Urinary Concentrations of Major Phthalate and Alternative Plasticizer Metabolites in Children of Thailand, Indonesia, and Saudi Arabia, and Associated Risks

Phthalate exposure during pregnancy and its association with thyroid hormones: A prospective cohort study

Phthalate esters (PAEs) possess endocrine-disrupting properties. Studies in humans have indicated that in utero phthalate exposure affects maternal thyroid hormones, which are essential for fetal growth and development. However, these studies also reported inconsistent results on the relationship between phthalates and thyroid hormones. This prospective cohort study aimed to assess phthalate exposure across the three trimesters of pregnancy and its association with thyroid hormone levels. From 2019 to 2022, we recruited 672 pregnant women, and two urine samples and one blood sample were collected from each participant during the pregnancy. We examined the urine samples from 663, 335, and 294 women in the first, second, and third trimester, respectively, for the following seven phthalate metabolites: monoethyl phthalate (MEP) from diethyl phthalate (DEP); mono-n-butyl phthalate (MnBP) and mono-iso-butyl phthalate (MiBP) from dibutyl phthalate (DBP); monobenzyl phthalate (MBzP) from butyl benzyl phthalate; and three di(2-ethylhexyl) phthalate (DEHP) metabolites, mono-(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), mono-(2-ethyl-5-oxohexyl) phthalate (MEOHP), and mono-(2-ethyl-5-carboxypentyl) phthalate (MECPP). Additionally, we examined the levels of free thyroxine (FT4), thyroid-stimulating hormone (TSH), and total triiodothyronine (TT3) in the serum samples of the following participants: 596, 627, and 576 in the first trimester; 292, 293, and 282 in the second trimester; and 250, 250, and 248 in the third trimester, respectively. Other than MBzP, which was detected in 25%-33% of the samples, other metabolites were detectable in >86% of urine samples, indicating widespread exposure to DEP, DBP, and DEHP. The detected phthalate exposure levels in our cohort were significantly higher than those reported in other countries. Metabolite levels varied across the trimesters, implying changes in exposure and metabolism throughout pregnancy. The observed variability in urinary concentrations of phthalate metabolites, which ranged from poor to moderate, underscores the importance of taking multiple measurements during pregnancy for precise exposure assessment. Using a linear mixed model, we analyzed the effects of repeated phthalate exposure on thyroid hormone levels while adjusting for potential confounders. We observed significant linear trends in FT4, TSH, and, to a lesser extent, TT3 across quartiles of specific phthalate metabolites. Comparing the highest to the lowest quartiles, we found a significant increase in FT4 levels, ranging from 2 to 3.7%, associated with MEP; MECPP; MEHHP; and the sum of seven metabolites (∑7PAE), three DEHP metabolites (∑3DEHP), two DBP metabolites (∑DBP), and both low molecular weight (∑LMW) and high molecular weight metabolites. Increased TSH levels (5%-16%) were observed for all phthalate metabolites (except MEHHP) and their molar sums, including ∑7PAE. For TT3, a significant increase was observed with MEP (2.2%) and a decrease was observed with ∑DBP (-2.7%). A higher TSH/FT4 ratio was observed with the highest quartiles (third or fourth) of several phthalate metabolites: MEP (8.8%), MiBP (8.7%), MnBP (22.2%), ∑7PAE (15.3%), ∑DBP (16.4%), and ∑LMW (18.6%). These hormonal alterations, most notably in the second and third trimesters, suggest that phthalate exposure may impact fetal growth and development by affecting maternal thyroid function.

