Di-(2-ethylhexyl) Phthalate Contamination Research Articles

Di (2-ethylhexyl) phthalate effects on the growth, development, and reproduction of Moina macrocopa (Crustacea: Cladocera)

Di (2-ethylhexyl) phthalate (DEHP) is used as a plasticizer in plastics. The effects of DEHP on terrestrial vertebrates have been extensively reported but the effects of DEHP contamination on aquatic ecosystems have not been thoroughly studied. Since water bodies are one of the main mediums through which DEHP is released worldwide, the impacts of DEHP contamination should be manifested in water fleas. Therefore, maternal Moina macrocopa were exposed to 1, 10, 100, and 1000 μg/L concentrations of DEHP. Changes in growth and reproduction were evaluated. The findings demonstrated that DEHP exposure did not have a negative impact on growth or the ability to reproduce. An analysis of the ovary yolk body (YB) demonstrated that the average size and number of yolk bodies (YBs) produced by M. macrocopa exposed to 1000 μg/L DEHP were not significantly different to the average size and number of YBs produced in blank control and solvent control conditions. These outcomes support the cellular pathology data gathered by other researchers. Nevertheless, when M. macrocopa was exposed to 1000 μg/L DEHP for five days, a significant increase in YB numbers was observed with changes in YB morphology. The critical cellular pathology of YB showed morphological abnormalities, including rod-shaped YBs, and YB density was higher than in the blank and solvent controls. Even though these results suggest that antioxidative stress can be induced by DEHP exposure, growth, and reproduction were not significantly different among exposed water fleas compared to fleas in the blank and solvent controls. The result was attributed to the antioxidant response of the water flea. In conclusion, the present study enhances our understanding of previous findings from risk assessments of DEHP contamination in aquatic ecosystems.

A novel method for assessing indoor di 2-ethylhexyl phthalate (DEHP) contamination and exposure based on dust-phase concentration

Phthalates (PAEs) are a group of typical semivolatile organic compounds that are widely present in indoor environments with multiple phases. Indoor air, airborne particle and settled dust are considered to be typical indicators of PAE contamination as well as media of human exposure, and the interactions between them are complex. Among various phthalate compounds, di 2-ethylhexyl phthalate (DEHP) was identified as the predominant individual phthalate in settled dust. The existing DEHP contamination assessment requires multiphase sampling or solving the dynamic mass transfer models with multiple partial differential equations, which are both complicated and time-consuming. This study investigated the influence of the indoor source loading rate, surface type, particle size and cleaning frequency on the partitioning between the settled dust-phase, airborne particle-phase and gas-phase. The concentration correlations of DEHP between multiphases were consequently derived, which balance accuracy and complexity well. By comparison with field sampling data in the literatures, the rationality and accuracy of the concentration correlations were validated. Based on the concentration correlations, a new method of directly using dust-phase concentration to estimate the non-dietary exposure to DEHP was proposed. The results indicated that ingestion of settled dust contributes the most to non-dietary exposure. Special attention should be given to infants and toddlers, who suffer the highest daily exposure to DEHP among all age groups. This study provides a new and efficient solution for estimating indoor DEHP pollution loads conveniently and rapidly, offering valuable insights for future research in this field.

The synergistic toxicity effect of di(2-ethylhexyl)phthalate and plant growth disturbs the structure and function of soil microbes in the rhizosphere

Di-(2-ethylhexyl) phthalate (DEHP) is a dominant phthalic acid ester in the environment and commonly occurs at high concentration in agricultural soils. Its influence on the soil microbial community has been widely reported, while research related to its effects on microbial structure, function, and interactions in the rhizosphere, a microbial hotspot region in the terrestrial ecosystem, is still limited. This study investigated the response of microbes in the rhizosphere to DEHP contamination. DEHP reduced microbial quantity, shifted the microbial community structure, and enriched the soil bacteria with potential DEHP degraders. Although the rhizosphere can alleviate DEHP toxicity, DEHP still played an important role in microbial community construction in the rhizosphere. Interestingly, some microbes were influenced by the synergistic toxicity effect of DEHP addition and plant growth, and there were significant differences in their relative abundance and alpha diversity in soil treated with both DEHP and planting compared to soils with just DEHP spiking or planting. The genes related to cell motility, metabolism of terpenoids and polyketides, protein families, genetic information processing, and replication and repair pathways changed only in soil treated with both DEHP and planting further proved the existence of synergistic toxicity. Anyway, the impact of DEHP on microbial function in the rhizosphere was important with 52.42‰ of the genes being changed. The change in cell motility, biofilm formation, and genes related to the quorum sensing pathway might affect the relationship between microbes, which play a crucial role in ecosystem function. This was further proven by changes in the microbial co-occurrence pattern. Our results can benefit risk evaluation of DEHP to microbial community in the rhizosphere, which is important for the effective function of terrestrial ecosystems and soil health.

