Phthalate and non-phthalate plasticizers in indoor dust from childcare facilities, salons, and homes across the USA

Identification and quantification of acetyl tributyl citrate (ATBC) metabolites using human liver microsomes and human urine

Plasticizers are chemicals that make plastics flexible, and phthalates are commonly used. Due to the toxic effects of phthalates, there is increasing use of non-phthalate plasticizers like acetyl tributyl citrate (ATBC). ATBC has emerged as a safer alternative, yet concerns about its long-term safety persist due to its high leachability and potential endocrine-disrupting effects. This study aims to identify ATBC metabolites using human liver microsomes and suspect screening methods, and to explore potential urinary biomarkers for ATBC exposure. Using ultra-high-performance liquid chromatography coupled with high-resolution mass spectrometry, we identified ATBC metabolites, including acetyl dibutyl citrate (ADBC), tributyl citrate (TBC), and dibutyl citrate (DBC). Urine samples from 15 participants revealed the presence of ADBC in 5, TBC in 11, and DBC in all samples, with DBC concentrations pointedly higher than the other metabolites. These metabolites show promise as biomarkers for ATBC exposure, though further validation with human data is required. Our results underscore the need for comprehensive studies on ATBC metabolism, exposure pathways, and urinary excretion to accurately assess human exposure levels.

DEHP (di(2-ethylhexyl)phthalate) stimulates skin pigmentation by perturbing cytoskeletal homeostasis

Phthalates are extensively employed plasticizers crucial for conferring flexibility and plasticity to polyvinyl chloride. Phthalates, including DEHP (di(2-ethylhexyl)phthalate), present in diverse products, have been identified in fine dust and are capable of infiltrating the body, potentially posing health hazards. Importantly, melanocytes, existing at the basal layer of the epidermis, are susceptible to toxic substances. In our study, we employed the 3D human pigmented epidermis model, MelanoDerm™, along with the B16F10 murine melanoma cell line, to examine the influence of DEHP exposure on melanocytes. The exposure to low concentrations of DEHP (~ 5 μM), resulted in the extension of melanocyte dendrites, indicating the stimulation of melanocytes. Analysis of gene expression and protein profiles unveiled the up-regulation of MITF, Arpc2, and TRP1 genes subsequent to DEHP exposure, indicating alterations in cytoskeletal and melanosome-related genetic and protein components in melanocytes. Notably, increased pigmentation was observed in MelanoDerm™ following DEHP exposure. DEHP-stimulated reactive oxygen species generation appeared to be involved in these events since the antioxidant, ascorbic acid attenuated ROS generation and MITF upregulation. Collectively, our study demonstrated that DEHP exposure can induce cytoskeletal disturbance and skin pigmentation through oxidative stress.

Phthalate alternatives and their monoesters in indoor dust from several regions, China and implications for human exposure

Household products, in response to regulations, increasingly incorporate phthalate (PAE) alternatives instead of traditional PAEs. However, limited information exists regarding the fate and exposure risk of these PAE alternatives and their monoesters in indoor environments. The contamination levels of PAE alternatives and their monoesters in indoor dust might vary across regions due to climate, population density, industrial activities, and interior decoration practices. By analyzing indoor dust samples from six geographical regions across China, this study aims to shed light on concentrations, profiles, and human exposure to 12 PAE alternatives and 9 their monoesters. Bis(2-ethylhexyl) benzene-1,4-dicarboxylate (DEHTP), tributyl 2-acetyloxypropane-1,2,3-tricarboxylate (ATBC), and tris(2-ethylhexyl) benzene-1,2,4-tricarboxylate (TOTM) were the main PAE alternatives in dust across all regions. The total concentrations of 12 PAE alternatives ranged from 0.125 to 4160 μg/g in indoor dust. High molecular weight PAE alternatives had significantly correlated concentrations (p < 0.05) based on Spearman analysis, suggesting their co-use in heat-resistant plastic products. A collective of nine monoesters were identified in most samples, with total concentrations ranging from 0.048 to 29.6 μg/g. The median concentrations of PAE alternatives were highest in North China (66.8 μg/g), while those of monoesters were highest in Southwest China (6.93 μg/g). A significant correlation (p < 0.05) between the concentrations of DEHTP and its monoester suggested that degradation could be a potential source of monoesters. Although hazard quotients (HQs) have been calculated to suggest that the current exposure is unlikely to pose a significant health risk, the lack of toxicity threshold data and the existence of additional exposure pathways necessitate a further confirmation.

A systematic review of global distribution, sources and exposure risk of phthalate esters (PAEs) in indoor dust

Phthalate esters (PAEs) are a class of plasticizers that are readily released from plastic products, posing a potential exposure risk to human body. At present, much attention is paid on PAE concentrations in indoor dust with the understanding of PAEs toxicity. This study collected 8187 data on 10 PAEs concentrations in indoor dusts from 26 countries and comprehensively reviewed the worldwide distribution, influencing factors, and health risks of PAEs. Di-(2-ethylhexyl) phthalate (DEHP) is the predominant PAE with a median concentration of 316 μg·g-1 in indoor dust. Polyvinyl chloride wallpaper and flooring and personal care products are the main sources of PAEs indoor dust. The dust concentrations of DEHP show a downward trend over the past two decades, while high dust concentrations of DiNP are found from 2011 to 2016. The median dust contents of 8 PAEs in public places are higher than those in households. Moreover, the concentrations of 9 PAEs in indoor dusts from high-income countries are higher than those from upper-middle-income countries. DEHP in 69.8% and 77.8% of the dust samples may pose a potential carcinogenic risk for adults and children, respectively. Besides, DEHP in 16.9% of the dust samples may pose a non-carcinogenic risk to children. Nevertheless, a negligible risk was found for other PAEs in indoor dust worldwide. This review contributes to an in-depth understanding of the global distribution, sources and health risks of PAEs in indoor dust.

Identification, semi-quantification and risk assessment of contaminants of emerging concern in Flemish indoor dust through high-resolution mass spectrometry

Indoor dust can contribute substantially to human exposure to known and contaminants of emerging concern (CECs). Novel compounds with high structural variability and different homologues are frequently discovered through screening of the indoor environment, implying that constant monitoring is required. The present study aimed at the identification and semi-quantification of CECs in 46 indoor dust samples collected in Belgium by liquid chromatography high-resolution mass spectrometry. Samples were analyzed applying a targeted and suspect screening approach; the latter based on a suspect list containing >4000 CECs. This allowed the detection of a total of 55 CECs, 34 and 21 of which were identified with confidence level (CL) 1/2 or CL 3, respectively. Besides numerous known contaminants such as di(2-ethylhexyl) phthalate (DEHP), di(2-ethylhexyl) adipate (DEHA) or tris(2-butoxyethyl) phosphate (TBOEP) which were reported with detection frequencies (DFs) > 90%, several novel CECs were annotated. These included phthalates with differing side chains, such as decyl nonyl and decyl undecyl phthalate detected with DFs >80% and identified through the observation of characteristic neutral losses. Additionally, two novel organophosphate flame retardants not previously described in indoor dust, i.e. didecyl butoxyethoxyethyl phosphate (DDeBEEP) and bis(butoxyethyl) butyl phosphate (BBEBP), were identified. The implementation of a dedicated workflow provided semi-quantitative concentrations for a set of suspects. Such data obtained for novel phthalates were in the same order of magnitude as the concentrations observed for legacy phthalates indicating their high relevance for human exposure. From the semi-quantitative data, estimated daily intakes and resulting hazard quotients (HQs) were calculated to estimate the exposure and potential health effects. Neither of the obtained HQ values exceeded the risk threshold, indicating no expected adverse health effects.

Multi-source exposure and health risks of phthalates among university students in Northeastern China

The endocrine disruptor phthalates (PAEs) are widely used as important chemical additives in a variety of areas around the globe. PAEs are toxic to reproduction and development and may adversely affect the health of adolescents. Risk assessments of exposure to PAEs from different sources are more reflective of actual exposure than single-source assessments. We used personal exposure parameters to estimate the dose of PAEs to 107 university students from six media (including dormitory dust, dormitory air, clothing, food, disposable food containers, and personal care products (PCPs)) and three exposure routes (including ingestion, inhalation, and dermal absorption). Individual factors and lifestyles may affect PAE exposure to varying degrees. Based on a positive matrix factorization (PMF) model, the results indicated that the main sources of PAEs in dust were indoor building materials and plastics, while PCPs and adhesives were the major sources of airborne PAEs. The relative contribution of each source to PAE exposure showed that food and air were the primary sources of dimethyl phthalate (DMP) and dibutyl phthalate (DBP). Air source contributed the most to diethyl phthalate (DEP) exposure, followed by PCPs. Food was the most significant source of diisobutyl phthalate (DiBP), benzyl butyl phthalate (BBP), and bis(2-ethylhexyl) phthalate (DEHP) exposure. Additionally, the exposure of DEHP to dust was not negligible. The ingestion pathway was the most dominant among the three exposure pathways, followed by dermal absorption. The non-carcinogenic risk of PAEs from the six sources was within acceptable limits. DEHP exhibits a low carcinogenic risk. We suggest university students maintain good hygienic and living habits to minimize exposure to PAEs.

