Environmental risk limits for two phthalates, with special emphasis on endocrine disruptive properties

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

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

Risk assessment of China's Eastern Route of the South-to-north Water Diversion Project from the perspective of Phthalate Esters occurrence in the impounded lakes

Phthalate esters (PAEs) are widely utilized and can accumulate in lacustrine ecosystems, posing significant ecological and human health hazards. Most studies on PAEs focus on individual lakes, lacking a comprehensive and systematic perspective. In response, we have focused our investigation on characteristic lakes situated along the Eastern Route of the South-to-north Water Diversion Project (SNWDP-ER) in China. We have detected 16 PAE compounds in the impounded lakes of the SNWDP-ER by collecting surface water samples using solid-phase extraction followed by gas chromatography analysis. The concentration of PAEs were found to between 0.80 to 12.92 μg L-1. Among them, Bis (2-ethylhexyl) phthalate (DEHP) was the most prevalent, with mean concentration of 1.56 ± 0.62 μg L-1 (48.44%), followed by Diisobutyl phthalate (DIBP), 0.64 ± 1.40 μg L-1 (19.87%). Spatial distribution showed an increasing trend in the direction of water flow. Retention of DEHP and DIBP has led to increased environmental risks. DEHP, Dimethyl phthalate (DMP) etc. determined by agriculture and human activities. Additionally, Dibutyl phthalate (DBP) and DIBP mainly related to the use of agricultural products. To mitigate the PAEs risk, focusing on integrated management of the lakes, along with the implementation of stringent regulations to control the use of plasticizes in products.

Contamination levels and ecological risk assessment of phthalate esters (PAEs) in the aquatic environment of Chaohu Lake

Phthalate esters (PAEs), widely recognized as synthetic organic compounds with extensive production and utilization, are known to disrupt physiological processes in both animals and humans, even at low environmental concentrations. This study investigated the occurrence, distribution, and potential ecological risk of five representative PAEs (DMP, Dimethyl phthalate; DEP, Diethyl phthalate; DBP, Dibutyl phthalate; DiBP, Diisobutyl phthalate; DEHP, Bis(2-ethylhexyl) phthalate) in a typical lake (Chaohu Lake, China). It was found that PAEs were detected in both the aqueous (1.09-6.402 µg/L) and solid phases (0.827-6.602 µg/g) of Chaohu Lake. Notably, DiBP and DBP were the predominant PAEs in the water, and DiBP and DEHP were the most prevalent in the sediments. The concentrations of PAEs exhibited significant seasonal variations in the aqueous phases, with total PAEs in summer being nearly twice those in winter. Toxicity assessments revealed that DEHP, DBP, and DiBP posed high risks to the survival of three indicator organisms (algae, Daphnia, and fish) in the aqueous phase. In the solid phase, the exceeding rate of DiBP was as high as 92.9%. On the other hand, DBP and DEHP generally presenting moderate risk, although some sites were identified as high-risk. This study's analysis of PAEs concentrations in Chaohu Lake reveals a discernible increasing trend when compared with historical data. These findings underscore the urgent need for interventions to mitigate the ecological threats posed by PAEs in Chaohu Lake.

Historical sedimentary and evolutionary characteristics of POPs and EDCs in typical regions of the three Gorges reservoir, China

The historical sedimentary and evolutionary characteristics of persistent organic pollutants and endocrine disruptors in typical regions of the Three Gorges Reservoir are scarcely studied. Herein, the 96-year data on contaminated sediment history were reconstructed using Caesium 137 isotope dating. Polychlorinated biphenyl concentrations in the involved sediment cores ranged from non-detected (ND) to 11.39 ng/g. The concentrations of polycyclic aromatic hydrocarbons ranged from ND to 2075.20 ng/g and peaked in the 1970s owing to natural, agricultural and human activities. Further, phthalate esters (PAEs) and heavy metals (HMs) were detected at concentrations ranging from ND to 589.2 ng/g and 12.10-93.67 μg/g, respectively, with highest values recorded in the 1980s owing to rapid industrialisation and insufficient management during China's early reform and development stages. PAE and HM concentrations have increased in recent years, suggesting the need to focus on industrial and agricultural activities that have caused this impact. Although current pollutant concentrations in sediments do not pose a risk to the aquatic ecosystem, they should be continuously monitored.

Phthalate esters pollution in the leachate, soil, and water around a landfill near the sea, Iran

This investigation aimed to scrutinize the level of phthalate esters (PEs) in the landfill leachate of a coastal city in the north of the Persian Gulf and the sensitive ecosystem (soil and water) around it. Soil (two depths) and water samples were prepared from 5 stations in wet and dry seasons. The studied landfill leachate contained 114-303 μg/L of phthalates. The highest concentration of phthalates was related to bis (2-ethylhexyl) phthalate (3257 ng/g) in the wet season at surface soil (0-5 cm) in the landfill site, while the lowest one (6 ng/g) belonged to dimethyl phthalate at sub-surface soil at 700 m from the landfill in the dry season. A significant change in the level of Σ6PEs in the dry (303 μg/L) and wet (114 μg/L) seasons (P ≤ 0.05) was observed for water samples. The PE concentrations in wet times were higher in all soil depths than in dry times. With increasing depth, the content of phthalates decreased in all studied environments. A direct relationship was observed between the phthalates concentration and the pH value of leachate/water and soil. The PEs concentration was linked to electrical conductivity (leachate: R2 = 0.65, P < 0.01 and surface soil: R2 = 0.77, P < 0.05) and the soil organic content. The ecological risk of di-n-butyl phthalate, benzyl butyl phthalate, bis (2-ethylhexyl) phthalate, and di-n-octyl phthalate in the wet season was greater than one. The results showed that significant levels of phthalate esters are released from landfills to the surrounding environment, which requires adequate measures to maintain the health of the ecosystem and nearby residents.