The Potential Biomarker of Di(2-ethylhexyl) Phthalate Exposure during Catheterization.

Di(2-ethylhexyl) phthalate (DEHP) may produce toxicity, posing a risk to human health. Medical devices composed of DEHP are frequently used in catheterization, but few studies have investigated DEHP exposure during catheterization. The aim of this prospective series was to characterize the exposure pattern of DEHP during catheterization. We enrolled 16 patients with congenital heart disease undergoing catheterization. Collection of urine was done to measure DEHP metabolites on hospitalization, before catheterization, after catheterization, and at discharge. The following DEHP metabolites were measured: mono-(2-ethylhexyl) phthalate (MEHP), mono (2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), and mono-(2-ethyl-5-oxohexyl) phthalate (MEOHP), and the ratio of MEHP to overall metabolites (MEHP%) was determined. DEHP exposure from polyvinyl chloride (PVC)-containing catheter and infusion systems were recorded in detail. Differences in DEHP levels before and after catheterization were analyzed. Urinary levels of MEHP, MEHHP, and MEOHP significantly decreased from before catheterization to after catheterization (all p < 0.01), but did not change significantly from initial hospitalization to before catheterization. Urinary MEHP% significantly decreased from initial hospitalization to before catheterization (p < 0.001), then increased after catheterization (p < 0.001), and decreased gradually at discharge (p = 0.03). Urinary MEHP% after catheterization and at discharge was significantly positively related to the duration of using PVC-containing catheter systems. There was a significant positive correlation between urinary MEHP% and the duration of using PVC-containing infusion system before catheterization, and a borderline significant correlation at both post-catheterization time slots. Our results demonstrated that urinary MEHP% may be a potential biomarker of DEHP contamination from the use of PVC-containing catheters or infusion systems.

Spatial distribution model of DEHP contamination categories in soil based on Bi-LSTM and sparse sampling

Soil pollution is a serious threat to human life and development. Different remedial measures are applied to soils with different levels of contamination. The degree of soil contamination in different areas is generally evaluated and categorised based on the analysis of samples. Regional soil sampling sites are generally sparse because of the cost of sampling and other factors, which makes it difficult to accurately assess the extent of regional soil contamination. In this study, a spatial classification model was established for the Di(2-ethylhexyl) phthalate (DEHP) pollution level using a Bi-directional Long Short-Term Memory (Bi-LSTM) neural network considering that the sampling information gradually diminishes with increasing distance between the sampling and prediction points. In this study, a method is proposed for the prediction of the spatial distribution of soil pollution categories based on sparse samples. We also established a model for the spatial distribution of organic pollution categories. The analysis of an actual contaminated area shows that the DEHP concentrations at different locations can be effectively predicted with the proposed method by categorising the contamination levels of specific DEHP samples. The results show that the method can be used to classify the degree of light/severe DEHP contamination. The results are in good agreement with the actual situation, verifying the validity of the method. This method is important for the rapid assessment of the spatial distribution of soil contamination levels based on sparse sampling.

Biodegradation of di-(2-ethylhexyl) phthalate by novel Rhodococcus sp. PFS1 strain isolated from paddy field soil.