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.

Comprehensive assessment of phthalates in indoor dust across China between 2007 and 2019: Benefits from regulatory restrictions

China is the largest producer and consumer of phthalates in the world. However, it remains unclear whether China's phthalate restrictions have alleviated indoor phthalate pollution. We extracted the concentrations of dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), diisobutyl phthalate (DIBP), benzyl butyl phthalate (BBP), and bis(2-ethylhexyl) phthalate (DEHP) in indoor dust at 2762 sites throughout China between 2007 and 2019 from the published literature. Based on these data, we investigated the effects of phthalate restrictions and environmental factors on the temporal-spatial distribution and sources of phthalates and estimated human exposure and risk of phthalates. The results revealed that the mean concentrations of phthalates in indoor dust throughout China decreased in the following order: DEHP > DBP > DIBP > DMP > DEP > BBP. The concentrations of six phthalates were generally higher in northern and central-western China than in southern regions. BBP and DEHP concentrations decreased by 73.5% and 17.9%, respectively, from 2007 to 2019. Sunshine was a critical environmental factor in reducing phthalate levels in indoor dust. Polyvinyl chloride materials, personal care products, building materials, and furniture were the primary sources of phthalates in indoor dust. The phthalates in indoor dust posed the most significant threat to children and older adults. This study provides a picture of phthalate pollution, thus supporting timely and effective policies and legislation.

Evaluating the risk of phthalate and non-phthalate plasticizers in dust samples from 100 Japanese houses

Phthalates are widely used as plasticizer and associated with various health issues. Recently, non-phthalate plasticizers are replacing phthalates; however, the exposure to these substances and the risk in Japan is unclear. In this study, we assessed the concentrations of phthalates, non-phthalate plasticizers, and phthalate degradation products in house dust and determined their respective exposure risks via oral and dermal routes. Twelve phthalates, seven non-phthalate plasticizers, and two degradation products were determined in the house dust obtained from 100 Japanese homes. The median concentration of di(2-ethylhexyl) phthalate (DEHP), accounting for 85 % of the total concentration of phthalates and non-phthalate plasticizers detected in this study, was 2.1 × 103 μg/g of dust. Apart from DEHP, diisononyl phthalate (DINP) and di(2-ethylhexyl) terephthalate (DEHT) were the most abundant in the house dust, accounting for 6.2 % (median: 1.7 × 102 μg/g of dust) and 6.1 % (median: 1.7 × 102 μg/g of dust) of the total concentrations, respectively. DEHP and DEHT concentrations in house dust were higher in apartment and small houses (floor area: ≤30 m2 or 31-60 m2 for DEHP and 31-60 m2 for DEHT) than in detached and large houses (floor area: ≥121 m2). Conversely, di-n-butyl phthalate (DnBP) concentrations were significantly higher in detached and large houses (floor area: ≥121 m2) than in apartment and small houses (floor area: ≤30 m2). The total hazard quotient (HQ), using the maximum concentration in house dust, revealed that oral and dermal exposure to house dust was 1.3 × 10-6-0.11 for adults (all substances) and 1.6 × 10-5-2.2 × 10-2 for preschool children (except for DnBP and DEHP), suggesting no risk. The HQs for DnBP and DEHP exposure via house dust for preschool children using the maximum values were 0.46 and 1.2, and 6.0 × 10-3 and 0.18 using the median values, indicating that risk of DEHP exposure should be exhaustively determined by considering other exposure routes that were not evaluated in this study, such as diet.

Efficient analysis of toxicity and mechanisms of environmental pollutants with network toxicology and molecular docking strategy: Acetyl tributyl citrate as an example

The study aims to promote network toxicology strategy to efficiently investigate the putative toxicity and underlying molecular mechanisms of environmental pollutants through an example of exploring brain injury induced by ATBC exposure. By utilizing ChEMBL, STITCH, GeneCards, and OMIM databases, we identified 213 potential targets associated with ATBC exposure and brain injury. Further refinements via STRING and Cytoscape software highlight 23 core targets, including AKT1, CASP3, and HSP90AA1. GO and KEGG pathway analysis conducted through DAVID and FUMA databases reveal that core targets of ATBC-induced brain toxicity are predominantly enriched in cancer signaling and neuroactive ligand receptor interaction pathways. Molecular docking was performed with Autodock, which confirmed robust binding between ATBC and core targets. Together, these findings suggest that ATBC may impact the occurrence and development of brain cancer and brain related inflammation, whereas pose risks for cognitive impairment and neurodegeneration, by modulating the apoptosis and proliferation of brain cancer cells, activating inflammatory signaling pathways, and regulating neuroplasticity. This research provides a theoretical basis for understanding the molecular mechanism of ATBC-induced brain toxicity, as well as establishing a foundation for the prevention and treatment of prostatic diseases associated with exposure to plastic products containing ATBC and certain ATBC-overwhelmed environments. Moreover, our network toxicology approach also expedites the elucidation of toxicity pathways for uncharacterized environmental chemicals.

Bisphenols and phthalates in Australian wastewater: A statistical approach for estimating contributions from diffuse and point sources

Chemicals associated with plastics, such as bisphenols and phthalates, enter sewerage from both diffuse (domestic/commercial) and point (industrial) sources. In this study, we aimed to devise a conservative, statistical baseline to estimate contributions from these source types when sampling of specific sources is not possible. Population-normalised mass loads of two bisphenols and nine phthalates were estimated in wastewater samples from 22 sewage treatment plants (STPs) in 2019. Two multiday (10 and 7 day) pools were created for each STP. Baseline (diffuse) release thresholds were set at the mean of the first quartile (Q1) plus 10 times the standard deviation (STDV) of this quartile [Q1 mean + (10 x STDV)], with contributions over this considered to come from point sources. Chemicals with at least one population-normalised mass load more than three times their baseline were classified as point-source dominant and the remaining as diffuse-source dominant. Eleven of the twelve chemicals examined were detected above limits of quantification in all wastewater samples. Bisphenol A (BPA), bisphenol S (BPS), di-isononyl phthalate (DiNP) and di-methyl phthalate (DMP) were classified as point-source dominant chemicals. The total annual mass loads entering STPs across Australia were estimated to be 4.2 tonnes/year from diffuse sources and 4.5 tonnes/year from point sources for bisphenols, and 47 tonnes/year from diffuse sources and 5.9 tonnes/year from point sources for phthalates.

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.

Acetyl Tributyl Citrate Exposure at Seemingly Safe Concentrations Induces Adverse Effects in Different Genders of Type 2 Diabetes Mice, Especially Brain Tissue

Acetyl tributyl citrate (ATBC) is a widely used phthalate substitute. Although ATBC is considered to be with a safe dosage of up to 1000 mg/kg/day, studies on its effects in some sensitive populations, such as diabetic patients, are relatively rare. Epidemiological studies have shown that there is a link between diabetes and nervous system diseases. However, toxicological studies have not fully confirmed this yet. In this study, glycolipid metabolism, cognitive deficits, brain tissue damage, levels of neurotransmitters, beta-amyloid plaques (Aβ), hyperphosphorylated tau protein (p-Tau), oxidative stress and inflammation, as well as glial cell homeostatic levels in the brain tissue of type 2 diabetes (T2DM) mice, were determined after ATBC exposure (0, 2, 20, and 200 mg/kg/day) for 90 days. The results confirmed that ATBC exposure aggravated the disorder of glycolipid metabolism and caused cognitive deficits in T2DM mice; induced histopathological alterations and Aβ and p-Tau accumulation, and reduced the levels of 5-hydroxytryptamine and acetylcholine in T2DM mouse brains; oxidative stress and glial cell homeostatic levels in T2DM mouse brains were also changed. Some of the adverse effects were gender-dependent. These findings support the theory that T2DM mice, especially males, are more sensitive to ATBC exposure. Although the safe dose of ATBC is high, prolonged exposure at seemingly safe concentrations has the potential to aggravate diabetes symptoms and cause brain tissue damage in T2DM mice.