Association of Di(2-ethylhexyl) Terephthalate and Its Metabolites with Nonalcoholic Fatty Liver Disease: An Epidemiology and Toxicology Study

As an alternative plasticizer to conventional phthalates, di(2-ethylhexyl) terephthalate (DEHTP) has attracted considerable concerns, given its widespread detection in the environment and humans. However, the potential toxicity, especially liver toxicity, posed by DEHTP remains unclear. In this study, based on the 2017-2018 National Health and Nutrition Examination Survey, two metabolites of DEHTP, i.e., mono(2-ethyl-5-hydroxyhexyl) terephthalate (MEHHTP) and mono(2-ethyl-5-carboxypentyl) terephthalate (MECPTP), were found to be present in the urine samples of nearly all representative U.S. adults. Moreover, a positive linear correlation was observed between the concentrations of the two metabolites and the risk of nonalcoholic fatty liver disease (NAFLD) in the population. Results of weighted quantile sum and Bayesian kernel machine regression indicated that MEHHTP contributed a greater weight to the risk of NAFLD in comparison with 12 conventional phthalate metabolites. In vitro experiments with hepatocyte HepG2 revealed that MEHHTP exposure could increase lipogenic gene programs, thereby promoting a dose-dependent hepatic lipid accumulation. Activation of liver X receptor α may be an important regulator of MEHHTP-induced hepatic lipid disorders. These findings provide new insights into the liver lipid metabolism toxicity potential of DEHTP exposure in the population.

Urinary concentrations of environmental phenol among pregnant women in the Japan Environment and Children's Study

Humans are exposed to various bisphenols, alkylphenols and nitrophenols through dietary intake, food packaging and container materials, indoor and outdoor air/dust. This study aimed to evaluate exposure of Japanese pregnant women to environmental phenols by measuring target compounds in urine samples. From a cohort of the Japan Environment and Children's Study, 4577 pregnant women were selected. Bisphenol A (BPA), bisphenol S (BPS), bisphenol F (BPF), bisphenol AF (BPAF), para-nitrophenol (PNP), 3-methyl-4-nitrophenol (PNMC), branched 4-nonylphenol (4-NP), linear 4-nonylphenol and 4-tert-octylphenol (4-t-OP) were analysed using a high-performance liquid chromatograph coupled to a triple-quadrupole mass spectrometer. The urinary metabolite data were combined with a questionnaire to examine the determinants of phenol exposure by machine learning. The estimated daily intake (EDI) and hazard quotient (HQ) of BPA were calculated. PNP (68.2%) and BPA (71.5%) had the highest detection frequencies, with median concentrations of 0.76 and 0.46 μg/g creatinine, respectively. PNMC, BPS, BPF and 4-NP were determined in 24.9%, 11.9%, 1.3% and 0.4% of samples, respectively, whereas BPAF (0.02%) and 4-t-OP (0.02%) were only determined in a few samples. The PNP concentrations measured in this study were comparable with those reported in previous studies, whereas the BPA concentrations were lower than those reported previously worldwide. The EDI of BPA was 0.014 μg/kg body weight/day. Compared with the tolerable daily intake set by the German Federal Institute for Risk Assessment, the median (95th percentile) HQ was 0.044 (0.2). This indicates that the observed levels of BPA exposure pose a negligible health risk to Japanese pregnant women. Determinants of bisphenol and nitrophenol exposure could not be identified by analysing the questionnaire solely, suggesting that biological measurement is necessary to assess exposure of pregnant women to bisphenols and nitrophenols. This is the first study to report environmental phenol exposure of Japanese pregnant women on a nationwide scale.

An eco-friendly sample preparation procedure based on air-assisted liquid-liquid microextraction for the rapid determination of phthalate metabolites in urine samples by liquid chromatography-tandem mass spectrometry

