Assessing microplastic ingestion and occurrence of bisphenols and phthalates in bivalves, fish and holothurians from a Mediterranean marine protected area

Microplastic (MP) ingestion, along with accumulated plasticizers such as bisphenol A (BPA), bisphenol F (BPF), and bisphenol S (BPS), and phthalates represented by diethyl phthalate (DEP), dibutyl phthalate (DBP) and bis (2-ethylhexyl) phthalate (DEHP), were quantified in bivalves, fish, and holothurians collected from a coastal pristine area at the western Mediterranean Sea. MP ingestion in sediment-feeders holothurians (mean value 12.67 ± 7.31 MPs/individual) was statistically higher than ingestion in bivalves and fish (mean 4.83 ± 5.35 and 3 ± 4.44 MPs/individual, respectively). The main ingested polymers were polyethylene, polypropylene, and polystyrene. The levels of BPS, BPF, and DEHP were highest in bivalves' soft tissue; BPA and DBP had the highest levels in the holothurians' muscle. In addition, the levels of all plasticizers assessed were lowest in fish muscle; only BPA levels in fish were higher than in bivalves, with intermediate values between those of bivalves and holothurians. This study provides data on exposure to MPs and plasticizers of different species inhabiting Cabrera Marine Protected Area (MPA) and highlights the differences in MP ingestion and levels of plasticizers between species with different ecological characteristics and feeding strategies.

Using fluorescence and circular dichroism (CD) spectroscopy to investigate the interaction between di-n-butyl phthalate and bovine serum albumin

The interaction between di-n-butyl phthalate (DBP) and bovine serum albumin (BSA) in physiological Tris-HCl buffer at pH 7.4 was investigated by fluorescence quenching technique. By analyzing the fluorescence spectrum and intensity, it was observed that the DBP had a strong ability to quench the intrinsic fluorescence of BSA through a static quenching procedure. The binding constants K and the number of binding sites n of DBP with BSA were calculated to be 0.11 × 10² L·mol^-1 and 0.52 at 298 K, respectively. The thermodynamic parameters of enthalpy change (ΔH) and entropy change (ΔS) were also calculated to be positive showing that hydrophobic forces might play a major role in the binding of DBP to BSA. The binding process was spontaneous in which Gibbs free energy change (ΔG) was negative. The distance (r) between the donor (BSA) and acceptor (DBP) was calculated to be 2.02 nm based on Forster's non-radiative energy transfer theory, which indicated that the energy transfer from BSA to DBP occurs with a high possibility. The synchronous fluorescence, three-dimensional fluorescence, and circular dichroism (CD) spectra showed that the binding of di-n-butyl phthalate to BSA induced conformational changes in BSA. The interaction between DBP and BSA can help researchers better understand the nature of poisons and serve people in the right way with first aid and detoxification.

Occurrence and Risk Assessment of Personal PM2.5-Bound Phthalates Exposure for Adults in Hong Kong

We performed personal PM_2.5 monitoring involving 56 adult residents in Hong Kong. Additionally, paired personal and residential indoor fine particle (PM_2.5) samples were collected from 26 homes and from 3 fixed monitoring locations (i.e., outdoor samples). Six PM_2.5-bound phthalate esters (PAEs)-including dimethyl phthalate (DMP), diethyl phthalate (DEP), di-n-butyl phthalate (DnBP), butyl benzyl phthalate (BBP), di(2-ethylhexyl) phthalate (DEHP), and di-n-octyl phthalate (DnOP)-were measured using a thermal desorption-gas chromatography/mass spectrometer method. Average ∑₆PAEs (i.e., summation of six PAE congeners) concentrations in personal PM_2.5 exposure (699.4 ng/m³) were comparable with those in residential indoors (646.9 ng/m³), and both were slightly lower than the outdoor levels. DEHP was the most abundant PAE congener (80.3%-85.0%) and found at the highest levels in different exposure categories, followed by BBP, DnBP, and DnOP. Strong correlations were observed between DEHP with DnBP (r_s: 0.81-0.90; p < 0.01), BBP (r_s: 0.81-0.90; p < 0.01), and DnOP (r_s: 0.87-0.93; p < 0.01) in each exposure category. However, no apparent intercorrelations were shown for PAE congeners. Higher indoor concentrations and a stronger correlation between DMP and DEP were found compared with outdoor concentrations. Principal component analysis affirmed heterogeneous distribution and notable variations in PAE sources across different exposure categories. The average daily intakes of ∑₆PAEs and DEHP via inhalation were 0.14-0.17 and 0.12-0.16 μg/kg-day for adults in Hong Kong. A time-weighted model was used to estimate PAE exposures incorporating residential indoor and outdoor exposure and time activities. The inhalation cancer risks attributable to measured and estimated personal exposure to DEHP exceeded the U.S. EPA's benchmark (1 × 10^-6). The results provide critical information for mitigation strategies, suggesting that PAEs from both ambient and indoor sources should be considered when exploring the inhalation health risks of PAEs exposure.