Pollution characteristics and affecting factors of phthalate esters in agricultural soils in mainland China

Phthalate esters (PAEs), the most commonly produced and used plasticizers, are widely used in plastic products and agroecosystems, posing risks to agricultural products and human health. However, current research on PAE pollution characteristics in agricultural soils in China is not comprehensive; affecting factors and relationships with microplastics and plasticizer organophosphate esters have not been sufficiently considered. In this study, farmland soil samples were collected with field questionnaires on a national scale across mainland China. The results showed that the detection rate of PAEs was 100% and the Σ16PAEs concentrations were 23.5 - 903 μg/kg. The level of PAEs was highest in the greenhouse, and significantly higher than that in mulched farmland (p < 0.05). The PAE concentration in northwestern China was the lowest among different physical geographic zones. PAEs in farmlands posed a low cancer risk to Chinese people. PAE pollution in farmlands was significantly (p < 0.05) affected by agronomic measures (such as disposal method), environmental factors, and socioeconomic factors. Overall, PAEs were significantly and positively correlated (p < 0.05) with organophosphate esters but not with microplastics. This study aims to provide scientific data for relevant prevention and control policies, as well as actionable recommendations for pollution reduction.

Levels, spatial distributions, and provision of petroleum hydrocarbons and phthalates in sediments from Obhur lagoon, Red Sea coast of Saudi Arabia

The levels, spatial distribution, and sources of petroleum hydrocarbons and phthalates were assessed in surface sediment samples from the urban lagoon of Obhur near Jeddah, the largest city on the Red Sea coast of Saudi Arabia. The lagoon was divided into the inner zone, middle zone, and outer zone based on its geomorphological features and developmental activities. n-Alkanes, hopane and sterane biomarkers, and unresolved complex mixture were the major petroleum hydrocarbon compounds of the total extractable organic matter. Phthalates were also measured in the sediment samples. In the three zones, n-alkanes ranged from 89.3 ± 88.5 to 103.2 ± 114.9 ng/g, whereas the hopane and sterane biomarkers varied from 69.4 ± 75.3 to 77.7 ± 69.9 ng/g and 72.5 ± 77.9-89.5 ± 82.2 ng/g, respectively. The UCM concentrations ranged from 821 ± 1119 to 1297 ± 1684 ng/g and phthalates from 37.4 ± 34.5 65 ± 68 ng/g. The primary origins of these anthropogenic hydrocarbons in the lagoon sediments were petroleum products (boat engine discharges, boat washing, lubricants, and wastewater flows) and plasticizers (plastic waste and litter). The proportions of anthropogenic hydrocarbons derived from petroleum products in the sediment's TEOM ranged from 43 ± 33 to 62 ± 15%, while the percentages for plasticizers varied from 2.9 ± 1.2 to 4.0 ± 1.6%. The presence and inputs of these contaminants from petroleum and plastic wastes in the lagoon's sediments will eventually have an impact on its habitats, including the benthic nursery and spawning areas.

Seasonal distribution characteristics and ecological risk assessment of phthalate esters in surface sediment of Songhua River basin

Phthalic acid esters (PAEs) are typical industrial chemicals used in China. PAEs have received considerable attention because of their ubiquity and potential hazard to humans and the ecology. The spatiotemporal distributions of six PAEs in the surface sediments of the Songhua River in the spring (March), summer (July), and autumn (September) are investigated in this study. The total concentration of phthalic acid esters (∑6PAEs) ranges from 1.62 × 102 ng g-1 dry weight (dw) to 3.63 × 104 ng g-1·dw, where the amount in the spring is substantially higher (p < 0.01) than those in the autumn and summer. Seasonal variations in PAEs may be due to rainfall and temperature. The ∑6PAEs in the Songhua River's upper reaches are significantly higher than those in the middle and lower reaches (p < 0.05). Dibutyl phthalate (DBP) and di(2-ethylhexyl) phthalate (DEHP) are the two most abundant PAEs. The ecological hazard of five PAEs is assessed using the hazard quotient method. DBP and DEHP pose moderate or high ecological risks to aquatic organisms at various trophic levels. PAEs originate primarily from industrial, agricultural, and domestic sources. Absolute principal components-multiple linear regression results indicate that agricultural sources are the most dominant contributor to the ∑6PAEs (53.7%). Guidelines for controlling PAEs pollution in the Songhua River are proposed.

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.

Trends of legacy and emerging organic contaminants in a sediment core from Cienfuegos Bay, Cuba, from 1990 to 2015

Legacy and emerging organic pollutants pose an ever-expanding challenge for the marine environment. This study analysed a dated sediment core from Cienfuegos Bay, Cuba, to assess the occurrence of polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), polybrominated diphenyl ethers (PBDEs), alternative halogenated flame retardants (aHFRs), organophosphate esters (OPEs), and phthalates (PAEs) from 1990 to 2015. The results evidence the continuing presence of historical regulated contaminants (PCBs, OCPs, and PBDEs) in the southern basin of Cienfuegos Bay. PCB contamination declined since 2007, likely in response to the gradual global phasing out of PCB containing materials. There have been relatively consistent low accumulation rates for OCPs and PBDEs at this location (in 2015 approximately 1.9 and 0.26ng/cm²/year, respectively, with 2.8ng/cm²/year for Σ₆PCBs), with indications of recent local DDT use in response to public health emergencies. In contrast, sharp increases are observed between 2012 and 2015 for the contaminants of emerging concern (PAEs, OPEs, and aHFRs), and in the case of two PAEs (DEHP and DnBP) the concentrations were above the established environmental effect limits for sediment dwelling organisms. These increasing trends reflect the growing global usage of both alternative flame retardants and plasticizer additives. Local drivers for these trends include nearby industrial sources such as a plastic recycling plant, multiple urban waste outfalls, and a cement factory. The limited capacity for solid waste management may also contribute to the high concentrations of emerging contaminants, especially plastic additives. For the most recent year (2015), the accumulation rates for Σ₁₇aHFRs, Σ₁₉PAEs, and Σ₁₇OPEs into sediment at this location were estimated to be 10, 46 000, and 750ng/cm²/year, respectively. This data provides an initial survey of emerging organic contaminants within this understudied region of the world. The increasing temporal trends observed for aHFRs, OPEs, and PAEs highlights the need for further research concerning the rapid influx of these emerging contaminants.

Advanced oxidation processes for the removal of phthalate esters (PAEs) in aqueous matrices: a review

Over the past few decades, phthalate esters (PAEs) used as additives to improve the persistence and flexibility of polymeric materials. They are also used in cosmetics, insect repellents, and propellants, and their continuous input into drinking waters has constituted a serious risk to human health and the environment. DBPs are compounds classified as hazardous substances and have teratogenic properties. Due to the high bioaccumulation of DBP, they have toxic properties in different organisms, making it very important to remove PAEs before discharging them into environments. In this study a systematic review was designed to evaluate Advanced oxidation processes (AOPs) studies which have successfully treated contaminated water with PAEs. Among AOPs, particularly photocatalytic, UV/H₂O₂ photolysis, sonolysis, and ozone-based processes were more tried to degrade PAEs in aqueous solutions. Additionally, a more detail of each AOPs was explained. Findings showed that all advanced oxidation processes, especially combined AOPs have good results in the degradation of PAEs in water.