Urinary phthalate metabolite (mPAEs) analysis is a reliable tool for assessing human exposure to phthalates. With growing interest in urinary biomonitoring of these metabolites, there is a need for fast and sensitive analytical methods. Therefore, a simple, rapid procedure for simultaneous determination of fifteen phthalate metabolites in human urine samples by liquid chromatography-tandem mass spectrometry was developed. The novelty of the present procedure is based on the use of diethyl carbonate as a green biobased extraction solvent and air-assisted liquid-liquid microextraction (AALLME) as a sample preparation step. A Plackett-Burman design was used for screening the factors that influence the AALLME extraction efficiency of mPAEs. The effective factors were then optimized by response surface methodology using a central composite rotatable design. Under the optimized conditions, good linearity can be achieved in a concentration range of 1.0-20.0 ng mL-1 with correlation coefficients higher than 0.99. The repeatability and reproducibility precision were in the range of 2-12% and 1-10% respectively. Recoveries ranging from 90% to 110%. This, and the low limits of detection, ranging from 0.01 to 0.05 ng mL-1, make the proposed procedure sensitive and suitable for human biomonitoring of phthalate exposures. For proof-of-principle, the new method was used to measure the urinary concentrations of mPAEs in 20 urine samples from Brazilian women. The high frequency of detections and in part high concentrations of mPAEs indicate to widespread exposure to several phthalates among Brazilian women.

The plastic health map: A systematic evidence map of human health studies on plastic-associated chemicals

BACKGROUND

The global production and use of plastic materials has increased dramatically since the 1960s and there is increasing evidence of human health impacts related to exposure to plastic-associated chemicals. There is, however, no comprehensive, regulatory, post-market monitoring for human health effects of plastic-associated chemicals or particles and it is unclear how many of these have been investigated for effects in humans, and therefore what the knowledge gaps are.

OBJECTIVE

To create a systematic evidence map of peer-reviewed human studies investigating the potential effects of exposure to plastic-associated particles/chemicals on health to identify research gaps and provide recommendations for future research and regulation policy.

METHODS

Medline and Embase databases were used to identify peer-reviewed primary human studies published in English from Jan 1960 - Jan 2022 that investigated relationships between exposures to included plastic-associated particles/chemicals measured and detected in bio-samples and human health outcomes. Plastic-associated particles/chemicals included are: micro and nanoplastics, due to their widespread occurrence and potential for human exposure; polymers, the main building blocks of plastic; plasticizers and flame retardants, the two most common types of plastic additives with the highest concentration ranges in plastic materials; and bisphenols and per- or polyfluoroalkyl substances, two chemical classes of known health concern that are common in plastics. We extracted metadata on the population and study characteristics (country, intergenerational, sex, age, general/special exposure risk status, study design), exposure (plastic-associated particle/chemical, multiple exposures), and health outcome measures (biochemical, physiological, and/or clinical), from which we produced the interactive database 'Plastic Health Map' and a narrative summary.

RESULTS

We identified 100,949 unique articles, of which 3,587 met our inclusion criteria and were used to create a systematic evidence map. The Plastic Health Map with extracted metadata from included studies are freely available at https://osf.io/fhw7d/ and summary tables, plots and overall observations are included in this report.

CONCLUSIONS

We present the first evidence map compiling human health research on a wide range of plastic-associated chemicals from several different chemical classes, in order to provide stakeholders, including researchers, regulators, and concerned individuals, with an efficient way to access published literature on the matter and determine knowledge gaps. We also provide examples of data clusters to facilitate systematic reviews and research gaps to help direct future research efforts. Extensive gaps are identified in the breadth of populations, exposures and outcomes addressed in studies of potential human health effects of plastic-associated chemicals. No studies of the human health effects of micro and/or nanoplastics were found, and no studies were found for 26/1,202 additives included in our search that are of known hazard concern and confirmed to be in active production. Few studies have addressed recent "substitution" chemicals for restricted additives such as organophosphate flame retardants, phthalate substitutes, and bisphenol analogues. We call for a paradigm shift in chemical regulation whereby new plastic chemicals are rigorously tested for safety before being introduced in consumer products, with ongoing post-introduction biomonitoring of their levels in humans and health effects throughout individuals' life span, including in old age and across generations.

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.