Di-(2-ethylhexyl)-phthalate (DEHP) is the phthalate ester frequently utilized as a plasticizer, commonly found in cosmetics, packaging materials; moreover, it has carcinogenic and mutagenic effects on humans. In the current study, we isolated the soil bacterium Rhodococcus sp. PFS1 and to assess its DEHP degradation ability in various environmental conditions. The strain PFS1 was isolated from paddy field soil and identified by the 16S rRNA sequencing analyses. The strain PFS1 was examined for its biodegradation ability of DEHP at various pH, temperature, salt concentration, glucose concentration, and high and low concentrations of DEHP. Moreover, the biodegradation of DEHP at a contaminated soil environment by strain PFS1 was assessed. Further, the metabolic pathway of DEHP degradation by PFS1 was analyzed by HPLC-MS analysis. The results showed that the strain PFS1 effectively degraded the DEHP at neutral pH and temperature 30°C; moreover, expressed excellent DEHP degradation at the high salt concentration (up to 50g/L). The strain PFS1 was efficiently degraded the different tested phthalate esters (PAEs) up to 90%, significantly removed the DEHP contamination in soil along with native organisms which are present in soil up to 94.66%; nevertheless, the PFS1 alone degraded the DEHP up to 87.665% in sterilized soil. According to HPLC-MS analysis, DEHP was degraded into phthalate (PA) by PFS1 strain via mono(2-ethylehxyl) phthalate (MEHP); then PA was utilized for cell growth. These results suggest that Rhodococcus sp. PFS1 has excellent potential to degrade DEHP at various environmental conditions especially in contaminated paddy field soil.

Quantification, distribution, and effects of di (2-ethylhexyl) phthalate contamination: Risk analysis and mitigation strategies in urban environment.

Phthalate acid ester, di (2-ethylhexyl) phthalate (DEHP) is ubiquitously detected contaminant of emerging concerns (CECs) in all the environmental samples. The present study attempted to understand the fate and transport of DEHP in urban areas by evaluating the quantities, distribution, risk, and effects in the Mysuru city, India. The study is anticipated to serve as a vital document for local and national regulators to frame a robust DEHP management plan and mitigate the risks associated. Liquid-liquid microextraction followed by gas chromatographic analysis was adopted to determine the concentrations of DEHP. The risk quotient method was adopted to assess potential risk, and a conceptual planning model framework was designed to mitigate the DEHP contamination. The municipal wastewater contained 115±9.2μg/L, whereas treated municipal wastewater showed 95±7.6μg/L DEHP that was attributed to the inefficiency of the treatment plant. Further, sediments in surface water, as well as groundwater samples of the study area, showed 8±0.64 to 12±0.96μg/L and 32±2.56 to 40±3.2μg/kg of DEHP, respectively. The risk quotient of 19.17 for samples in around treatment indicated highest risk, whereas groundwater samples had a risk quotient of 1-2 indicating relative risk to aquatic organisms. In addition, the study highlighted the source, possible entry pathways, and management strategies including treatment aspects to draw an understanding of the distribution and potential ecological imbalances with contamination of DEHP in the urban sector. PRACTITIONER POINTS: Understand the fate and transportation of DEHP in urban wastewater. Primary investigation and assessment to possible health and environmental risks of DEHP contamination in urban wastewater. Revealed the associated health risks and proposed possible management strategies.

The Inhibitory Role of Di-2-ethylhexyl Phthalate on Osteogenic Differentiation of Mesenchymal Stem Cells Via Down-regulation of RUNX2 and Membrane Function Impairment

Background: Blood contamination of di-2-ethyl hexyl phthalate (DEHP) has been reported due to its release following medical procedures such as blood transfusion and vital liquid injection. We investigated the effect of DEHP on osteogenic differentiation of mesenchymal stem cells and their viability. Methods: The rat bone marrow mesenchymal cells (MSCs) were cultured three times, and the third passage kept in the differentiation medium with the presence of DEHP. The viability of differentiated cells, sodium and potassium level, calcium concentration, total protein concentration, and the activity of lactate dehydrogenase, alkaline phosphatase, alanine transaminase, and aspartate transaminase were determined. Also, the concentration of malondialdehyde, total antioxidant capacity, the activity of superoxide dismutase and catalase were estimated. Finally, the level of matrix deposition and expression of alkaline phosphatase (ALP) and runt-related transcription factor 2 (RUNX2) genes were evaluated.Results: We observed a concentration-dependent and significant reduction of matrix mineralization based on alizarin red and calcium analysis. Besides, the expression of ALP and RUNX2 gene was down-regulated, and alkaline-phosphatase activity reduced significantly. Also, we observed cell viability reduction but the elevation of lactate dehydrogenase activity and malondialdehyde level. Sodium level was elevated too, whereas the activity of transaminases, oxidative stress enzymes, potassium level, and total antioxidants decreased. Conclusion: DEHP contamination reduced matrix mineralization due to the down-regulation of the genes involved in osteogenic differentiation and viability reduction via electrolyte and metabolic imbalance as well as induction of oxidative stress.

