Occurrence and emission of phthalates and non-phthalate plasticizers in sludge from wastewater treatment plants in Korea

Temporal trends of plastic additive contents in sediment cores of three French rivers (Loire, Meuse and Moselle) over the last decades

Sediment cores from three major French watersheds (Loire, Meuse and Moselle) have been dated by 137Cs and 210Pbxs from 1910 (Loire), 1947 (Meuse) and 1930 (Moselle) until the present in order to reconstruct trajectories of plastic additive contaminants including nine phthalate esters (PAEs) and seven organophosphate esters (OPEs), measured by gas chromatography-mass spectrometer (GC-MS-MS). Historical levels of ∑PAEs were higher than those of ∑OPEs in the Loire and the Moselle sediments, while ∑PAEs and ∑OPEs contents were of the same order of magnitude in the Meuse sediments. Although increases in concentrations do not evolve linearly, our results clearly indicate an increase in OPEs and PAEs concentrations from the 1950-1970 period onwards, compared with the first half of the 20th century. Our results show that, ∑OPE contents increase gradually over time in the Loire and Meuse rivers but evolve more randomly in the Moselle River. Trajectories of ∑PAEs depend on the river and no generality can be established, suggesting sedimentary reworking and/or local contamination. Data from this study allowed comparisons of contents of ∑OPEs and ∑PAEs between rivers, with ∑OPE concentrations in the Moselle River > Meuse River > Loire River, and concentrations of ∑PAEs in the Loire River > Moselle River > Meuse River. Among all PAEs, di(2-ethylhexyl) phthalate (DEHP) was the most abundant in all sediment samples, followed by diisobutyl phthalate (DiBP). Tris (2-chloroisopropyl) phosphate (TCPP) was the most abundant OPE in sediments of the three rivers. In addition, strong positive Pearson correlations were observed between organic matter (OM) parameters and OPE concentrations, and to a lesser extent, between OM parameters and PAE concentrations. This is particularly true for the Moselle River and for the Loire River, but less so for the Meuse River.

Occurrence and ecological risk assessment of 16 plasticizers in the rivers and estuaries in Japan

Owing to growing concerns about the adverse effects of phthalate plasticizers, non-phthalate plasticizers are being increasingly used as their replacement. However, information on the residual environmental concentrations and ecological risks posed by these plasticizers is limited. In this study, we analyzed the environmental contamination of 11 phthalates and 5 non-phthalate plasticizers in Class A and B rivers in Japan. In the considered river water samples, phthalates and non-phthalates were detected in the following order of detection frequency: phthalates (DEHP > DMP > DMEP > BBP > DNPP > DNP > DEEP > DBEP = DNOP) and non-phthalates (ATBC > DEHS > DEHA > TOTM = DIBA). Phthalate plasticizers were the most abundant and included DEHP (157-859 ng/L), DMP ( Collapse

Key Words

• acetyl tributyl citrate (ATBC)
• acute toxicity
• chronic toxicity
• di-(2-ethylhexyl) phthalate (DEHP)
• non-phthalate plasticizers
• phthalate plasticizer

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Affiliation(s)

Dorcas Uaciquete Research Center for Inland Seas (KURCIS), Kobe University, Fukaeminami-machi, Higashinada-ku, Kobe 658-0022, Japan.
Ayaka Sawada Faculty of Maritime Science, Kobe University, Fukaeminami-machi, Higashinada-ku, Kobe 658-0022, Japan
Takashi Chiba College of Agriculture, Food and Environment Sciences, Department of Environmental and Symbiotic Science, Rakuno Gakuen University, Japan
Espino Maria Pythias Institute of Chemistry, University of the Philippines Diliman, Quezon City, 1101, Philippines
Taisen Iguchi Graduate School of Nanobioscience, Yokohama City University, 22-2 Seto, Kanazawa-ku, Yokohama 236-0027, Japan
Yoshifumi Horie Research Center for Inland Seas (KURCIS), Kobe University, Fukaeminami-machi, Higashinada-ku, Kobe 658-0022, Japan

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Modulating responses of indicator genes in cellular homeostasis, immune defense and apoptotic process in the Macrophthalmus japonicus exposed to di(2-ethylhexyl) phthalate as a plastic additive

Di(2-ethylhexyl) phthalate (DEHP), have been increasingly used as plasticizers to manufacture soft and flexible materials and ubiquitously found in water and sediments in the aquatic ecosystem. The aim of the present study was to evaluate the effect of DEHP exposure on cellular homeostasis (HSF1 and seven HSPs), immune responses (ILF), and apoptotic responses (p53, BAX, Bcl-2). DEHP exposure upregulated the expression of HSF1 and ILF. Moreover, it altered the expression levels of HSPs (upregulation of HSP70, HSP90, HSP40, HSP83, and HSP67B2 and downregulation of HSP60 and HSP21) in conjunction with HSF1 and ILF in the gills and hepatopancreas of M. japonicus exposed to DEHP. At the protein level, DEHP exposure changed apoptotic signals in both tissues of M. japonicus. These findings indicate that chronic exposures to several DEHP concentrations could disturb cellular balance, damage the inflammatory and immune systems, and induce apoptotic cell death, thereby affecting the survival of M. japonicus.

Thyroid and sex hormone disrupting effects of DEHTP at different life stages of zebrafish (Danio rerio)

Di(2-ethylhexyl) terephthalate (DEHTP) is an alternative plasticizer widely used in numerous consumer products, replacing di(2-ethylhexyl) phthalate (DEHP). Hence, DEHTP has been frequently detected in the environment and humans. As a structural isomer and functional analog of DEHP, DEHTP is a suspected endocrine disruptor. Here, we evaluated thyroid-disrupting effects of DEHTP using embryo-larval and adult male zebrafish. We also investigated its sex hormone disruption potential in the adult zebrafish. After 5- and 7-days of exposure to DEHTP, significant increases in whole-body thyroid hormonal levels were observed in the larval fish. Down-regulation of several thyroid-regulating genes, including trh, tshβ, nis, and dio2, was observed, but only after 5-day exposure. Following a 21-day exposure, the adult male zebrafish exhibited a significant decrease in total triiodothyronine and an increase in thyroid-stimulating hormones. Potential changes in the deiodination of thyroid hormones, supported by the up-regulation of two deiodinases, dio1 and dio3a, along with the down-regulation of dio2, could explain the thyroid hormone changes in the adult zebrafish. Moreover, significant trends of decrease in estradiol and 11-ketotestosterone, along with increase of testosterone (T), were observed in the adult zebrafish. Up-regulation of several steroidogenic genes may explain elevated T, while exact mechanisms of action warrant further investigation. Our results demonstrate that DEHTP can cause disruptions of thyroid and sex hormones at different life stages in zebrafish.