Spatial distribution and characteristics of microplastics and associated contaminants from mid-altitude lake in NW Himalaya

Despite the worldwide concern over the impact of microplastics (MPs) and associated organic contaminants, the information regarding the occurrence and characteristics of these emerging class of pollutants is limited in freshwater environment. We present data on the distribution and concentration levels of MPs and phthalate esters (PAEs) from Rewalsar Lake, a shallow eutrophic lake in Northwest Himalaya. The MPs were identified in all samples, with concentration of 13-238 particles L^-1 and 750 to 3020 particles kg^-1 dry weight (dw) in surface water and sediments respectively. Majority of MPs were dominated by polystyrene, polyethylene, polypropylene polymers that principally occurred in the form of pellets and fragments. The MPs distribution was different among sampling sites, being more abundant to sites in the proximity of domestic sewage effluents and high level of religious and tourist activities. The di-isobutyl phthalate, dibutyl phthalate (DBP) and its branched isomer, di(2-ethylhexyl) phthalate (DEHP) are the identified PAE congeners in sediments, and the measured total concentrations of Σ₃PAE ranged from 1.69 μg/g to 4.03 μg/g dw. Notably, concentration values of DEHP were higher as compared to other detected phthalates, and exceeded recommended environmental risk limit. The findings of this study emphasize the requirement for proper waste management measures in the region to reduce entry of these pollutants into the ecosystem. Further, this work contributes to the understanding of MPs and PAEs potential contamination profiles and sources in freshwater environments, and provides valuable information for future management decisions.

Cumulative Exposure to Phthalates and Their Alternatives and Associated Female Reproductive Health: Body Burdens, Adverse Outcomes, and Underlying Mechanisms

The global birth rate has recently shown a decreasing trend, and exposure to environmental pollutants has been identified as a potential factor affecting female reproductive health. Phthalates have been widely used as plasticizers in plastic containers, children's toys, and medical devices, and their ubiquitous presence and endocrine-disrupting potential have already raised particular concerns. Phthalate exposure has been linked to various adverse health outcomes, including reproductive diseases. Given that many phthalates are gradually being banned, a growing number of phthalate alternatives are becoming popular, such as di(isononyl) cyclohexane-1,2-dicarboxylate (DINCH), di(2-ethylhexyl) adipate (DEHA), and di(2-ethylhexyl) terephthalate (DEHTP), and they are beginning to have a wide range of environmental effects. Studies have shown that many phthalate alternatives may disrupt female reproductive function by altering the estrous cycle, causing ovarian follicular atresia, and prolonging the gestational cycle, which raises growing concerns about their potential health risks. Herein, we summarize the effects of phthalates and their common alternatives in different female models, the exposure levels that influence the reproductive system, and the effects on female reproductive impairment, adverse pregnancy outcomes, and offspring development. Additionally, we scrutinize the effects of phthalates and their alternatives on hormone signaling, oxidative stress, and intracellular signaling to explore the underlying mechanisms of action on female reproductive health, because these chemicals may affect reproductive tissues directly or indirectly through endocrine disruption. Given the declining global trends of female reproductive capacity and the potential ability of phthalates and their alternatives to negatively impact female reproductive health, a more comprehensive study is needed to understand their effects on the human body and their underlying mechanisms. These findings may have an important role in improving female reproductive health and in turn decreasing the number of complications during pregnancy.

Silibinin supplementation ameliorates the toxic effects of butyl benzyl phthalate on porcine oocytes by eliminating oxidative stress and autophagy

Butyl benzyl phthalate (BBP) is a common environmental pollutant, it is high in paints, adhesives and other decorative materials, food packaging bags, cleaning agents, is a plasticizer is very widely used in daily life. However, it remains unknown whether BBP causes damage to oocytes cultured in vitro and whether there is an effective rescue strategy. Here, we evaluated the effects of exposure to different concentrations of BBP (10, 50, and 100 μM) on the meiosis of porcine oocytes. The results showed that exposure to BBP (100 μM) severely impaired expansion of cumulus-oocyte complex (COCs) and PBE (control:71.6% vs 100 μM: 48.8%). Spindle conformation and chromosome alignment were also significantly abnormal (34.8% and 46.0%, respectively) compared to the control (11.1% and 17.5%, respectively), and BBP caused damage to microfilaments and cortical granules (CGs). In addition, oocyte exposure to BBP induced impaired mitochondrial function and disrupted mitochondrial integrity. Silibinin is a natural active substance isolated from the seeds of Silybum marianum (L.) Gaertneri with strong antioxidant and anti-inflammatory effects. Noteworthy, we added different concentrations of silibinin (10, 20, and 50 μM) to BBP-exposed oocytes for rescue experiments, where 50 μM effectively rescued BBP-induced meiotic failure (70.6%). It also prevented the generation of excessive autophagy and apoptosis in oocytes by inhibiting the production of ROS. In a word, our results suggest that supplementation of silibinin attenuates the impaired oocyte development caused by BBP exposure，which provides a potential strategy to protect oocytes from environmental pollutants.

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.

Environmental impacts of covid-19 pandemic: Release of microplastics, organic contaminants and trace metals from face masks under ambient environmental conditions

The covid-19 pandemic era was characterized by heavy usage and disposal of medical face masks, now estimated at over 1.24 trillion. Few studies had attempted to demonstrate the release of microplastics from face masks using simulated conditions and application of mechanical forces, far different from the effects experienced by face masks dumped in the open environment, in landfills and dumpsites. In the current study, we monitored the release of microplastics, organic contaminants and toxic metals from medical face masks degraded under normal outdoor environmental conditions, over a period of 60 weeks. We showed that face mask's decomposition proceeded via sunlight (UV) - initiated oxidative degradation, leading to the replacement of methylene (CH2-) and alkyl (CH3-) groups in face mask's polypropylene backbone with hydroxyl and ketonic functional groups. Organic compounds released from decaying face masks into the surrounding soil included alkanes, alkenes, carboxylic acids/diesters and phthalate esters. Mean maximum concentration of phthalates in the soil ranged from 3.14 mg/kg (diethyl phthalate) to 11.68 mg/kg di(2-ethylhexyl) phthalate. Heavy metals, including Cu, Pb, Cd, As, Sn and Fe, were released into the soil, leading to contamination factors of 3.11, 2.84, 2.42, 2.26, 1.80 and 0.99, respectively. Together, the metals gave a pollution load index (PLI) of 2.102, indicating that they constitute moderate pollution of the soil surrounding the heap of face masks. This study provides a realistic insight into the fate and impacts of the enormous amounts of face masks, disposed or abandoned in soil environments during the covid-19 pandemic.