Effect of plastic pollution on freshwater flora: A meta-analysis approach to elucidate the factors influencing plant growth and biochemical markers

The deterioration in the water quality of urban water bodies through plastic contamination is emerging as a matter of serious concern. Microplastics (MPs) and nanoplastics (NPs) both affect the growth and productivity of aquatic flora. However, there have been a lot of variations in the reported studies which calls for revisiting the results with an analytical approach. Therefore, this study was designed to systematically evaluate the publications based on PRISMA (2020) guidelines. In this connection, 43 eligible articles were selected for meta-analysis followed by subgroup analysis to determine the impact of size, concentration, plastic polymers, and effect of plant classes on several physiological and biochemical parameters (growth, chlorophyll-a, carotenoids, protein, and antioxidant enzymes). The results indicated that the higher concentrations of plastics negatively affected the growth, and also enhanced the protein content and antioxidative enzyme activity. While, NPs were found to impart an inhibitory effect on pigment contents, along with a significant increase in protein content and antioxidative enzyme activity. Among the plastic polymers, dibutyl phthalate (DBP) showed a comparatively higher effect on growth, whereas the photosynthetic pigments were disrupted to a greater extent in the presence of polyvinyl chloride (PVC) plastics. Moreover, the growth parameters under plastic exposure were affected in the algal members to a greater extent in comparison to the other plant groups. Lastly, several plants like Komvophoron, Elodea, Myriophyllum, Nostoc, Raphidocelis, Scenedesmus, Utricularia, Dunaliella, and Lemna appeared to be more tolerant than others (Tolerance Index ≥ 0.8), showing a significantly minimal effect on growth inhibition.

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.

[Accumulation Characteristics and Sources of PAEs in Agricultural Soils in Gansu Province]

In order to understand the composition and accumulation characteristics of phthalates esters (PAEs) in agricultural soils in Gansu province, a total of 41 soil samples from four agricultural soils in Gansu province were collected, and the content of six PAEs compounds was analyzed using a gas chromatography-single quadrupole mass spectrometer (GC-MS). The results showed that the average value of PAEs compounds in agricultural soils in Gansu province was 432.4 μg·kg^-1. The detection rates of DMP, DEP, DnBP, DEHP, and DNOP in the soil were 100%, and BBP was not detected. The order of the average value of PAEs content in the four agricultural soils in Gansu province was:greenhouse>farmland (open field)>forest>grassland. The exceeding rates of dibutyl phthalate (DnBP), dimethyl phthalate (DMP), and dimethyl phthalate (DEP) were 94%, 28%, and 27%, and the remaining three did not exceed the standard. The composition of PAEs in different agricultural soils was different due to their different sources. DEHP and DnBP components in the six different PAEs monomers accounted for a higher proportion and were the main pollutants of PAEs in agricultural soils in Gansu province. In this study, the contents of soil PAEs and DEHP were significantly positively correlated with the residual amount of mulch film in the farmland (P<0.05). In general, the content of soil PAEs in the Hexi area of Gansu province was significantly higher than that in the Longdong area.

Phthalates released from microplastics inhibit microbial metabolic activity and induce different effects on intestinal luminal and mucosal microbiota