Simultaneous targeted and non-targeted analysis of plastic-related contaminants in e-waste impacted soil in Agbogbloshie, Ghana

An LC-MS based analytical method was developed and validated for the simultaneous targeted analysis and suspect screening of plastic-related contaminants in e-waste impacted soils. Satisfactory recoveries (97 ± 13 %) were achieved using ultrasound-assisted extraction for 14/15 of the targeted analytes (7 bisphenols and 8 plasticizers) in a range of agricultural and non-agricultural soils. The method was applied to 53 soil samples collected in May 2015 in the region of Agbogbloshie (Ghana) at e-waste facilities (incl. Dump, trade, and burn sites), neighboring non-agricultural (incl. upstream, downstream, and community) and agricultural fields, and at two control agricultural sites away from e-waste recycling facilities. Bisphenol A (BPA) and bis(2-ethylhexyl) phthalate (DEHP) were the two dominant contaminants in e-waste soil (with concentrations up to 48.7 and 184 μg g-1, respectively), especially at the trade site, where e-waste was sorted and dismantled. The non-targeted workflow was successfully applied to identify additional plastic-related contaminants previously unreported in e-waste impacted soils, including bis(2-propylheptyl) phthalate, diisononyl phthalate, trioctyl trimellitate, 4-dodecylbenzenesulfonic acid, perfluorooctanesulfonic acid, perfluorobutanesulfonic acid, diphenyl phosphate, and triethylene glycol monobutyl ether. The agricultural soils surrounding the e-waste sites were also contaminated by plastic-related chemicals (especially DEHP), highlighting the impact of e-waste activities on the surrounding agricultural system.

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.

Pretreatment of marine sediment for the removal of di-(2-ethylhexyl) phthalate by sulfite in the presence of sorghum distillery residue-derived biochar and its effect on microbiota response

This study investigates the mechanism behind the oxidation di-(2-ethylhexyl) phthalate (DEHP) in marine sediment by coupling sulfite using biochar prepared from sorghum distillery residue (SDRBC). The rationale for this investigation stems from the need to seek effective methods for DEHP-laden marine sediment remediation. The aim is to assess the feasibility of sulfite-based advanced oxidation processes for treating hazardous materials such as DEHP containing sediment. To this end, the sediment in question was treated with 2.5 × 10-5 M of sulfite and 1.7 g L-1 of SDRBC700 at acidic pH. Additionally, the study demonstrated that the combination of SDRBC/sulfite with a bacterial system enhances DEHP removal. Thermostilla bacteria were enriched, highlighting their role in sediment treatment. This study concludes that sulfite-associated sulfate radicals-driven carbon advanced oxidation process (SR-CAOP) offers sustainable sediment pretreatment through the SDRBC/sulfite-mediated microbial consortium, in which the SO3•- and 1O2 were responsible for DEHP degradation. SDRBC/sulfite offers an effective and environmentally friendly method for removing DEHP. Further, these results can be targeted at addressing industry problems related to sediment treatment.

Responses of multifunctional immune complement component 1q (C1q) and apoptosis-related genes in Macrophthalmus japonicus tissues and human cells following exposure to environmental pollutants

Apoptosis is a key defense process for multiple immune system functions, playing a central role in maintaining homeostasis and cell development. The purpose of this study was to evaluate the effects of environmental pollutant exposure on immune-related apoptotic pathways in crab tissues and human cells. To do this, we characterized the multifunctional immune complement component 1q (C1q) gene and analyzed C1q expression in Macrophthalmus japonicus crabs after exposure to di(2-ethylhexyl) phthalate (DEHP) or hexabromocyclododecanes (HBCDs). Moreover, the responses of apoptotic signal-related genes were observed in M. japonicus tissues and human cell lines (HEK293T and HCT116). C1q gene expression was downregulated in the gills and hepatopancreas of M. japonicus after exposure to DEHP or HBCD. Pollutant exposure also increased antioxidant enzyme activities and altered transcription of 15 apoptotic signaling genes in M. japonicus. However, patterns in apoptotic signaling in response to these pollutants differed in human cells. HBCD exposure generated an apoptotic signal (cleaved caspase-3) and inhibited cell growth in both cell lines, whereas DEHP exposure did not produce such a response. These results suggest that exposure to environmental pollutants induced different levels of immune-related apoptosis depending on the cell or tissue type and that this induction of apoptotic signaling may trigger an initiation of carcinogenesis in M. japonicus and in humans as consumers.

Assessment of phthalic acid esters plasticizers in sediments of coastal Alabama, USA: Occurrence, source, and ecological risk

Considering the ubiquitous occurrences and ecotoxicity of phthalates (PAEs), it is essential to understand their sources, distribution, and associated ecological risks of PAEs in sediments to assess the environmental health of estuaries and support effective management practices. This study provides the first comprehensive dataset on the occurrence, spatial variation, inventory, and potential ecological risk assessment of PAEs in surface sediments of commercially and ecologically significant estuaries in the southeastern United States, Mobile Bay and adjoining eastern Mississippi Sound. Fifteen PAEs were widely detected in the sediments of the study region, with total concentrations varying between 0.02 and 3.37 μg/g. The dominance of low-molecular-weight (LMW) PAEs (DEP, DBP and DiBP) relative to high-molecular-weight (HMW) PAEs (DEHP, DOP, DNP) indicates that residential activities have stronger impacts than industrial activities on PAE distributions. The total PAE concentrations displayed an overall decreasing trend with increasing bottom water salinity, with the maximum concentrations occurring near river mouths. These observations suggest that river inputs were an important pathway by which PAEs were transported to the estuary. Linear regression models identified sediment adsorption (measured by total organic carbon and median grain size) and riverine inputs (measured by bottom water salinity) as significant predictors for the concentrations of LMW and HMW PAEs. Estimated 5-year total inventories of sedimentary PAEs in Mobile Bay and the eastern Mississippi Sound were 13.82 tons and 1.16 tons, respectively. Risk assessment calculations suggest that LMW PAEs posed a medium-to-high risk to sensitive aquatic organisms, and DEHP posed a low or negligible risk to the aquatic organisms. The results of this study provide important information needed for establishing and implementing effective practices for monitoring and regulating plasticizer pollutants in estuaries.

