Concentrations and distribution of phthalate esters in the seamount area of the Tropical Western Pacific Ocean

Effects of plasticizer Di(2-ethylhexyl) phthalate (DEHP) on the microbiome of the marine sponge Hymeniacidon heliophila

Marine pollution research in the last 15 years focused on an emerging anthropogenic contaminant: plastic debris and more specifically, microplastics. Since, not only its physical impacts on marine invertebrates were studied, but also its additives. Phthalate, a plasticizer commonly found in the ocean and known endocrine disruptor was already observed in different aquatic invertebrates, but few is known about its presence and possible effects in Porifera physiology. Our study aimed to analyze potential shifts in Hymeniacidon heliophila (Desmosponge) microbiome after exposure to Di(2-ethylhexyl) phthalate (DEHP), the most common phthalate found in the ocean, in three different doses for 4 and 24 h. Results indicate that alpha diversity had significantly changed between control and exposed organisms but not in all multicomparisons. Microbial community structure changed after exposure as well although most abundant phyla did not vary along the experiment. The core microbiome between control and each exposed organisms contained the vast majority of total ASVs and a few ASVs were exclusive to each experimental group. After DEHP exposure, microbial classes had significant changes and species with phthalate degradation enzymes were identified in a specifically dose dependent manner pointing to a possible bacterial consortium responsible for the phthalate degradation. The bacterial detoxification activity may lead to H. heliophila resistance during DEHP exposure in polluted environmental conditions.

Synthesis of azelaic acid copolyester plasticizers and their application in PVC

A series of 2-methyl-1,3-propanediol (MPO) modified azelaic acid and hexylene glycol copolyester (PHMAZ) plasticizers with varying contents were synthesized using a direct esterification melt polycondensation method, and their structures were characterized systematically. Analysis using infrared spectroscopy and nuclear magnetic resonance spectroscopy confirmed the synthesis of the designed copolyester structure. Gel permeation chromatography (GPC) tests indicated that the number average molecular weight of each copolyester sample ranged between 2000 and 3000. These copolyesters were used to plasticize polyvinyl chloride (PVC) resin, and the glass transition temperature of the plasticized PVC samples was tested using a differential scanning calorimeter (DSC). Further characterization of the plasticizing effects was conducted using an electronic universal testing machine. The research results showed that as the content of MPO increased, the plasticizing effect of the copolyester initially increased and then decreased. Specifically, the copolyester containing 45% MPO, PHMAZ-45, demonstrated the best plasticizing effect on PVC, with the glass transition temperature of the plasticized PVC system around -35 °C, elongation at break at 908.4%, and a plasticizing efficiency of 254.5%. Additionally, this new type of copolyester plasticizer uses bio-based raw materials, exhibits excellent plasticizing effects, and the preparation process is stable and controllable. It holds promising potential to replace traditional volatile and toxic phthalate esters, presenting significant industrial application value.

Phthalate acid esters: A review of aquatic environmental occurrence and their interactions with plants

The increasing use of phthalate acid esters (PAEs) in various applications has inevitably led to their widespread presence in the aquatic environment. This presents a considerable threat to plants. However, the interactions between PAEs and plants in the aquatic environment have not yet been comprehensively reviewed. In this review, the properties, occurrence, uptake, transformation, and toxic effects of PAEs on plants in the aquatic environment are summarized. PAEs have been prevalently detected in the aquatic environment, including surface water, groundwater, seawater, and sediment, with concentrations ranging from the ng/L or ng/kg to the mg/L or mg/kg range. PAEs in the aquatic environment can be uptake, translocated, and metabolized by plants. Exposure to PAEs induces multiple adverse effects in aquatic plants, including growth perturbation, structural damage, disruption of photosynthesis, oxidative damage, and potential genotoxicity. High-throughput omics techniques further reveal the underlying toxicity molecular mechanisms of how PAEs disrupt plants on the transcription, protein, and metabolism levels. Finally, this review proposes that future studies should evaluate the interactions between plants and PAEs with a focus on long-term exposure to environmental PAE concentrations, the effects of PAE alternatives, and human health risks via the intake of plant-based foods.

The release, degradation, and distribution of PVC microplastic-originated phthalate and non-phthalate plasticizers in sediments

This study investigated the leaching of phthalate and non-phthalate plasticizers from polyvinyl chloride microplastics (MPs) into sediment and their degradation over a 30-d period via abiotic and biotic processes. The results showed that 3579% of plasticizers were released into the sediment from the MPs and > 99.9% degradation was achieved. Although a significantly higher degradation was found in plasticizer-added microcosms under biotic processes (overall, 94%), there was a noticeable abiotic loss (72%), suggesting that abiotic processes also play a role in plasticizer degradation. Interestingly, when compared with the initial sediment-water partitioning for plasticizers, the partition constants for low-molecular-weight compounds decreased in both microcosms, whereas those for high-molecular-weight compounds increased after abiotic degradation. Furthermore, changes in the bacterial community, abundance of plasticizer-degrading bacterial populations, and functional gene profiles were assessed. In all the microcosms, a decrease in bacterial community diversity and a notable shift in bacterial composition were observed. The enriched potential plasticizer-degrading bacteria were Arthrobacter, Bacillus, Desulfovibrio, Desulfuromonas, Devosia, Gordonia, Mycobacterium, and Sphingomonas, among which Bacillus was recognized as the key plasticizer degrader. Overall, these findings shed light on the factors affecting plasticizer degradation, the microbial communities potentially involved in biodegradation, and the fate of plasticizers in the environment.

Analysis and remediation of phthalates in aquatic matrices: current perspectives

Phthalic acid esters (PAEs) are high production volume chemicals used extensively as plasticizers, to increase the flexibility of the main polymer. They are reported to leach into their surroundings from plastic products and are now a ubiquitous environmental contaminant. Phthalate levels have been determined in several environmental matrices, especially in water. These levels serve as an indicator of plasticizer abuse and plastic pollution, and also serve as a route of exposure to different species including humans. Reports published on effects of different PAEs on experimental models demonstrate their carcinogenic, teratogenic, reproductive, and endocrine disruptive effects. Therefore, regular monitoring and remediation of environmental water samples is essential to ascertain their hazard quotient and daily exposure levels. This review summarises the extraction and detection techniques available for phthalate analysis in water samples such as chromatography, biosensors, immunoassays, and spectroscopy. Current remediation strategies for phthalate removal such as adsorption, advanced oxidation, and microbial degradation have also been highlighted.

Phthalates contamination in sediments: A review of sources, influencing factors, benthic toxicity, and removal strategies

Sediments provide habitat and food for benthos, and phthalates (PAEs) have been detected in numerous river and marine sediments as a widely used plastic additive. PAEs in sediments is not only toxic to benthos, but also poses a threat to pelagic fish and human health through the food chain, so it is essential to comprehensively assess the contamination of sediments with PAEs. This paper presents a critical evaluation of PAEs in sediments, which is embodied in the analysis of the sources of PAEs in sediments from multiple perspectives. Biological production is indispensable, while artificial synthesis is the most dominant, thus the focus was on analyzing the industrial and commercial sources of synthetic PAEs. In addition, since the content of PAEs in sediments varies, some factors affecting the content of PAEs in sediments are summarized, such as the properties of PAEs, the properties of plastics, and environmental factors (sediments properties and hydrodynamic conditions). As endocrine disruptors, PAEs can produce toxicity to its direct contacts. Therefore, the effects of PAEs on benthos immunity, endocrinology, reproduction, development, and metabolism were comprehensively analyzed. In addition, we found that reciprocal inhibition and activation of the systems lead to genotoxicity and apoptosis. Finally, the paper discusses the feasible measures to control PAEs in wastewater and leachate from the perspective of source control, and summarizes the in-situ treatment measures for PAEs contamination in sediments. This paper provides a comprehensive review of PAEs contamination in sediments, toxic effects and removal strategies, and provides an important reference for reducing the contamination and toxicity of PAEs to benthos.

