GC–MS determination of phthalate esters in human urine: A potential biomarker for phthalate bio-monitoring

Residual status and source analysis of phthalate esters in Ulungur Lake, China

Ulungur Lake is the largest lake in northern Xinjiang and undertakes important aquatic tasks. It is the No. 1 fishing ground in northern Xinjiang, and the problem of persistent organic pollution in the water has received much attention. However, there are few studies on phthalate esters (PAEs) in the water of Ulungur Lake. Understanding the pollution levels, distribution characteristics and sources of PAEs is of great significance for the protection and prevention of water. Fifteen sampling sites are established in Ulungur Lake to collect water samples during flood and dry periods, then seventeen PAEs are extracted from the water samples and purified by liquid-liquid extraction-solid-phase purification. Gas chromatography-mass spectrometry is used to detect the pollution levels and distribution characteristics of the 17 PAEs and analyse their sources. Results show that the concentrations of PAEs in the dry and flood periods are 0.451-9.97 µg/L and 0.0490-6.38 µg/L, respectively. The concentration of ∑PAEs with time is characterised by the dry period > the flood period. The change in flow is the main reason for the diverse concentration distributions of PAEs in different periods. The concentration of ΣPAEs in the dry period is much lower on the side near the lake entrance of the Ulungur River and Irtysh River. In the dry period, PAEs mainly come from chemical production and the use of cosmetics and personal care products; in the flood period, they mainly come from chemical production. River input and atmospheric sedimentation are the main sources of PAEs in the lake.

Widespread distribution of phthalic acid esters in indoor and ambient air samples collected from Hanoi, Vietnam

In the present study, distribution characteristics of ten typical phthalic acid esters (PAEs) were investigated in 90 air samples collected from the urban areas in Hanoi, Vietnam from May to August 2022. The total concentrations of PAEs in indoor and ambient air samples were in the range of 320-4770 ng/m³ and 35.9-133 ng/m³, respectively. Total concentrations of PAEs in indoor air were about one order of magnitude higher than those in ambient air. Among PAEs studied, di-(2-ethyl)hexyl phthalate (DEHP) was measured at the highest levels in all air samples, followed by di-n-octyl phthalate (DnOP) and di-n-butyl phthalate (DnBP). The PAEs concentrations in air samples collected from laboratories at nighttime were significantly higher than those during daytime (p < 0.05). Meanwhile, the distributions of PAEs in various micro-environments in the same house are no statistically significant difference. The median exposure doses of PAEs through inhalation for adults and children were 248 and 725 ng/kg-bw/d, respectively. These exposure levels were still lower than the respective reference doses (RfD) proposed by the US EPA for selected compounds such as diethyl phthalate (DEP), DnBP, and DEHP.

Prenatal exposure to phthalates and polybrominated diphenyl ethers on neonatal health: A birth cohort study in Guangxi, China

Few epidemiological studies have focused on prenatal phthalates (PAEs) and polybrominated diphenyl ethers (PBDEs) exposure to neonatal health in China. This study aimed to assess the associations between prenatal PAEs and PBDEs exposure and neonatal health in Guangxi, a Zhuang autonomous region of China. Concentrations of 4 PAEs metabolites (mPAEs) and 5 PBDEs congeners were measured in the serum of 267 healthy pregnant women. Birth outcomes and clinical data of neonates were collected after delivery. Mono-(2-Ethylhexyl) phthalate (MEHP) (81.52%) and BDE47 (35.21%) were the mPAEs and PBDEs congeners with the highest detection rate in serum. Prenatal exposures to mono-n-butyl phthalate (MBP), MEHP, and ΣmPAEs were negatively associated with birth weight (BW), birth length (BL), and gestational age (GA). Higher exposures to MBP, MEHP, and ΣmPAEs were associated with an increased odds ratio (OR) for low birth weight (LBW), but exposure to BDE28 exhibited the opposite effect. Moreover, higher exposures to MBP, MEHP, ΣmPAEs, BDE99, and ΣPBDEswere associated with an increased OR for premature birth (PTB) (P < 0.05). In contrast to MBP exposure, BDE28 exposure was associated with a higher OR for neonatal jaundice (NNJ) (P < 0.05). The interaction analysis showed a positive interaction between monoethyl phthalate (MEP) and BDE28 on the risk of NNJ and positive interaction between ΣmPAEs and BDE47 on the risk of NNJ. In addition, there are ethnicity-specific associations of prenatal PBDEs exposure with neonatal health in individuals of Zhuang and Han nationalities, and boy neonates were more sensitive to prenatal PBDEs exposure than girl neonates. The results revealed that prenatal exposure to mPAEs and PBDEs might have adverse effects on neonatal development, and the effects might be ethnicity- and sex-specific.