Composition, distribution, health risks, and drivers of phthalates in typical red paddy soils

The accelerated accumulation of phthalate esters (PAEs) in paddy soils poses a serious threat to human health. However, related studies mainly focus on facility vegetable fields, drylands, and orchards, and little is known about paddy soils. In this study, 125 samples were collected from typical red paddy fields to investigate the pollution characteristics, sources, health risks, and main drivers of PAEs. Soil physicochemical properties, enzyme activity, and bacterial community composition were also measured simultaneously. The results showed that eight PAE congeners were detected ranging from 0.17 to 1.97 mg kg-1. Di-n-butyl phthalate (DBP), di-(2-ethylhexyl) phthalate (DEHP), and di-isobutyl phthalate (DIBP) were the most abundant PAE congeners, accounting for 81% of the total PAEs. DEHP exhibited a potential carcinogenic risk to humans through the intake route. The main PAEs were positively correlated with soil organic matter (SOM) and soil water content (SWC) contents. Low levels of PAEs increased bacterial abundance. Furthermore, most PAE congeners were positively correlated with hydrolase activity. Soil acidity and nutrient dynamics played a dominant role in the bacterial community composition, with PAE congeners playing a secondary role. These findings suggest that there may be a threshold response between PAEs and organic matter and nutrient transformation in red paddy soils, and that microbial community should be the key driver. Overall, this study deepens the understanding of ecological risks and microbial mechanisms of PAEs in red paddy soils.

Spatial distribution and source identification of phthalates and organochlorine compounds in Galician mussels (NW Spain)

The spatial distribution of five phthalate esters (PAEs) and 17 organochlorine compounds (OCs) in wild and raft mussels from Galician littoral collected in 2020, and its relationship with anthropogenic activities was studied in this work. The Rías de Foz and Muros-Noia were the most polluted by PAEs, while the Rías de Ferrol and Barqueiro by PCBs. The highest levels of all contaminants were present in wild mussel, except DEHP that were predominant in raft mussel. The levels of most PAEs were negatively correlated with levels of the lower chlorinated PCBs and OCPs. The spatial distribution of pollutants confirmed by PCA was affected by the proximity to anthropogenic sources, phthalates by urban wastewater and PCBs by industrial inputs, mainly. The study of human exposure assessment suggests that Risk Quotient values were < 1, so the consumption of Galician raft mussels did not pose a risk to human health.

Co-occurrence of macroplastics, microplastics, and legacy and emerging plasticisers in UK soils

Despite a theoretical link between plastic and plasticiser occurrence in the terrestrial environment, there are few empirical studies of the relationship between these contaminants in soils. We carried out a field study to assess the co-occurrence of plastic waste, and legacy and emerging plasticisers in UK soils (n = 19) from various land uses (woodlands, urban roadsides, urban parklands, landfill-associated). Surface plastics and soil microplastics were quantified and characterised using ATR-FTIR and μ-FTIR. Eight legacy (phthalate) and three emerging (adipate, citrate, trimellitate) plasticisers were quantified using GC-MS. Surface plastics were found at higher prevalence at landfill-associated and urban roadside sites, with levels significantly (2 orders of magnitude) greater than in woodlands. Microplastics were detected in landfill-associated (mean 12.3 particles g^-1 dw), urban roadside (17.3 particles g^-1 dw) and urban parkland (15.7 particles g^-1 dw) soils, but not in woodland soils. The most commonly detected polymers were polyethene, polypropene and polystyrene. Mean ∑plasticiser concentration in urban roadside soils (3111 ng g^-1 dw) was significantly higher than in woodlands (134 ng g^-1 dw). No significant difference was found between landfill-associated (318 ng g^-1 dw) and urban parkland (193 ng g^-1 dw) soils and woodlands. Di-n-butyl phthalate (94.7% detection frequency) and the emerging plasticiser trioctyl trimellitate (89.5%) were the most commonly detected plasticisers, with diethylhexyl phthalate (493 ng g^-1 dw) and di-iso-decyl phthalate (96.7 ng g^-1 dw) present at the highest concentrations. ∑plasticiser concentrations were significantly correlated with surface plastic (R² = 0.23), but not with soil microplastic concentrations. Whilst plastic litter seems a fundamental source of plasticisers in soils, mechanisms such as airborne transport from source areas may be as important. Based on the data from this study, phthalates remain the dominant plasticisers in soils, but emerging plasticisers are already widespread, as reflected by their presence in all land uses studied.

Evaluation of cadmium and mercury on cardiovascular and neurological systems: Effects on humans and fish

Chemicals are at the top of public health concerns and metals have received much attention in terms of toxicological studies. Cadmium (Cd) and mercury (Hg) are among the most toxic heavy metals and are widely distributed in the environment. They are considered important factors involved in several organ disturbances. Heart and brain tissues are not among the first exposure sites to Cd and Hg but they are directly affected and may manifest intoxication reactions leading to death. Many cases of human intoxication with Cd and Hg showed that these metals have potential cardiotoxic and neurotoxic effects. Human exposure to heavy metals is through fish consumption which is considered as an excellent source of human nutrients. In the current review, we will summarize the most known cases of human intoxication with Cd and Hg, highlight their toxic effects on fish, and investigate the common signal pathways of both Cd and Hg to affect heart and brain tissues. Also, we will present the most common biomarkers used in the assessment of cardiotoxicity and neurotoxicity using Zebrafish model.

Pollution characteristics and health risk assessment of phthalate esters in agricultural soil of the Yellow River Delta, China

A total of 100 agricultural soil samples, collected in the Yellow River Delta, China, were analyzed for six U.S. Environmental Protection Agency priority phthalate esters (PAEs), focusing on the characteristics of PAEs contamination and potential health risks. The detection frequencies of ∑₆PAEs were 100%, where the concentration ranged from 1.087 to 14.391 mg·kg^-1, with a mean value of 4.149 mg·kg^-1. The most abundant PAEs were di(2-ethylhexyl) phthalate (DEHP) and di-n-butyl phthalate (DnBP). The areas with higher contents of ∑₆PAEs are distributed in the western and central parts of the Yellow River Delta region and around Laizhou Bay. PAEs in the Yellow River Delta agricultural soil were attributed to pollutant emissions from petrochemical industries, plasticizers or additives, fertilizers, and pesticides. The non-carcinogenic risk of human exposure to PAEs in agricultural soils is relatively low, but the non-carcinogenic risk is higher in children than in adults, and children are a sensitive group. Under the dietary route, both DEHP and ∑₂PAEs (BBP, and DEHP) pose some degree of carcinogenic risk to both local adults and children. Efforts must be made to enhance the prevention and control of PAEs contamination of agricultural soils in the Yellow River Delta region to reduce the potential risk to humans.