The intestine is not only the main accumulation organ of microplastics (MPs), but also the intestinal environment is very conductive to the release of additives in MPs. However, the kinetics of release process, influence factors, and the related effects on gut microbiota remain largely unknown. In this study, a mucosal-simulator of the human intestinal microbial ecosystem (M-SHIME) was used to investigate the influence of gut microbiota on the release of phthalates (PAEs) from MPs and the effects of MPs on the intestinal luminal microbiota and mucosal microbiota. We found that di-(2-ethylhexyl) phthalate (DEHP), di-n-butyl phthalate (DBP), and dimethyl phthalate (DMP) were the dominant PAEs released in the gut. Gut microbiota accelerated the release of PAEs, with the time to reach the maximum release was shortened from 7 days to 2 days. Moreover, MPs induced differential effects on luminal microbiota and mucosal microbiota. Compared with mucosal microbiota, the luminal microbiota was more susceptible to the leaching of PAEs from MPs, as evidenced by more microbiota alterations. MPs also inhibited the metabolic activity of intestinal flora based on the reduced production of short chain fatty acids (SCFA). These effects were mainly contributed by the release of PAEs. Acidaminococcus and Morganella were simultaneously correlated to the release of PAEs and the inhibition of metabolic activity of intestinal microbiota and can be used as indicators for the intestinal exposure of MPs and additives.

Development of Ag/Ag2O/ZnO photocatalyst and their photocatalytic activity towards dibutyl phthalate decomposition in water

The photocatalyst Ag/Ag₂O-modified ZnO, fabricated by a simple one-step calcination method, was applied into the degradation of organic pollutant dibutyl phthalate (DBP). Ag/ZnO and Ag₂O/ZnO were prepared as a reference comparison. The prepared catalysts were evaluated by scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), BET surface area measurement, and photoluminescence spectra (PL) and UV-Vis diffuse reflectance spectroscopy (DRS) and electrochemical measurements. After the irradiation with ultraviolet light (352 nm), the solution was sampled and subjected to HPLC to evaluate the degradation efficiency of DBP. Ag/Ag₂O/ZnO showed the best results with the excellent degradation of DBP. Ag/Ag₂O/ZnO was four times more efficient, relative to zinc oxide alone. According to photocatalyst characterization, the total pore volume of photocatalyst was improved by loading Ag and Ag₂O, suggesting an increase in the active sites. Also, the efficient electron transfer of Ag/Ag₂O/ZnO was mainly responsible for the enhanced activity. The reaction mechanism for Ag/Ag₂O/ZnO was determined to become a Z-scheme. From the radical scavenger tests, the main active species was identified as superoxide radicals. The stability of Ag/Ag₂O/ZnO could be confirmed after five cycling reutilization. It was found from the radical scavenger test that •O₂ ^- play an important role as the main reactive species in the photocatalytic degradation of DBP. Consequently, Ag/Ag₂O/ZnO with a simple fabrication method seems to become one of the powerful photocatalyst for the photocatalytic degradation of organic pollutant in water.Implications: This study discusses the usefulness of Ag/Ag₂O/ZnO composites. This photocatalyst could be an approach to solve the environmental pollution caused by organic pollutants, which is a growing problem all over the world. In addition, the highly efficient photocatalyst Ag/Ag₂O/ZnO is an inexpensive and reusable catalyst with great practical potential.Furthermore, to the best of our knowledge, there are very few reports that have examined the combination of Ag, Ag₂O and ZnO. In addition, the photocatalytic mechanism has not been understood. Here, we introduce Ag into Ag₂O/ZnO to improve the photocatalytic performance and photostability, enhance the activity, and elucidate the mechanism of Ag/Ag₂O/ZnO.

Pollution Characteristics and Health Risk Assessment of Phthalate Esters in PSW Recycling Sites: A Typical Case Study

The concentrations of six priority phthalate esters (PAEs) in 700 soil samples and 110 sediment samples from an area in China containing plastic solid waste (PSW) recycling sites were determined. The total concentrations of the six PAEs in soil and sediment were not detected - 274 and not detected - 597 mg kg^-1, respectively, and the mean concentrations in soil and sediment were 14.4 and 31.7 mg kg^-1, respectively. The dominant PAEs were di(2-ethylhexyl) phthalate and di-n-butyl phthalate. PAEs were detected in soil collected from the surface to 0.5 m below ground level around the PSW recycling sites, and the concentrations were markedly higher in these areas than at other polluted sites. PSW recycling is an important source of PAEs to soil and sediment. The di(2-ethylhexyl)phthalate concentrations in soil were higher than the relevant concentrations that pose environmental risks for sensitive land uses and non-sensitive land uses (42 and 121 mg kg^-1, respectively), indicating emissions of PAEs from PSW recycling sites may pose environmental risks. The results indicate that PAE pollution at PSW sites needs to be better controlled and managed.