Unlocking India's Potential in Managing Endocrine-Disrupting Chemicals (EDCs): Importance, Challenges, and Opportunities

Endocrine-disrupting chemicals (EDCs) are a prime concern for the environment and health globally. Research shows that in developing countries such as India both the environment and human populations are severely exposed to EDCs and consequently experience rising incidents of adverse health effects such as diabetes and cancers. In this paper, we discuss the current EDC management approach in India, critically assess its limitations, and describe opportunities for potential improvements. Foremost, current EDC management actions and interventions in India are fragmented and outdated, and far behind the modern and comprehensive approaches adopted in the European Union and other developed countries. Strong and well-planned actions are required on various fronts of science, policy, commerce, and public engagement. These actions include the adoption of a dedicated and modern regulatory framework for managing EDCs, enhancing capacity and infrastructure for EDC monitoring in the environment and human population, employing public-private partnership programs for not only managing EDCs but also in the sectors that indirectly contribute toward the mismanagement of EDCs in the country, and raising awareness on EDCs and promoting health-preserving consumption habits among the public. As India hosts a large proportion of the global human population and biodiversity, the success or failure of its actions will substantially affect the direction of global efforts to manage EDCs and set an example for other developing countries.

Screening of antimicrobials, fragrances, UV stabilizers, plasticizers and preservatives in sewage treatment plants (STPs) and their risk assessment in India

Community/industrial wastewater is the prime source of anthropogenic chemicals, its treatment is often a daunting task and unaffordable for many countries. Emerging Contaminants (ECs) have been drained into wastewater after continuous use/misuse and Conventional treatments in STPs do not remove them completely. ECs including antimicrobial agents, synthetic musks, Benzotriazole UV stabilizers (BUVSs), plasticizers, and preservatives are frequently reported in environment, and cause health effects to non-target organisms. Monitoring of ECs is important to understand their status in aquatic environment. Hence, it was aimed to monitor ECs (n = 21) from 11 STPs in Tamil Nadu, India. The detection frequency of most of these analytes was >90%. Antimicrobials ranged from 247 to 22,714 ng/L and 11-14,369 ng/L in influents and effluents, respectively. The synthetic musks were in the order of Tonalide > Galaxolide > Musk Ketone. BUVSs ranged from 4 to 1632 ng/L (influents) and < LOD to 29,853 ng/L (effluents). Concentration of phthalates in influents and effluents were < LOD - 11,311 ng/L and < LOD - 17,618 ng/L, respectively. Parabens were found in the order of Prophyl > Methyl > Ethyl > Butyl in influents and Methyl > Prophyl > Butyl > Ethyl in effluents. Mass loads of ECs through STPs were found as antimicrobials > plasticizers > fragrances > BUVSs > Preservatives. This study reveals increasing usage of ECs and inadequate treatment processes at STPs in India. Also helps to adopt suitable treatment processes to remove ECs from wastewater and to reuse the wastewater.

Alterations in the conformation and function of human serum albumin induced by the binding of methyl hydrogen phthalate

Phthalate esters (PAEs) are widely used as plasticizer components in production. Methyl hydrogen phthalate (MHP) is a metabolite of dimethyl phthalate (DMP, a kind of PAEs), and its toxic residues accumulate in the nature and can enter the human body. Here, the interaction between MHP and human serum albumin (HSA) was probed by using multi-spectral, computer simulations, and biochemical techniques. The results showed that MHP was spontaneously embedded in site I of HSA to form a complex by H-bonds and van der Waals forces (ΔH < 0, ΔS < 0). The binding constant (K_a) of the HSA-MHP system was 1.136 ± 0.026 × 10⁴ M^-1 (298 K). The combination of MHP produced conformational variations of HSA, as shown by the 3D fluorescence spectrum, CD spectra, and molecular dynamics simulation. Additionally, molecular docking indicated that MHP was surrounded by multiple residues, such as Lys199, Leu203, Phe206, and Trp214. Specifically, Lys199 and Trp214 exerted a crucial effect on the interaction of HSA and MHP. The residues with important energy contribution were mostly located in site I. The ASA values of the aromatic amino acids of HSA changed after combining with MHP. The R_g and SASA values of HSA increased after adding MHP, suggesting that the structure of HSA was less compact. Moreover, the esterase-like activity of HSA increased after adding MHP to HSA, indicating that MHP may disturb the normal physiological activities in the human body. This study was helpful to understand the biological function of MHP and provided some insights for its side effect in the human body.