Seasonal variations of airborne phthalates and novel non-phthalate plasticizers in a test residence in cold regions: Effects of temperature, humidity, total suspended particulate matter, and sources

As a class of plasticizers widely used in consumer products, some phthalate esters (PAEs) have been restricted due to their adverse health effects and ubiquitous presence, leading to the introduction of alternative non-phthalates plasticizers (NPPs) to the market. However, few studies focus on the influence of environmental parameters on the presence of these plasticizers and the potential human health risks for people living in poorly ventilated indoor spaces in cold regions. We investigated the trends of PAEs and NPPs in air in a typical indoor residence in northern China for over one year. The air concentrations of PAEs were significantly higher than those of NPPs (p < 0.05), indicating that PAEs are still the dominant plasticizers currently being used in the studied residence. PAEs showed seasonal fluctuation patterns of the highest levels found in summer and autumn. The temperature and relative humidity dependence for most PAEs and NPPs decreased with decreasing vapor pressure. Concentrations of the high molecular weight NPPs and PAEs positively correlated with total suspended particles (TSP). It is worth noting that the peak concentrations of PAEs and NPPs were found when the haze occurred in autumn. Principal component analysis (PCA) suggested the diverse applications of PAEs and NPPs in the indoor environment. The hazard index (HI) values observed in this study were all below international guidelines (<1); however, the average carcinogenic risk (CR) values for some compounds exceeded acceptable levels (One in a million), which raised concerns about the possibility of carcinogenicity for people living indoors for long periods of time in cold regions.

Occurrence and seasonal variation of plasticizers in sediments and biota from the coast of Mahdia, Tunisia

Plasticizers are compounds often involved in the manufacturing of plastic products. Nevertheless, the ageing of the latter generates plasticizers that generally end up in the marine environment. In fact, marine pollution by phthalate acid esters (PAEs) and their alternatives has become an environmental and health issue of serious concern, as they are largely and ubiquitously present in the environment and aquatic organisms. In the present study, four PAEs, such as diethyl phthalate (DEP), diisobutyl phthalate (DiBP), dibutyl phthalate (DBP), and di(2-ethylhexyl) phthalate (DEHP), and one non-phthalate plasticizer (NPP), namely di-2-ethylhexyl terephthalate (DEHT), are wanted in different marine compartments from the coast of Mahdia in Tunisia such as sediment, seagrass, and mussel. The most abundant and frequently detected congener was DEHT at the concentrations reached 1.181 mg/kg in the sediment, 1.121 mg/kg in the seagrass, and 1.86 mg/kg in the mussel. This result indicates that the DEHT could emerge through the food chain and therefore bioaccumulate in marine compartments. In addition, we noticed that the seasonal variations of plasticizers were seriously affected by environmental factors including industrial and urban discharges.

Chemicals/materials of emerging concern in farmlands: sources, crop uptake and potential human health risks

Certain chemicals/materials that are contaminants of emerging concern (CECs) have been widely detected in water bodies and terrestrial systems worldwide while other CECs occur at undetectable concentrations. The primary sources of CECs in farmlands are agricultural inputs, such as wastewater, biosolids, sewage sludge, and agricultural mulching films. The percent increase in cropland area during 1950-2016 was 30 and the rise in land use for food crops during 1960-2018 was 100-500%, implying that there could be a significant CEC burden in farmlands in the future. In fact, the alarming concentrations (μg kg^-1) of certain CECs such as PBDEs, PAEs, and PFOS that occur in farmlands are 383, 35 400 and 483, respectively. Also, metal nanoparticles are reported even at the mg kg^-1 level. Chronic root accumulation followed by translocation of CECs into plants results in their detectable concentrations in the final plant produce. Thus, there is a continuous flow of CECs from farmlands to agricultural produce, causing a serious threat to the terrestrial food chain. Consequently, CECs find their way to the human body directly through CEC-laden plant produce or indirectly via the meat of grazing animals. Thus, human health could be at the most critical risk since several CECs have been shown to cause cancers, disruption of endocrine and cognitive systems, maternal-foetal transfer, neurotoxicity, and genotoxicity. Overall, this comprehensive review provides updated information on contamination of chemicals/materials of concern in farmlands globally, sources for their entry, uptake by crop plants, and their likely impact on the terrestrial food chain and human health.

Occurrence and distribution of phthalate esters and microplastics in wastewater treatment plants in Taiwan and their toxicological risks

Phthalate esters (PAEs) are fat soluble synthetic chemicals, usually regarded as plasticizers for being added in numerous plastic products. Thus, environmental and health hazards of PAEs are associated with increasing plastic pollution. In this study, PAEs from sludge samples collected from water, sewage, and industrial treatment plants (N = 17) were analyzed using Gas Chromatography/Mass Spectrometry. Microplastics (MPs) were also quantified and correlated with PAEs. Results showed the highest average PAE concentrations in sewage treatment plants. The greatest ΣPAEs concentration were found in sewage treatment plant (STP4) with 32,414 μg/kg dw, while the lowest found in water treatment plant (WTP3) with 2062 μg/kg dw. Among different PAEs, di-(2-ethyl hexyl) phthalate (DEHP) contributes the highest. Similarly, DEHP, di-n-octyl phthalate (DnOP) and diisononyl phthalate (DiNP) significantly correlated with the total PAEs indicating their large contribution to sludge contamination. The abundance of microplastics in sludge ranged between 1 and 7 MP/g, highest at ITP6, but not detected in some stations. While microplastics may potentially increase PAEs, there was no significant relationship between ΣPAEs and MP abundance. The estimated human daily intake of DEHP and di-n-butyl phthalate (DnBP) when contaminated sludge be used showed low toxicological risks to exposed adults. This research presents the sludge characteristics, PAEs, and microplastic concentrations in different wastewater treatment plants in Taiwan. PAE contamination was highly contributed by domestic and industrial wastes shown by their significant amounts in STP and ITP. Results further provide evidence for potential sludge recycling (WTP sludge) and application to soil.