Characterizing the Contribution of Indoor Residential Phthalate and Phthalate Alternative Dust Concentrations to Internal Dose in the US General Population: An Updated Systematic Review and Meta-Analysis

Diet is the primary exposure pathway for phthalates, but relative contributions of other exposure sources are not well characterized. This study quantifies the relative contribution of indoor residential dust phthalate and phthalate alternative concentrations to total internal dose estimated from the National Health and Nutrition Examination Survey (NHANES) urinary metabolite concentrations. Specifically, median phthalate and phthalate alternative concentrations measured in residential dust were determined by updating a pre-existing systematic review and meta-analysis published in 2015 and the attributable internal dose was estimated using intake and reverse dosimetry models. Employing a predetermined search strategy, 12 studies published between January 2000 and April 2022 from Web of Science and PubMed measuring phthalates and phthalate alternatives in residential dust were identified. From the data extracted, it was estimated that dust contributed more significantly to the internal dose of low-molecular weight chemicals such as DEP and BBP when compared to high-molecular weight chemicals such as DEHTP. Additionally, findings showed that the chemical profile of residential dust is changing temporally with more phthalate alternatives being detected in the indoor environment. Future studies should seek to characterize the contribution of dust to an overall phthalate and phthalate alternative intake for individuals who have higher than normal exposures.

Exposure Trends to the Non-phthalate Plasticizers DEHTP, DINCH, and DEHA in Children from 2012 to 2017: The Hokkaido Study

Phthalates owing to their endocrine-disrupting effects are regulated in certain products, leading to their replacement with substitutions such as di-2-ethylhexyl terephthalate (DEHTP), 1,2-cyclohexane dicarboxylic acid di(isononyl) ester (DINCH), and di(2-ethylhexyl) adipate (DEHA). However, information on human exposure to these substitutes, especially in susceptible subpopulations such as children, is limited. Thus, we examined the levels and exposure trends of DEHTP, DINCH, and DEHA metabolites in 7 year-old Japanese school children. In total, 180 urine samples collected from 2012 to 2017 were used to quantify 10 DEHTP, DINCH, and DEHA metabolites via isotope dilution liquid chromatography with tandem mass spectrometry. DEHTP and DINCH metabolites were detected in 95.6 and 92.2% of the children, respectively, and DEHA was not detected. This study, annually conducted between 2012 and 2017, revealed a significant (p < 0.05) 5-fold increase in DEHTP metabolites and a 2-fold increase in DINCH metabolites. However, the maximum estimated internal exposures were still below the health-based guidance and toxicological reference values. Exposure levels to DEHTP and DINCH have increased considerably in Japanese school children. DEHA is less relevant. Future studies are warranted to closely monitor the increasing trend in different aged and larger populations and identify the potential health effects and sources contributing to increasing exposure and intervene if necessary.

Levels and health risk assessments of Phthalate acid esters in indoor dust of some microenvironments within Ikeja and Ota, Nigeria

The levels, profiles of Phthalate acid esters (PAEs) and their associated health risk in children and adults using indoor dust samples were assessed from nine (9) microenvironments in Nigeria. Six PAEs congeners were determined using Gas Chromatography-Mass Spectrometry and the human health risk assessments of PAEs exposure to children and adults were computed using the United States Environmental Protection Agency (USEPA) exposure model. The mean concentrations of the total PAEs (Σ₆PAEs) in indoor dust across the study locations ranged from 1.61 ± 0.12 to 53.3 ± 5.27 μg/g with 72.0% of di-n-octyl phthalate (DnOP) as the most predominant contributor of PAEs in sample locations B, C, D, E, F and G. PAEs estimated daily intake results exceeded the USEPA value of 20 and 50 kg/bw/day for children and adults respectively in some locations. Non-carcinogenic risk exposure indicated no risk (HI < 1), while the carcinogenic risk was within the recommended threshold of 1.00 × 10^-4 to 1.00 × 10^-6 for benzyl butyl phthalate and bis-2-ethylhexyl phthalate. From our findings, lower levels of PAEs were observed in locations with good ventilation system. Also, the human health risk evaluation indicated indoor dust ingestion as the dominant exposure route of PAEs for both children and adults, while the children were at a higher risk of PAEs exposure. To protect children susceptible to these endocrine-disrupting pollutants, soft vinyl children's toys and teething rings should be avoided. Appropriate policies and procedures on the reduction of PAEs exposure to humans should be enacted by all stakeholders, including government regulatory agencies, industries, school administrators and the entire community.

Assessment of lipid metabolism-disrupting effects of non-phthalate plasticizer diisobutyl adipate through in silico and in vitro approaches

Diisobutyl adipate (DIBA), as a novel non-phthalate plasticizer, is widely used in various products. However, little effort has been made to investigate whether DIBA might have adverse effects on human health. In this study, we integrated an in silico and in vitro strategy to assess the impact of DIBA on cellular homeostasis. Since numerous plasticizers could activate peroxisome proliferator-activated receptor γ (PPARγ) pathway to interrupt metabolism systems, we first utilized molecular docking to analyze interaction between DIBA and PPARγ. Results indicated that DIBA had strong affinity with the ligand-binding domain of PPARγ (PPARγ-LBD) at Histidine 499. Afterwards, we used cellular models to investigate in vitro effects of DIBA. Results demonstrated that DIBA exposure increased intracellular lipid content in murine and human hepatocytes, and altered transcriptional expression of genes related to PPARγ signaling and lipid metabolism pathways. At last, target genes regulated by DIBA were predicted and enriched for Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis. Protein-protein interaction (PPI) network and transcriptional factors (TFs)-genes network were established accordingly. Target genes were enriched in Phospholipase D signaling pathway, phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt) and Epidermal growth factor receptor (EGFR) signaling pathway which were related to lipid metabolism. These findings suggested that DIBA exposure might disturb intracellular lipid metabolism homeostasis via targeting PPARγ. This study also demonstrated that this integrated in silico and in vitro methodology could be utilized as a high throughput, cost-saving and effective tool to assess the potential risk of various environmental chemicals on human health.

Endocrine disrupting chemicals in indoor dust: A review of temporal and spatial trends, and human exposure

Several chemicals with widespread consumer uses have been identified as endocrine-disrupting chemicals (EDCs), with a potential risk to humans. The occurrence in indoor dust and resulting human exposure have been reviewed for six groups of known and suspected EDCs, including phthalates and non-phthalate plasticizers, flame retardants, bisphenols, per- and polyfluoroalkyl substances (PFAS), biocides and personal care product additives (PCPs). Some banned or restricted EDCs, such as polybrominated diphenyl ethers (PBDEs), di-(2-ethylhexyl) phthalate (DEHP), bisphenol A (BPA), perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA), are still widely detected in indoor dust in most countries, even as the predominating compounds of their group, but generally with decreasing trends. Meanwhile, alternatives that are also potential EDCs, such as bisphenol S (BPS), bisphenol F (BPF), decabromodiphenyl ethane (DBDPE) and organophosphate flame retardants (OPFRs), and PFAS precursors, such as fluorotelomer alcohols, have been detected in indoor dust with increasing frequencies and concentrations. Associations between some known and suspected EDCs, such as phthalate and non-phthalate plasticizers, FRs and BPs, in indoor dust and paired human samples indicate indoor dust as an important human exposure pathway. Although the estimated daily intake (EDI) of most of the investigated compounds was mostly below reference values, the co-exposure to a multitude of known or suspected EDCs requires a better understanding of mixture effects.

Enhanced migration of plasticizers from polyvinyl chloride consumer products through artificial sebum

In the present study, the migration of plasticizers from modeled and commercial polyvinyl chloride (mPVC and cPVC, respectively) to poly(dimethylsiloxane) via artificial sebum was assessed to mimic the dermal migration of plasticizers. In addition, the various factors affecting migration of phthalic acid esters (PAEs) from diverse PVC products were investigated. The migrated mass and migration ratio of PAEs increased but the migration rate decreased over time. The migration rate increased with sebum mass, contact time, and temperature but decreased under higher pressure. Low-molecular-weight PAEs (dimethyl phthalate and diethyl phthalate) migrated in higher amounts than high-molecular-weight PAEs (dicyclohexyl phthalate [DCHP] and diisononyl phthalate [DINP]). Diffusion of all PAEs in mPVC increased with temperature, with diffusion coefficients ranging from 10^-13 to 10^-15, 10^-12 to 10^-14, and 10^-10 to 10^-12 cm²·s^-1 at 25 °C, 40 °C, and 60 °C, respectively; the enthalpy of activation ranged between 127 and 194 kJ·mol^-1. Moreover, migration depended on total PAE content of the product, as the diffusion coefficient for DINP in cPVC (softer PVC) was approximately three orders of magnitude higher than that for DINP in mPVC (harder PVC); this may be due to the increase in free volume with increasing plasticizer content. Finally, the daily exposure doses of the plasticizers were estimated. These findings will be helpful for estimating dermal exposure risk.