Phthalate levels in common sea anemone Actinia equina and Anemonia viridis: A proxy of short-term microplastic interaction?

Phthalates are widely employed plasticizers blended to plastic polymers that, during plastic aging and weathering are prone to leach in the surrounding environment. Thus, phthalates were proposed to indirectly evaluate MPs contamination in marine environments, with still uncertain and scarce data, particularly for wildlife. This study investigates simultaneously microplastics (MPs) and phthalates (PAEs) occurrence in wild Actinia equina and Anemonia viridis, two common and edible sea anemone species. Both species had a 100 % frequency of MPs occurrence, with similar average concentrations. PAEs were detected in 70 % of samples, with concentrations up to 150 ng/g in A. equina and 144.3 ng/g for A. viridis. MPs and PAEs present in sea anemone tissues appear to reflect seawater plastic contamination conditions in the study area. Given the rapid biodegradation of PAEs, occurrence and concentrations of both these additives and their metabolites could be useful tracers of short-term plastic debris-biota interactions.

Novel insights into DEHP-induced zebrafish spleen damage: Cellular apoptosis, mitochondrial dysfunction, and innate immunity

DEHP (Di(2-ethylhexyl) phthalate) is the most abundant phthalate component detected in environmental samples as it is widely used in the manufacturing of children's toys, medical devices and furniture. Due to its wide prevalence and propensity to accumulate in the food chain, significant concerns have risen about the safety profile of DEHP. Here, we used a zebrafish model to investigate the toxicity mechanisms of DEHP. Our results indicated that exposure to DEHP altered the ROS content in zebrafish spleen and inhibited the activities of antioxidant enzymes SOD and CAT, detoxification enzyme GSH-Px and induced histopathological damage. In addition, elucidated the mechanism of DEHP significantly promoted apoptosis and caused damage in spleen cells through the bax/bcl-2 pathway. Further genetic testing demonstrated significant alterations in mitochondrial biogenesis, fission, and fusion-related genes and suggested potential mechanistic pathways, including GM10532/m6A/FIS1 axis, the STAT3/POA1 axis, and the NFR1/TFAM axis. Serological and genomic analysis indicated that DEHP exposure activated the C3 complement cascade immune pathway and interfered with innate immune function. IBRv2 analysis proposes that innate immunity may serve as a signal indicator of early toxic responses to DEHP pollutants. This study provided comprehensive cellular and genetic data for DEHP toxicity studies and emphasized the need for future management and remediation of DEHP contamination. It also provides data to specifically support the health risk assessments of DEHP, as well as contributing to broader health and environmental research.

A global meta-analysis of phthalate esters in drinking water sources and associated health risks

Phthalate esters (PAEs) are known as esters of phthalic acid, which are commonly used as plasticizers in the plastic industry. Due to the lack of chemical bonding with the polymer matrix, these compounds are easily separated from plastic products and enter the environment. To investigate the growth of concentration of PAEs like DBP (Dibutyl phthalate), DEP (Diethyl phthalate), DMP (Dimethyl phthalate), DIBP (Diisobutyl phthalate), and TPMBP (tris(2-methylbutyl) phosphate) in different water sources, a study from January 01, 1976, to April 30, 2021, was implemented via a global systematic review plus meta-analysis in which, 109 articles comprising 4061 samples, 4 water types, and 27 countries were included. Between various types of water sources, river water and lake water were the most contaminated resources with PAEs. Among all studies of PAEs, DBP and DEP with the values >15,573 mg L-1 have the highest average concentration and TPMBP with the value 0.002885 mg L-1 has the lowest average concentration in water sources. The most contaminated water sources with PAEs were in Nigeria and the least contaminated was in China. Besides, Monte-Carlo simulation indicated that for DMP and DEP minimum values that are lower than the acceptable limit are generated. However, most of the population (>75 %) is at risk for both adults and child cases. For DIBP and DBP the situation is much worse, the simulations not providing at least one case where the R index is lower than the acceptable limit of 1E-06.

Occurrence and correlation of microplastics and dibutyl phthalate in rivers from Pearl River Delta, China

Microplastics have been identified as the novel contaminants in various environments. Phthalates would be released from plasticized microplastics into a riverine environment while transporting to a marine region, but data on their relationship in rivers have been scarce. In this study, the occurrence, distribution and correlation of microplastics and dibutyl phthalate (DBP) in two rivers from the Pearl River Estuary were investigated. The elevated level of DBP in the Qianshan River (2.70 ± 0.20 μg/L) was in alignment with the presence of highest microplastic concentration at the same sampling site (15.8 ± 9.8 items/L). A positive correlation was observed between microplastics and DBP in all sampling sites (p < 0.05). The results showed that UV irradiation from sunlight was a majorly inducing factor of DBP leaching from polyethylene microplastics. The concentrations of chemical additives in some degrees reflect the microplastic pollution, but environmental factors and multidimensionality of microplastics such as residence times and types may cause spatial differences of chemical additives in aquatic systems.

Microplastics and phthalate esters release from teabags into tea drink: occurrence, human exposure, and health risks

Tea, the most common infusion worldwide, is usually sold in teabags due to the ease of usage. The increase in the use of plastic materials in the food packaging industry has led to an increase in released contaminants, such as microplastics (MPs) and phthalates (PAEs), in various food products including teabags. In this research, the abundance and features of MPs as well as PAEs concentration were investigated in 45 teabag samples of different Persian and German brands. The abundance of MPs in the Persian and German teabag samples was averagely 412.32 and 147.28 items/single teabag, respectively. Also, average PAEs levels in the Persian and German teabag samples were 2.87 and 2.37 mg/g, respectively. The predominant size category of MPs was related to 100-250 μm. Fibers and transparent were the dominant shape and color of detected MPs in teabags, respectively. Polyethylene (PE) and nylon were the most common MP polymer types. The most prominent PAEs congeners in teabag samples were diethylhexyl phthalate (DEHP) and diisobutyl phthalate (DiBP). Furthermore, MP exposure hazard through tea ingestion was analyzed for children and adults. DEHP showed the cancer risk (CR) for children and adults. The findings of this research indicated that high MPs and PAEs levels are released from teabags into tea drinks. Considering a daily drinking of a volume of 150 and 250 mL tea by children and adults, 486 and 810 MPs may enter their bodies, respectively. Thus, tea prepared with teabag-packed herbs may pose a significant health risk for consumers.

Air-Sea Exchange and Atmospheric Deposition of Phthalate Esters in the South China Sea

Phthalate esters (PAEs) have been investigated in paired air and seawater samples collected onboard the research vessel SONNE in the South China Sea in the summer of 2019. The concentrations of ∑₇PAEs ranged from 2.84 to 24.3 ng/m³ with a mean of 9.67 ± 5.86 ng/m³ in air and from 0.96 to 8.35 ng/L with a mean of 3.05 ng/L in seawater. Net air-to-seawater deposition dominated air-sea exchange fluxes of DiBP, DnBP, DMP, and DEP, while strong water-to-air volatilization was estimated for bis(2-ethylhexyl) phthalate (DEHP). The estimated net atmospheric depositions were 3740 t/y for the sum of DMP, DEP, DiBP, and DnBP, but DEHP volatilized from seawater to air with an average of 900 t/y. The seasonally changing monsoon circulation, currents, and cyclones occurring in the Pacific can significantly influence the concentration of PAEs, and alter the direction and magnitude of air-sea exchange and particle deposition fluxes. Consequently, the dynamic air-sea exchange process may drive the transport of PAEs from marginal seas and estuaries toward remote marine environments, which can play an important role in the environmental transport and cycling of PAEs in the global ocean.