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

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

Occurrence, distribution and sources of phthalates and petroleum hydrocarbons in tropical estuarine sediments (Mandovi and Ashtamudi) of western Peninsular India

The present study provides baseline information on the concentration levels, distribution characteristics and pollution sources of environmental contaminants, such as phthalic acid esters (PAEs or phthalates) and petroleum hydrocarbons in surface sediments of the tropical estuaries (Mandovi and Ashtamudi) from western Peninsular India. Total PAEs (∑₅PAEs), hopanes, steranes and diasteranes concentrations from Ashtamudi estuary ranged from 7.77 to 1478.2 ng/g, n.d.-363.2 ng/g, n.d.-121.5 ng/g and n.d.-116.6 ng/g, respectively. Likewise, PAEs (∑₆PAEs), steranes and diasteranes concentrations from Mandovi estuary ranged from 60.1 to 271.9 ng/g, 2.33-40.1 ng/g and 2.28-23.0 ng/g, respectively. The PAEs comprising di-isobutyl phthalate (DIBP), dibutyl phthalate (DBP), an isomer peak for DBP, di(2-ethylhexyl) phthalate (DEHP), di-isononyl phthalate were dominant in Ashtamudi estuary sediments, while PAEs including diethyl phthalate, DIBP, DBP and its isomer, DEHP, di(2-ethylhexyl) terephthalate were detected in the Mandovi sediment samples. The results of this study show an insignificant correlation of TOC with PAEs, and indicates that the varying spatial distributions of the PAEs in both the estuaries can be the result of discharge sources. The higher concentration of PAE congeners was noticed in Ashtamudi, a Ramsar wetland site, that can be attributed to land-based plastic waste. The petroleum biomarkers were abundantly present in Mandovi estuary due to anthropogenic activities such as boating and spillage from oil tankers. The findings of the present study will serve as a reference point for future investigation of organic contaminants in Indian estuaries, and calls for attention towards implementing effective measures in controlling the pervasion of the PAEs and petroleum biomarkers.

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.

Phthalate Exposures and Placental Health in Animal Models and Humans: A Systematic Review

Phthalates are ubiquitous compounds known to leach from the plastic products that contain them. Due to their endocrine-disrupting properties, a wide range of studies have elucidated their effects on reproduction, metabolism, neurodevelopment, and growth. Additionally, their impacts during pregnancy and on the developing fetus have been extensively studied. Most recently, there has been interest in the impacts of phthalates on the placenta, a transient major endocrine organ critical to maintenance of the uterine environment and fetal development. Phthalate-induced changes in placental structure and function may have significant impacts on the course of pregnancy and ultimately, child health. Prior reviews have described the literature on phthalates and placental health; however to date, there has been no comprehensive, systematic review on this topic. Here, we review 35 papers (24 human and 11 animal studies) and summarize phthalate exposures in relation to an extensive set of placental measures. Phthalate-related alterations were reported for placental morphology, hormone production, vascularization, histopathology, and gene/protein expression. The most consistent changes were observed in vascular and morphologic endpoints, including cell composition. These changes have implications for pregnancy complications such as preterm birth and intrauterine growth restriction as well as potential ramifications for children's health. This comprehensive review of the literature, including common sources of bias, will inform the future work in this rapidly expanding field.

A novel report on phthalates levels in Biscayne Bay surface waters and drinking water from South Florida

In this research, we have developed and validated a modified version of the U.S.EPA method 506 using a liquid-liquid extraction method followed by gas-chromatography mass spectrometry analysis to assess the occurrence and spatial and seasonal variation of six phthalates (di(2-ethylhexyl) phthalate-DEHP, dibutyl phthalate-DBP, butyl benzyl phthalate-BBP, diethyl phthalate-DEP, dimethyl phthalate-DMP, and di-n-octyl phthalate-DOP) in surface and tap waters from South Florida, collected during the wet and dry seasons. The most frequently detected phthalate was DEHP, with concentrations up to 1.56 μg/L in surface water. Higher DEHP concentrations were observed in tap water during the wet season, which aligns with the higher temperature during the summer months facilitating leaching from plastic materials. Preliminary ecological and human health risk assessments suggested low hazard risk based on concentrations observed in tap and surface waters, respectively. PAEs could however still constitute a great concern to sensitive marine species, including early stages organisms and coral reefs.

Diffuse phthalate acid esters losses induced from large amount of agricultural plastic film residues caused low risks for water quality in China during 1991-2017

Extensive application of agricultural plastic films has resulted in abundant film residues in farmlands. Phthalate acid esters (PAEs) are vital additives of the agricultural plastic film and are easily emitted into soils. However, spatio-temporal variations of diffuse PAEs loss to water bodies have not been explored in China. This study used an integrated estimation framework and high-resolution activity data to conduct a comprehensive inventory of diffuse PAEs loss associated with plastic films of six main crop types in China for 1991-2017. We found that the diffuse PAEs loss induced from agricultural plastic films increased 10.57-46.30 kg over the same time. Di-butyl phthalate (DBP) and bis(2-ethylhexyl) phthalate (DEHP) accounted for ~75% of the national total loss. High PAEs loss regions are mainly located in Eastern China, the Middle-Lower Yangtze Plain, and eastern Yunnan and Sichuan provinces. We proved that PAEs emission, agricultural film residues, surface runoff, precipitation, and soil organic carbon explained 19.64%, 17.50%, 15.45%, 12.88%, and 9.83% of the total variation, respectively. The potential ecological risks to the various aquatic species were assessed to be low. Overall, our results are valuable for addressing severe agricultural plastic film residues and associated pollutant emissions and losses in China.