Degradation of dimethyl phthalate through Fe(II)/peroxymonosulphate heightened by fulvic acid: efficiency and possible mechanism

Ferrous iron (Fe(II)) reacts with peroxymonosulphate (PMS) to form active oxidants that can degrade refractory organic pollutants. However, the conversion rate of Fe(III) to Fe(II) is slow, which limits its actual application. In the study, the effect of fulvic acid (FA) on the degradation of dimethyl phthalate (DMP) by Fe(II)/PMS was investigated. Moreover, the degradation process of DMP was predicted by the preliminary identification of active free radicals and intermediates. As expected, FA gave rise to a higher concentration of Fe(II) than that in Fe(II)/PMS to enhance the removal of DMP in Fe(II)/PMS system. The precipitate, involved in FA and iron, was an important composite to promote the degradation of DMP in the system. Also, the response surface methodology (RSM) was applied to model and optimize the degradation conditions of DMP. The highest removal efficiency (85.70%) was obtained at pH = 3.86, [PMS] = 0.96 mM, [FA] = 11.44 mg/L and [DMP] = 5 µM. The results of free radical quenching experiments and EPR showed that •OH and SO₄^•- were the main active radicals in this system. The degradation intermediates of DMP were monomethyl phthalate (MMP), phthalic acid and benzoic acid. Discoveries of this study had raised the current understanding of the application of FA keeping the cycles of Fe(II)/Fe(III) for peroxymonosulphate activation, which could afford valuable information for the degradation of organic pollutants by FA/Fe(II)/PMS.

Nonphthalate Plasticizers in House Dust from Multiple Countries: An Increasing Threat to Humans

Along with the restrictions of phthalate esters (PAEs), a variety of nonphthalate plasticizers (NPPs) have been increasingly used for industrial needs. Knowledge remains limited on the environmental occurrences, fate, and human exposure risks of many emerging NPPs. In this study, we investigated a suite of 45 NPPs along with the major PAEs in house dust from five regions in the Asia-Pacific region and the United States. The findings clearly demonstrated ubiquitous occurrences of many NPPs in the home environment, particularly acetyl tributyl citrate (ATBC), tricapryl trimellitate (TCTM), trioctyl trimellitate (TOTM), glycerol monooleate (GMO), methyl oleate (MO), and diisobutyl adipate (DiBA). The median total concentrations of NPPs ranged from 17.8 to 252 μg/g in the study regions, while the mean ratios of ΣNPPs to ΣPAEs ranged from 0.19 (Hanoi) to 0.72 (Adelaide). Spatial differences were observed not only for the chemical abundances but also for the composition profiles and the hazard quotient (HQ) prioritization of individual chemicals. Although the current exposure may unlikely cause significant health risks according to the HQ estimation, potential exposure risks cannot be overlooked, due to the lack of appropriate toxic threshold data, the existence of additional exposure pathways, and possible cocktail effects from coexisting NPPs and PAEs.

Characterizing the obesogenic and fatty liver-inducing effects of Acetyl tributyl citrate (ATBC) plasticizer using both in vivo and in vitro models

The global incidence of obesity and non-alcoholic fatty liver disease (NAFLD) is rising rapidly in recent years. Environmental factors including usage of plastics and exposure to chemicals have been proposed as important contributors to the obesity pandemic. Acetyl tributyl citrate (ATBC) is a non-phthalate plasticizer widely used in food packaging, personal care products, medical devices and children's toys etc. Due to its high leakage rate from plastics, exposure risk of ATBC keeps increasing. Although there are some studies investigating the safety of ATBC on human health, these studies mainly focused on high dosages and information regarding ATBC safety at environmental-relevant low levels is still limited. In this study, we aimed to evaluate the safety of subchronic exposure to environmentally-relevant concentrations of ATBC. C57BL/6J mice were orally exposed to ATBC for 6 or 14 weeks. Results indicated that ATBC exposure increased the body weight gain, the body fat content and the size of adipocytes, induced liver steatosis in mice. Consistent with in vivo effects, ATBC treatment increased the intracellular lipid accumulation in vitro hepatocytes. Transcriptome sequencing, qRT-PCR analysis and western blotting revealed that ATBC exposure affected the expression of genes involved in de novo lipogenesis and lipid uptake. Therefore, based on our subchronic and in vitro results, it suggested that ATBC might be a potential environmental obesogen with metabolism-disturbing and fatty liver-inducing risk, and its application in many consumer products should be carefully re-evaluated.

Is e-waste a source of phthalate and novel non-phthalate plasticizers? A comparison study on indoor dust

Nine traditional phthalate plasticizers and 33 novel non-phthalate plasticizers were determined in indoor dust from a typical e-waste recycling area. The median concentrations ranged from <LOQ to 22,700 ng/g for phthalates and from <LOQ to 1250 ng/g for non-phthalates. Bis-(2-ethylhexyl) phthalate (DEHP) and di-isononyl phthalate (DINP) were the two major phthalates in dust, while glycerol monooleate (GMO) and methyl oleate (MO) were the predominant non-phthalates. Different pollutant patterns among different sites implied multiple sources of the plasticizers. Using the ratio of DINP/DEHP as an indicator, we evaluated the impact of e-waste source emission on the sampling sites, resulting in an impact rank of Matou > Dakeng > Baihetang > Shiding > Jieyang, which was consistent with the local e-waste dismantling activities and supported by polybrominated diphenyl ethers (PBDEs) levels. The correlations between chemical levels and the indicators indicated that most phthalates and non-phthalate plasticizers in the dust, might not be primarily influenced by e-waste emission sources. Additionally, the estimated median human exposures of phthalates and non-phthalates via dust ingestion were 30.6 and 1.82 ng/kg/day for adults, and 299 and 17.8 ng/kg/day for toddlers respectively, indicating negligible health risks.

Effects of plasticizer diisobutyl adipate on the Japanese medaka (Oryzias latipes) endocrine system

Plasticizer pollution of the water environment is one of the world's most serious environmental issues. Phthalate plasticizers can disrupt endocrine function in vertebrates. Therefore, this study analyzed thyroid-related, reproduction-related, and estrogen-responsive genes in Japanese medaka (Oryzias latipes) to determine whether non-phthalate diisobutyl adipate (DIBA) plasticizer could affect endocrine hormone activity or not. Developmental toxicity during fish embryogenesis was also evaluated. At a concentration of 11.57 mg/l, embryonic exposure to DIBA increased the mortality rate. Although abnormal development, including body curvature, edema, and lack of swim bladder inflation, was observed at 3.54 and 11.57 mg/l DIBA, growth inhibition and reduced swimming performance were also observed. In addition, DIBA exposure increased the levels of thyroid-stimulating hormone beta-subunit (tshβ) and deiodinase 1 (dio1) but decreased the levels of thyroid hormone receptor alpha (trα) and beta (trβ). These results suggest that DIBA has thyroid hormone-disrupting activities in fish. However, kisspeptin (kiss1 and kiss2), gonadotropin-releasing hormone (gnrh1), follicle-stimulating hormone beta (fshβ), luteinizing hormone beta (lhβ), choriogenin H (chgH), and vitellogenin (vtg1) expression did not change dose-dependently in response to DIBA exposure, whereas gnrh2 and vtg2 expression was elevated. These results indicate that DIBA has low estrogenic activity and does not disrupt the endocrine reproduction system in fish. Overall, this is the first report indicating that non-phthalate DIBA plasticizer is embryotoxic and disrupt thyroid hormone activity in fish.

Development, testing, parameterisation, and calibration of a human PBK model for the plasticiser, di (2-ethylhexyl) adipate (DEHA) using in silico, in vitro and human biomonitoring data

Introduction: A physiologically based biokinetic model for di (2-ethylhexyl) adipate (DEHA) based on a refined model for di-(2-propylheptyl) phthalate (DPHP) was developed to interpret the metabolism and biokinetics of DEHA following a single oral dosage of 50 mg to two male and two female volunteers. Methods: The model was parameterized using in vitro and in silico methods such as, measured intrinsic hepatic clearance scaled from in vitro to in vivo and algorithmically predicted parameters such as plasma unbound fraction and tissue:blood partition coefficients (PCs). Calibration of the DEHA model was achieved using concentrations of specific downstream metabolites of DEHA excreted in urine. The total fractions of ingested DEHA eliminated as specific metabolites were estimated and were sufficient for interpreting the human biomonitoring data. Results: The specific metabolites of DEHA, mono-2-ethyl-5-hydroxyhexyl adipate (5OH-MEHA), mono-2-ethyl-5-oxohexyl adipate (5oxo-MEHA), mono-5-carboxy-2-ethylpentyl adipate (5cx-MEPA) only accounted for ∼0.45% of the ingested DEHA. Importantly, the measurements of adipic acid, a non-specific metabolite of DEHA, proved to be important in model calibration. Discussion: The very prominent trends in the urinary excretion of the metabolites, 5cx-MEPA and 5OH-MEHA allowed the important absorption mechanisms of DEHA to be modelled. The model should be useful for the study of exposure to DEHA of the general human population.