Levels and health risk assessments of Phthalate acid esters in indoor dust of some microenvironments within Ikeja and Ota, Nigeria

The levels, profiles of Phthalate acid esters (PAEs) and their associated health risk in children and adults using indoor dust samples were assessed from nine (9) microenvironments in Nigeria. Six PAEs congeners were determined using Gas Chromatography-Mass Spectrometry and the human health risk assessments of PAEs exposure to children and adults were computed using the United States Environmental Protection Agency (USEPA) exposure model. The mean concentrations of the total PAEs (Σ₆PAEs) in indoor dust across the study locations ranged from 1.61 ± 0.12 to 53.3 ± 5.27 μg/g with 72.0% of di-n-octyl phthalate (DnOP) as the most predominant contributor of PAEs in sample locations B, C, D, E, F and G. PAEs estimated daily intake results exceeded the USEPA value of 20 and 50 kg/bw/day for children and adults respectively in some locations. Non-carcinogenic risk exposure indicated no risk (HI < 1), while the carcinogenic risk was within the recommended threshold of 1.00 × 10^-4 to 1.00 × 10^-6 for benzyl butyl phthalate and bis-2-ethylhexyl phthalate. From our findings, lower levels of PAEs were observed in locations with good ventilation system. Also, the human health risk evaluation indicated indoor dust ingestion as the dominant exposure route of PAEs for both children and adults, while the children were at a higher risk of PAEs exposure. To protect children susceptible to these endocrine-disrupting pollutants, soft vinyl children's toys and teething rings should be avoided. Appropriate policies and procedures on the reduction of PAEs exposure to humans should be enacted by all stakeholders, including government regulatory agencies, industries, school administrators and the entire community.

Accumulation, functional and antioxidant responses to acute exposure to Di(2-ethylhexyl)phthalate (DEHP) in Mytilus galloprovincialis

Mussels were exposed to di-(2-ethylhexyl) phthalate (DEHP) (0.4 mg L^-1 and 4.0 mg L^-1) for 24 h and 48 h and its effect on hemocyte cellular composition and spontaneous reactive oxygen production (ROS) levels in hemocytes were evaluated. Exposure to DEHP induced a loss in spontaneous ROS production levels in hemocytes and decreased agranulocyte number in hemolymph. DEHP was found to accumulate in hepatopancreas of mussels and this process was associated with an increase of catalase (CAT) activity after 24 h incubation. At the end of the experimental period (48 h) CAT activity recovered up to control levels. Superoxide dismutase (SOD) activity in hepatopancreas increased following 48 h exposure to DEHP. The results indicated that DEHP could affect hemocyte immune properties, and also cause non-specific general stress-response of the antioxidant complex, which, in turn, was not associated with pronounced oxidative stress.

Microplastic occurrence and phthalate ester levels in neuston samples and skin biopsies of filter-feeding megafauna from La Paz Bay (Mexico)

The impacts of microplastics on filter feeders megafauna have recently received increased attention. These organisms are potentially exposed to plastic ingestion and the release of added/sorbed contaminants during feeding activities. An assessment of microplastic abundance and the chemical impact of Phthalates esters (PAEs) were performed in neustonic samples and skin biopsies of Balaenoptera physalus and Rhincodon typus inhabiting the Gulf of California (Mexico). Sixty-eight percent of the net tows contained plastics with a maximum of 0.24 items/m³ mainly composed of polyethylene fragments. PAE levels were detected both in environmental and skin biopsy samples, with the highest values in the fin whale specimens (5291 ng/g d.w). Plasticizer fingerprint showed a similar distribution pattern between neustonic samples and filter-feeding species, with DEHP and MBP having the highest concentrations. The detection of PAE levels confirmed their potential role as plastic tracers and give preliminary information about the toxicological status of these species feeding in La Paz Bay.

Occurrence and ecological risks of microplastics and phthalate esters in organic solid wastes: In a landfill located nearby the Persian Gulf

Landfill sites are the main source of plastic waste. Thus, municipal solid waste (MSW) in landfills may act as a reservior of microplastics (MPs) and related pollutants such as phthalate esters (PAEs) into surrounding environment. However, there is limited information on MPs and PAEs in landfill sites. Levels of MPs and PAEs in organic solid waste disposed in a landfill of Bushehr port were investigated for the first time in this study. The mean MPs and PAEs levels in organic MSW samples were 12.3 items/g and 7.99 μg/g, respectively, and the mean PAEs concentration in MPs was 87.5 μg/g. The highest number of MPs was related to the size classes of >1000 μm and <25 μm. The highest dominant type, color, and shape of MPs in organic MSW were nylon, white/transparent, and fragments, respectively. Di (2-ethylhexyl) phthalate (DEHP) and diisobutyl phthalate (DiBP) were the dominant compounds of PAEs in organic MSW. Based on the finding of present study, MPs showed a high hazard index (HI). DEHP, dioctyl phthalate (DOP), and DiBP demonstrated high-level hazards for sensitive organisms in water. This work illustrated considerable MPs and PAEs levels from an uncontrolled landfill without adequate protection, possibly contributing to their release into the environment. The sites of landfill located near marine environments, such as Bushehr port landfill adjacent to the Persian Gulf, may indicate critical threats to marine organisms and the food chain. Continuous landfills control and monitoring, especially the ones near the coastal area, is highly recommended to prevent further environmental pollution.

Effects of UV radiation on natural and synthetic materials

The deleterious effects of solar ultraviolet (UV) radiation on construction materials, especially wood and plastics, and the consequent impacts on their useful lifetimes, are well documented in scientific literature. Any future increase in solar UV radiation and ambient temperature due to climate change will therefore shorten service lifetimes of materials, which will require higher levels of stabilisation or other interventions to maintain their lifetimes at the present levels. The implementation of the Montreal Protocol and its amendments on substances that deplete the ozone layer, controls the solar UV-B radiation received on Earth. This current quadrennial assessment provides a comprehensive update on the deleterious effects of solar UV radiation on the durability of natural and synthetic materials, as well as recent innovations in better stabilising of materials against solar UV radiation-induced damage. Pertinent emerging technologies for wood and plastics used in construction, composite materials used in construction, textile fibres, comfort fabric, and photovoltaic materials, are addressed in detail. Also addressed are the trends in technology designed to increase sustainability via replacing toxic, unsustainable, legacy additives with 'greener' benign substitutes that may indirectly affect the UV stability of the redesigned materials. An emerging class of efficient photostabilisers are the nanoscale particles that include oxide fillers and nanocarbons used in high-performance composites, which provide good UV stability to materials. They also allow the design of UV-shielding fabric materials with impressive UV protection factors. An emerging environmental issue related to the photodegradation of plastics is the generation of ubiquitous micro-scale particles from plastic litter exposed to solar UV radiation.

Distribution, Source Apportionment and Risk Assessment of Phthalate Esters in the Overlying Water of Baiyang Lake, China

As a kind of endocrine disruptor compounds, the presence of phthalate esters (PAEs) has become a global concern. In this study, the pollution levels and spatial distribution of sixteen PAEs were investigated. Their potential sources and eco-environmental health risk were discussed in Baiyang Lake and its upstream rivers during different periods. PAEs were detected in all of samples, ranging from 1215 to 3014 ng·L-1 in October 2020 and 1384 to 3399 ng·L-1 in May 2021. Dibutyl phthalate (DBP) and di-isobutyl phthalate (DIBP) were the predominant monomers, with a detection rate of 100% and the highest concentrations in the overlying water. Restricted by multiple factors, the spatial distribution difference between Baiyang Lake and its upstream rivers in October was more significant than in May. The source apportionment revealed that agricultural cultivation and disorderly use and disposal of plastic products were the primary factors for the contamination. The human health risk assessment indicated that eight PAE congeners did not pose significant carcinogenic and non-carcinogenic harms to males, females and children. However, the ecological risks of DBP, DIBP and di (2-ethylhexyl) phthalate to algae, crustaceans and fish species were moderate or high-risk levels. This study provides an appropriate dataset for the assessment of the pollution of PEs to the water ecosystem affected by anthropogenic activities.