Uptake and toxicity of di-(2-ethylhexyl) phthalate in Brassica chinensis L

This work focuses on the bioaccumulation and toxic effects of di-(2-ethylhexyl) phthalate (DEHP) in the leafy vegetable Shanghaiqing (SHQ) (Brassica chinensis L.). The accumulated DEHP amount in the edible part and roots of SHQ increased as the DEHP concentration in the soil increased. DEHP accumulation was higher in the roots than in the edible part of the plant. The root concentration factors and bioaccumulation factors for DEHP in SHQ were 0.13–2.49 and 0.03–2.00, respectively. The DEHP translocation factors were below 1.0, indicating that DEHP preferentially accumulated in plant roots. The DEHP risk index in the edible part of SHQ in relation to the human body and in terms of dietary exposure risk assessment was also below 1.0, indicating a low health risk. High DEHP concentrations caused 1) inhibition of SHQ growth, 2) an increase in SHQ chlorophyll and malondialdehyde contents and 3) a decrease in soluble sugar and vitamin contents. Low DEHP concentrations stimulated total superoxide dismutase, peroxidase and catalase activities, while high DEHP levels showed an inhibitory effect. DEHP presence in soil affected not only SHQ growth but also quality. Our results provide the data needed for the proper assessment of food safety and the ecological impact of DEHP contamination in agricultural soils.

Responses of bacterial communities in wheat rhizospheres in different soils to di-n-butyl and di(2-ethylhexyl)phthalate contamination

Di-n-butyl phthalate (DBP) and di(2-ethylhexyl)phthalate (DEHP) are commonly used as plasticizers to enhance the flexibility of plastic products. They are universal pollutants and well-known endocrine disruptors, and their effects on rhizosphere organisms have aroused great concern. In the present study, the effects of DBP and DEHP contamination on bacterial community structure and functions in wheat rhizospheres in fluvo-aquic, cinnamon, and brown soils were investigated using Illumina HiSeq 2500 sequencing. Operational taxonomic unit richness and bacterial diversity were decreased in DEHP-contaminated fluvo-aquic and brown soils, but not in DEHP-contaminated cinnamon and DBP-polluted soils. The relative abundance of some families was positively associated with soil pH, total nitrogen content (TN), and soil organic matter (SOM), and negatively correlated with DBP/DEHP concentration. The relative abundances of families that can extremely effectively degrade DBP/DEHP were enhanced by DBP/DEHP pollution, whereas the relative abundances of some genera that are beneficial to soil health were reduced in the DBP/DEHP-polluted soils. Soil pH, TN, and SOM were crucial in determining the fate and effect of PAEs in the soil ecosystems. In conclusion, DBP/DEHP pollution alters the rhizosphere bacterial community structure and affects microbial metabolic behavior and functional diversity during wheat growth.

Early life exposure to di(2-ethylhexyl)phthalate causes age-related declines associated with insulin/IGF-1-like signaling pathway and SKN-1 in Caenorhabditis elegans

Di(2-ethylhexyl)phthalate (DEHP) is an ubiquitous and emerging contaminant that is widely present in food, agricultural crop, and the environment, posing a potential risk to human health. This study utilized the nematode Caenorhabditis elegans to decipher the toxic effects of early life exposure to DEHP on aging and its underlying mechanisms. The results showed that exposure to DEHP at 0.1 and 1.5 mg/L inhibited locomotive behaviors. In addition, DEHP exposure significantly shortened the mean lifespan of the worms and further adversely affected pharyngeal pumping rate and defecation cycle in aged worms. Moreover, DEHP exposure also further enhanced accumulation of age-related biomarkers including lipofuscin, lipid peroxidation, and intracellular reactive oxygen species in aged worms. In addition, exposure to DEHP significantly suppressed gene expression of hsp-16.1, hsp-16.49, and hsp-70 in aged worms. Further evidences showed that mutation of genes involved in insulin/IGF-1-like signaling (IIS) pathway (daf-2, age-1, pdk-1, akt-1, akt-2, and daf-16) restored lipid peroxidation accumulation upon DEHP exposure in aged worms, whereas skn-1 mutation resulted in enhanced lipid peroxidation accumulation. Therefore, IIS and SKN-1 may serve as an important molecular basis for DEHP-induced age-related declines in C. elegans. Since IIS and SKN-1 are highly conserved among species, the age-related declines caused by DEHP exposure may not be exclusive in C. elegans, leading to adverse human health consequences due to widespread and persistent DEHP contamination in the environment.