Emerging Plasticizers in South China House Dust and Hand Wipes: Calling for Potential Concern?

Following regulations on legacy plasticizers, a large variety of industrial chemicals have been employed as substitutes to manufacture consumer products. However, knowledge remains limited on their environmental distributions, fate, and human exposure risks. In the present work, we screened for a total of 34 emerging plasticizers in house dust from South China and matched hand wipes collected from volunteers (n = 49 pairs). The results revealed a frequent detection of 27 emerging plasticizers in house dust, with the total concentrations reaching a median level of 106 700 ng/g. Thirteen of them had never been investigated by any environmental studies prior to our work, which included glycerol monooleate (median: 61 600 ng/g), methyl oleate (16 400 ng/g), butyl oleate (411 ng/g), 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate (341 ng/g), 2,2,4-trimethyl-1,3-pentanediol diisobutyrate (105 ng/g), isopropyl myristate (154 ng/g), di(2-ethylhexyl) sebacate (69.1 ng/g), triisononyl trimellitate (64.4 ng/g), as well as a few others. Emerging plasticizers were also frequently detected in hand wipes, with a median total level of 4680 ng, indicating potential exposure via hand-to-mouth contact. Several chemicals, including acetyl tributyl citrate, tributyl citrate, di-n-butyl maleate, isopropyl myristate, and isopropyl palmitate, exhibited significant correlations between dust and hand wipe. However, other plasticizers did not follow this pattern, and the chemical compositional profiles differed between dust and hand wipe, suggesting chemical-specific sources and exposure pathways. Although the estimation of daily intake (EDI) indicated no substantial risks through dust ingestion or hand-to-mouth transfer of emerging plasticizers, continuous monitoring is needed to explore whether some of the important plasticizers are safe replacements or regrettable substitutions of the legacy ones.

Molecular signatures of organic particulates as tracers of emission sources

Chemical signature of airborne particulates and deposition dusts is subject of study since decades. Usually, three complementary composition markers are investigated, namely, (i) specific organic compounds; (ii) concentration ratios between congeners, and (iii) percent distributions of homologs. Due to its intrinsic limits (e.g., variability depending on decomposition and gas/particle equilibrium), the identification of pollution sources based on molecular signatures results overall restricted to qualitative purposes. Nevertheless, chemical fingerprints allow drawing preliminary information, suitable for successfully approaching multivariate analysis and valuing the relative importance of sources. Here, the state-of-the-art is presented about the molecular fingerprints of non-polar aliphatic, polyaromatic (PAHs, nitro-PAHs), and polar (fatty acids, organic halides, polysaccharides) compounds in emissions. Special concern was addressed to alkenes and alkanes with carbon numbers ranging from 12 to 23 and ≥ 24, which displayed distinct relative abundances in petrol-derived spills and exhausts, emissions from microorganisms, high vegetation, and sediments. Long-chain alkanes associated with tobacco smoke were characterized by a peculiar iso/anteiso/normal homolog fingerprint and by n-hentriacontane percentages higher than elsewhere. Several concentration ratios of PAHs were identified as diagnostic of the type of emission, and the sources of uncertainty were elucidated. Despite extensive investigations conducted so far, the origin of uncommon molecular fingerprints, e.g., alkane/alkene relationships in deposition dusts and airborne particles, remains quite unclear. Polar organics resulted scarcely investigated for pollution apportioning purposes, though they looked as indicative of the nature of sources. Finally, the role of humans and living organisms as actual emitters of chemicals seems to need concern in the future.

Occurrence, exposure and risk assessment of semi-volatile organic compounds in Chinese homes

Indoor semi-volatile organic compounds (SVOCs) can have a significant impact on human health. Previous studies involved the detection of limited classes of indoor SVOCs in different regions of China. However, overall indoor pollution profiles and the associated health risks via multiple exposure pathways remain unclear. High-throughput screening of SVOCs would help clarify the overall indoor pollution status and identify high-risk pollutants. We collected indoor air and dust samples from 35 Chinese homes and investigated the occurrence of a wide range of SVOCs. Ninety-seven SVOCs including phthalate esters (PAEs), polycyclic aromatic hydrocarbons (PAHs), organophosphate esters, alcohols, fatty acids, phenols, etc., were detected in the air (total concentrations: 0.13-48 μg/m³; median: 3.4 μg/m³) and dust (total concentrations: 120-1500 μg/g; median: 490 μg/g) samples. PAEs were the most abundant, accounting for 55.3 ± 28.6% and 43.4 ± 16.9% of the total SVOC concentrations in the air and dust samples respectively. Human exposure and health risks of 34 SVOCs with detection frequencies >10% were assessed based on inhalation, ingestion and dermal absorption of SVOCs from air and dust by infants and adults. In the case of indoor SVOCs with log K_oa < 9, inhalation and dermal contact with air was >90% for adults and >69% for infants. The following five SVOCs in air samples posed significant non-carcinogenic risks and are listed based on their decreasing risk level: dibutyl phthalate > phenanthrene > stearic acid > methyl palmitate > lauryl alcohol. Four PAHs with 2-4 rings posed potential carcinogenic risks, with phenanthrene exceeding the acceptable risk level of 10^-4. The high risks posed by SVOCs were due to inhalation exposure. Therefore, keeping the air concentrations of SVOCs, especially that of PAEs and PAHs under check would greatly benefit human health in indoor environments.

Prenatal Exposure to Emerging Plasticizers and Synthetic Antioxidants and Their Potency to Cross Human Placenta

Gestational exposure to environmental chemicals and subsequent permeation through the placental barrier represents potential health risks to both pregnant women and their fetuses. In the present study, we explored prenatal exposure to a suite of 46 emerging plasticizers and synthetic antioxidants (including five transformation products of 2,6-di-tert-butyl-4-hydroxytoluene, BHT) and their potency to cross human placenta based on a total of 109 maternal and cord serum pairs. Most of these chemicals have rarely or never been investigated for prenatal exposure and associated health risks. Eleven of them exhibited detection frequency greater than 50% in maternal blood, including dibutyl fumarate (DBF), 2,6-di-tert-butylphenol (2,4-DtBP), 1,3-diphenylguanidine (DPG), methyl-2-(benzoyl)benzoate (MBB), triethyl citrate (TEC), BHT, and its five metabolites, with a median concentration from 0.05 to 3.1 ng/mL. The transplacental transfer efficiency (TTE) was determined for selected chemicals with valid measurements in more than 10 maternal/cord blood pairs, and the mean TTEs exhibited a large variation (i.e., 0.29-2.14) between chemicals. The determined TTEs for some of the target chemicals were comparable to the predicted values by our previously proposed models developed from molecular descriptors, indicating that their transplacental transfer potency could be largely affected by physicochemical properties and molecular structures. However, additional biological and physiological factors may influence the potency of environmental chemicals to cross human placenta. Overall, our study findings raise concern on human exposure to an increasing list of plastic additives during critical life stages (e.g., pregnancy) and potential health risks.

A Pilot Study to Quantify Volatile Organic Compounds and Their Sources Inside and Outside Homes in Urban India in Summer and Winter during Normal Daily Activities

Indian cities have some of the poorest air quality globally but volatile organic compounds (VOCs)—many of which adversely affect health—and their indoor sources remain understudied in India. In this pilot study we quantified hundreds of VOCs inside and outside 26 homes in Ahmedabad and Gandhinagar, Gujarat, in May 2019 and in January 2020. We sampled in the morning and afternoon/evening to capture temporal variability. Total indoor VOCs were measured at higher concentrations in winter (327.0 ± 224.2 µgm−3) than summer (150.1 ± 121.0 µgm−3) and exceeded those measured outdoors. Using variable reduction techniques, we identified potential sources of compounds (cooking, plastics [with an emphasis on plasticizers], consumer products, siloxanes [as used in the production of consumer products], vehicles). Contributions differed by season and between homes. In May, when temperatures were high, plastics contributed substantially to indoor pollution (mean of 42% contribution to total VOCs) as compared to in January (mean of 4%). Indoor cooking and consumer products contributed on average 29% and 10% to all VOCs indoors in January and 16% and 4% in May. Siloxane sources contributed <4% to any home during either season. Cooking contributed substantially to outdoor VOCs (on average 18% in January and 11% in May) and vehicle-related sources accounted for up to 84% of VOCs in some samples. Overall, results indicate a strong seasonal dependence of indoor VOC concentrations and sources, underscoring the need to better understand factors driving health-harming pollutants inside homes to facilitate exposure reductions.