Mass Spectrometry as an Analytical Tool for Detection of Microplastics in the Environment

Plastic particles smaller than 5 mm accumulate in aqueous, terrestrial, and atmospheric environments and their discovery has been a serious concern when it comes to eco-toxicology and human health risk assessment. In the following review, the potential of mass spectrometry (MS) for the detection of microplastic (MP) pollutants has been elaborately reviewed. The use of various mass spectrometric techniques ranging from gas chromatography–mass spectrometry (GC-MS), liquid chromatographic mass spectrometric (LC-MS) to matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS), including their variants, have been reviewed. The lapses in the detection system have been addressed and future recommendations proposed. The challenges facing microplastics and their detection have been discussed and future directions, including mitigation methods, have been presented.

Limited effects of environmentally-relevant concentrations in seawater of dibutyl phthalate, dimethyl phthalate, bisphenol A, and 4-nonylphenol on the reproductive products of coral-reef organisms

Plastic additives (PAs) are chemical compounds incorporated into the plastic during the manufacturing process. Phthalate acid esters, bisphenols, and nonylphenols are all PAs found in marine environments and associated with endocrine-disrupting processes. However, our knowledge regarding the impact of endocrine-disrupting PAs on coral-reef organisms is limited. As reef population structure is directly linked to reproduction and larval settlement processes, interference with hormonal systems can impact coral-reef community structure, particularly if the effects of PAs differ among species. In the current study we exposed the reproductive products of four tropical coral-reef invertebrates to environmentally-relevant concentrations of four prevalent PAs in seawater: dibutyl phthalate (DBP), dimethyl phthalate, (DMP), 4-nonylphenol (4-NP), and bisphenol A (BPA), as well as to 10³ higher laboratory concentrations of these PAs. Our results revealed that apart from the significant negative effect of the 1 μg/L of 4-NP on the settlement of the soft coral Rhytisma fulvum, none of the other tested materials demonstrated a significant effect on the exposed organisms at environmentally-relevant concentrations in seawater. The 4-NP high laboratory concentration (1000 μg/L), however, had significant negative effects on all the examined species. The high laboratory BPA concentration (1000 μg/L) significantly reduced fertilization success in the solitary ascidian Herdmaniamomus, up to its complete failure to reproduce. Moreover, the high laboratory DMP concentration (100 μg/L) had a significant negative effect on planulae settlement of the stony coral Stylophora pistillata. Our findings demonstrate the negative and selective effects of PAs on the development and reproduction of coral-reef organisms; and, specifically, the significant effect found following exposure to 4-NP. Consequently, if we aim to fully understand the impact of these contaminants on this endangered ecosystem, we suggest that the actual concentrations within the living organism tissues should be tested in order to produce relevant risk assessments for brooding-coral species.

Aquatic and human health risk assessment of Humanogenic Emerging Contaminants (HECs), Phthalate Esters from the Indian Rivers

Phthalate esters (PEs) one of the widely used plasticizers, and are known for their environmental contamination and endocrine disruption. Hence, it is important to study their distribution in a riverine environment. This study was aimed to determine the Spatio-temporal trends of 16 PEs in surface water, sediment and fish from rivers in southern India, and to assess their environmental health risks. Phthalates were quantified in all matrices with the mean concentrations (∑₁₆PEs) in water, sediment and fish as 35.6 μg/L, 1.25 μg/kg and 17.0 μg/kg, respectively. The Kaveri River is highly loaded with PEs compared to the Thamiraparani and Vellar Rivers. PEs such as DBP, DEHP, DCHP and DiBP were most frequently detected in all matrices, and at elevated concentrations in the dry season. The risk quotient (RQ < 1) suggests that the health risk of PEs from river water and fish to humans is negligible. However, DBP and DEHP from the Kaveri River pose some risk to aquatic organisms (HQ > 1). DEHP from the Vellar River may pose risks to algae and crustaceans. Non-priority phthalate (DiBP) may pose risks to Kaveri and Vellar River fish. The bioaccumulation factor of DCHP and DEHP was found to be very high in Sardinella longiceps and in Centropristis striata, and also exceeded the threshold limit of 5000 suggesting that PEs in the riverine environment may pose some health concerns. This is the first study to assess the spatio-temporal distribution, riverine flux and potential ecological effects of 16 PEs from the southern Indian Rivers.

Occurrence, seasonal distribution, and ecological risk assessment of microplastics and phthalate esters in leachates of a landfill site located near the marine environment: Bushehr port, Iran as a case

Plastic wastes are produced in a large amount everywhere, and are commonly disposed in landfills. So landfill leachate seems an obvious source of microplastics (MPs) and phthalate esters (PAEs) due to a huge usage as plastic additives and plasticizers. But this issue still lacks attention and the present study provides the first information on the levels of MPs and PAEs in the fresh landfill leachate of Bushehr port during different seasons. The mean levels of MPs and PAEs in the fresh leachate in all seasons were 79.16 items/L and 3.27 mg/L, respectively. Also, the mean levels of PAEs in MPs were 48.33 μg/g. A statistically significant difference was detected in the levels of MPs and PAEs among different seasons with the highest values in summer and fall. MPs with a size of >1000 μm had the highest abundance in all seasons. The most prominent shape, color, and type of MPs in the leachate were fibers black, and nylon, respectively. Dibutyl phthalate (DBP) and Di(2-ethylhexyl) phthalate (DEHP) were the most dominant PAEs present in the leachate samples. The results of this study revealed high hazard index (HI) and pollution load index (PLI) of MPs in all seasons. Dioctyl phthalate (DOP), DEHP, DBP, diisobutyl phthalate (DiBP), butyl benzyl phthalate (BBP), and diethyl phthalate (DEP) represented a high risk to the sensitive organisms. The results of this study showed that significant levels of MPs and PAEs may release into the surrounding environment from the landfill sites without sufficient protection. This issue is more critical when the landfill sites in particular are located near the marine environments like the Bushehr landfill that is located near the Persian Gulf, which can lead to serious environmental problems. Thus permanent control and monitor of landfills, especially in the coastal areas are highly needed to prevent further pollution.

Nongenomic effects and mechanistic study of butyl benzyl phthalate-induced thyroid disruption: Based on integrated in vitro, in silico assays and proteome analysis

Based on in vitro and in silico assays as well as proteome analysis, this study explored the nongenomic mechanism for butyl benzyl phthalate (BBP)-induced thyroid disruption. Molecular docking simulations showed that BBP could dock into the Arg-Gly-Asp (RGD) domain of integrin α_vβ₃ and form hydrogen bonds with a docking energy of -35.80 kcal/mol. This chemical enhanced rat pituitary tumor cell (GH3) proliferation and exhibited thyroid hormone-disrupting effects at 5-10 μmol/L. Meanwhile, BBP upregulated β₃ gene expression and activated the downstream mitogen-activated protein kinase (MAPK) pathway in GH3 cells. Interestingly, GH3 cell proliferation was attenuated by integrin α_vβ₃ inhibitor (RGD peptide) or ERK1/2 inhibitor (PD98059), suggesting that the disruptions might be partly attributed to its interaction with integrin α_vβ₃ and activation of MAPK. Furthermore, quantitative proteomic analysis of zebrafish embryos exposed to BBP at an environmentally relevant concentration of 0.3 μmol/L revealed that BBP perturbed proteins and pathways related to cell communication (e.g., integrin binding) and signal transduction (e.g., MAPK signaling pathway). Taken together, our results supported that the biological effects of BBP-activated integrin α_vβ₃ mediated by the nongenomic pathway play an important role in its thyroid disruption. CAPSULE: The nongenomic pathway plays a vital role in the thyroid disruption-inducing actions of BBP.