Effects of phthalate esters on soil microbial community under different planting patterns in Northern China: Case study of Hebei Province

Soil microorganisms are biological factors involved in the farmland environment. The factors that shape soil microbial communities and how these are influenced by geographic location, planting pattern (open-field or greenhouse), and soil organic pollutants (phthalate esters, PAEs) remain poorly understood at large scales. Using 16 S rRNA gene and ITS sequencing, we characterized the soil microbiota in open-field and greenhouse soils in Hebei Province, China, and correlated their structure and composition to geographic location, planting pattern and PAEs. Compared with geographic location, planting pattern is more decisive for shaping soil microbes and has more significant effects on bacteria, and the effects are shaped by the number and types of core OTUs. PAEs participated in the shaping of soil microbial communities by altering the relative abundances of dominant microorganisms in the two planting patterns, and the effects of PAEs with high K_ow were more significant. PAEs have a greater impact on bacteria than fungi in both planting patterns. Bacteria in the greenhouse soil were sensitive to the 9 kinds of PAEs detected, however in the open-field samples, mainly responded to PAEs with high K_ow and rarely respond to PAEs with low K_ow. DEHP and DBP, as two monomers with the highest concentration, have significant effects on dominant genera of microorganisms under both planting patterns, with inhibiting effect on bacteria and significantly promotion on fungi. Our study clarified the factors that have a substantial impact on soil microorganisms at the provincial scale and the mechanisms involved in shaping soil microbial community structure, as well as the significant impact of PAEs on soil microbial dominant microorganisms.

Simultaneous assessment of organophosphate flame retardants, plasticizers, trace metals, and house dust mite allergens in settled house dust

Settled house dust (SHD) is a reservoir for various contaminants, including endocrine-disrupting chemicals (EDCs), trace metals, and house dust mite allergens. This study aimed to characterize various chemical and biological contaminants in SHD and identify determinants governing the indoor contaminants. In total, 106 SHD samples were collected from 106 houses in Seoul and Gyeonggi Province, Korea, in 2021. Bedding dust samples were collected from 30 of these 106 houses. All participants completed a questionnaire comprised of housing and lifestyle-related factors. The samples were analyzed for 18 organophosphate flame retardants (OPFRs), 16 phthalates, five alternative plasticizers (APs), seven trace metals, and two house dust mite allergens (Dermatophagoides farinae type 1 [Der f1] and Dermatophagoides pteronyssinus type 1 [Der p1]). A multiple regression analysis was conducted to identify the determinants governing the concentrations and profiles of various contaminants. OPFRs, phthalates, APs, and trace metals were detected in all SHD samples, indicating ubiquitous contamination in indoor environments. Among the three EDC groups, APs were detected at the highest concentrations (geometric mean [GM] (geometric standard deviation, [GSD]): 1452 (1.6) μg/g in total), followed by phthalates (GM (GSD): 676 (1.4) μg/g in total) and OPFRs (GM (GSD): 10 (1.4) μg/g in total). Der f1 was detected in all bedding dust samples with significantly higher levels than Der p1 (GM (GSD): 0.1 (1.8) μg/g vs. 1.4 × 10^-3 (2.3) μg/g). The concentrations of OPFRs, plasticizers, and trace metals in SHD were significantly associated with the type and number of electronic appliances and combustion activities. Der f1 was significantly associated with the number of occupants and water penetration. Ventilation, vacuum cleaning, and wet cleaning or dry mopping significantly reduced the levels of most contaminants in SHD. As residents are persistently exposed to a wide array of pollutants, comprehensive and adequate measures are required to prevent potential exposures.

Distribution and ecological risk assessment of phthalic acid esters in surface sediments of three rivers in Northern Vietnam

Pollution status and distribution characteristics of ten typical phthalic acid esters (PAEs) were investigated in 36 sediment samples collected from three rivers in Northern Vietnam from June to October 2020. The total concentrations of PAEs in sediment samples collected from the To Lich River (n = 9), the Nhue River (n = 12), and the Day River (n = 15) were in ranges of 11,000-125,000 ng/g-dwt (mean/median: 50,000/42,200 ng/g-dwt), 2140-89,900 ng/g-dwt (mean/median: 29,300/20,700 ng/g-dwt), and 1140-43,100 ng/g-dwt (mean/median: 13,800/10,400 ng/g-dwt), respectively. Among ten PAEs studied, di-(2-ethylhexyl) phthalate (DEHP) was found at the highest levels in all samples meanwhile dimethyl phthalate (DMP), diethyl phthalate (DEP), and dipropyl phthalate (DPP) were detected at low frequency and concentration. Significant correlations have existed between the median-chain (C₄-C₇) PAE pairs in sediment samples. Due to the high accumulation in the sediments, the median-chain PAEs had a higher ecological risk than the short-chain (C₁-C₃) PAEs. These contaminants may present a longstanding influence on organisms and ecosystems.

Non-covalent binding interaction between phthalic acid esters and DNA

The interaction of phthalic acid esters (PAEs) with DNA is known to be responsible for the disruption of endocrine functions and the teratogenic and carcinogenic effects. However, the binding strength and mechanism of this important process has often been neglected. Here, we confirmed the binding interaction between PAEs and DNA via fluorescence titration quenching experiment. The linear fitting curve proved that PAEs could bind to DNA, and the binding constants (K_A) were 4.11 × 10⁵, 1.04 × 10⁵, 7.60 × 10⁴, 1.99 × 10⁴, and 1.42 × 10³ L/mol for diethyl phthalate (DEP), bis(2-ethylhexyl) phthalate (DEHP), dibutyl phthalate (DBP), dimethyl phthalate (DMP), and benzyl butyl phthalate (BBP), respectively. DNA melting point, UV-vis spectra and Fourier transform infrared spectroscopy (FTIR) analyses revealed that PAEs interact predominantly with thymines in the DNA minor groove. Quantum chemical calculations showed that hydrogen bonding and van der Waals force formation between PAEs and DNA bases dominated the binding interaction. However, PAEs-DNA binding did not induce any DNA conformation change since the circular dichroism and FTIR spectra of B-DNA were not change. The electrostatic surface potential (ESP) might act an important role in PAEs-DNA binding interaction. This work will broaden our understanding of the interaction between PAEs and genetic materials.

Phthalates in the environment: characteristics, fate and transport, and advanced wastewater treatment technologies

Phthalates are well-known emerging contaminants that harm human health and the environment. Therefore, this review aims to discuss about the occurrence, fate, and phthalates concentration in the various environmental matrices (e.g., aquatic, sediment, soil, and sewage sludge). Hence, it is necessary to treat sources containing phthalates before discharging them to aqueous environment. Various advanced wastewater treatments including adsorption process (e.g., biochar, activated carbon), advanced oxidation processes (e.g., photo-fenton, ozonation, photocatalysis), and biological treatment (membrane bioreactor) have been successfully to address this issue with high removal efficiencies (70-95%). Also, the degradation mechanism was discussed to provide a comprehensive understanding of the phthalate removal for the reader. Additionally, key factors that influenced the phthalates removal efficiency of these technologies were identified and summarized with a view towards pilot-scale and industrial applications.