Effects of dibutyl phthalate and di (2-ethylhexyl) phthalate on hepatic structure and function of adult male mice

The objective of the present research was to determine if dibutyl phthalate (DBP) and di-(2-ethylhexyl) phthalate (DEHP) alone and combined exposure induced pathological alterations in laboratory reared albino mice. Adult male mice were equally divided (n = 10) into Control, corn oil (CO), DBP, DEHP, and DBP+DEHP treated groups. Dibutyl phthalate (250 mg/kg), DEHP (300 mg/kg), and DBP+DEHP (250+300 mg/kg), respectively, were administered by oral gavage mixed in corn oil (0.2 mL) for 28 days. All animals were sacrificed following 28 days of treatment and blood was collected for serum lipid profiles and liver function tests. Liver samples were also collected for observation of histological changes. Microphotographs of hematoxylin and eosin-stained sections were used for computer-based micrometry. CO, DBP, DEHP, and DBP+DEHP treatment resulted in a significant increase in the mean body and liver weights as compared with the Control group. Histological examination of the livers with DBP and/or DEHP treatment showed marked alterations leading to hepatic hypertrophy. In the treated groups, a significant increase in the mean number of mononucleated, binucleated cells, and oval cells per unit area was noticed with disorganized trabecular arrangement as compared with the Control group. Treatment with DBP and/or DEHP resulted in large regeneration zones in the liver and an increased relative nucleo-cytoplasmic index of mononuclear shepatocytes when compared with the Control group. All treatments caused a significant increases in the liver enzymes and proteins as well as altered serum cholesterol, triglycerides, LDL, and VLDL levels. The histopathological and serological findings confirmed the toxic potentials to hepatic tissue of DBP and DEHP either given alone or in combination.

PM2.5-bound phthalates and phthalate substitutes in a megacity of southern China: spatioseasonal variations, source apportionment, and risk assessment

Plasticizers are ubiquitous pollutants in the environment, whereas few efforts have been made to elucidate their emission sources in the atmosphere. In this research, the spatioseasonal variations and sources of particle-bound (PM_2.5) phthalates (PAEs) and their substitutes (APs) at residential sites in seven districts and at four potential point-source sites across a megacity in South China were revealed. The total concentrations of PAEs ranging from 10.7 to 528 ng/m³ were substantially higher than those of APs (1.45.58.5 ng/m³). Significant spatial variations in the concentrations of the pollutants were observed, which were generally higher at the sites with intensive industrial activities and the point-source sites. Most atmospheric plasticizer levels peaked in summer, probably due to the temperature-promoted volatilization. Seven sources of plasticizers were identified by the positive matrix factorization (PMF) model. The sources in less industrialized districts are mainly associated with domestic and commercial emissions and with industry in the industrialized districts. Specifically, plastics and personal care products together contributed 60% of the plasticizers in the atmosphere of this city, followed by solvents and polyester industry sources. The incremental lifetime cancer risk of inhalation exposure to bis(2-ethylhexyl) phthalate in the study city is below the acceptable level. Relatively higher risks were found for residents living around sites with intensive industrial activities and around wastewater treatment plant.

Indoor exposure to phthalates and its burden of disease in China

China's profoundly rapid modernization in the past two decades has resulted in dramatic changes in indoor environmental exposures. Among these changes, exposure to phthalates has attracted increasing attention. We aimed to characterize indoor phthalate exposure and to estimate the disease burden attributable to indoor phthalate pollution from 2000 to 2017 in China. We integrated the national exposure level of indoor phthalates from literature through systematic review and Monte Carlo simulation. Dose-response relationships between phthalate exposure and health outcomes were obtained by systematic review and meta-analysis. Based on existing models for assessing probabilities of causation and a comprehensive review of available data, we calculated the disability-adjusted life years (DALYs) among the general Chinese population resulting from exposure to indoor phthalate pollution. We found that DnBP, DiBP, and DEHP were the most abundant phthalates in indoor environments of residences, offices, and schools with medians of national dust phase concentration from 74.5 µg/g to 96.3 µg/g, 39.6 µg/g to 162.5 µg/g, 634.2 µg/g to 1,394.7 µg/g, respectively. The national equivalent exposure for children to phthalates in settled dust was higher than that of adults except for DiBP and DnOP. Dose-response relationships associated with DEP, DiBP, DnBP, BBzP, and DEHP exposures were established. Between 2000 and 2017, indoor phthalate exposure in China has led to 3.32 million DALYs per year, accounting for 0.90% of total DALYs across China. The annual DALY associated with indoor phthalate pollution in China was over 2000 people per million, which is about 2~3 times of the DALY loss due to secondhand smoke (SHS) in six European countries or the sum of the DALY loss caused by indoor radon and formaldehyde in American homes. Our study indicates a considerable socioeconomic impact of indoor phthalate exposure for a modernizing human society. This suggest the need for relevant national standard and actions to reduce indoor phthalate exposure.

Phthalic acid esters (PAEs) in workplace and house dust from Vietnam: concentrations, profiles, emission sources, and exposure risk

The occurrence of nine phthalic acid esters (PAEs) were determined in indoor dust samples collected from vehicle repair shops, waste processing workshops, and homes in Vietnam. Concentrations of total PAEs ranged from 585 to 153,000 (median 33,400 ng/g), which fall in the lower end of global range. The PAE levels in workplace dust (median 49,100; range 9210-153,000 ng/g) were significantly higher than those in house dust (median 23,700; range 585-83,700 ng/g), indicating waste processing activities as potential PAE sources. The most predominant compound was di-(2-ethyl)hexyl phthalate (DEHP), accounting for 62 ± 18% of total PAEs. Other major compounds were benzyl butyl phthalate (BzBP) (10 ± 12%), di-n-butyl phthalate (DnBP) (9.7 ± 7.7%), di-n-octyl phthalate (DnOP) (7.9 ± 8.1%), and diisobutyl phthalate (DiBP) (6.9 ± 5.0%). Proportions of BzBP and DnBP in some workplace dust samples were markedly greater than in common house dust, suggesting specific emission sources. Daily intake doses of selected PAEs (e.g., DnBP, DiBP, BzBP, and DEHP) through dust ingestion were much lower than reference doses, implying acceptable levels of risk.

Widespread occurrence of phthalate and non-phthalate plasticizers in single-use facemasks collected in the United States

Single-use or disposable facemasks have been widely used by the public for personal protection against the spread of COVID-19. The majority of disposable facemasks are made of synthetic polymers such as polypropylene, polyethylene terephthalate (as polyester), and polystyrene, and could therefore be a source of human exposure to plasticizers that are incorporated into these polymers during production. Little is known, however, about the occurrence of plasticizers in facemasks. In this study, we determined the concentrations of nine phthalate diesters and six non-phthalate plasticizers in 66 facemasks purchased in the United States. Among phthalate diesters, dibutyl phthalate, di(2-ethylhexyl)phthalate, di-iso-butyl phthalate, and butyl benzyl phthalate were found in all facemask samples, at median concentrations of 486, 397, 254, and 92 ng/g, respectively. Among non-phthalate plasticizers, dibutyl sebacate (median: 3390 ng/g) and di(2-ethylhexyl)adipate (352 ng/g) were found at notable concentrations. Inhalation exposure to select phthalate and non-phthalate plasticizers from the use of facemasks was estimated to range from 0.1 to 3.1 and 3.5 to 151 ng/kg-bw/d, respectively. To our knowledge, this is the first study to report the occurrence of phthalate and non-phthalate plasticizers in facemasks collected from the United States.

Indoor exposure to phthalates and polycyclic aromatic hydrocarbons (PAHs) to Canadian children: the Kingston allergy birth cohort

BACKGROUND

Canadian children are widely exposed to phthalates and polycyclic aromatic hydrocarbons (PAHs) from indoor sources. Both sets of compounds have been implicated in allergic symptoms in children.

OBJECTIVE

We characterize concentrations of eight phthalates and 12 PAHs in floor dust from the bedrooms of 79 children enrolled in the Kingston Allergy Birth Cohort (KABC).

METHOD

Floor dust was collected from the bedrooms of 79 children who underwent skin prick testing for common allergens after their first birthday. Data were collected on activities, household, and building characteristics via questionnaire.

RESULTS

Diisononyl phthalate (DiNP) and phenanthrene were the dominant phthalate and PAH with median concentrations of 561 µg/g and 341 ng/g, respectively. Benzyl butyl phthalate (BzBP) and chrysene had the highest variations among all tested homes, ranging from 1-95% to 1-99%, respectively.

SIGNIFICANCE

Some phthalates were significantly associated with product and material use such as diethyl phthalate (DEP) with fragranced products and DiNP and DiDP with vinyl materials. Some PAHs were significantly associated with household characteristics, such as benzo[a]pyrene with smoking, and phenanthrene and fluoranthene with the presence of an attached garage. Socioeconomic status (SES) had positive and negative relationships with some concentrations and some explanatory factors. No significant increases in risk of atopy (positive skin prick test) was found as a function of phthalate or PAH dust concentrations.