Spatial-temporal distributions and influential factors of phthalate acid esters in sediments of three lakes in Inner Mongolia

The spatiotemporal distributions, influential factors, and ecological risks of 15 phthalate acid esters (PAEs) in the sediments of three typical lakes in Inner Mongolia were investigated in this work. PAEs were widespread in all surface sediments ranging from 598.3 to 3873.8 μg/kg dry weight. Average PAE concentrations were highest in the surface sediments of Wuliangsuhai Lake followed by Daihai and Hulun Lakes, which were consistent with population density and intensity of anthropogenic activities. Dibutyl phthalate, di-iso-butyl phthalate (DIBP), and diethyl phthalate (DEP) were the dominant PAEs with similar abundance orders for the three lakes. The cold climate could explain the higher DEP abundance in the sediments of lakes at higher latitudes. The highest Σ PAE and most individual PAE concentrations were located at one of the discharge river estuaries because most PAEs were terrestrial pollutants. Σ PAE concentrations in the core sediments increased with years and fluctuations owing to the increasing PAE usage and input. The second highest PAE concentration peaks were associated with the high gross domestic product growth rates in 2003-2008. Redundancy analysis revealed that butyl benzyl phthalate and diamyl phthalate in the surface sediments of Hulun Lake were principally positively influenced by organic matter (65.6% contribution among geochemical variables), Fe oxides (25.1% contribution among metals), and Mn oxides (23.8% contribution among metals). The DIBP and DEP exhibited high risks to sensitive fish according to a risk quotient assessment. This work presents new insights into PAE status and deposition mechanisms in the lakes within high latitudes or cold climates, and provides important information for future environmental protection and management.

Estrogenic activity and ecological risk of steroids, bisphenol A and phthalates after secondary and tertiary sewage treatment processes

Effluents of sewage treatment plants (STPs) are an important source of estrogenic substances to the receiving water bodies affecting their ecological safety. In this study, steroids, bisphenol A (BPA) and phthalates were assessed in the secondary (SE) and tertiary effluent (TE) of three typical urban STPs in Beijing (China). In addition, the overall estrogenic activity in these effluents was assessed by an in-vitro bioassay (ERE-CALUX). Results showed that the concentrations and activities of estrogenic compounds in TE were lower than those in SE. The residual concentration of 17β-estradiol (E2) was the highest among the detected steroids, accounting for 51.6 ± 5.1% in SE and 57.5 ± 24.8% in TE. The residual level (25.2-41.6 ng/L) of BPA in effluents was significantly higher than that of steroids (0.2-28.8 ng/L). The residual concentration of diethyl phthalate was the highest among the detected phthalates accounting for 47.1 ± 5.1% in SE and 37.6 ± 11.5% in TE. Steroids and BPA had a higher removal rate (83.5% and 96.7%) in secondary and tertiary treatment than phthalates (68.8% and 83.1%). The hydrophobic characteristics of these estrogenic compounds determined the removal mechanism. The removal of steroids, BPA, dimethyl phthalate and diethyl phthalate (LogKow= 1.61-4.15) mainly occurred through biodegradation in the water phase, while the removal of dibutyl phthalate, butylbenzyl phthalate and di(2-ethylhexyl) phthalate (LogKow= 4.27-7.50) mainly occurred in the solid phase after adsorption on and sedimentation of the suspended particulate matter. According to ERE-CALUX, the estrogenic activity in the final STP effluents was 3.2-45.6 ng E2-equivalents/L, which is higher than reported levels in the effluents of European STPs. Calculation of estrogenic equivalents by using substance specific chemical analysis indicated that the dominant contributor was E2 (56.4-88.4%), followed by 17α-ethinylestradiol (EE2) (4.1-34.8%), both also exerting a moderate risk to the aquatic ecosystem. While the upgrade of treatment processes in STPs has efficiently reduced the emission of estrogenic substances, their ecological risk was not yet phased out.

Distribution Dynamics of Phthalate Esters in Surface Water and Sediment of the Middle-Lower Hanjiang River, China

Phthalate esters (PAEs) are endocrine-disrupting chemicals that pose potential risks to human health. Water and sediments are crucial carriers and storage media for the migration and transformation of PAEs. In this study, six congeners of PAEs were measured in water and sediment samples to elucidate their spatial distribution, congener profiles, and ecological risks in the middle-lower Hanjiang River during the wet and dry seasons. The concentration of the Σ6PAEs ranged from 592 to 2.75 × 103 ng/L with an average of 1.47 × 103 ng/L in surface water, while the concentration of the Σ6PAEs ranged from 1.12 × 103 to 6.61 × 103 ng/g with an average of 2.69 × 103 ng/g in sediments. In general, PAE concentrations were ranked as sediment > water, and dry season > wet season. DEHP and DBP were the dominant PAEs in the middle-lower Hanjiang River in surface water and sediments. SPSS analysis showed that dissolved organic carbon (DOC) in surface water was significantly correlated with the concentration of DBP, DEHP, and the ∑6PAEs, while organic matter (OM) was significantly correlated with the concentration of the ∑6PAEs in sediments. The concentrations of PAEs were irregularly distributed and varied significantly in surface water and sediments. Compared with other regions at home and abroad, the pollution levels of surface water and sediments in the middle-lower Hanjiang River were relatively low and not enough to have a negative impact on the local water’s ecological environment. However, the supervision of land-based discharge should still be strengthened.

Polyethylene terephthalate and di-(2-ethylhexyl) phthalate in surface and core sediments of Bohai Bay, China: Occurrence and ecological risk

Bohai Bay, a typical semi-enclosed bay, is close to the Beijing-Tianjin-Hebei Region, the economic center of north China. The release of emerging contaminants was considerably increasing with the fast urbanization and industrialization along the coastline. However, such data, e.g. plastic polymers, are still limited. Here, polyethylene terephthalate (PET) and di-(2-ethylhexyl) phthalate (DEHP) in surface sediments and sediment cores from the coastal area of Bohai Bay were investigated. The ranges of PET and DEHP concentrations in surface sediments are 1.49-13.90 mg/kg and 0.23-19.26 mg/kg, respectively. The relatively high contents of PET and DEHP were found near the Haihe River estuary, indicating the importance of riverine input. The PET and DEHP profiles in the cores dated by the ²¹⁰Pb method showed increasing trends with time. The PET in Bohai Bay was low risk evaluated by the potential ecological risk assessment. Low ecological risks of DEHP to the benthic organisms were found in the sediments, using the environmental risk limits, risk quotient, threshold effect level and probable effect level methods. The pollution levels of PET and DEHP in Bohai Bay obtained in this study may provide important data for making pollution control strategies.