Consequences of a contaminant mixture of bisphenol A (BPA) and di-(2-ethylhexyl) phthalate (DEHP), two plastic-derived chemicals, on the diversity of coastal phytoplankton

To assess the impact of two plastic derived chemicals: bisphenol A (BPA) and the di-2-ethylhexyl phthalate (DEHP), on phytoplankton biomass and community structure, microcosm incubations were performed during spring and summer, with offshore and lagoon waters of a south-western Mediterranean ecosystem. Phytoplankton were exposed to an artificial mixture of BPA and DEHP and to marine water previously enriched with plastic-derivative compounds, originated from in situ water incubations of plastic debris for 30 days. After 96 h of incubation, changes were observed in phytoplankton biomass in the contaminated microcosms, with a net decrease (up to 50% of the control) in the concentration of Chlorophyll a in offshore waters. Concomitantly, plastic-derivative contamination provoked structural changes, especially for offshore waters. This suggests a relative tolerance of the lagoon communities to BPA and DEHP contamination, related to the dominance of Chaetoceros spp., which could potentially be used as a bioindicator in bioassessment studies.

Fate of di (2-ethylhexyl) phthalate and its impact on soil bacterial community under aerobic and anaerobic conditions

In this study, we examined the influence of oxygen on the degradation of di (2-ethylhexyl) phthalate (DEHP), the accumulation of its monoester metabolite mono (2-ethylhexyl) phthalate (MEHP) and their impact on soil bacterial communities. Soil microcosms artificially contaminated with DEHP (0, 100 and 1000 mg kg−1) were incubated under aerobic and anaerobic flooded conditions, and sacrificed after 0, 21 and 42 days. The results indicated that DEHP degradation proceeded at similar rates in aerobic and anaerobic flooded soils, but accumulation of metabolite MEHP was more likely to occur in anaerobic soils. Moreover, MEHP generated from DEHP degradation seemed to be readily released into the water phase, which may arouse health concerns. Illumina Miseq sequencing showed that MEHP had a greater impact on soil bacterial community than DEHP at the same dosage, and a wide range of bacterial phylotypes were inhibited by MEHP under anaerobic conditions. High DEHP contamination (1000 mg kg−1) significantly reduced bacterial diversity and altered bacterial community structure under anaerobic conditions, but not under aerobic conditions. Firmicutes was constantly inhibited by DEHP under both aerobic (Bacillus) and anaerobic (unclassified Clostridiales Family_XVIII) conditions. On the other hand, bacterial phylotypes belonging to Actinobacteria, β-Proteobacteria and Gemmatimonadaceae were constantly enriched by DEHP in anaerobic soils, however no such a clear pattern existed in aerobic soils. This work greatly expanded our understanding of the fate of DEHP and its modifying effect on bacterial communities under different environmental conditions.

Fate of di (2‑ethylhexyl) phthalate in different soils and associated bacterial community changes

Di (2‑ethylhexyl) phthalate (DEHP) is a ubiquitous organic pollutant, which has caused considerable pollution in arable soils. In this study, the relationship between DEHP degradation potential and soil properties in 12 agricultural soils (S1-S12) was examined in a microcosm based experiment. Six of these soils were then selected to monitor patterns in bacterial community responses. It was found that DEHP degradation was positively correlated with bacterial counts in the original soils, suggesting a key role for bacteria in degradation. However, DEHP metabolism did not always lead to complete degradation. Its monoester metabolite, mono (2‑ethylhexyl) phthalate (MEHP), was present at appreciable levels in the two acidic soils (S1 and S2) during the incubation period of 35 days. Based on high-throughput sequencing data, we observed a greater impact of DEHP contamination on bacterial community structure in acidic soils than in the other soils. Nocardioides, Ramlibacter and unclassified Sphingomonadaceae were enriched in the two near-neutral soils where degradation was highest (S4 and S7), suggesting that these organisms might be efficient degraders. The relative abundance of Tumibacillus was greatly reduced in 50% of the six soils examined, demonstrating a high sensitivity to DEHP contamination. Furthermore, putative organic-matter decomposing bacteria (including Tumebacillus and other bacteria taxa such as members from Micromonosporaceae) were greatly reduced in the two acidic soils (S1 and S2), possibly due to the accumulation of MEHP. These results suggest a crucial role of soil acidity in determining the fate and impact of DEHP in soil ecosystems, which deserves further investigation. This work contributes to a better understanding of the environmental behavior of DEHP in soil and should facilitate the development of appropriate remediation technologies.