Ecological and human health risks assessment of some polychlorinated biphenyls (PCBs) in surface soils of central and southern parts of city of Tehran, Iran

PURPOSE

The present study was conducted to evaluate the carcinogenic and non-carcinogenic hazards of polychlorinated biphenyls (PCBs) in topsoil across business districts, public green space, cultural and educational areas, and roadside and residential areas in city of Tehran, in 2019.

METHOD

A total of 30 surface urban soil specimens were collected and after preparing them in the laboratory, PCBs contents were determined using gas chromatography-mass spectrometry.

RESULTS

Based on the results of data analyses, the median concentrations of PCB18, PCB28, PCB 29, PCB 31, PCB 44, PCB 52, PCB 101, PCB 138, PCB 141, PCB 149, PCB 153, PCB 189 and PCB 194, were found to be 6.81, 0.759, 0.005, 1.75, 2.51, 0.059, 2.31, 3.76, 5.82, 0.599, 0.408, 0.008 and 0.008 µg/kg, respectively. Also, the overall daily PCBs intakes via soil ingestion, inhalation and skin contact were 5.48E-04, 1.19E + 00 and 1.62E-04 µg/kg, respectively. Thus it was decided that the inhalation of soil could be the main pathway of exposure to PCBs, and that, based on the carcinogenic risk outcomes, children would be more at risk of cancer than adults would.

CONCLUSIONS

In general, considering that among the studied urban spaces, the contents of PCBs in public green spaces were more than their rates in other areas, and considering that children normally play in the green areas are, it is recommended that special attention be paid to these areas in controlling and removing pollution caused by PCBs in urban areas.

Phthalates and Alternative Plasticizers Differentially affect Phenotypic Parameters in Gonadal Somatic and Germ Cell Lines

The developmental and reproductive toxicity associated with exposure to phthalates has motivated a search for alternatives. However, there is limited knowledge regarding the adverse effects of some of these chemicals. We used high-content imaging to compare the effects of mono (2-ethylhexyl) phthalate (MEHP) with six alternative plasticizers: di-2-ethylhexyl terephthalate (DEHTP); diisononyl-phthalate (DINP); di-isononylcyclohexane-1,2-dicarboxylate (DINCH); 2-ethylhexyl adipate (DEHA); 2,2,4-trimethyl 1,3-pentanediol diisobutyrate (TXIB) and di-iso-decyl-adipate (DIDA). A male germ spermatogonial cell line (C18-4), a Sertoli cell line (TM4) and two steroidogenic cell lines (MA-10 Leydig and KGN granulosa) were exposed for 48h to each chemical (0.001-100 μM). Cell images were analyzed to assess cytotoxicity and effects on phenotypic endpoints. Only MEHP (100 μM) was cytotoxic and only in C18-4 cells. However, several plasticizers had distinct phenotypic effects in all four cell lines. DINP increased Calcein intensity in C18-4 cells, whereas DIDA induced oxidative stress. In TM4 cells, MEHP, and DINCH affected lipid droplet numbers, while DEHTP and DINCH increased oxidative stress. In MA-10 cells, MEHP increased lipid droplet areas and oxidative stress; DINP decreased the number of lysosomes, while DINP, DEHA and DIDA altered mitochondrial activity. In KGN cells, MEHP, DINP and DINCH increased the number of lipid droplets, whereas DINP decreased the number of lysosomes, increased oxidative stress and affected mitochondria. The Toxicological Priority Index (ToxPi) provided a visual illustration of the cell line specificity of the effects on phenotypic parameters. The lowest administered equivalent doses were observed for MEHP. We propose that this approach may assist in screening alternative plasticizers.

Analysis and health risk assessment of phthalate esters (PAEs) in indoor dust of preschool and elementary school centers in city of Tehran, Iran

Individuals spend a lot of time indoors; thus they are generally exposed to phthalates used in consumer products. Therefore, those exposed to phthalates as indoor contaminants are at high risks. The present study was conducted to evaluate the carcinogenic and non-carcinogenic hazard of phthalate esters (PAEs), like dimethyl phthalate, diethyl phthalate, di(nbutyl) phthalate, butyl benzyl phthalate, dioctyl phthalate, and di(2-ethylhexyl) phthalate in the dust obtained from 21 schools in Tehran, in 2019. A total of 63 indoor dust specimens were obtained by a vacuum cleaner. After transferring dust samples to the laboratory, 100 mg of each sample was centrifuged and mixed with 20 ml acetone and kept through a night and ultrasonicated within 30 min. Eventually, PAEs' contents were measured via gas chromatography-mass spectrometry. Based on the findings, median concentrations of DMP, DEP, DnBP, BBP, DEHP, and DnOP were 0.90, 0.10, 6.0, 0.20, 118.30, and 4.10 mg kg^-1 respectively. Moreover, the overall average daily exposure doses (ADD) of phthalate esters via dust ingestion, skin contact, and inhalation were 1.56E-03, 1.70E-06, and 1.56E-07 mg kg^-1 day^-1, respectively, and the lifetime average daily exposure doses (LADD) were 1.83E-04, 2.34E-08, and 2.46E-08 mg kg^-1 day^-1, respectively; thus ingestion of dust particles was found to be the main pathway of exposure to phthalate for non-carcinogenic and carcinogenic risks. Although based on the results, the studied samples were below the US Environmental Protection Agency threshold of 1.00E-06, due to the disadvantages of phthalates in human safety, these kinds of investigations are helpful in understanding the main ways of exposure to PAEs and providing a science-based framework for the future attempts for mitigating the PAEs indoor emissions.

Identifying Citric Acid Esters, a Class of Phthalate Substitute Plasticizers, in Indoor Dust via an Integrated Target, Suspect, and Characteristic Fragment-Dependent Screening Strategy

Citrate acid esters (CAEs) have been proposed as a class of phthalate substitute plasticizers; however, information on their occurrence in indoor environments is rare. By using liquid chromatography coupled with a quadrupole-Orbitrap mass spectrometer, we developed an integrated strategy that can be applied for target, suspect, and characteristic fragment-dependent screening of CAEs. In n = 50 indoor dust samples collected from Nanjing City (China), three CAEs, namely, acetyl tributyl citrate (ATBC; mean: 412,000 ng/g), tributyl citrate (TBC, 11,600 ng/g), and triethyl citrate (TEC, 10,900 ng/g), exhibited the greatest contamination levels. Total concentrations of CAEs (∑₈CAEs) were statistically significantly (p < 0.01) greater than those of common organophosphate triesters (OPTEs), a class of ubiquitous contaminants in dust. Suspect and characteristic fragment-dependent screening (m/z 111.0078 ([C₅H₃O₃]⁺) and m/z 129.0181 ([C₅H₅O₄]⁺)) of CAEs were further conducted for the same batch of samples. We tentatively identified six novel CAEs, and the most frequent and abundant CAE was fully identified as tributyl aconitate (TBA). Statistically significant correlation relationships were observed on dust levels between TBA vs ATBC (r = 0.650; p < 0.01) and TBA vs TBC (r = 0.384; p < 0.01), suggesting their similar sources in dust samples.

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.

Dimethyl phthalate damages Staphylococcus aureus by changing the cell structure, inducing oxidative stress and inhibiting energy metabolism

Dimethyl phthalate (DMP), used as a plasticizer in industrial products, exists widely in air, water and soil. Staphylococcus aureus is a typical model organism representing Gram-positive bacteria. The molecular mechanisms of DMP toxicology in S. aureus were researched by proteomic and transcriptomic analyses. The results showed that the cell wall, membrane and cell surface characteristics were damaged and the growth was inhibited in S. aureus by DMP. Oxidative stress was induced by DMP in S. aureus. The activities of succinic dehydrogenase (SDH) and ATPase were changed by DMP, which could impact energy metabolism. Based on proteomic and transcriptomic analyses, the oxidative phosphorylation pathway was enhanced and the glycolysis/gluconeogenesis and pentose phosphate pathways were inhibited in S. aureus exposed to DMP. The results of real-time reverse transcription quantitative PCR (RT-qPCR) further confirmed the results of the proteomic and transcriptomic analyses. Lactic acid, pyruvic acid and glucose were reduced by DMP in S. aureus, which suggested that DMP could inhibit energy metabolism. The results indicated that DMP damaged the cell wall and membrane, induced oxidative stress, and inhibited energy metabolism and activation in S. aureus.