Effects of di-(2-ethylhexyl) terephthalate on hypothalamus-pituitary-gonad axis in adult zebrafish

Di-(2-ethylhexyl) terephthalate (DEHTP) is frequently used in food packaging and medical devices as an alternative to di-(2-ethylhexyl) phthalate (DEHP). In this study, zebrafish pairs were exposed to DEHTP for 21 d and the effects on fertility, sex hormone levels, vitellogenin levels, and transcription of genes along the hypothalamic-pituitary-gonad axis were evaluated. Results showed that mean egg numbers were significantly reduced in the 30 and 300 μg/L DEHTP groups. The adverse effects of DEHTP on hormones and gene transcripts were more prominent in males than in females. In male fish, the gonadosomatic index, hepatosomatic index, and vitellogenin concentration were significantly increased. The results of a significant decrease in testosterone (T) and an increase in the 17β-estradiol (E2)/T ratio in males exposed to 3-300 μg/L DEHTP suggest that the endocrine potential of DEHTP is similar that of DEHP. In females, genes related to gonadotropin-releasing hormone and gonadotropin were up-regulated while E2 was significantly down-regulated. These findings suggest that positive E2 feedback mechanisms in the hypothalamus and pituitary gland are activated to balance sex hormones. The effects of chronic exposure to DEHTP on the neuroendocrine system require further investigation.

Profiling of phthalates, brominated, and organophosphate flame retardants in COVID-19 lockdown house dust; implication on the human health

In this study, brominated flame retardants (BFRs), phthalates, and organophosphate flame retardants (PFRs) were analyzed in indoor household dust collected during the COVID-19 related strict lockdown (April-July 2020) period. Floor dust samples were collected from 40 households in Jeddah, Saudi Arabia. The levels of most of the analyzed chemicals were visibly high and for certain chemicals multifold high in analyzed samples compared to earlier studies on indoor dust from Jeddah. Bis (2-ethylhexyl) phthalate (DEHP) was the primary chemical in these dust samples, with a median concentration of 769,500 ng/g of dust. Tris (2-butoxy ethyl) phosphate (TBEP) and Decabromodiphenyl ether (BDE 209) contributed the highest among PFRs and BFRs with median levels of 5990 and 940 ng/g of dust, respectively. The estimated daily exposure in the worst case scenario (23,700 ng/kg bw/day) for Saudi children was above the reference dose (20,000 ng/kg bw/day) for DEHP, and the hazardous index (HI) was also >1. The long-term carcinogenic risk was above the 1 × 10^-5, indicating a risk to the health of Saudi young children from getting exposed to DEHP from indoor dust. This study draws attention to the increased indoor pollution during the lockdown period when all of the daily activities by adults and children were performed indoors, which negatively impacted human health, as suggested by the calculated risk. However, the current study has limitations and warrants more monitoring studies from different parts of the world to understand the phenomenon. At the same time, this study also highlights another side of COVID-19 related to our lives.

Quantitative Measurement of Phthalate Exposure Biomarker Levels in Diaper-Extracted Urine of Japanese Toddlers and Cumulative Risk Assessment: An Adjunct Study of JECS Birth Cohort

Phthalate exposure monitoring and risk assessment in non-toilet-trained children are rarely reported. This adjunct study of the Japan Environment and Children's Study assessed cumulative health risks in 1.5-year-old toddlers in the Aichi regional subcohort by biomonitoring 16 urinary metabolites of eight phthalate plasticizers. Overnight urine was extracted from toddlers' diapers (n = 1077), and metabolites were quantified using ultraperformance liquid chromatography coupled with tandem mass spectrometry. The analyses' quality was assured by running quality control samples. The highest geometric mean concentration was found for mono-(2-ethyl-5-carboxypentyl) phthalate, followed by mono-isobutyl phthalate (23 and 21 μg/L, respectively). Di-2-ethylhexyl phthalate (DEHP) and di-butyl phthalate exhibited higher risks [hazard quotient (HQ) > 1] than the cutoff level in a small proportion of toddlers; 8 and 14% of toddlers were at cumulative risk of multiple phthalates beyond the cutoff level [hazard index, (HI) > 1], based on the tolerable daily intake of the European Food Safety Authority and the United States Environmental Protection Agency Reference Dose. HI > 1 for antiandrogenicity in creatinine-unadjusted and -adjusted estimations were exhibited by 36 and 23% of the children, respectively. Thus, identifying exposure sources and mitigating exposure are necessary for risk management. Additionally, continuous exposure assessment and evaluation of health outcomes, especially antiandrogenic effects, are warranted.