PM2.5-bound phthalates and phthalate substitutes in a megacity of southern China: spatioseasonal variations, source apportionment, and risk assessment

Plasticizers are ubiquitous pollutants in the environment, whereas few efforts have been made to elucidate their emission sources in the atmosphere. In this research, the spatioseasonal variations and sources of particle-bound (PM_2.5) phthalates (PAEs) and their substitutes (APs) at residential sites in seven districts and at four potential point-source sites across a megacity in South China were revealed. The total concentrations of PAEs ranging from 10.7 to 528 ng/m³ were substantially higher than those of APs (1.45.58.5 ng/m³). Significant spatial variations in the concentrations of the pollutants were observed, which were generally higher at the sites with intensive industrial activities and the point-source sites. Most atmospheric plasticizer levels peaked in summer, probably due to the temperature-promoted volatilization. Seven sources of plasticizers were identified by the positive matrix factorization (PMF) model. The sources in less industrialized districts are mainly associated with domestic and commercial emissions and with industry in the industrialized districts. Specifically, plastics and personal care products together contributed 60% of the plasticizers in the atmosphere of this city, followed by solvents and polyester industry sources. The incremental lifetime cancer risk of inhalation exposure to bis(2-ethylhexyl) phthalate in the study city is below the acceptable level. Relatively higher risks were found for residents living around sites with intensive industrial activities and around wastewater treatment plant.

The effect of heavy rainfall on the exposure risks of sedimentary phthalate esters to aquatic organisms

Phthalate esters (PAEs) have known widely being used in plastic products leading to being ubiquitous in the environment by easy to release from those products. This study aims to understand the impact of heavy rainfall on the concentration of PAEs in surface sediments of the Salt River in Kaohsiung, Taiwan, and its potential ecological risks on aquatic organisms. The potential ecological risk assessment of sediment PAEs is based on the total risk quotient (TRQ) method. The total concentration of 10 PAEs (∑PAE10) in sediments of the Salt River is 333-13,615 ng/g dw, with an average of 4212 ± 3753 ng/g dw. Before the rainy season, the ∑PAE10 concentration in sediments at the outlets of domestic sewage in upstream was 9768-13,615 ng/g dw, which were relatively higher than other sites (542-3721 ng/g dw). During the rainy season, the ∑PAE10 concentration was 2820-12,041 ng/g dw, which was 1-11 times higher than that determined before the rainy season. After the rainy season, the ∑PAE10 concentration recorded was 530-6652 ng/g dw, which is 1-11 times lower than the value obtained during the rainy season. PAEs in sediments of the Salt River may have low to moderate potential risks to algae, crustaceans, and fish. Bis(2-ethylhexyl) phthalate (DEHP) and diisobutyl phthalate (DiBP) are the main PAE that poses a potential risk to algae and crustaceans, and to fish respectively, whose values of risk quotient accounts for 40-69% of the TRQ value. The distribution of TRQ values for these aquatic organisms show a decreasing trend of PAEs level with respect to the rainy season: during the rainy season > after the rainy season > before the rainy season. Heavy rainfall may cause more serious pollution in sediments and increase the exposure risk of PAEs to aquatic organisms.

Occurrence of microplastics and phthalate esters in urban runoff: A focus on the Persian Gulf coastline

Urban runoff seems an obvious pathway for the transfer of microplastics (MPs) and phthalate acid esters (PAEs) from land-based sources to the marine environment; an issue that still lacks attention. This study presents the first results on MP and PAE levels in the urban runoff into the northern part of the Persian Gulf during the dry season. Average concentrations of MPs and PAEs in the urban runoff of eight selected sampling sites (N = 72) along the Bushehr coast were 1.86 items/L and 53.57 μg/L, respectively. MPs with a size range of 500-1000 μm had the highest abundance, and the mean levels of PAEs in MPs were 99.77 μg/g. The results of this study show that urban runoff is a main source of MP and PAE contaminants that are discharged into the Persian Gulf. Therefore, to decrease these pollutants from entering the aquatic environment, decision-makers in the area should consider this problem and stop the direct discharging of urban runoff into water bodies.

Seasonal Variation of Phthalate Esters in Urban River Sediments: A Case Study of Fengshan River System in Taiwan

The Fengshan River system is one of the major rivers in Kaohsiung City, Taiwan. This study investigated the concentration of eight phthalate esters (PAEs) in sediments of the river and the impact of potential ecological risks during the dry and wet seasons. The potential risk assessment of sediment PAEs was evaluated by adopting the total risk quotient (TRQ) method. The total PAEs concentrations (∑PAEs) in the sediments of the Fengshan River system are between 490–40,190 ng/g dw, with an average of 8418 ± 11,812 ng/g dw. Diisononyl phthalate (38.1%), bis(2-ethylhexyl) phthalate (36.9%) and di-isodecyl phthalate (24.3%) accounted for more than 99.3% of ∑PAEs. The concentration of ∑PAEs in sediments at the river channel stations is higher during the wet season (616–15,281 ng/g dw) than that during the dry season (490–1535 ng/g dw). However, in the downstream and estuary stations, the wet season (3975–6768 ng/g dw) is lower than the dry season (20,216–40,190 ng/g dw). The PAEs in sediments of the Fengshan River may have low to moderate potential risks to aquatic organisms. The TQR of PAEs in sediments at the downstream and estuary (TQR = 0.13) is higher than that in the upstream (TQR = 0.04). In addition, during the wet season, rainfall transported a large amount of land-sourced PAEs to rivers, leading to increased PAEs concentration and potential ecological risks in the upper reaches of the river.

Phthalic acid esters degradation by a novel marine bacterial strain Mycolicibacterium phocaicum RL-HY01: Characterization, metabolic pathway and bioaugmentation

Phthalic acid esters (PAEs) are one of the most widely used plasticizers and the well-studied environmental pollutants with endocrine disrupting properties. Investigation about PAEs in terrestrial ecosystem has been extensively conducted while the fate of PAEs in marine environment remains underexplored. In this study, a novel di-(2-ethylhexyl) phthalate (DEHP) degrading marine bacterial strain, Mycolicibacterium phocaicum RL-HY01, was isolated and characterized from intertidal sediments. Strain RL-HY01 could utilize a range of PAE plasticizers as sole carbon source for growth. The effects of different environmental factors on the degradation of PAEs were evaluated and the results indicated that strain RL-HY01 could efficiently degrade PAEs under a wide range of pH (5.0 to 9.0), temperature (20 °C to 40 °C) and salinity (below 10%). Specifically, when Tween-80 was added as solubilizing agent, strain RL-HY01 could rapidly degrade DEHP and achieve complete degradation of DEHP (50 mg/L) in 48 h. The kinetics of DEHP degradation by RL-HY01 were well fitted with the modified Gompertz model. The metabolic intermediates of DEHP by strain RL-HY01 were identified by ultra-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) analysis and then the metabolic pathway of DEHP was deduced. DEHP was transformed into di-ethyl phthalate (DEP) via β-oxidation and then DEP was hydrolyzed into phthalic acid (PA) by de-esterification. PA was further transformed into gentisate via salicylic acid and further utilized for cell growth. Bioaugmentation of strain RL-HY01 with marine samples was performed to evaluate its application potential and the results suggested that strain RL-HY01 could accelerate the elimination of DEHP in marine samples. The results have advanced our understanding of the fate of PAEs in marine ecosystem and identified an efficient bioremediation strategy for PAEs-polluted marine sites.

