplastics (MPs) on human health. As drinking water is the most direct route of human exposure to MPs, there is an urgent need to elucidate MPs source and fate in drinking water distribution system (DWDS). Here, we showed polypropylene random plastic pipes exposed to different water quality (chlorination and heating) and environmental (freeze-thaw) conditions accelerated MPs generation and chemical leaching. MPs showed various morphology and aggregation states, and chemical leaches exhibited distinct profiles due to different physicochemical treatments. Based on the physiological toxicity of leachates, oxidative stress level was negatively correlated with disinfection by-products in the leachates. Microbial network analysis demonstrated exposure to leachates (under three treatments) undermined microbial community stability and increased the relative abundance and dominance of pathogenic bacteria. Leachate physical and chemical properties (i.e., MPs abundance, hydrodynamic diameter, zeta potential, total organic carbon, dissolved ECs) exerted significant (p < 0.05) effects on the functional genes related to virulence, antibiotic resistance and metabolic pathways. Notably, chlorination significantly increased correlations among pathogenic bacteria, virulence genes, and antibiotic resistance genes. Overall, this study advances the understanding of direct and indirect risks of these MPs released from plastic pipes in the DWDS.

Emerging and legacy plasticisers in coastal and estuarine environments: A review

The occurrence of plastic waste in the environment is an emerging and ongoing concern. In addition to the physical impacts of macroplastics and microplastics on organisms, the chemical effects of plastic additives such as plasticisers have also received increasing attention. Research concerning plasticiser pollution in estuaries and coastal environments has been a particular focus, as these environments are the primary entry point for anthropogenic contaminants into the wider marine environment. Additionally, the conditions in estuarine environments favour the sedimentation of suspended particulate matter, with which plasticisers are strongly associated. Hence, estuary systems may be where some of the highest concentrations of these pollutants are seen in freshwater and marine environments. Recent studies have confirmed emerging plasticisers and phthalates as pollutants in estuaries, with the relative abundance of these compounds controlled primarily by patterns of use, source intensity, and fate. Plasticiser profiles are typically dominated by mid-high molecular weight compounds such as DnBP, DiBP, and DEHP. Plasticisers may be taken up by estuarine and marine organisms, and some phthalates can cause negative impacts in marine organisms, although further research is required to assess the impacts of emerging plasticisers. This review provides an overview of the processes controlling the release and partitioning of emerging and legacy plasticisers in aqueous environments, in addition to the sources of plasticisers in estuarine and coastal environments. This is followed by a quantitative analysis and discussion of literature concerning the (co-)occurrence and concentrations of emerging plasticisers and phthalates in these environments. We end this review with a discussion the fate (degradation and uptake by biota) of these compounds, in addition to identification of knowledge gaps and recommendations for future research.

Occurrence of phthalates in facemasks used in India and its implications for human exposure

Synthetic polymers with additives are used in the manufacturing of face masks (FMs); hence, FMs could be a potential source of exposure to phthalic acid esters (PAEs). India stands second in the world in terms of the FMs usage since the beginning of Covid-19 pandemic. However, little is known about the PAEs content of FMs used in India. Some PAEs, such as DEHP and DBP are suspected endocrine disrupting chemicals (EDCs); hence, wearing FM may increase the risk of exposure to these EDCs. In this study, we collected 91 samples of FMs from eight Indian cities and analyzed for five PAEs viz. DMP, DEP, DBP, BBP, and DEHP. The PAEs contents in FMs ranged from 101.79 to 27,948.64 ng/g. The carcinogenic risk of N 95 with filter, N-95, and cloth masks was higher than the threshold levels. The findings indicate the need to control PAEs in FMs through regulatory actions.