Legacy and alternative plasticizers in surface sediment of black-odorous urban rivers across China: Occurrence, spatial distribution, and ecological risk assessment

In this study, surface sediment samples from 173 black-odorous urban rivers in 74 cities of China were investigated regarding the occurrence, spatial distribution, and ecological risk of legacy phthalates (LPs) and alternative plasticizers (APs). The total concentrations of Σ₇LPs and Σ₆APs ranged from 0.0035 to 522 μg/g dw (median: 33 μg/g dw; mean: 60 μg/g dw) and from 0.0015 to 16 μg/g dw (median: 16 μg/g dw; mean: 2.2 μg/g dw), respectively. Di(2-ethylhexyl) phthalate (DEHP), di-n-butyl phthalate (DnBP), and di-iso-butyl phthalate (DiBP) were the dominant LPs, and di-iso-decyl phthalate and di-iso-nonylcyclohexane-1,2-dicarboxylate were the dominant APs. The concentrations and compositions of the LPs and APs varied among different sites and regions, implying location-specific use or production of LPs and APs. The pollutant concentrations in southern and central China were higher than those in northern China. Among the seven regions, Northwest China had the lowest concentrations of LPs and APs. This could be related to industry development level, municipal facilities, and population density. Total organic carbon (TOC) was significantly and positively correlated with the pollutant concentrations, implying that TOC could be an important influencing factor for the distribution of LPs and APs in sediments. The risk quotients of DiBP and DnBP in almost all sediment samples were above 1, indicating the high ecological risks to aquatic organisms. Nevertheless, DEHP, di-methyl phthalate, di-ethyl phthalate, and di-n-octyl phthalate showed low or moderate ecological risks for most sampling sites.

Occurrence, effects, and biodegradation of plastic additives in sludge anaerobic digestion: A review

The retention of microplastics, a complex blend of polymers and plastic additives (PAs), in municipal sludge has been reported. The inevitable release of PAs from microplastics might affect the subsequent biological disposal of sludge, and their final fate are of great public concern. Therefore, this review describes the current knowledge in the occurrence of PAs in sludge and significant advances in their effects on sludge anaerobic digestion (AD) and their biodegradation performance. Specifically, the compositions and contents of plasticizers, stabilizers, and flame retardants in sludge worldwide are systematically summarized. The discrepant impacts of PAs on hydrolysis, acidification, and methanogenesis processes are analyzed and compared, with corresponding trends deduced. Furthermore, the biodegradation performances of PAs during sludge AD are also discussed. For most of the PAs detected in sludge, available data for their fate and effects on AD is yet limited. Moreover, the potential role of AD microbes in the release of PAs from microplastics was still unknown. Especially, the potential effects of PAs released from biodegradable microplastics on sludge AD and their fate should be of concern. The obtained knowledge would update our understanding of the risk assessment and control of PAs in sludge AD. Recommendations for future investigation are made.

Severe contamination and time trend of legacy and alternative plasticizers in a highly industrialized lake associated with regulations and coastal development

Few studies have been conducted on aquatic contamination by alternative plasticizers. Phthalates and novel plasticizers were measured in sediments from a highly industrialized lake to assess occurrence, sources, time trends, and ecological risks. Legacy and alternative plasticizers were detected in all sediments. Di(2-ethylhexyl) phthalate (DEHP) was a predominant plasticizer, indicating its popular industrial consumption for the last two decades. Predominant novel plasticizers were changed over time. The highest sedimentary DEHP level was recorded on the global scale. Legacy and alternative plasticizers in creek sediments significantly increased from 2008 to 2016, while those from inshore and offshore regions of the lake significantly decreased in association with a dilution effect caused by the operation of a tidal power plant. Concentration ratios of alternative plasticizers to DEHP increased for the last decade, implying a shift in consumption of plasticizers. Sedimentary DEHP concentrations in creeks exceeded almost all threshold values associated with ecological risks.

Global trends and characteristics of nano- and micro-bubbles research in environmental engineering over the past two decades: A scientometric analysis

The present study has two primary goals, the first goal is to investigate a bibliometric analysis and assess the trends to evaluate the global scientific production of microbubbles and nanobubbles from 2000 to 2020. The aim is to elucidate the cornucopia of benefits the two technologies (micro and nanobubbles) can offer in environmental sciences and environmental amelioration such as wastewater treatment, seed germination, separation processes, etc. The second goal is to explicate the reason behind every chart and trend through environmental engineering perspectives, which can confer value to each analysis. The data was acquired from the Web of Science and was delineated by VOS viewer software and GraphPad Prism. Considering 1034 publications in the area of micro-and nanobubbles, this study was conducted on four major aspects, including publication growth trend, countries contribution assessment, categories, journals and productivity, and keywords co-occurrence network analysis. This article revealed a notable growth in microbubbles and nanobubbles-related publications and a general growth trend in published articles in a 20-year period. China had the most significant collaboration with other countries, followed by the USA and Japan. The most dominant categories for microbubbles were environmental sciences and environmental engineering comprising 22.5% of the total publications, while multidisciplinary subjects such as nanotechnology and nanosciences (8%) were among the dominant categories for nanobubbles. Keyword's analysis results showed that microbubbles had reached the apex since their discovery. Consequently, they are being used mostly in water/wastewater treatment or environmental improvement. On the other hand, nanobubbles are still in their infancy, and their pervasive use is yet to be fully materialized. Most of the publications are still striving to understand the nature of nanobubbles and their stability; however, a critical analysis showed that during the past two years, the trend of using nanobubbles as a cost-effective and environmentally friendly approach has already begun.

Contamination and human health risks of phthalate esters in vegetable and crop soils from the Huang-Huai-Hai region of China

The widespread presence of phthalate esters (PAEs) in a variety of agricultural inputs has led to PAE contamination in soils and farm products. The endocrine disruption and carcinogenicity of PAEs have attracted much attention. Our research investigated the characteristics of PAE pollution in the soils of vegetable fields and adjacent stable crop fields in four provinces/municipalities across a major agricultural production area in China. We found that the concentrations of PAEs in vegetable soils were not significantly higher than those in stable crop soils. The noncarcinogenic and carcinogenic risks from bis (2-ethylhexyl) phthalate (DEHP) and dibutyl phthalate (DBP) to humans were calculated to represent the risk posed by PAEs. The results showed that diet was the main route for noncarcinogenic risks from PAEs in crop soil and vegetable soils. Because of the combined effect of the population dietary structure and the concentration of PAEs in soils, the noncarcinogenic risks from PAEs in crop soils were similar to or higher than those in vegetable soils. The same pattern was also applicable to the carcinogenic risk from DEHP. Low noncarcinogenic and carcinogenic risks posed by DEHP and DBP indicated that the current level of PAEs in soils did not decrease the safety of agricultural products in the Huang-Huai-Hai region. Stable crop soil, as a non-negligibly phthalate-polluted area, is worthy of as much attention as vegetable soil. This study provides scientific support for food safety risk assessment and control of PAE pollution in the main agricultural production areas in China.