Transient effect of bisphenol A (BPA) and di-(2-ethylhexyl) phthalate (DEHP) on the cosmopolitan marine diatom Chaetoceros decipiens-lorenzianus

Incubation under controlled laboratory conditions were performed to assess the toxic effects of two plastic derived chemicals, bisphenol A (BPA) and di-(2-ethylhexyl) phthalate (DEHP), on the growth, photosynthetic efficiency and photosynthetic activity of the cosmopolitan diatom Chaetoceros decipiens-lorenzianus. Non-axenic diatom cells were exposed to concentrations of BPA and DEHP (separately and in mixture), mimicking concentrations observed in contaminated marine ecosystems, for seven days. Upon short-term exposure (i.e., during the first 48 h), BPA and DEHP induced a slight but significant stimulation of biomass and photosynthetic activity relative to the control, whereas, no significant impact was observed on the photosynthetic efficiency. Nevertheless, this pattern was transient. The stimulation was followed by a return to control conditions for all treatments at the end of incubation. These results showed that the cosmopolitan diatom Chaetoceros was not impacted by representative in situ concentrations of plastic derivatives, thus confirming its ability to thrive in coastal anthropogenic environments.

Comprehensive Insight from Phthalates Occurrence: From Health Outcomes to Emerging Analytical Approaches

Phthalates are a group of chemicals used in a multitude of important industrial products (e.g., medical devices, children's toys, and food packages), mainly as plasticizers to improve mechanical properties such as flexibility, transparency, durability, and longevity of polyvinyl chloride (PVC). The wide occurrence of phthalates in many consumer products, including foods (e.g., bottled water, soft drinks, wine, milk, and meat) brings that most people are exposed to phthalates every day, which raises some concerns. Adverse health outcomes from phthalates exposure have been associated with endocrine disruption, deformities in the human reproductive system, increased risk of preterm birth, carcinogen exposure, among others. Apprehension related to the health risks and ubiquitous incidence of phthalates in foods inspires the development of reliable analytical approaches that allow their detection and quantification at trace levels. The purpose of the current review is to provide information related to the presence of phthalates in the food chain, highlighting the health risks associated with their exposure. Moreover, an overview of emerging extraction procedures and high-resolution analytical approaches for a comprehensive quantification of phthalates is presented.

Targeted and suspect screening of contaminants in coastal water and sediment samples in Qatar

In recent years, high resolution mass spectrometry (HRMS) combined with separation techniques has allowed comprehensive analysis of contaminants of emerging concern (CECs) as well as their metabolites and transformation products in various environmental samples via retrospective screening. However, to date, only a few suspect or non-targeted studies on the occurrence of CECs in marine aquatic system are reported. In this study, two methods, based on direct injection for seawater, or ultrasound-assisted extraction for sediments, followed by LC-Q-TOF-MS analysis were developed and applied for the simultaneous targeted and screening of contaminants in coastal samples (seawater, particulates and sediment) from Qatar collected in 2017-2018. Among the twenty-one target analytes (pesticides, PPCPs and a plasticizer), two compounds only were detected in seawater. Caffeine was detected in seawater samples at all sampling sites, and cotinine was detected in seawater samples collected in Umm Bab in 2018 and seawaters receiving stormwater. Traces of trimethoprim and carbamazepine were detected in sediment samples collected at four sites in 2017. These results suggest some inputs of domestic wastewater in the coastal waters in Qatar. In total, twelve molecular features were tentatively identified from suspect screening at concentration levels significantly higher than that in procedure blanks. The presence of four plasticizers and one pesticide were further confirmed using reference standards: diethyl phthalate (DEP), dibutyl phthalate (DBP), and tributyl phosphate (TBP) in seawater samples; bis(2-ethylhexyl) phthalate (DEHP) in sediment and particulate samples; and dinoterb in seawater after storm event and particulate samples. Overall, this study demonstrated the potential of high resolution LC-Q-TOF-MS/MS for combined targeted and non-targeted analyses of trace contaminants in marine systems over a broad range of log P values.

Contaminant occurrence, mobility and ecological risk assessment of phthalate esters in the sediment-water system of the Hangzhou Bay

The pollution characteristics, spatiotemporal variation, sediment-water partitioning, and potential ecological risk assessment of phthalate esters (PAEs) in the sediment-seawater system of the Hangzhou Bay (HZB) in summer and autumn were researched. The sum of the concentrations of the 10 PAEs in seawater ranges from 7305 ng/L to 22,861 ng/L in summer and from 8100 ng/L to 33,329 ng/L in autumn, with mean values of 15,567 ± 4390 and 17,884 ± 6850 ng/L, respectively. The Σ_16PAEs in the sediments are between 118 and 5888 μg/kg and 145 and 4746 μg/kg in summer and autumn, respectively. The level of PAEs in seawater varies with the seasons, but it is relatively stable in the sediments. Di(2-ethylhexyl) phthalate (DEHP), di-n-butyl phthalate (DnBP), and diisobutyl phthalate (DiBP) are the predominant PAE congeners in the HZB. The DnBP and DiBP concentrations in seawater are greater than the DEHP concentration, which is the opposite in the sediments. The sediment-seawater equilibrium distribution study indicates that the PAEs with medium molecular weights, such as DiBP, butyl benzyl phthalate, and DnBP, are near dynamic equilibrium in the sediment-seawater system; PAEs with high molecular weights (e.g., di-n-octyl phthalate and DEHP) tend to transfer from water to the sediments; and PAEs with low molecular weights (e.g., dimethyl phthalate, diethyl phthalate, and diamyl phthalate) tend to spread to seawater. The risk assessment results in seawater indicate that DEHP and DiBP might pose high potential risks to sensitive organisms, and DnBP might exhibit medium ecological risks. In the sediment, DiBP might display a high potential risk to fish, and the potential risk of DEHP is high in several sites.

Distributions, temporal trends and ecological risks of polyethylene terephthalate (PET) and di-(2-ethylhexyl) phthalate (DEHP) in sediments of Jiaozhou Bay, China

Spatiotemporal distribution and ecological risk of the polyethylene terephthalate (PET) plastic polymer and plasticizer di-(2-ethylhexyl) phthalate (DEHP) were investigated using both surface and core sediments in Jiaozhou Bay, China. The concentrations of PET and DEHP ranged 210.6-1929.7 μg/kg and 0-591.2 μg/kg, respectively. The depth profiles of PET and DEHP in the sediment cores indicated that PET and DEHP pollution increased since the 1970s, which is in accord with the regional PET and DEHP consumption history. The levels of PET in Jiaozhou Bay was found to represent low ecological risk based on the assessment models for Potential Ecological Risk factor and Potential Ecological Risk. The amounts of DEHP also posed a low risk to the aquatic organisms in the sediment phase as indicated by the Risk Quotient method.

Effects of butyl benzyl phthalate exposure on Daphnia magna growth, reproduction, embryonic development and transcriptomic responses

Butyl benzyl phthalate (BBP) is widely used as a plasticizer to increase the plasticity and flexibility of plastic products. Although the potential health hazards of BBP have recently received extensive attention, its toxicological properties and mechanisms remain largely undefined. In the present work, growth, reproductive and developmental toxicity of BBP to Daphnia magna were evaluated, and the transcriptomic alteration of early embryos upon BBP exposure was analyzed. In a 21-day chronic toxicity test, reduced survival ratio, decreased body length, increased abnormal ratio, advanced time to first brood, and reduced offspring of D. magna were observed. BBP exposure inhibited expression of the vitellogenin gene. In addition, embryotoxicity of BBP was observed, which showed not only in the induction of abnormal neonates, but also in the shortened embryonic development cycle. RNA-Seq of early embryo treated with 0.1 mg/L BBP indicated that the pathways involved in signal transduction, cell communication, and embryonic development were significantly down-regulated, while those of biosynthesis, metabolism, cell homeostasis, redox homeostasis were remarkably up-regulated upon BBP exposure, which was consistent with the above phenotypic results. Taken together, our results highlight the toxic effects of BBP on the embryonic development and larval growth of D. magna.