Environmental Concerns and Toxicogenetic Endpoints of Priority Substances (PSs) and Contaminants of Emerging Concerns (CECs): A Comprehensive Review

Priority Substance (PSs) and Contaminant of Emerging Concerns (CECs) exhibited a wide range of environmental and public health concerns worldwide. This review summarized the documented studies related to the current surface water occurrence, spatial distribution, ecological risks and toxicity of selected PSs, such as polycyclic aromatic hydrocarbons (PAHs) and CECs, such as Di(2-Ethylhexyl) Phthalate (DEHP) and Pharmaceuticals and Personal Care Products (PPCPs). The spatial distribution analysis revealed alarming levels of PAHs in the surface waters of Asian counties, e.g., 84210 ng L-1 in Gomti River, India, 29325 ng L-1 in Daya Bay, China and 1287 ng L-1 in Chenab River, Pakistan. As for DEHP, the highest concentrations of 13050 µg L-1 in Liao River, China, and 2306 µg L-1 in Rivers of Eastern Cape, South Africa were reported. These environmental levels of PAHs and DEHP were many folds higher than the surface water permissible levels devised by WHO and USEPA. Contrarily, the emerging PPCPs were reported in relatively lower levels in the surface waters globally, compared to that of PAHs and DEHP. Consistent with the environmental levels, PAHs and DEHP revealed alarming ecological risks in the surface water sources, compared to that of PPCPs. Regarding to the sources of PSs and CECs, PAHs emissions were mostly linked to the incomplete combustion of petroleum products, DEHP contamination was associated to its applications in consumption and production of plastic appliances and PPCPs emissions were largely related to the domestic and industrial effluents. As for toxic endpoints of PAHs, DEHP and PPCPs, all of these were reported to cause DNA damage, genotoxicity, reproductive toxicity, developmental toxicity and immunotoxicity, as revealed in reviewed in vitro/vivo studies. In addition, the current review also highlighted the existing environmental regulations to control the emissions of these pollutants to the environmental matrices. Taken together, this review concluded that despite the existing environmental regulations, the current levels of organic pollutants are still on rising, especially in Asian countries. Therefore, the strict implementation of the existing regulations is highly necessary to control these pollutants to ensure public health and ecological integrity.

Impact of two plastic-derived chemicals, the Bisphenol A and the di-2-ethylhexyl phthalate, exposure on the marine toxic dinoflagellate Alexandrium pacificum

The effects of two plastic-derived chemicals: Bisphenol A (BPA) and di-2-ethylhexyl phthalate (DEHP) were assessed on abundance and physiological responses of the marine toxic dinoflagellate Alexandrim pacificum. During 7days experiment, A. pacificum was exposed to different levels of BPA and DEHP (separately and in mixture). The responses were evaluated and compared with controls. Results showed that A. pacificum was highly sensitive to this contaminants comparing to other phytoplankton species. BPA and DEHP caused the decrease of the biomass (1.2 to 50 times lower relative to the controls), as well as the perturbation of the photosystem and the photosynthetic activity. Nevertheless, our results show a recovery of contaminated cells activity depending on exposure time and BPA and DEHP contamination. This could be related to an adaptation to induced stress or a degradation of BPA and DEHP in the medium.

Leaching of the plasticizer di(2-ethylhexyl)phthalate (DEHP) from plastic containers and the question of human exposure.