The effects of salinity, temperature, and UV irradiation on leaching and adsorption of phthalate esters from polyethylene in seawater

In this study, the leaching of six phthalic acid esters (PAEs) from three common consumer plastics was investigated: low and high density polyethylene (LDPE, HDPE) and recycled polyethylene (RP). The effects of salinity, temperature, and ultraviolet irradiation (UVR) on leaching were investigated. The study of leaching of phthalates in aqueous environments in batch experiments is challenging due to their readsorption by the high hydrophobicity of PAEs, and there are no standard methods to study release processes. Here with the experiments, leaching (A) and spiking (B) using six PAEs to study the readsorption in the leaching process. PAEs were identified and quantified using GC-MS. Dibutyl phthalate (DBP) and benzyl butyl phthalate (DEHP) showed considerable leaching during the 5-day incubation: 14 ± 1 to 128 ± 14 and 25 ± 2 to 79 ± 5 ng/cm², respectively, under UVR, corresponding approximately to (1.9-13%) and (12.4-22.4%) of the solvent extracted mass. The highest K_d values were measured for RP polymers (0.3-9.4), followed by LDPE (0.5-5.4) and HDPE (0.2-2.2) polymers. Thus, readsorption of PAEs at the surface removed 30-80% of the leached PAEs in the dissolved phase. For example in LDPE, the calculated total release of DBP was up to 54 ± 4 ng/cm², while the dissolved amount was 8.5 ± 1 ng/cm² during the 5-day incubation under freshwater conditions. Increasing salinity negatively affected the leaching rate, which decreased for DBP from 54 ± 4 ng/cm² in freshwater to 44 ± 3 and 38 ± 3 ng/cm² at salinity of 20 and 40 g/L, respectively, from LDPE during the 5-day incubation. Temperature and UVR had a positive effect on the leaching rate, with the release of DBP from LDPE increasing from 44 ± 3 ng/cm² at room temperature (25 °C) to 60 ± 6 and 128 ± 14 ng/cm² at high temperature (40 °C) and UVR, respectively. Overall, this study highlights the positive relationship between temperatures, UVR on the extent of leaching and surface adsorption on the leaching measurements.

National-scale urinary phthalate metabolites in the general urban residents involving 26 provincial capital cities in China and the influencing factors as well as non-carcinogenic risks

Phthalates (PAEs) are widely used in daily products but can cause a variety of adverse effects in humans. Few studies have been carried out on human internal exposure levels of PAEs on a large-scale, especially in developing countries. In the present study, 1161 urine samples collected from residents of 26 provincial capitals in China were analyzed for nine phthalate metabolites (mPAEs). The chemicals were widely detected, and the median specific gravity adjusted urinary concentration of Σ₉mPAEs was 278 μg/L. Di-(2-ethylhexyl) phthalate (DEHP) and di-n-butyl phthalate (DnBP) were the main parent PAEs that the residents were exposed to. Demographic characteristics, such as age and educational level, were significantly associated with PAE exposure. Children and the elderly had higher mPAE levels. Subjects with lower educational levels were more frequently exposed to DnBP and DEHP. However, mono-ethyl phthalate showed the opposite trend, i.e., higher concentrations in subjects aged 18-59 years and with higher educational levels. Geographic differences were detected at the national scale. Residents in northeastern and western China had higher levels of mPAEs than those in central China, most likely because of different industrial usage of the chemicals and different living habits and living conditions of the residents. Health risk assessment showed that hazard indices of PAEs ranged from 0.07 to 9.34, with 20.0% of the subjects being concern for potential non-carcinogenic risk as assessed by Monte Carlo simulation. DEHP and DnBP were the primary contributors, representing 96.7% of total risk. This first large-scale study on PAE human internal exposure in China provides useful information on residents' health in a developing country, which could be used for chemical management and health protection.

Effects of di-n-butyl phthalate on aerobic composting process of agricultural waste: Mainly based on bacterial biomass and community dynamics analysis

Phthalic acid esters (PAEs) pollution has become a major environmental problem in agricultural waste composting. However, little information was available about the how the PAEs alter microbial processes during composting. This study investigated the effects of di-n-butyl phthalate (DBP) on bacterial biomass and community dynamics during composting. The results showed that a decreasing of DBP was observed from thermophilic phase and 43.26% of DBP was degraded after composting. The bacterial biomass and diversity during composting were reduced under DBP stress, so delaying the decomposition of organic matter. Moreover, the changes in bacterial community were observed since the thermophilic phase of DBP-contaminated composting. KEGG pathway analysis indicated that DBP stress decreased the relative abundance of the main metabolic pathways and inhibited compost maturation. Moreover, DBP stress had more significant correlation with the dominant bacteria. This work will expand the understanding of PAEs-contaminated organic waste composting and further control of PAEs pollutants.