Recent Attempts in the Design of Efficient PVC Plasticizers with Reduced Migration

This paper reviews the current trends in replacing commonly used plasticizers in poly(vinyl chloride), PVC, formulations by new compounds with reduced migration, leading to the enhancement in mechanical properties and better plasticizing efficiency. Novel plasticizers have been divided into three groups depending on the replacement strategy, i.e., total replacement, partial replacement, and internal plasticizers. Chemical and physical properties of PVC formulations containing a wide range of plasticizers have been compared, allowing observance of the improvements in polymer performance in comparison to PVC plasticized with conventionally applied bis(2-ethylhexyl) phthalate, di-n-octyl phthalate, bis(2-ethylhexyl) terephthalate and di-n-octyl terephthalate. Among a variety of newly developed plasticizers, we have indicated those presenting excellent migration resistance and advantageous mechanical properties, as well as those derived from natural sources. A separate chapter has been dedicated to the description of a synergistic effect of a mixture of two plasticizers, primary and secondary, that benefits in migration suppression when secondary plasticizer is added to PVC blend.

Single-use plastics: Production, usage, disposal, and adverse impacts

Single-use plastics (SUPs), invented for the modern "throwaway society," are intended to be used only once. They are being increasingly produced and used globally, most notably as packaging or consumables, such as SUP shopping bags or disposable tableware. We discuss how most SUPs are landfilled or incinerated, which causes pollution, consumes valuable land, and squanders limited natural resources. Only relatively small amounts are currently recycled, a hindrance to the concept of a circular economy. Moreover, SUP litter aggregation in the natural environment is a major concern. This article briefly reviews SUP contamination in various environmental media including soil, rivers, lakes and oceans around the world. In the face of mounting evidence regarding the threat posed to plant growth, soil invertebrates and other land animals, (sea) birds, and marine ecosystems, there is a growing push to minimize SUPs. Regulatory tools and voluntary actions to reduce SUP usage have been put forward, with some suggestions for minimizing SUP waste.

Pollution characteristics, spatial variation, and potential risks of phthalate esters in the water-sediment system of the Yangtze River estuary and its adjacent East China Sea

Spatiotemporal variability in seawater, spatial variation in sediment, pollution characteristics, and risks related to 16 phthalate esters (PAEs) were investigated in the Yangtze River estuary and its adjacent East China Sea. The total concentrations of ΣPAEs in surface water were 0.588-17.7 μg L^-1 in summer, 2.63-22.9 μg L^-1 in winter, and 1.93-20.7 μg L^-1 in spring, with average values of 2.05, 10.2, and 4.89 μg L^-1, respectively. PAE concentrations exhibited notable seasonal variations with the highest value in winter and the lowest value in summer. The seasonal variation in PAE concentrations may be influenced by runoff and diluted water from the Yangtze River. The chemical composition of PAEs showed that di-n-butyl phthalate (DnBP), diisobutyl phthalate (DiBP), and di(2-ethylhexyl) phthalate (DEHP) had significantly higher (p < 0.05) concentrations than the other congeners and were the most abundant PAE species in sediment and seawater in all three seasons. In addition, DnBP and DiBP were the two main congeners in seawater, and DEHP concentrations were higher in sediment than in seawater. DEHP had higher potential risks to sensitive organisms in water environment than DnBP and DiBP, and DiBP and DnBP which presented high levels of risk in sedimentary environment. DMP and DEP in watery and sedimentary environments and DEHP in sedimentary environment showed no or low risks to sensitive organisms.

Occurrence of phthalate esters and microplastics in urban secondary effluents, receiving water bodies and reclaimed water treatment processes

The occurrence of phthalate esters (PAEs) and microplastics (MPs) was simultaneously investigated in four wastewater treatment plants (WWTPs), receiving water bodies and reclaimed water treatment processes (RWTPs) in winter and spring. Four PAEs (dimethyl phthalate, dibutyl phthalate, diisobutyl phthalate, and di(2-ethylhexyl)phthalate) were detected. The total concentrations of PAEs were 568.9-1847.5 ng/L in the four WWTP effluents and 39.9-1847.5 ng/L in the four receiving water bodies. Di(2-ethylhexyl)phthalate had the highest concentration among the PAEs. MPs were mostly in the form of granules and fragments with size <0.01 mm in the four WWTP effluents (276-1030 items/L) and receiving water bodies (103-4458 items/L). The four WWTP effluents were important sources of PAEs to the receiving water bodies in spring but were not likely to be the sources of MPs. The overall removal rates of PAEs and MPs were 47.7%-81.6% and 63.5%-95.4% in the four RWTPs. Low or negative removal rates of PAEs were observed in chlorination and ozonation. Clarification, filtration (except ultrafiltration) and reverse osmosis were the dominant processes, contributing 42.7%-69.2%, 25.3%-59.3%, and 22.6%-51.0%, respectively, of the MP removal in the RWTPs. According to the Spearman analysis results, the levels of PAEs and MPs had more significant correlations with the physicochemical parameters of water samples from the RWTPs (including the WWTP effluents) than those of the receiving water bodies. The results indicated that the levels of PAEs and MPs in surface waters could be significantly influenced by the surrounding environment.

Plastic-derived contaminants in Aleutian Archipelago seabirds with varied foraging strategies

Phthalates, plastic-derived contaminants, are of increasing global concern. This study quantified phthalates in seabirds collected across >1700 km of the Aleutian Islands, Alaska, and contributes to a body of knowledge on plastic contaminants in marine wildlife. We measured six phthalate congeners in seabirds representing ten species and four feeding guilds. Phthalates were detected in 100% of specimens (n = 115), but varied among individuals (3.64-539.64 ng/g). DEHP and DBP occurred at an order of magnitude higher than other congeners. Total phthalates did not vary geographically, but differed among feeding guilds, with significantly higher concentrations in diving plankton-feeders compared to others. Plastic particles were detected in 36.5% of randomly subsampled seabird stomachs (n = 74), suggesting plastic ingestion as a potential route of phthalate exposure. Our findings suggest feeding behavior could influence exposure risk for seabirds and lend further evidence to the ubiquity of plastic pollutants in marine ecosystems.

Occurrence and distribution of microplastics-sorbed phthalic acid esters (PAEs) in coastal psammitic sediments of tropical Atlantic Ocean, Gulf of Guinea

Baseline microplastic pollution and the occurrence, spatial distribution and ecological risk of microplastic-sorbed phthalate esters (PAEs) in littoral sandflat sediments of the Gulf of Guinea were investigated. A total of 150 sediment samples were collected using a 0.5 × 0.5 × 0.2 m quadrant placed along designated high, drift and current waterlines at five (5) beaches. Analysis for 6 PAEs-sorbed to microplastics (MPs) was carried out using gas chromatography - mass spectrometry (GC-MS). Microplastic particles (1-5 mm) were identified visually and FTIR spectroscopy was also used for identification. The MPs distribution was variably heterogenous with a total of 3424 particles per m² found within the drift and high waterlines across all sites. Results indicated fragments as the dominant microplastic type compared to pellets and fibres. Polyethylene terephthalate was the major polymer type and accounted for a weighted average of 41% of the total plastics, followed by polystyrene (28%), and polypropylene (21%). The ∑₆PAEs concentration ranged from BDL to 164.09 mg/kg dw, dominated by di(2-ethylhexyl) phthalate (DEHP), dibutyl phthalate (DnBP), and dimethyl phthalate. The preliminary ecological risk assessment of PAEs in the microplastic fraction, RQ_mp, showed DEHP and DnBP may present medium to high biological risks to marine organisms, suggesting that future study of PAEs in total sediment versus the MP fraction might be useful to refine ecological risk assessments. Land-based anthropogenic activities are primary sources of MPs, whereas oceanographic peculiarities of the area constitute the major distribution driving force.