Urinary concentration of endocrine-disrupting phthalates and breast cancer risk in Indian women: A case-control study with a focus on mutations in phthalate-responsive genes

BACKGROUND

Phthalates are known endocrine-disrupting chemicals used indiscriminately as constituents in consumer products including food processing, and packaging, cosmetics, personal care and household items. Although, few studies have assessed the risk of breast cancer on exposure to phthalates, their association with breast cancer risk in Indian women have not yet been evaluated.

METHODS

We conducted a case-control study involving 171 participants. Urinary concentrations of six phthalate dieters; DMP (Dimethyl phthalate), DEP (Diethyl phthalate), DBP (Dibutyl phthalate), BBP (benzyl butyl phthalate), DEHP (Di-2-ethyl-hexyl phthalate), DINOP (Di-n-octyl phthalate) were estimated by GC-MS and geometric means were calculated. Univariate and multivariable logistic regression was performed to assess breast cancer risk on exposure to phthalates. Genes responsive to phthalates were identified through literature search and matched with NGS data, and gene-enrichment analysis was performed.

RESULTS

Significant associations were observed between urinary phthalate concentrations and increased risk of breast cancer for di-butyl phthalate (OR=1.5, 95% CI; 1.06, 2.11, p = 0.002) and di-2-ethyl-hexyl phthalate (>median vs ≤ median; OR=2.97, 95% CI; 1.18, 7.47, p = 0.005) in multivariable analyses. We also found several phthalate-responsive gene mutations in paired breast tumor tissues, which include PTPRD (76.19%), AR (42.86%), CYP1A1 (42.86%), CYP19A1 (23.81%), AHRR (19.05%), PIK3CA (19.05%), CYP1B1 (9.52%), RB1 (9.52%) and MMP9 (9.52%). Gene-enrichment analysis revealed that these genes form a major part of ER/PR, PPAR and HIF-1α-TGF-β signaling cascades involved in breast cancer CONCLUSION: Although the sample size is small, in this first case-control study from India, DBP and DEHP were found to be associated with increased risk of invasive breast cancer and tumor tissues revealed mutations in several phthalate-responsive genes. It is, therefore suggested that human biomonitoring in India and larger studies evaluating the early life genetic and epigenetic alterations on phthalates exposure are required to establish their role in breast carcinogenesis.

An introduction to the sources, fate, occurrence and effects of endocrine disrupting chemicals released into the environment

Many classes of compounds are known or suspected to disrupt the endocrine system of vertebrate and invertebrate organisms. This review of the sources and fate of selected endocrine disrupting chemicals (EDCs) in the environment includes classes of compounds that are "legacy" contaminants, as well as contaminants of emerging concern. EDCs included for discussion are organochlorine compounds, halogenated aromatic hydrocarbons, brominated flame retardants, per- and polyfluoroalkyl substances, alkylphenols, phthalates, bisphenol A and analogues, pharmaceuticals, drugs of abuse and steroid hormones, personal care products, and organotins. An exhaustive survey of the fate of these contaminants in all environmental media (e.g., air, water, soil, biota, foods and beverages) is beyond the scope of this review, so the priority is to highlight the fate of EDCs in environmental media for which there is a clear link between exposure and endocrine effects in humans or in biota from other taxa. Where appropriate, linkages are also made between the fate of EDCs and regulatory limits such as environmental quality guidelines for water and sediments and total daily intake values for humans.