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.

Contamination and historical trends of legacy and emerging plasticizers in sediment from highly industrialized bays of Korea

Domestic and global regulations on phthalates have led to the introduction of non-phthalate plasticizers (NPPs) in industrial markets as alternative plasticizers. In this study, phthalates and NPPs from surface and core sediment samples taken from industrialized bays in Korea were measured to determine their distribution, contamination sources, historical records, and the ecological risks they posed. Phthalates and alternative plasticizers were detected in all surface samples and sediment cores, indicating ubiquitous contamination. Predominant phthalates were di(2-ethylhexyl)phthalate (DEHP), diisononyl phthalate (DiNP), and diisodecyl phthalate (DiDP) and di(2-ethylhexyl)terephthalate (DEHT) and tris(2-ethylhexyl)trimellitate (TOTM) were the most common NPPs. The total concentrations of phthalates and NPPs ranged from 76.3 to 59,400 ng/g dry weight and <0.02 to 35,300 ng/g dry weight, respectively. The highest concentrations of phthalates and NPPs were observed in sediment from rivers, streams, and inner parts of bays, with the levels decreasing gradually toward the outer parts of the bays. Our findings suggest that proximity to industrial complexes is crucial for sedimentary distribution for plasticizers. Historical records in a sediment core show clearly increasing trends in phthalate and NPP levels from the 1970s to the 2010s, consistent with their production history. In particular, TOTM has rapidly increased over the last decade, presenting an emerging concern of contaminant in the coastal environment. Industrialization and population growth were suggested as major factors affecting plasticizer contamination. Almost all sediment (>95%) exceeded quality guidelines for DEHP, implying a potential risk for benthic organisms. This is the first report on historical trends of phthalates and alternative plasticizers.

Exposure to phthalates and bisphenol analogues among childbearing-aged women in Korea: Influencing factors and potential health risks

Phthalates and bisphenol A (BPA), widely applied in industrial and consumer products, can affect hormones associated with the human reproductive system. Because the incidence of reproductive diseases is increasing, a comprehensive exposure assessment of phthalates and bisphenol analogues (BPs) is required for childbearing-aged women. Phthalate metabolites and BPs were measured in urine samples collected from 509 childbearing-aged women (20-48 years) in Korea to investigate their current exposure status, profiles, influencing factors, and potential health risks. DEHP metabolites and BPA were the dominant compounds found, indicating that they are highly consumed in daily life. Bisphenol S (BPS), as an alternative to BPA, was detected in most urine samples. Total concentrations of phthalate metabolites and BPs ranged from 3.42 to 3570 (GM: 45.6) ng/mL and from <LOQ to 80.3 (0.91) ng/mL, respectively, which were within the ranges observed in women in previous studies. Exposure to diethyl phthalate (DEP) was significantly associated with the use of cosmetics and personal care products such as perfume, body lotion, and sunscreen. Higher ratios of urinary BPS/BPA were observed in younger and more highly educated women and in women living in urbanized regions than others. This result suggests that a shift in consumption from BPA to BPS was preferentially occurring in urbanized regions. The assessment of the cumulative risk posed by phthalates and BPs showed that they pose only a small health risk to Korean women. This study provides baseline data on exposure levels, profiles, and influencing factors for phthalates and BPs in childbearing-aged women.

Phthalates and non-phthalate plasticizers in Tunisian marine samples: Occurrence, spatial distribution and seasonal variation

Seawater, sediment, seagrass and fish from several sites along the Tunisian coast were monitored for several phthalate esters (PAEs) and non-phthalate plasticizers (NPPs) during 2018-2019. In water and sediment, NPPs were higher than PAEs, being di(2-ethylhexyl) phthalate (DEHP, 0.0717 and 4.59 μg/g), and di(2-ethylhexyl) terephthalate (DEHT, 0.634 and 2.42 μg/g) most abundant. As expected, sediments acted as a sink for plasticizers, thus revealing a stronger contamination than water. Seagrass was less contaminated than fish, being DEHP (0.726 and 1.77 μg/g) and DEHT (9.19 and 23.2 μg/g) predominant. Biota poorly concentrated/accumulated plasticizers from water and sediment depending on the logK_oct/wat and water solubility of single congeners. The spatial distribution of plasticizers was affected by the proximity to anthropogenic sources and the rate of coastal currents; whereas their seasonal variation may be related to the length of time of touristic/industrial inputs and factors such as rainfall and urban stormwater runoff.

Large scale micropollutants and lipids screening in the sludge layers and the ecosystem of a vertical flow constructed wetland

Wastewater is one of the major sources of micropollutant release into the environment. In order to reduce the impact of wastewater, wastewater treatment plants (WWTP) have been set up, in the instance of vertical flow constructed wetlands (VFCWs). Besides, micropollutants could represent a vast diversity of compounds and compound's choice could bias studies focused on their fate. To overcome this bias, non-targeted screening approaches can be performed. Therefore, the diffusion of micropollutants from raw wastewater in the VFCW compartments (wastewater, plants and sludge) as well as their fate have been investigated using this non-target approach with liquid chromatography (LC) coupled to high resolution mass spectrometry (HRMS) and gas chromatography (GC) coupled to mass spectrometry. To help the operators in their sludge management, this study will be focused on the following question: Is there a specific distribution of micropollutants according to sludge layers? To eliminate the background contamination found both inside the CW and in the surrounding environment, a control coring was performed in bank. A specific distribution could be observed in the top (191 compounds) and bottom layers (38 compounds). However, a distribution over the whole depth for xenobiotics was observed. Micropollutants classes and the main microbial productivity were preferably found in the top layer. The micropollutants fate could however not be restricted to the sludge compartment. Therefore, the specific micropollutants distribution was analyzed in the outputs of the system in their interactions with wastewater (effluent, sludge, and reed rhizomes) to understand their fate. In our study, the results highlighted a consistent part of compounds found in at least two or three of these compartments, with a similar trend in each compartment. These results underline the interactions between the compartments and the global issues of micropollutants distribution as well as its wide spreading in the whole CW ecosystem.