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.

Non-targeted analysis by DLLME-GC-MS for the monitoring of pollutants in the Mar Menor lagoon

Non-targeted analysis for the monitoring of organic pollutants resulting from agricultural and industrial practices, plastics and pharmaceutical products of seawater from the Mar Menor lagoon (SE Spain) is proposed using dispersive liquid-liquid microextraction (DLLME) and gas chromatography-mass spectrometry (GC-MS). Initially, a home-made MS database including 118 environmental organic pollutants, whose presence in different ecosystems has already been reported, was created. The analytical method was applied for the analysis of 42 samples and a total of 18 pollutants were detected and identified. Samples were obtained from different sites around the Mar Menor in three sampling campaigns, enabling the assessment of impact of rain on the input of the detected chemicals and their distribution. In addition, this methodology was validated using a standard mixture containing 54 of the environmental pollutants included in the database, allowing the quantification of the 9 of the identified compounds (dibutyl phthalate, diisobutyl phthalate, diethyl phthalate, bis(2-ethylhexyl) phthalate, anthracene, 2-methylnaphthalene, hexachlorocyclopentadiene, bis(2-ethylhexyl) adipate and oleamide) with concentration between 3 and 271 μg L^-1.

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.

Assessment of anthropogenic pollution by monitoring occurrence and distribution of chemicals in the river Liffey in Dublin

This paper evaluates for the first time the spatial distribution of a wide group of organic (phthalates, nitro, aliphatic, halogen, aromatic, phenol and amino compounds) and inorganic pollutants along the Liffey river in Dublin city. The work takes into account the effect of short-term weather conditions on the occurrence of these contaminants. The results showed that rainfall conditions affect the levels of pollutants along the river in the days following a rainfall event. In addition, the tributaries entering the river Liffey were not found to impact its water quality. In relation to organic pollutants, 2,4,6-trichlorophenol, 2-nitrophenol and phthalate compounds were found in many water samples between concentrations of 0.21 and 2.17 μg L-1. On the other hand, dimethyl phthalate was present in certain samples at levels around 100 μg L-1. The levels of these contaminants in the river were lower than the toxicity values reported in the literature. Regarding inorganic pollutants, nitrates were detected from 0.59 to 6.81 mg L-1 increasing from upstream to downstream. Based on the chemical nature and applications of detected pollutants, the river contamination can be mainly related to agricultural, industrial activities as well as diffuse urban contributions. These vary with location within a short distance and have the potential to impact aquatic biodiversity as the chemical composition changes with rainfall events.

Remediation of Diethyl Phthalate in Aqueous Effluents with TiO2-Supported Rh0 Nanoparticles as Multicatalytic Materials

An innovative “domino” process, based on an arene hydrogenation followed by a photocatalytic step, was designed for the remediation of endocrine disrupting compounds, in highly concentrated aqueous effluents. The novelty relies on the use of TiO2-supported zerovalent Rh nanoparticles as multicatalytic materials (MCMs) for this two-step treatment, applied on diethyl phthalate, which is a model aromatic pollutant frequently present in aquatic environments. This nanocomposite advanced material, which was easily prepared by a green, wet impregnation methodology, proved to be active in the successive reactions, the reduction in the aromatic ring, and the photodegradation step. This sustainable approach offers promising alternatives in the case of photoresistive compounds.

Extraction and identification methods of microplastics and nanoplastics in agricultural soil: A review

As the abundance of microplastics and nanoplastics (MPs/NPs) increases in the environment, their presence in agricultural soil has become of interest. MPs/NPs can affect soil physical and chemical properties and be absorbed by plants and soil animals, causing physical and chemical damage. Soil MPs exceeding a certain concentration cause significant harm. Therefore, the extraction and identification of MPs in soil are vital for determining soil pollution. However, soils contain many other particles of similar size to MPs/NPs, making it more difficult to distinguish them than in water bodies. No standardized extraction and identification method is available to quantify MPs/NPs in soil. Various methods have been described in the literature, but they involve many different procedures for sampling, purification, digestion, and identification. This paper reviews extraction and identification methods for MPs/NPs in soil, sediment, and water and summarizes agricultural soil sampling and preservation, MPs/NPs separation, organic matter removal, and MPs/NPs identification. We also compare the advantages and disadvantages of existing methods and propose future research topics.

Consequences of combined exposure to thermal stress and the plasticiser DEHP in Mytilus spp. differ by sex

Little is known about the combined effect of environmental factors and contaminants on commercially important marine species, and whether this effect differs by sex. In this study, blue mussels were exposed for seven days to both single and combined stressors (i.e., +3 °C elevated temperature and two environmentally relevant concentrations of the plastic softener DEHP, 0.5 and 50 μg/l) in a factorial design. Males were observed to be more sensitive to high temperature, demonstrated by the significant increase in out-of-season spawning gonads and higher gene expression of the antioxidant catalase and the estrogen receptor genes. On the other hand, while the gametogenesis cycle in females was more resilient than in males, DEHP exposure altered the estrogen-related receptor gene expression. We show that the combined stressors DEHP and increased temperature, in environmentally relevant magnitudes, have different consequences in male and female mussels, with the potential to impact the timing and breeding season success in Mytilus spp.

Bioaccumulation and health risk assessment of phthalate esters in cultured low trophic level fish feded with food waste-based diets

The present study aimed at using different types of food waste as a protein source for the fish feeds to produce safe and quality fish. The results showed the concentrations of ∑PAEs in grass crap (0.24 μg g^-1 ww) and bighead carp (0.15 μg g^-1 ww) fed with Food waste B feeds (mainly containing fruit, vegetable and cereal waste) was significantly lower than those fed Food waste A feeds (mainly containing meat waste) and control feeds (p<0.05), and the highest ∑PAEs concentration (1.75 μg g^-1 ww) was found in the mud carp fed with control feeds in experimental ponds (p<0.05). In addition, there was no biomagnification of PAEs in the food chains within the ponds. The health risk assessment results showed no non-carcinogenic and carcinogenic risks from the PAEs via ingestion of the fish fed with food waste feeds for the local residents.

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

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

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.

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.