Occurrence of Phthalate Acid Esters (PAEs) in Protected Agriculture Soils and Implications for Human Health Exposure

This study explored occurrence of phthalic acid esters (PAEs) in protected agriculture soils and assessed their potential health risks to humans. Results showed that DEHP and DBP were the most abundant PAEs congeners, with mean concentrations of 318.68 μg/kg and 137.56 μg/kg, respectively. DOP and BBP concentrations were relatively low, and DMP and DEP were not detected in all samples. DBP concentrations were higher than the allowable concentration standard value. Additionally, soil pH and organic matter were key environmental parameters which may play the vital roles to the occurrence of organic pollutants. Heath risk assessment results indicated that dermal contact was the predominant human exposure route under non-dietary conditions, and children obtained higher health risk scores than adults. In summary, the overall health risk scores were at an acceptable level. These results provide insights for assessing soil environmental safety and ecological risks in protected agricultural soil.

Spatiotemporal variation and risk assessment of phthalate acid esters (PAEs) in surface water of the Yangtze River Basin, China

Spatiotemporal variation, potential sources, and risk assessment of phthalate acid esters (PAEs) in surface water of the Yangtze River Basin were investigated. Total cumulative concentrations of 15 PAEs (Σ₁₅PAEs) ranged from 1594.47 ng·L^-1 to 5155.50 ng·L^-1, and the dominant components were di (2-ethylhexyl) phthalate (DEHP) (35.9-60.1%), dibutyl phthalate (DBP) (16.6-38.8%), and diisobutyl phthalate (DIBP) (6.7-18.2%). Σ₁₅PAEs in surface water showed a trend of normal season > wet season > dry season. Σ₁₅PAEs increased from the upstream (2341.7 ± 428.5 ng·L^-1) to the mid- and downstream (3892.1 ± 842.8 and 2504.3 ± 355.9 ng·L^-1, respectively), indicating the influence from production and consumptions of plasticizer-containing items. PAEs additives emission from daily necessities (28.9-62.3%) and construction and industrial production (18.7-31.2%) were the dominant sources of PAEs in this study. The risk quotient (RQ) method was employed to assess the potential ecological risk of specific components. High ecological risk of DEHP to the sensitive algae and crustacean, together with moderate ecological risk of DEHP and DIBP to the sensitive fish species were found in surface water regardless of the region and season. The spatial distribution of RQ values showed an increasing trend from the upstream to the midstream and downstream of the Yangtze River, indicating the influences from regional urbanization and industrialization levels.

Di-n-butyl phthalate negatively affects humic acid conversion and microbial enzymatic dynamics during composting

To understand the effects of phthalic acid esters (PAEs) on humic acid (HA) conversion, enzymatic and specific metabolic dynamics during composting under di-n-butyl phthalate (DBP) stress were evaluated for the first time. The results indicated that HA conversion was mainly related to bacteria rather than fungi, with positive associations with Actinobacteria, Chloroflexi, and Gemmatimonadota (all P < 0.05), and negative associations with Proteobacteria and Bacteroidota (all P < 0.05), while DBP stress retarded HA formation by altering the core microbes related to HA formation and their metabolic functions. Moreover, typical hydrolase and oxidoreductase activities were altered under DBP stress, proteases and cellulases were hindered, and peroxidases as well as polyphenol oxidases were promoted during composting. Overall, our data shows that DBP stress can retard HA formation and compost maturation by interfering with microbial activity. This study provides potentially useful information for the degradation and reuse of PAE-contaminated waste.