Exposure Characteristics and Cumulative Risk Assessment for Phthalates in Children Living near a Petrochemical Complex

BACKGROUND

School-aged children living near plastics-producing factories may have higher risk of exposure to phthalates released during the manufacturing processes.

OBJECTIVES

We aimed to investigate the urinary concentrations of phthalate metabolites in school-aged children living near a petrochemical complex and estimate the cumulative risk of phthalate exposure.

METHODS

We used a well-established cohort (Taiwan Petrochemical Complex Cohort for Children, TPE3C) of school-aged children (6-13 years old) living near polyvinyl chloride (PVC) and vinyl chloride monomer (VCM) factories in central Taiwan from October 2013 to September 2014. A total of 257 children were included from five elementary schools: Syu-Cuo Branch (n = 58, school A, ~0.9 km), Feng-An (n = 40, school B, ~2.7 km), Ciao-Tou (n = 58, school C, ~5.5 km), Mai-Liao (n = 37, school D, ~6.9 km), and Lung-Feng (n = 57, school E, ~8.6 km). We analyzed 11 metabolites of seven phthalates (including di-2-ethylhexyl phthalate (DEHP) and di-n-butyl phthalate (DnBP)) in urine. Daily intakes (DIs) were compared with acceptable intake levels to calculate the hazard quotient (HQ) for individual phthalates, and the cumulative risk for each child was assessed using a hazard index (HI), which was the sum of the the individual HQs.

RESULTS

The geometric mean and proportion of participants with HIs exceeding one for hepatic (HI_hep) and reproductive (HI_rep) effects were 0.33 (13.2%) and 0.24 (7.8%), respectively. The major contributors to phthalate exposure risk were DEHP, di-iso-butyl phthalate (DiBP) and DnBP in all children. Moreover, we observed a U shaped distribution of DEHP exposure by school distance from the PVC and VCM factories (school A: 7.48 μg/kg/day and school E: 80.44 μg/kg/day). This may be due to emissions (closest) and and being located downwind of PVC scrap incineration (farthest).

CONCLUSIONS

Our findings suggest that children living near a petrochemical complex were at a greater risk of phthalate exposure than normal school-aged children and that phthalate exposure was mainly attributed to DEHP, DiBP and DnBP. In addition, inhalation may have been a risk factor for people living near to PVC and VCM factories.

Urinary phthalate concentrations are associated with total fat mass in Thai children

OBJECTIVES

Phthalate is one of the endocrine-disrupting chemicals found in many daily consumer products. Chronic exposure to phthalate may associate with obesity and metabolic abnormalities. However, there is limited information showing a direct relationship between phthalate and body compositions. The aim of the study was to determine the association between urinary phthalate concentration and body composition measure among Thai children.

METHODS

A cross-sectional analytic study on urinary phthalate concentrations and body composition in elementary school children, aged 6-13 years in Bangkok, was conducted during October 2019 to 2020. Urinary phthalate metabolites; (mono-methyl phthalate-MMP, mono-ethyl phthalate- MEP, mono-buthyl phthalate-MBP, and mono-ethylhexyl phthalate-MEHP), in early morning spot urine samples were measured by liquid chromatography tandem mass spectrometry (LC-MSMS) with a quantitation limit of 1 ng/mL. Phthalate exposures were identified through questionnaires. Body composition was measured by Tanita BC-418^®. Multivariate logistic regression analysis was performed to determine significant associations.