Comprehensive insights into the interactions of dicyclohexyl phthalate and its metabolite to human serum albumin

Phthalate esters (PAEs) are a type of persistent organic pollutants and have received widespread concerns due to their adverse effects on human health. Dicyclohexyl phthalate (DCHP) and its metabolite monocyclohexyl phthalate (MCHP) were selected to explore the mechanism for interaction of PAEs with human serum albumin (HSA) through molecular docking and several spectroscopic techniques. The results showed that DCHP/MCHP can spontaneously occupy site I to form a binary complex with HSA, and DCHP exhibited higher binding affinity to HSA than MCHP. At 298 K, the binding constants (K_b) of DCHP and MCHP to HSA were 24.82 × 10⁴ and 1.04 × 10⁴ M^-1, respectively. Hydrogen bonds and van der Waals forces were the major driving forces in DCHP/MCHP-HSA complex. The presence of DCHP/MCHP induced the secondary structure changes in HSA, and the pi electrons of the benzene ring skeleton of DCHP/MCHP played a key role in this binding processes. Exposure of DCHP/MCHP to TM4 cells revealed that interactions between PAEs and serum albumin can affect their cytotoxicity; DCHP showed higher toxicity than MCHP. The binding affinity of PAEs with HSA may be a valuable parameter for rapid assessment of their toxicity to organisms.

Toxicity remission of PAEs on multireceptors after molecular modification through a 3D-QSAR pharmacophore model coupled with a gray interconnect degree method

In the proposed model, the gray interconnect degree method was employed to process the acute toxicity values of phthalate acid esters (PAEs) to green algae, daphnia, mysid, and fish (predicted by EPI Suite software) and to obtain the comprehensive characterization value of the multireceptor toxicity effect (MTE) of PAEs. The 3D-QSAR pharmacophore model indicated that hydrophobic groups significantly affected the MTE of PAEs. Based on this, 16 PAEs derivative molecules with significantly decreased comprehensive characterization value (more than 10%) of the toxic effects of multireceptors were designed. Among them, 13 PAEs derivative molecules reduced the toxicity values (predicted by the EPI Suite software) of four receptor organisms to varying degrees. Finally, two derivative molecules from PAEs were screened and could exist stably in the environment. The derivative molecule's reduced toxicity to the receptor was obtained through molecular docking methods and simulated the PAEs' primary metabolic response pathways. The above research results break through the pharmacophore model's limitation of only being suitable for the single effect of pollutants. Its application provides a new theoretical verification basis for expanding the multieffect pharmacophore model.

Abnormalities of Serum Fatty Acids in Children With Henoch-Schönlein Purpura by GC-MS Analysis

Purpose: The objectives of this work were to test the levels of serum medium- and long- chain fatty acids (MLCFAs) in children and to discover their possible relationship with Henoch-Schönlein Purpura (HSP), also known as Immunoglobulin A vasculitis. Methods: A total of 57 children with HSP (HSP group) and 28 healthy children (CON group) were recruited for this study. Serum specimens were collected to detect the compositions and contents of MLCFAs by gas chromatography with mass spectrometry (GC-MS) analysis. Results: The contents of all detected 37 MLCFAs in the HSP group were higher than the healthy group. Thirty-one species of MLCFAs were discovered to have a significant difference (p < 0.05) in two groups. Comparing to healthy controls, there were 31, 31, 18 fatty acids showed a statistical difference in the untreated group, regular treated group, and withdrawal group of HSP, respectively. The trend of fatty acids in the three HSP groups was similar to the healthy controls, as well as the untreated group and regular treated group changed more obviously than the withdrawal group. Almitate (C16:0) and 18 carbon atoms (C18) of fatty acids were abundant in all three HSP groups, divided according to the treatment of glucocorticoid. Some fatty acids were found having considerable differences (p < 0.05) in three groups. Monounsaturated fatty acids (MUFAs), including elaidate (C18:1T), cis-11,14,17-eicosatrienoic acid ester (C20:1), and cis-15-tetracosenoate (C24:1), were distinctly higher in HSP children with renal damage. Conclusion: Our study revealed that the abnormalities in MLCFA may be associated with the development of HSP. Another interesting finding was that fatty acids contents were changing during the glucocorticoid treatment. Meanwhile, long-chain MUFAs may have an impact on renal damage in HSP patients. Further studies need to be carried out in order to explore the specific mechanism of fatty acids in the course of HSP.