Di(2-ethylhexyl)phthalate (DEHP) is a widely used plasticizer to render poly(vinyl chloride) (PVC) soft and malleable. Plasticized PVC is used in hospital equipment, food wrapping, and numerous other commercial and industrial products. Unfortunately, plasticizers can migrate within the material and leach out of it over time, ending up in the environment and, frequently, the human body. DEHP has come under increased scrutiny as its breakdown products are believed to be endocrine disruptors and more toxic than DEHP itself. DEHP and its breakdown products have been identified as ubiquitous environmental contaminants, and daily human exposure is estimated to be in the microgram per kilogram level. The objective of this review is to summarize and comment on published sources of DEHP exposure and to give an overview of its environmental fate. Exposure through bottled water was examined specifically, as this concern is raised frequently, yet only little exposure to DEHP occurs through bottled water, and DEHP exposure is unlikely to stem from the packaging material itself. Packaged food was also examined and showed higher levels of DEHP contamination compared to bottled water. Exposure to DEHP also occurs in hospital environments, where DEHP leaches directly into liquids that passed through PVC/DEHP tubing and equipment. The latter exposure is at considerably higher levels compared to food and bottled water, specifically putting patients with chronic illnesses at risk. Overall, levels of DEHP in food and bottled water were below current tolerable daily intake (TDI) values. However, our understanding of the risks of DEHP exposure is still evolving. Given the prevalence of DEHP in our atmosphere and environment, and the uncertainty revolving around it, the precautionary principle would suggest its phaseout and replacement. Increased efforts to develop viable replacement compounds, which necessarily includes rigorous leaching, toxicity, and impact assessment studies, are needed before alternative plasticizers can be adopted as viable replacements.

Impact of irreversible sorption of phthalate acid esters on their sediment quality criteria

The equilibrium partitioning (EqP) method has been applied to establish sediment quality criteria (SQC); however, it does not consider the nonlinear irreversible sorption of many organic contaminants. In this research, the sorption and desorption of two phthalate esters (PAEs), dimethyl phthalate (DMP) and di(2-ethylhexyl) phthalate (DEHP), in four natural sediments collected from the Yangtze River and the Yellow River were studied; the impact of irreversible sorption of DMP and DEHP on SQC has been evaluated. Based on the reversible and irreversible biphasic sorption model, the values of maximum irreversible sorption capacity (q(max)(irr)) were 125.19 μg g(-1)-337.37 μg g(-1) for DMP and 515.87 μg g(-1)-591.40 μg g(-1) for DEHP. The q(max)(irr) value was positively related to the organic carbon and black carbon contents, cation exchange capacity, and surface area of the sediments. The values of the irreversible sorption coefficient K(oc)(irr) for both DEHP and DMP in the four sediments approximated to a constant of 10(6.46 ± 0.38), which was 1-2 orders of magnitude higher than their reversible sorption coefficient K(oc)(irr). The values of SQC for PAEs based on the EqP method were modified by involving the irreversible sorption. The modified SQC of DEHP could be 2 to 20 times higher than the value predicted by the EqP method, and the assessment results for DEHP contamination in the sediments with the modified SQC were more reasonable than those with the non-modified SQC. It indicated that the current SQC based on the EqP method may be unnecessarily strict for specific organic compounds and the irreversible sorption should be taken into account.

Uptake of Di-(2-ethylhexyl) Phthalate of Vegetables from Plastic Film Greenhouses

Uptake of di-(2-ethylhexyl) phthalate (DEHP) of nine vegetables including potherb mustard, bok choy, celery, spinach, cabbage, leaf of tube, lettuce, garlic, and edible amaranth in plastic film greenhouses with different plastic films, film thickness, greenhouse age, and greenhouse height was studied. The results showed that the higher the DEHP content of film, the thicker the film, the lower the height of the greenhouse, and the younger the age of the greenhouse were, the higher the DEHP concentration of vegetables was. The results afford significant information for production of safe vegetables with low level DEHP contamination.

Uptake of di-(2-ethylhexyl)phthalate from plastic mulch film by vegetable plants

The uptake of di-(2-ethylhexyl) phthalate (DEHP) from plastic mulch film used in field cultivation by 10 vegetable plants was investigated by experiments carried out in pots. The results showed that DEHP was transferred from the mulch film to all vegetable plants. Wax gourd (Benincasa hispida) showed the greatest capacity for uptake of DEHP, while cucumber (Cucumis sativus) and pumpkin (Cucurbita moschata) could also accumulate high levels. This implies that wax gourd, cucumber and pumpkin may be sources of DEHP contamination in the human diet. Moreover, Chinese cabbage (Brassica parachinensis) also accumulated a high level of DEHP from mulch plastic film giving dietary exposure close to the daily intake limit for DEHP.