Characteristics and Health Risks of Phthalate Ester Contamination in Soil and Plants in Coastal Areas of South China

Phthalate esters (PAEs) are widely used as plasticizers in industrial and commercial products, and are classified as endocrine-disrupting compounds. In this study, we investigated the contamination characteristics and health risks of PAEs in the soil–plant system in coastal areas of South China. PAEs were detected in soil and plant samples at all 37 sampling sites. The total concentration of the 15 PAEs in soil samples ranged from 0.445 to 4.437 mg/kg, and the mean concentration was 1.582 ± 0.937 mg/kg. The total concentration of the 15 PAEs in plant samples ranged from 2.176 to 30.276 mg/kg, and the mean concentration was 8.712 ± 5.840 mg/kg. Di(2-Ethylhexyl) phthalate (DEHP) and di-n-butyl phthalate (DnBP) were the major PAEs compounds in all samples. The selected contaminants exhibited completely different spatial distributions within the study area. Notably, higher concentrations of PAEs were found in the coastal Guangdong Province of South China. The average noncarcinogenic risks of Σ6 PAEs were at acceptable levels via dietary and nondietary routes. However, the noncarcinogenic risks posed by DEHP and DBP at some sampling sites were relatively high. Furthermore, dietary and nondietary carcinogenic risks were very low for BBP, but carcinogenic risks posed by DEHP via diet. The results suggest that PAEs in the coastal soil–plant system in South China, through human risk assessment, will induce some adverse effects on human health, especially in children. This study provides an important basis for risk management of PAEs in agriculture, and safety in coastal areas of South China.

Exposure to phthalates in early pregnancy and the risk of fetal growth restriction: a nested case-control study in a Zhuang Chinese population

Phthalates (PAEs) are common endocrine disrupting chemicals (EDCs) that disrupt fetal development. The present study aimed to evaluate the effects of single and coexposure to phthalates in early pregnancy on fetal growth restriction (FGR) by a nested case-control study based on the Guangxi Zhuang Birth Cohort (GZBC). Maternal serum concentrations of seven phthalates in 97 neonates with FGR and 291 matched controls were detected through gas chromatography-mass spectrometry (GC-MS). The associations between phthalates and FGR were analyzed using multiple logistic regression, weight quantile sum (WQS) regression, and Bayesian kernel machine regression (BKMR) models. We found that exposures to butyl-benzyl phthalate (BBP, OR_adj = 1.849, 95% CI: 1.080-3.177, P_adj = 0.025, P_trend = 0.046), di (2-ethyl-hexyl) phthalate (DEHP, OR_adj = 3.893, 95% CI: 1.305-11.910, P_adj = 0.015, P_trend = 0.098) and dimethyl phthalate (DMP, OR_adj = 1.722, 95% CI: 1.089-2.725, P_adj = 0.020, P_trend = 0.002) were significantly positively associated with the risk of FGR, while mono-butyl phthalate (MBP) showed a significant negative association with FGR (OR_high = 0.192, 95% CI: 0.036-0.795, P_adj = 0.033, P_trend = 0.035) only among girls. The WQS model identified that BBP, di(2-ethyl)phthalate (DEP), DMP, DEHP, di-n-butyl phthalate (DBP), and MBP were highly weighted in the association with FGR. The BKMR model supported the positive association between joint exposure to phthalates and the risk of FGR and identified no significant interaction between the seven phthalates. Overall, maternal exposure to BBP, DEHP, and DMP may cause adverse effects on FGR, especially with combined effects.

Freeze-thaw alternations accelerate plasticizers release and pose a risk for exposed organisms

The application of plastic mulch films brings convenience to agricultural production, but also causes plastic waste that can be degraded into microplastics (MPs). However, little is known about the fate of plastic waste in agricultural ecosystem under freeze-thaw alternation in middle and high latitudes, as well as in highlands around the world. Whether the release of plasticizers, i.e. phthalate esters (PAEs), under such conditions would pose a potential risk to exposed organisms due to bioaccumulation is also unknown. To fill these data gaps, the agricultural fields in Liaoning of China with typical freeze-thaw alternation was selected as the study area. The transformation of plastic film was demonstrated by simulation freeze-thaw alternating from -30 to 20 ℃. Soil samples were collected to investigate the patterns of MP composition, abundance, and distribution. Concurrently, the concentrations of two PAEs including bis(2-ethylhexyl) phthalate (DEHP) and diethyl phthalate (DEP) in soils were analyzed to provide information on the correlation between MPs abundance and PAEs concentrations as well as potential risks. The results showed that freeze-thaw alternating can accelerate the formation of MPs and release of PAEs from plastic waste. The abundance of MPs was positively correlated with the concentration of PAEs. Soil PAEs ranged from 3268 ± 213-6351 ± 110 μg/kg, indicating that over 40 % of the PAEs were transferred from plastic films to soils. Such residual amounts could pose risk for exposed organisms. Hence, the current study suggested that special concerns should be given to the release plasticizers in plastic waste of agricultural soils.