Biochemical and behavior effects induced by diheptyl phthalate (DHpP) and Diisodecyl phthalate (DIDP) exposed to zebrafish

Both Diheptyl-phthalate (DHpP) and Diisodecyl-phthalate (DIDP) were used extensively as plasticizers. Recently, their occurrence in the environmental matrices and human body fluids have been reported. Unfortunately, these phthalate congeners are without basic toxicity profiles. Hence, we studied the toxic effects of both DHpP and DIDP in the median lethal concentration (LC₅₀ 96-h) on zebrafish (Danio rerio). We assessed swimming behavior strength and tissues biomarker responses including total antioxidants capacity (TAOC), transaminases, and acetylcholinesterase (AChE) enzyme. Fish exposed to phthalate congeners (Treatment-I and-II) for 15-days showed alterations on fish swimming behavior and circadian rhythm. At the end of the exposure period, both liver and heart tissue transaminases activities were found to be accelerated in DHpP and DIDP treated fish, when compared to control group. TAOC and AChE activities were found to be decreased in brain, gills, intestine, and muscle tissues of phthalate congeners treated fish than the control group. Alterations observed in the studied biomarkers were concentration-based response. Among treatment groups DHpP showed higher effects. Comparative studies on swimming behavior and biochemical activities were reasonable to know the swimming responses are mediated due to external stress or internal stress. More studies on molecular and biomarkers assessments are warranted on toxicity of emerging contaminants.

Phthalic acid esters in the sea-surface microlayer, seawater and sediments of the East China Sea: Spatiotemporal variation and ecological risk assessment

The spatial and temporal distribution, congener profiles and ecological risk of phthalic acid esters (PAEs) were investigated in the seawater and sediment samples from the East China Sea in spring and autumn. The average concentrations of ΣPAEs in water samples were 3.16 ± 2.16 μg L^-1 in autumn and 1.63 ± 1.20 μg L^-1 in spring. The ΣPAEs in sediment was much higher than that in seawater, with an average value of 7.36 ± 6.70 mg kg^-1 (dw). PAEs levels in the sea-surface microlayer (SML) in spring were 3.61 ± 3.36 μg L^-1, indicating that the PAEs were noticeably concentrated in the SML, with an average enrichment factor of 2.10. Among the 16 PAE congeners, di-n-butyl phthalate (DnBP), diisobutyl phthalate (DiBP), and di(2-ethylhexyl) phthalate (DEHP) were the preponderant PAEs in both sediment and seawater samples. Additionally, PAE concentrations in autumn were higher than those in spring, and this difference resulted mainly from the terrigenous input and marine transportation. The horizontal distributions of PAEs showed an opposite distribution pattern to salinity and temperature, a pattern which might be influenced by the inputs of fresh water. The vertical distributions of ΣPAEs were characterized by high concentrations in the surface waters, with a slight decrease with depth, and then an increase close to the seabed. The results of ecological risk in the water-phase showed that the level of potential risk followed the order of DEHP > DiBP and DnBP > DMP and DEP, which posed a high (DEHP), medium (DiBP and DnBP) and low (DMP and DEP) risk to the sensitive organisms, respectively. For the sediment-phase, DiBP and DnBP represented a high risk to the sensitive organisms, whereas DMP, DEP and DEHP had only a low risk.

Microplastic pollution in deep-sea sediments and organisms of the Western Pacific Ocean

Microplastics are ubiquitous in marine environments. Sediments and marine organisms are recognized as the carriers and final destinations of microplastics. However, research on the concentration and abundance of microplastics in deep-sea sediments and organisms is limited. In this study, samples of sediments and organisms were collected from deep-sea locations of the western Pacific Ocean, with the depth ranging from 4601 m to 5732 m. Microplastics were extracted from the samples and analyzed by micro-Fourier-transform infrared spectroscopy. The average abundance of microplastics in the sediments was 240 items per kg dry weight of sediment. The microplastics were predominantly fibrous in shape (52.5%), blue in color (45.0%), and less than 1 mm in size (90.0%). The most commonly detected polymers were poly(propylene-ethylene) copolymer (40.0%) and polyethylene terephthalate (27.5%). The concentrations of polychlorinated biphenyls (PCBs), which are representatives of persistent organic pollutants, in the pore water of sediment samples were also investigated. A significant correlation between the distribution of microplastics and the PCB concentrations in sediments was found (P = 0.016). Microplastics were also detected in deep-sea organisms (i.e., Crinoidea, Pheronematidae, Ophiuroidea, and Gammaridea) in the sampling region, with an abundance of 0-3 items per individual biological sample. This assessment of microplastics in deep-sea sediments and benthic organisms of the western Pacific Ocean confirms that microplastic pollution exists in the deep-sea ecosystems of this region.

Trace metal comparative analysis of sinking particles and sediments from a coastal environment of the Jiaozhou Bay, North China: Influence from sediment resuspension

To constrain the resuspension influence to the biogeochemical behavior of trace metals (TMs) in settling materials, the concentrations and chemical speciations of macro-elements (Al, Fe, Mn) and selected particulate TMs (V, Cr, Co, Cu, Zn, Ga, Sr, Cd, Ba, Tl, Pb, U) in trap-collected particles (TCPs), surface sediments (SS) and core sediment samples (CS5) of the Jiaozhou Bay were compared. Two approaches, mass conservation method and vertical two end-members mixing model, both calculated a resuspension ratio of more than 90%. Greater TM concentrations and Al-normalization levels than SS/CS5 determined the TCPs an important TM-sink, predominantly owing to grain-size effects and TCP-specific characteristics, i.e., structural capacity of organic-Fe associations for TMs' scavenging, preferential remineralization of TM than biogenic elements in autochthonous microorganisms. Comparison revealed distinct, Fe mineral controls on TM sequestration patterns: higher metal sequestration associated with amorphous Fe oxyhydroxides, while less reactive crystalline Fe oxides hold less metal. Nevertheless, turbulent hydrodynamics muted the wide TM retention divergences between TCP and SS, which should have happened based on different Fe minerals distribution for TCP/SS. The net effect of TM release by the organic carrier phase and then adsorption principally onto Mn/Fe oxyhydroxide phase for raised overall TCP-TM concentrations was also identified.

Occurrence and seasonal distribution of microplastics and phthalates in sediments from the urban channel of the Ria and coast of Campeche, Mexico

Microplastics (MPs) are part of a global problem affecting all countries including those with smaller populations. Coastal sediments are a reservoir of pollutants generated in basins. Phthalate esters (PAEs) are used as additives to make plastics stronger and more flexible. Urban ecosystems are the most susceptible to receive and transport pollutants. In this study, we determined the presence of MPs and PAEs in coastal sediments and in an urban and natural drainage system, known as the "Ria" in San Francisco de Campeche city. Plastics were detected in all samples taken from both regions, with plastics ranging in size from 0.3 to 5 mm in diameter. This indicates that they are particles of plastics, paints, and fibers, which may come from boats and nylon nets or synthetic products. The greatest abundance of MPs was detected on the coast with quantities of 1392 items/m² (dry weight), which is double than that seen in the urban channel. As for PAEs, the highest concentrations were determined in two sites: M7A with 18.292 μg g^-1 dw and PE with 21.702 μg g^-1 dw, with the Ría channel being the area with the highest concentration of PAEs totaling 49.315 μg g^-1 dw. The amounts of MPs detected in the sediments of the coast and the Ria vary significantly among the sites (p = 0.001) and seasons (p = 0.001), with the rainy season being the season where the greatest amount of MPs were detected. Likewise, the concentrations of ∑PAEs varied significantly among seasons (p = 0.0002) and sampling sites (p = 0.0001), with the west sub-basin being the site where the greatest concentration of PAEs was detected. A strong correlation was found between the ∑PAEs and MPs, which indicates that the conditions of the system favor the release and extended presence of PAEs on the coast.