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

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

Efficacy coefficient method assisted quadruple-activities 3D-QSAR pharmacophore model for application in environmentally friendly PAE molecular modification

Phthalate acid esters (PAEs) are among the most widely used plasticizers in plastic products. They are easily diffused from plastic during use and seriously affect the environment and human health. Therefore, designing environmentally friendly PAE derivatives has important practical applications. In this paper, the environmentally friendly molecular modification of PAEs was carried out according to a comprehensive structural evaluation based on a three-dimensional quantitative structure-activity relationship (3D-QSAR) pharmacophore model of four activity modes. First, the efficacy coefficient method was used to process the mobility, toxicity, degradation and bioconcentration data of the PAEs to calculate comprehensive evaluation values. The PAE 3D-QSAR pharmacophore complex model was constructed based on the PAE four-activity comprehensive evaluation value (a comprehensive value representing the mobility, toxicity, degradation and bioconcentration of the PAEs), and a total of 4 PAE derivatives with reduced comprehensive evaluation values were obtained. Functional evaluation of the derivatives showed that the five PAEs with lower comprehensive evaluation values were stable in the environment, while the insulating properties of the derivative molecules were less affected. Following the four-activity pharmacophore model (Hypo 1) of the target molecules, dimethyl phthalate (DMP) and di-n-octyl phthalate (DNOP), comprehensive evaluation models and their mobility, toxicity, degradation and bioconcentration single-activity models, the substitution sites selected by the comprehensive evaluation model were demonstrated to be highly representative. By constructing a two-dimensional quantitative structure-activity relationship (2D-QSAR) model of the comprehensive evaluation values of the PAEs and the four single-effect 2D-QSAR models of their derivatives, the different effects of the five key parameters on the comprehensive evaluation values, toxicity, degradation, mobility and bioconcentration of molecules were analysed.

Analytical Method Development and Chemometric Approach for Evidencing Presence of Plasticizer Residues in Nectar Honey Samples

Over the years, anthropogenic sources have increasingly affected food quality. One of the most sensitive and nutritional matrices affected by chemical contamination is honey, due to the use of acaricides. Recently, the attention has moved to the presence of phthalates (PAEs) and bisphenol A (BP-A), molecules present in plastic materials used both in the production phase and in the conservation of honey. In this study, an analytical method for the simultaneous determination of PAEs (dimethyl phthalate DMP, diethyl phthalate DEP, diisobutyl phthalate DiBP, dibutyl phthalate DBP, bis(2-ethylhexyl) phthalate DEHP, and di-n-octyl-phthalate DnOP) and BP-A was developed. The extraction technique is the ultrasound-vortex-assisted dispersive liquid-liquid microextraction (UVA-DLLME), using 150 µL of toluene as an extraction solvent, followed by the gas chromatography coupled with ion trap mass spectrometry analysis (GC-IT/MS). The developed method is sensitive, reliable, and reproducible: it shows high correlation coefficients (R > 0.999); limits of detection (LODs) less than 11 ng·g-1; limits of quantification (LOQs) less than 16 ng·g-1; repeatability below 3.6%, except BP-A (11.6%); and accuracy below 4.8%, except BP-A (17.6%). The method was applied to 47 nectar honey samples for evidencing similarities among them. The chemometric approach based on Hierarchical Cluster Analysis and Principal Component Analysis evidenced some similitudes about sample origin as well as marked differences between PAE and BP-A sources.

Application of catastrophe theory in comprehensive ecological security assessment of plastic greenhouse soil contaminated by phthalate esters

Large amount of phthalate esters (PAEs) used as plasticizers in polyvinyl chloride (PVC) products has caused ubiquitous contamination to the environment and potential ecology security risk all around the world, especially in places plastic films were indispensably utilized due to the widely proposing of facility agriculture in China. A case of PAEs contamination in four suburb areas of Nanjing was analyzed and discussed in this study. A new frame work has been put forward based on multi-criteria evaluation model and mathematical method of catastrophe theory, using farming work, laboratory determination and relevant environmental standards to measure the ecology security risk of PAEs in study areas. The factors were selected based on the availability of the data and the local conditions. The assessment model involves the contamination status of PAEs in soil and vegetables, the contamination effects of PAEs to human and soil organisms and the contamination source of PAEs from plastic films and other products in the four study facility agriculture areas. An evaluation system of the model was composed of thirteen mesosphere indicators and twenty-five underlying indicators including total PAEs concentration in soils, single PAE concentration in soils, total PAEs concentrations in roots, leafy, solanaceous and stem vegetables, PAE human risks, soil microbial counts, microorganism diversity indices, atmospheric deposition of PAEs, whether sewage wastewater irrigation, planting mode of the facility agriculture areas and climate condition of study areas. The modified evaluation system was used in the assessment of ecology security of the same place based on the data of 2012, and the results suggested that the ecology security indicators were reliable and were agree well with the practical situation of the study areas. The results could provide guidance for the application of health risk assessment of soil environment for the strong objectivity of catastrophe theory compared with other evaluation methods.