Simple ultrasensitive electrochemical detection of the DBP plasticizer for the risk assessment of South Korean river waters

Rapid detection of contaminants for the purpose of sensitive and quantitative monitoring of environmental hazards is an essential first step in realizing the avoidance of human health risks. In this regard, we present a fast and simple electrochemical method of detecting di-n-butyl phthalate (DBP) from river water samples using a phthalic acid group specific aptamer modified on a gold nanoparticle (AuNP) functionalized graphene oxide nano-platelet (GO) and ionic liquid (IL) nanocomposite. Here, the IL/GO nanocomposite allows an enhanced interaction with phthalate esters, thereby increasing the sensitivity of the sensor surface. The proposed sensor showed a wide linear dynamic range from 0.14 pg mL^-1 to 0.35 ng mL^-1 and from 0.35 ng mL^-1 to 7 ng mL^-1 with a detection limit of ≤0.042 pg mL^-1, which were evaluated using standard, analytical grade DBP; the limit of quantification was determined using different concentrations of DBP in DI water in comparison with gas chromatography-mass spectroscopy (GC/MS) values. The proposed sensor was used to monitor the DBP concentrations in river water samples collected from various locations across South Korea. The quantitative data from the measurements in comparison with standard GC/MS values were then used to ascertain the human health risk posed by the daily consumption of these river waters.

A review on the removal of phthalate acid esters in wastewater treatment plants: from the conventional wastewater treatment to combined processes

In the past decades, phthalate acid esters (PAEs), as a new class of recalcitrant environmental contaminant, have attracted increasing concern due to their potential hazards to reproductive system. wastewater treatment plants (WWTPs) are generally regarded as a crucial barrier to prevent a variety of contaminants from introducing into aquatic environment. This paper reviews the occurrence, fate, and removal efficacy of six widely appearing PAEs in conventional wastewater treatment. PAEs removal appears to be compound- and process-dependent. Advanced treatment processes, including activated carbon, advanced oxidation process (AOPs), membrane filtration, and membrane bioreactor, show good performance in PAEs elimination, but many methods have been commercially limited by toxic byproducts, high operation, and maintenance costs. Even though combined processes are qualified as a promising alternative, further studies are required to optimize these processes, especially the competitiveness between technique and economy.

Mimicking human ingestion of microplastics: Oral bioaccessibility tests of bisphenol A and phthalate esters under fed and fasted states

Notwithstanding the fact that microplastic fragments were encountered in the human stool, little effort has been geared towards elucidating the impact of chemical additives upon the human health. In this work, standardized bioaccessibility tests under both fasting and fed conditions are herein applied to the investigation of human oral bioaccessibility of plastic additives and monomers (i.e. eight phthalate esters (PAEs) and bisphenol A (BPA)) in low-density polyethylene (LDPE) and polyvinyl chloride (PVC) microplastics. The generation of phthalate monoesters is evaluated in the time course of the bioaccessibility tests. Maximum gastric and gastrointestinal bioaccessibility fractions are obtained for dimethyl phthalate, diethyl phthalate and BPA, within the range of 55-83%, 40-68% and 37-67%, respectively, increasing to 56-92% and 41-70% for dimethyl phthalate and diethyl phthalate, respectively, whenever their hydrolysis products are considered. Bioaccessibility fractions of polar PAEs are dependent upon the physicochemical characteristics of the microplastics, with greater bioaccessibility for the rubbery polymer (LDPE). With the method herein proposed, oral bioaccessible pools of moderately to non-polar PAEs can be also accurately assessed for risk-assessment explorations, with values ranging from 1.8% to 32.2%, with again significantly larger desorption percentages for LDPE. Our results suggested that the highest gastric/gastrointestinal bioaccessibility of the eight PAEs and BPA is reached under fed-state gastrointestinal extraction conditions because of the larger amounts of surface-active biomolecules. Even including the bioaccessibility factor within human risk assessment/exposure studies to microplastics, concentrations of dimethyl phthalate, di-n-butyl phthalate and BPA exceeding 0.3% (w/w) may pose severe risks after oral uptake in contrast to the more hydrophobic congeners for which concentrations above 3% (w/w), except for diethylhexyl phthalate, would be tolerated.