Atmospheric phthalate pollution in plastic agricultural greenhouses in Shaanxi Province, China

Phthalate pollution in soil and vegetables in plastic agricultural greenhouses has attracted wide concern. Investigating airborne phthalates in this environment can improve understanding of air-soil or air-vegetable phthalate migration. However, studies of phthalates in plastic agricultural greenhouse air are rare. To fill this gap, 25 gas-phase and 23 particle-phase samples were collected from 12 typical plastic greenhouses in Shaanxi. 16 types of phthalates were measured by a gas chromatography-mass spectrometry system (GC-MS) to analyse their pollution features and variations. Results showed that in the air of the plastic greenhouses, the median concentration of the sum of sixteen type phthalates (∑₁₆ phthalates) was 5305 ng m^-3, with 5th-95th value of 1214-9616 ng m^-3. Phthalates in gas-phase samples were over 100 times higher than the levels in particle-phase samples. Air phthalate concentrations in the plastic greenhouses were higher than those in the control groups (P < 0.05). Air bis (2-ethylhexyl) phthalate (DEHP) and di-n-butyl phthalate (DnBP) accounted for 66.9% and 29.3% of total ∑₁₆ phthalate concentrations, respectively. Air phthalate concentrations in the plastic greenhouses in winter were 1.1-5.3 times higher than the levels in summer respectively (P < 0.05). Gas-particle partition coefficients (K_P) values of DEHP in summer (median of 1.52 × 10^-4 m³ μg^-1) were higher than K_P values of DnBP in summer (0.60 × 10^-4 m³ μg^-1). Log-transformed K_P values of DnBP and DEHP were linear correlated to the reciprocal of air temperatures, respectively (P < 0.05).

Deterministic Assessment of the Risk of Phthalate Esters in Sediments of U-Tapao Canal, Southern Thailand

This baseline study evaluated the ecological risk associated with the concentration of six common Phthalate esters (PAEs) in sediment samples collected from the U-Tapao canal in Southern Thailand. Deterministic approaches consisting of standard sediment quality guidelines (SQGs) and Risk quotient (RQ) were used to evaluate the potential ecological risk of individuals and a mixture of Phthalate esters (PAEs) detected in sediment samples. Of the 6 PAEs measured, only three, including di-n-butyl phthalate (DBP), di-2-ethyl hexyl phthalate (DEHP) and di-isononyl phthalate (DiNP), were identified and quantified. The total concentration of the 3 PAEs congeners found in the sediment samples ranged from 190 to 2010 ng/g dw. The results from the SQGs and RQ were not consistent with each other. The SQGs results for individual PAEs showed that DEHP and DBP found in sediment was estimated to cause moderate risk on benthic organisms, DiNP was not estimated due to lack of SQGs data. However, the RQ method indicated a low risk of DEHP and DBP on algae, crustacean and fish, whereas DiNP poses no risk on crustacean. Furthermore, based on the result obtained in this study, the consensus SQGs for mixture effects prove to be a more protective tool than the RQ concentration addition approach in predicting mixture effects. Despite inevitable uncertainties, the integration of several screening approaches of ecological risk assessment (ERA) can help get a more inclusive and credible result of the first tier of individuals and a mixture of these pollutants.

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

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

Impacts of anthropogenic activities on spatial variations of phthalate esters in water and suspended particulate matter from China's lakes

In the largest developing country, China, plastic has become a serious environmental issue because of its overuse and non-treatment. In fact, plasticizers, such as phthalate esters (PAEs), are more toxic than plastic, and their global awareness is rising. To determine the response of sensitive PAE congeners to the anthropogenic activities in a typical lake ecosystem of China, in the present study, 12 PAEs in the water and the suspended particulate matter (SPM) phases of 46 lakes in China were measured. The concentrations of all the Σ₁₂ PAEs in water and SPM phases ranged from 3.647 to 65.618 μg/L and 0.175 to 10.921 μg/L, respectively. Di-n-butyl phthalate (DnBP) was the predominant PAEs in the water phase, whereas diisobutyl phthalate (DIBP), DnBP, and bis(2-ethylhexyl) phthalate (DEHP) were the dominating PAEs in the SPM phase. Forty-six lakes were divided into four groups based on the anthropogenic activity intensities. The PAEs in both the water and SPM phases had increasing tendency along the human activity gradient. DIBP appears to be a sensitive PAE indicator that could distinguish the lake regions with different human industrial and agricultural activities. Dimethyl phthalate (DMP) and diethyl phthalate (DEP) are intensely affected by industrial development. DnBP and DEHP were positively correlated with agricultural activities, including the use of films and pesticides. It is suggested to control the addition and usage of PAEs in agricultural activities and improve their removal rates in industrial wastewater to reduce the PAE pollution in the water bodies in the environment management of China.

Spatial distribution of phthalate acid esters in sediments of the Laizhou Bay and its relationship with anthropogenic activities and geochemical variables

Spatial distribution and ecological risks of phthalate acid esters (PAEs) in sediments of the Laizhou Bay were investigated, and the relationships of PAEs with human activities and geochemical variables were studied in this work. Thirteen detectable PAEs were widespread occurrence, and the total PAE concentrations ranged from 813.1 to 11,975.6 μg/kg dry weight in sediments of the Laizhou Bay. Di-(2-ethylhexyl) phthalate (DEHP) and di-butyl phthalate (DBP) were predominant and accounted for 51.9% of ΣPAEs. The major sources of PAEs with their characteristic PAE congeners or composition could be classified as riverine runoff from catchments of the Yellow River and the rivers Xiaoqing & Zhimai, and direct discharge from the west coast and Binhai Zone, according to continuous PAE spatial distribution patterns generated by GIS techniques. The concentrations of most PAEs gradually decreased from west inshore to east offshore in inverted S shapes, which was consistent with the tide field of the Laizhou Bay. There are negative correlations between sediment depth and all PAEs, and nine PAEs exhibited negative correlations with salinity using Pearson correlation analysis. Depth and salinity exerted negative influence on PAEs (contributions of 55.8% and 32.0%, respectively) according to redundancy analysis. The DBP concentrations of 15.1% sites exceeded the ERLs and only one site had the DEHP concentration exceeded environmental risk limits. The DBP risk quotient values of 11.3% (for algae), 3.8% (for crustaceans) and 43.4% (for fish) sites exceeded 1, and most of these sites are near to four major sources. These results might benefit the implementation of effective environmental management and remediation practices.