Exposure to phthalates and correlations with phthalates in dust and air in South China homes

We spend more than half of our daily time in indoor environments, and the contributions of phthalates present in it to total exposure are important. Here, we determined phthalate concentrations in paired indoor settled dust/air and their metabolites in human urine from 100 general families in south China to explore such kind of effect. The total concentrations of phthalates/metabolites were 48.7-2850 μg/g, 279-5080 ng/m³ and 10.7-2840 ng/mL in the indoor dust, air and urine samples, respectively. Among all targets, di-n-butyl phthalate, di-isobutyl phthalate and di-(2-ethylhexyl) phthalate and their metabolites were the predominant compounds. The daily intakes (DIs) of phthalates via dust or air decreased with age, except for infant, and the values of dust ingestion, air inhalation and air dermal uptake were 2720 ± 2460, 1300 ± 973 and 3590 ± 2890 ng/kg/day for toddlers and 236 ± 194, 360 ± 179 and 1120 ± 586 ng/kg/day for adults, respectively. The ratios of DIs from air to dust were greater than 1.0 for people in all age groups, and the ratio was the highest for adults. Furthermore, the contributions of phthalates from indoor dust and air to total DIs from all sources (estimated from urinary phthalate metabolites) were 0.60%-5.23% and 2.65%-12.2% for different ages, respectively. Our results indicated that indoor air was a quite important source for human exposure to phthalates in indoor environment in south China.

Targeted and suspect screening of plasticizers in house dust to assess cumulative human exposure risk

Indoor dust is an important exposure route to anthropogenic chemicals used in consumer products. Plasticizers are common product additives and can easily leach out of the product and partition to dust. Investigations of plasticizers typically focus on a subset of phthalate esters (PEs), but there are many more PEs in use, and alternative plasticizers (APs) are seeing greater use after recognition of adverse health effects of PEs. In this study we use full scan high resolution mass spectrometry for targeted and suspect screening of PEs and APs in house dust and to assess the potential risk of human exposure. House dust samples from Eastern Slovakia were investigated and concentrations of ∑₁₂PEs and ∑₅APs ranged 12-2765 μg/g and 45-13,260 μg/g, respectively. APs were at similar levels to PEs, indicating common usage of these compounds in products in homes. Evaluation of individual compound toxicity combined with human intake via dust ingestion suggested PEs are of lower priority compared to semivolatile organic compounds such as polychlorinated biphenyls due to their lower toxicity. However, cumulative risk assessment (CRA) is a more appropriate evaluation of risk, considering the presences of many PEs in dust and their similar toxic mode of action. CRA based on median toxicity reference values (TRVs) suggested acceptable risks for dust ingestion, however, the wide range of literature-derived TRVs is a large uncertainty, especially for the APs. Use of newer TRVs suggest risk from dust ingestion alone, i.e. not even considering diet, inhalation, and dermal contact. Additionally, screening of full-scan instrumental spectra identified a further 40 suspect PE compounds, suggesting the CRA based on the 12 target PEs underestimates the risk.

Occupational Exposures to Phthalates among Black and Latina U.S. Hairdressers Serving an Ethnically Diverse Clientele: A Pilot Study

Hairdressers may be differentially exposed to phthalates through hair salon services provided and products used, yet no U.S. studies have investigated these exposures in this population. We characterized concentrations and exposure determinants to nine phthalate metabolites in postshift urine samples among 23 hairdressers from three Black and three Dominican salons, as well as a comparison group of 17 female office workers from the Maryland/Washington D.C. metropolitan area. Overall, hairdressers had higher metabolite concentrations than office workers. The geometric mean (GM) for monoethyl phthalate (MEP) was 10 times higher in hairdressers (161.4 ng/mL) than office workers (15.3 ng/mL). Hairdressers providing select services and using certain products had higher GM MEP concentrations than those who did not: permanent waves/texturizing (200.2 vs 115.4 ng/mL), chemical straightening/relaxing (181.6 vs 92.1 ng/mL), bleaching (182.3 vs 71.6 ng/mL), permanent hair color (171.9 vs 83.2 ng/mL), and Brazilian blowout/keratin treatments (181.4 vs 134.6 ng/mL). Interestingly, hairdressers providing natural services had lower GM MEP concentrations than those who did not: twists (129.1 vs 215.8 ng/mL), sister locs/locs (86.0 vs 241.9 ng/mL), and afros (94.7 vs 203.9 ng/mL). Larger studies are warranted to confirm our findings and identify disparities in occupational phthalate exposures.

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.

Polycyclic aromatic hydrocarbon exposure, oxidative potential in dust, and their relationships to oxidative stress in human body: A case study in the indoor environment of Guangzhou, South China

A comparative study of internal and external exposure is a good method to comprehensively understand human exposure to environmental contaminants that may trigger oxidative stress in human body. Information is limited regarding the influences of reactive oxygen species (ROS) on human health from the environment. In addition, data on the contribution of polycyclic aromatic hydrocarbons (PAHs) from indoor environments, especially air, to total human exposure are still insufficient. The present study measured PAHs in paired indoor dust (n = 101), gas (polyurethane foams, n = 100), and particle samples (quartz fiber filters, n = 100) and their hydroxy metabolites (OH-PAHs) in 205 urine samples from 101 families in Guangzhou, South China. The oxidative potential (OP) in dust samples was quantified with a dithiothreitol (DTT) assay to reflect the oxidizability of ROSs, and explore the relationship between environmental ROSs and oxidative stress in humans (using urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) as a biomarker). The estimated daily intakes (EDIs) of Σ₁₆PAH via air inhalation were much higher than those from gas dermal contact, dust dermal contact, and dust ingestion (mean: 19.5 > 4.27 > 3.75 > 1.60 ng/kg_bw/day). Generally, approximately 16% of naphthalene, 28% of fluorene, 9% of phenanthrene, and 3% of pyrene were derived from indoor environments for all residents when compared with the total PAH exposure amount from all sources. Significantly positive relationships were found between OH-PAHs and 8-OHdG (coefficients β: 0.129-0.366, p < 0.05) checked by linear mixed effect models, and males seemed to be more susceptible than females to the DNA oxidative damage related to PAH exposure. The mean OP value in dust was 7.14 ± 6.68 pmol/(min·μg). Individual PAHs in dust gradually intensified the oxidizability of dust particles as their molecular weight increased. A potential but not significant dose-relationship was found between dusty OP and urinary 8-OHdG. Further work should determine the impact of chemical profiles on OP in different environmental media and continuously explore the potential to use OP as a useful indicator to reflect the total oxidizability of several groups of environmental pollutants.

ExpoKids: An R-based tool for characterizing aggregate chemical exposure during childhood

BACKGROUND

Aggregate exposure, the combined exposures to a single chemical from all pathways, is a critical children's health issue.

OBJECTIVE

The primary objective is to develop a tool to illustrate potential differences in aggregate exposure at various childhood lifestages and the adult lifestage.

METHODS

We developed ExpoKids (an R-based tool) using oral exposure estimates across lifestages generated by US EPA's Exposure Factors Interactive Resource for Scenarios Tool (ExpoFIRST).

RESULTS

ExpoKids is applied to illustrate aggregate oral exposure, for ten media, as average daily doses (ADD) and lifetime average daily doses (LADD) in five graphs organized across seven postnatal childhood lifestages and the adult lifestage. This data visualization tool conveys ExpoFIRST findings, from available exposure data, to highlight the relative contributions of media and lifestages to chemical exposure. To evaluate the effectiveness of ExpoKids, three chemical case examples (di[2-ethylhexyl] phthalate [DEHP], manganese, and endosulfan) were explored. Data available from the published literature and databases for each case example were used to explore research questions regarding media and lifestage contributions to aggregate exposure.

SIGNIFICANCE

These illustrative case examples demonstrate ExpoKids' versatile application to explore a diverse set of children's health risk assessment and management questions by visually depicting specific media and lifestage contributions to aggregate exposure.

Removal of phthalates from aqueous solution by semiconductor photocatalysis: A review

While phthalate esters are commonly used as plasticizers to improve the flexibility and workability of polymeric materials, their presence and detection in various environments has become a significant concern. Phthalate esters are known to have endocrine-disrupting effects, which affects reproductive health and physical development. As a result, there is now increased focus and urgency to develop effective and energy efficient technologies capable of removing these harmful compounds from the environment. This review explores the use of semiconductor photocatalysis as an efficient and promising solution towards achieving removal and degradation of phthalate esters. A comprehensive review of photocatalysts reported in the literature demonstrates the range of materials including commercial TiO₂, solar activated catalysts and composite materials capable of enhancing adsorption and degradation. The degradation pathways and kinetics are also considered to provide the reader with an insight into the photocatalytic mechanism of removal. In addition, through the use of two key platforms (the technology readiness level scale and electrical energy per order), the crucial parameters associated with advancing photocatalysis for phthalate ester removal are discussed. These include enhanced surface interaction, catalyst platform development, improved light delivery systems and overall system energy requirements with a view towards pilot scale and industrial deployment.