Microplastics: A major source of phthalate esters in aquatic environments

Phthalate esters (PAEs) are predominant additives in plastics, their widespread contamination in aquatic environments has raised global concern. Here, twelve plastic products were prepared as microplastics to investigate their release behaviors of PAEs. Six out of 15 PAEs were quantified after 14 days of incubation in water. The leaching potentials were plastic type-specific, where the pencil case (polyvinyl chloride, PVC) represented the highest migrations with total ∑₁₅ PAEs concentration of 6660 ± 513 ng/g, followed by the cleaning brush-1 (polyamide, PA, ~1830 ng/g) and rubber glove (1390 ± 57.5 ng/g). Conversely, the straw (polypropylene, PP), cleaning brush-2 (polyethylene terephthalate, PET) and shampoo bottle (PET) released the lowest amounts of PAEs, with 50.3 ± 8.21, 93.9 ± 91.8 and 104.35 ng/g, respectively. The release patterns of PAE congeners were polymer type-related, where di-n-butyl phthalate (DBP) dominated the leaching from PA, PP and PET microplastics (47-84%), diethyl phthalate leached the most from PVC and rubber microplastics (45-92%), while diisobutyl phthalate and DBP dominated the leaching from PE microplastics (68-94%). Water chemical properties could affect PAEs migration and the kinetic leaching process was well fitted with the pseudo-first-order model. Approximately 57.8-16,100 kg/year of PAEs were estimated to be released into oceans from microplastics.

Phthalate metabolites in paired human serum and whole blood

Presence of phthalate metabolites (PMs) in human serum has been well documented. However, the distribution pattern of PMs in different human blood matrixes remains not well known. To investigate this, paired serum and whole blood samples were collected from 145 adults (76 males and 69 females) in Quzhou, China, and analyzed for nine PMs in this study. All PMs had high detection frequencies (> 70%) in human serum and whole blood, except mono benzyl phthalate. Total concentrations of detected PMs in serum and whole blood were 0.70-61 ng/mL (mean 12 ng/mL) and 1.6-33 ng/mL (7.5 ng/mL), respectively. Mono methyl phthalate (MMP), mono (2-ethylhexyl) phthalate, and mono butyl phthalate were consistently the predominant PMs in human serum and whole blood, with the mean concentrations of 3.4 and 2.0 ng/mL, 3.3 and 2.1 ng/mL, and 2.8 and 1.8 ng/mL, respectively. Females had higher mean serum concentrations of PMs, except MBP, than males. Youngest age group (20-30 years) consistently had the lowest mean whole blood levels of all PMs. For the first time, the distribution pattern of PMs in human blood was evaluated based on the calculated partitioning coefficient (K_p) between serum and whole blood. MMP had the highest mean K_p value (1.6; 10th-90th percentile: 1.0-2.2), while mono (2-ethyl-5-oxohexyl) phthalate had the lowest mean K_p value (0.63; 10th-90th percentile: 0.25-1.3). These results help better understand the occurrence of PMs in human blood.

Comparison of Different Chemical Extraction Methods for Predicting the Bioavailability and Phytotoxicity of Soil PAEs to Green Vegetables (Brassica Rapa Var. Chinensis)

The aim of the present study was to compare the predictive ability of four chemical extraction methods, i.e., Tenax, hydroxypropyl[β]cyclodextrin (HPCD), n-butanol and low-molecular-weight-organic-acids (LMWOA), for predicting the bioavailability and phytotoxicity of soil phthalic acid esters to the green vegetable Shanghaiqing (SHQ). Results showed that the extraction ability of different extraction methods varies significantly. For dibutyl phthalate (DBP), the extraction ability followed the order of Tenax > LMWOA > HPCD > n-butanol. For di-(2-ethylhexyl) phthalate (DEHP), the order of the extraction ability was n-butanol > HPCD > Tenax > LMWOA. All the extraction methods underestimated the DBP concentration while overestimating the DEHP concentration accumulated by SHQ. The concentrations of DBP and DEHP extracted by Tenax were most related to the concentrations accumulated by SHQ and the phytotoxicity indicators of SHQ. Tenax can serve as a good chemical extractant to assess the bioavailability and phytotoxicity of soil DBP and DEHP to SHQ.

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.