RESULTS

A total of 364 children were enrolled in the study (boy 51.4%). After adjusting for confounders (sex, caregiver educations, family income, BMI-SDS: Body mass index-standard deviation score, TV watching, and exercise frequency), total urinary phthalate concentrations were associated with fat mass 8.24 (0.94, 15.53), trunk percent fat 7.69 (3.26, 12.12), arm percent fat 3.69 (0.47, 6.91), arm fat mass 72.88 (1.08, 144.67), and leg fat mass 17.79 (2.37, 33.22).

CONCLUSIONS

Higher urinary phthalate concentrations were significantly associated with elevated total fat mass among Thai school-aged children. These findings were not mediated through the degree of obesity defined by BMI. These finding emphasized to be careful when being use phthalate-containing products.

Biomarker-Determined Nonylphenol Exposure and Associated Risks in Children of Thailand, Indonesia, and Saudi Arabia

Nonylphenol (NP) is an endocrine disruptor and environmental contaminant. Yet, data on individual body burdens and potential health risks in humans, especially among children, are scarce. We analyzed two specific urinary NP metabolites, hydroxy-NP (OH-NP) and oxo-NP. In contrast to parent NP, OH-NP has a much higher urinary excretion fraction (F_ue), and both are insusceptible to external contamination. We investigated spot urine samples from school children of Thailand (n = 104), Indonesia (n = 89), and Saudi Arabia (n = 108) and could quantify OH-NP in 100% of Indonesian and Saudi children (median concentrations: 8.12 and 8.57 μg/L) and in 76% of Thai children (1.07 μg/L). Median oxo-NP concentrations were 0.95, 1.10, and <0.25 μg/L, respectively, in line with its lower F_ue. Median daily NP intakes (DIs), back-calculated from urinary OH-NP concentrations, were significantly higher in Indonesia and Saudi Arabia [0.47 and 0.36 μg/(kg bw·d), respectively] than in Thailand [0.06 μg/(kg bw·d)]. Maximum DIs were close to the preliminary tolerable DI of 5 μg/(kg bw·d) from the Danish Environmental Protection Agency. Dominant sources of exposure or relevant exposure pathways could not be readily identified by questionnaire analyses and also potentially varied by region. The novel biomarkers provide long-needed support to the quantitative exposure and risk assessment of NP.

Insights into the Endocrine Disrupting Activity of Emerging Non-Phthalate Alternate Plasticizers against Thyroid Hormone Receptor: A Structural Perspective

Many endocrine-disrupting chemicals (EDCs) have a ubiquitous presence in our environment due to anthropogenic activity. These EDCs can disrupt hormone signaling in the human and animal body systems including the very important hypothalamic-pituitary-thyroid (HPT) axis causing adverse health effects. Thyroxine (T4) and triiodothyronine (T3) are hormones of the HPT axis which are essential for regulation of metabolism, heart rate, body temperature, growth, development, etc. In this study, potential endocrine-disrupting activity of the most common phthalate plasticizer, DEHP, and emerging non-phthalate alternate plasticizers, DINCH, ATBC, and DEHA against thyroid hormone receptor (TRα) were characterized. The structural binding characterization of indicated ligands was performed against the TRα ligand binding site employing Schrodinger’s induced fit docking (IFD) approach. The molecular simulations of interactions of the ligands against the residues lining a TRα binding pocket, including bonding interactions, binding energy, docking score, and IFD score were analyzed. In addition, the structural binding characterization of TRα native ligand, T3, was also done for comparative analysis. The results revealed that all ligands were placed stably in the TRα ligand-binding pocket. The binding energy values were highest for DINCH, followed by ATBC, and were higher than the values estimated for TRα native ligand, T3, whereas the values for DEHA and DEHP were similar and comparable to that of T3. This study suggested that all the indicated plasticizers have the potential for thyroid hormone disruption with two alternate plasticizers, DINCH and ATBC, exhibiting higher potential for thyroid dysfunction compared to DEHA and DEHP.