Spatial distribution of phthalate acid esters in sediments and its relationships with anthropogenic activities and environmental variables of the Jiaozhou Bay

The spatial distribution of phthalate acid esters (PAEs) in sediments of the Jiaozhou Bay and its relationships with anthropogenic activities and environmental variables were investigated in this work. Thirteen PAEs were prevalent in sediments and the total PAE concentrations ranged from 462.1 to 15,133.2 μg/kg. The PAE concentrations increased northeastward and northwestward from the bay mouth in saddle shapes and the highest concentrations were located in the northeastern region according to the spatial distribution patterns generated by geographic information systems. The rivers were the main routes for transporting pollutants into the bay and terrigenous PAEs diluted offshore, so the PAE distribution in sediments was originated from anthropogenic activity intensity. There were strong positive correlations among PAEs with each other, except for di-n-octyl phthalate, and the average residence time (ART) exerted a significant positive impact on the PAE concentrations by Pearson correlation and redundancy analysis. The dibutyl phthalate and di-(2-ethylhexyl) phthalate had high risks to organisms in the northeast and west regions according to the environmental risk limits and risk quotients. The results might provide new insights into the PAE researches and supply information for environmental management and remediation.

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 biodegradable plastic film mulching on soil microbial communities in two agroecosystems

Plastic mulch films are used globally in crop production but incur considerable disposal and environmental pollution issues. Biodegradable plastic mulch films (BDMs), an alternative to polyethylene (PE)-based films, are designed to be tilled into the soil where they are expected to be mineralized to carbon dioxide, water and microbial biomass. However, insufficient research regarding the impacts of repeated soil incorporation of BDMs on soil microbial communities has partly contributed to limited adoption of BDMs. In this study, we evaluated the effects of BDM incorporation on soil microbial community structure and function over two years in two geographical locations: Knoxville, TN, and in Mount Vernon, WA, USA. Treatments included four plastic BDMs (three commercially available and one experimental film), a biodegradable cellulose paper mulch, a non-biodegradable PE mulch and a no mulch plot. Bacterial community structure determined using 16S rRNA gene amplicon sequencing revealed significant differences by location and season. Differences in bacterial communities by mulch treatment were not significant for any season in either location, except for Fall 2015 in WA where differences were observed between BDMs and no-mulch plots. Extracellular enzyme assays were used to characterize communities functionally, revealing significant differences by location and sampling season in both TN and WA but minimal differences between BDMs and PE treatments. Overall, BDMs had comparable influences on soil microbial communities to PE mulch films.

Distribution and risk assessment of phthalates in water and sediment of the Pearl River Delta

Phthalate esters (PAEs) are widely used industrial raw materials that are well known for their environmental contamination and toxicological effects as "endocrine disruptors." In this study, environmental levels of PAEs and eco-toxicological risk assessments were determined in the eight estuaries of the Pearl River (Estuaries), main upstream tributary (Xijiang River), urban river network (River network), and nature reserve reservoir (Reservoirs). Water and sediment samples from the above water systems were collected during the low-water period (May) and the high-water period (August) between 2012 and 2014. Solid phase and ultrasonic methods were used to extract 14 different PAEs that were analyzed by gas chromatography. The analytical average recovery of PAEs in water and sediment was 75.4% ± 4.9% and 121.5% ± 8.9%, respectively. The results showed that PAEs were detected in all of the samples, and the di-n-butyl phtalate (DBP) and benzyl butyl phthalate (BBP) monomers had a detection rate of 100% in water. Similarly, in sediment samples, the detection rates of diisobutyl phthalate (DiBP), DBP, dimethoxyethyl phthalate (DMEP), BBP, di-n-octyl phthalate (DnOP), and DNP ranged from 66.7 to 100%. Among these, in sediment samples, di(2-ethylhexyl) phthalate (DEHP) and phthalic acid bis(2-butoxyethyl) ester (DBEP) had detection rates of 95.8% to 100% in the Estuaries, Xijiang River, and River network. The concentrations of Σ₁₄PAEs in water samples and sediments ranged from 12.95 ± 1.97 to 6717.29 ± 112.37 ng/L and 71.99 ± 8.72 to 17,340.04 ± 227.83 ng/g-dw, respectively. During the low-water period, the average concentration of Σ₁₄PAEs in water and sediment was 1159.58 ± 97.22 ng/L and 2842.50 ± 178.21 ng/g-dw, respectively, and during the high-water period, 822.83 ± 53.19 ng/L and 1936.42 ± 111.31 ng/g-dw, respectively. In water, the average concentration of Σ₁₄PAEs in 2013 and 2014 was 963.39 ± 19.55 ng/L and 2815.35 ± 176.32 ng/L, respectively. In sediment, the average concentrations of Σ₁₄PAEs in 2012 to 2014 were 990.10 ± 23.33 ng/g-dw, 1084.20 ± 112.12 ng/g-dw, and 1816.89 ± 79.97 ng/g-dw, respectively, with concentrations showing an increasing trend year after year (2014 > 2013 > 2012). Potential risk assessment of water ecological, the results show that exceeding environmental risk level (ERL) value in higher molecular weight plasticizer (DEHP, DMEP, DNOP, DNP) was mainly distributed in water, the lower molecular weight plasticizer (BMP, DiBP) was mainly distributed in sediment.

Distributions, compositions, and ecological risk assessment of polycyclic aromatic hydrocarbons and phthalic acid esters in surface sediment of Songhua river, China

The distribution, composition, and ecological risk of 16 types of polycyclic aromatic hydrocarbons (PAHs) and 6 types of phthalic acid esters (PAEs) in the surface sediment of Songhua river, northeast China, were investigated. The total weight of the PAHs (∑₁₆PAHs) varied from 226.70 to 7086.62 ng/g dry weight (dw), whereas that of the PAEs (∑₆PAEs) ranged from 819.44 to 24,035.39 ng/g dw. The dominant PAHs were four-membered ring PAHs, which varied from 18.65% to 78.10% of the total PAHs. The most abundant PAEs was di-2-ethylhexyl phthalate ester (DEHP), which accounted for 65.02-99.07% of the total PAEs, followed by di-n-butyl phthalate ranging from 1.50 to 55.43%. Pyrolytic origin was the dominant PAH source. Approximately 12.70% target PAHs in the Songhua river sediment exhibited moderate ecological risk with 23.49-1404.09 ng/g carcinogenic toxicity equivalent. DEHP in 80.95% of the sediment samples exceeded the effects range low, indicating its potential harmfulness to the aquatic environment.