Gaseous emissions from wastewater facilities

A review of the literature published in 2019 on topics relating to gaseous emissions from wastewater facilities is presented. This review is divided into the following sections: odorant emissions from Water Resource Recovery Facilities (WRRFs); greenhouse gas (GHG) emissions; gaseous emissions from wastewater collection systems; physiochemical odor/emissions control methods; biological odor/emissions control methods; odor/GHG characterization and monitoring; and odor impacts/risk assessments. © 2020 Water Environment Federation PRACTITIONER POINTS: Provide a quick reference list for readers who do not have time to go through the 2019 published articles. This prescreening of relevant literatures will save them time and effort. Utilities, engineers, and researchers can identify knowledge gaps, which help them to plan for future testing and R&D needs. Designers can make use of the lit review findings to support their design.

Pollution characteristics and health risk assessment of phthalate esters in agricultural soil and vegetables in the Yangtze River Delta of China

As an important environmental reservoir of phthalate esters (PAEs), soil-plant system constitutes a key exposure pathway to human health. In this study, agricultural soil and vegetable samples were collected from the Yangtze River Delta (approximately 211,700 km²), one of the most developed regions in China, to determine the contamination characteristics of priority PAEs. The total concentrations of six PAEs ranged from 5.42 to 1580 ng·g^-1 dry weight in soils and from 10.9 to 16,400 ng·g^-1 dry weight in vegetables. Di-(2-ethylhexyl) phthalate (DEHP) accounted for 88.3% and 61.9% of the total PAEs in soils and vegetables, respectively. The spatial distribution of PAEs in the soils was as follows: Shanghai city (70.8-1583 ng·g^-1 dw) > Anhui province (46.8-1530 ng·g^-1 dw) > Jiangsu province (14.4-558 ng·g^-1 dw) > Zhejiang province (5.40-488 ng·g^-1 dw). Non-cancer risks exist for adults and children in 6.5% and 7.8% of the sites, respectively. Carcinogenic risks were regarded unacceptable in 5.6% and 1.3% of the sites for adults and children, respectively. The bioconcentration factor (BCF) of PAEs showed positive correlation with lipid content of vegetables. A basic reference of the lipid-content threshold to guarantee the safety of leafy vegetables was proposed based on partition-limited model. We suggested to cultivate vegetables with lipid content <0.21% in most heavily contaminated area in the region. This study provides information for effectively controlling PAEs contamination in soil-plant system in developed districts.

Phthalates and non-phthalate plasticizers in sediment from Korean coastal waters: Occurrence, spatial distribution, and ecological risks

Due to regulations on phthalates, non-phthalate plasticizers (NPPs) are now used as an alternative. Limited studies have been conducted on the occurrence and distribution of NPPs. In this study, sediment samples were collected from 50 locations along the Korean coast to assess the occurrence, distribution, sources, and ecological risks of phthalates and NPPs. Phthalates and NPPs were detected in all sediments, indicating ubiquitous contamination of the coastal environment. Di(2-ethylhexyl)phthalate (DEHP) and di(2-ethylhexyl)terephthalate (DEHT) were dominant, suggesting that DEHT could be an emerging contaminant of concern. The highest concentrations of phthalates and NPPs were found in sediment samples from harbors, implying they are contaminated hotspots. Sedimentary organic carbon was a major factor governing the distribution of phthalates and NPPs. Significant correlations were observed among phthalates and NPPs, suggesting similar sources and geochemical behavior. DEHP concentration exceeded threshold values, indicating potential health risks to benthic organisms in sediments.

Effects of di-(2-ethylhexyl) phthalate on Transcriptional Expression of Cellular Protection-Related HSP60 and HSP67B2 Genes in the Mud Crab Macrophthalmus japonicus

Di-2-ethylhexyl phthalate (DEHP) has attracted attention as an emerging dominant phthalate contaminant in marine sediments. Macrophthalmus japonicus, an intertidal mud crab, is capable of tolerating variations in water temperature and sudden exposure to toxic substances. To evaluate the potential effects of DEHP toxicity on cellular protection, we characterized the partial open reading frames of the stress-related heat shock protein 60 (HSP60) and small heat shock protein 67B2 (HSP67B2) genes of M. japonicus and further investigated the molecular effects on their expression levels after exposure to DEHP. Putative HSP60 and small HSP67B2 proteins had conserved HSP-family protein sequences with different C-terminus motifs. Phylogenetic analysis indicated that M. japonicus HSP60 (Mj-HSP60) and M. Japonicus HSP67B2 (Mj-HSP67B2) clustered closely with Eriocheir sinensis HSP60 and Penaeus vannamei HSP67B2, respectively. The tissue distribution of Heat shock proteins (HSPs) was the highest in the gonad for Mj-HSP60 and in the hepatopancreas for Mj-HSP67B2. The expression of Mj-HSP60 Messenger Ribonucleic Acid (mRNA) increased significantly at day 1 after exposure to all doses of DEHP, and then decreased in a dose-dependent and exposure time-dependent manner in the gills and hepatopancreas. Mj-HSP67B2 transcripts were significantly upregulated in both tissues at all doses of DEHP and at all exposure times. These results suggest that cellular immune protection could be disrupted by DEHP toxicity through transcriptional changes to HSPs in crustaceans. Small and large HSPs might be differentially involved in responses against environmental stressors and in detoxification in M. japonicus crabs.

Occurrence, distribution, and sources of phthalates and non-phthalate plasticizers in sediment from semi-enclosed bays of Korea

Due to strong regulation of phthalates, non-phthalate plasticizers (NPPs) have been introduced to the industrial market. In this study, concentrations of 16 phthalates and five NPPs in sediment were measured to investigate the occurrence, potential source, and ecotoxicological implications of these contaminants. Phthalates and NPPs were detected in all sediment samples, indicating ubiquitous contaminants. Di(2-ethylhexyl)phthalate (DEHP) and trioctyl trimellitate (TOTM) were the dominant for phthalates and NPPs, respectively, implying emerging contamination by TOTM. Spatial distribution of these contaminants showed decreasing gradients from inner to outer bays. Clear declining trends in phthalate and NPP concentrations were found in sediment near a wastewater treatment plant outfall, suggesting a potential source of contamination. Approximately 95% of sediment samples exceeded sediment quality guidelines for DEHP suggested by previous studies, implying that benthic organisms are suffering from adverse biological effects. This is the first report on the occurrence of NPPs in the coastal environment.