Thiodiglycolic Acid Research Articles

Liver impairment status toward workers exposed to vinyl chloride under different techniques

To analyse potential differences towards liver impairment status on vinyl chloride monomer(VCM) exposed population from technique under acetylene hydrochlorination to the one of ethylene oxychlorination respectively and to explore the possible reasons, which will pave the way for occupational health promotion in terms of hazard reduction. a cross-sectional study was initiated between June and September in 2022 towards 2 groups of VCM exposed population from the facility of acetylene hydrochlorination(n=78) and the one of ethylene oxychlorination(n=69) in a PVC petrochemical complex enterprise(abbreviation of H) in Tianjin City. The demographic information concerning age, gender, messages on occupational history, field investigation were inquired through questionnaire interview. Then, venous blood(4 mL/person) and urine(10-50 mL/person) were collected during the physical exam phase and indices of 8-hydroxy-2 deoxyguanosine(8-OHdG) in blood and thiodiglycolic acid(TDGA) in urine were detected through ELISA and solid phase extraction-ion chromatography respectively. The 2 groups of population were matched well in terms of average age distribution and gender composition ratio, with significant differences on population composition ratio were found on variables of working years, alcohol consumption and daily sleeping duration(P<0.01 or P<0.05). It was found that the average content of TDGA in acetylene hydrochlorination group was(0.81±0.05)mg/L while the content in ethylene oxychlorination group reached to(0.83±0.06)mg/L, noteworthy differences were only found among 6 posts in the acetylene hydrochlorination group and 5 others in the ethylene oxychlorination group after classification for specific posts, however, the average concentration of 8-OHdG in acetylene hydrochlorination group(122(78.3, 168.8) μg/m~3) was different from the one in ethylene oxychlorination group(101.7(79.6, 149.7) μg/m~3)(Z=6.82, P<0.05). Moreover, a series of positive correlations in moderate intensity between 8-OHdG concentration and TDGA content were observed among posts of polymerization cleaners(r=0.53), aggregation operators(r=0.47), maintenance repairers(r=0.45), sampling operators(r=0.41) in acetylene hydrochlorination group(P<0.05) and posts of cracking reactants(r=0.64), DCS operators(r=0.51), oxychlorination operators(r=0.50) and chemical loaders(r=0.44) in ethylene oxychlorination group(P<0.05). Liver function indices such as content on ALT(χ~2=15.41, P<0.01), AST(χ~2=9.95, P<0.01) and ALP(χ~2=3.79, P<0.01) were different in the 2 groups population with statistical significance, then proportions on population composition ratio that exceeded normal ranges of indices on ALT, AST, AST/ALT ratio, ALP and Alb/Glb ratio were higher in acetylene hydrochlorination group than ones in ethylene oxychlorination group with great significance(P<0.05), so as to the abnormalities in liver B altrosonography test between groups(χ~2=17.33, P<0.01). Binary logistic regression model indicated that 8-OHdG concentration in blood that exceed 90 μg/m~3, TDGA content in urine that exceed 0.60 mg/L, working years that were over 10a, alcohol consumption, sleeping duration less than 6 h per day and male workers were potential risky factors for liver impairment(P<0.05). The degree on liver impairment status was higher in acetylene hydrochlorination group than ones in in ethylene oxychlorination group under the same PVC factory, which might be associated with the oxidative stress injury induced from the combination of higher VCM concentration at workplaces, longer cumulative exposure time, longer working years, alcohol consumption habits and sleep shortage caused by shift work patterns.

Simultaneous biomonitoring of volatile organic compounds’ metabolites in human urine samples using a novel in-syringe based fast urinary metabolites extraction (FaUMEx) technique coupled with UHPLC-MS/MS analysis

Assessing the impact of human exposure to environmental toxicants is often crucial to biomonitoring the exposed dose. In this work, we report a novel fast urinary metabolites extraction (FaUMEx) technique coupled with UHPLC-MS/MS analysis for the highly sensitive and simultaneous biomonitoring of the five major urinary metabolites (thiodiglycolic acid, s-phenylmercapturic acid, t,t-muconic acid, mandelic acid, and phenyl glyoxylic acid) of common volatile organic compounds' (VOCs) exposure (vinyl chloride, benzene, styrene, and ethylbenzene) in human. FaUMEx technique comprises of two-steps, liquid-liquid microextraction was performed first in an extraction syringe using 1 mL of methanol (pH 3) as an extraction solvent and then, the extractant was passed through a clean-up syringe (pre-packed-with various sorbents including 500 mg anhydrous MgSO4, 50 mg C18, and 50 mg SiO2) to obtain the high order of matrice clean-up and preconcentration efficiency. The developed method displayed excellent linearity, and the correlation coefficients were >0.998 for all the target metabolites with detection and quantification limits of 0.02–0.24 ng mL−1 and 0.05–0.72 ng mL−1, respectively. Furthermore, the matrix effects were < ±5%, and inter and intra-day precision were <9%. Moreover, the presented method was applied and validated to real sample analysis for biomonitoring of VOC's exposure levels. The results showed that the developed FaUMEx-UHPLC-MS/MS method is fast, simple, low-cost, low-solvent consumption, high sensitivity with good accuracy and precision for five targeted urinary VOCs' metabolites. Therefore, the presented dual-syringe mode FaUMEx strategy with UHPLC-MS/MS technique can be applied to biomonitoring of various urinary metabolites to assess human exposure to environmental toxicants.

Numerical Recognition System and Ultrasensitive Fluorescence Sensing Platform for Al3+ and UO22+ Based on Ln (III)-Functionalized MOF-808 via Thiodiglycolic Acid Intermediates

Continuous accumulation of Al3+ in the human body and unintended leakage of UO22+ have posed a great threat to human health and the global environment; thus searching an efficient probe for the detection of Al3+ and UO22+ is of great importance. Herein, we designed and synthesized two hydrolytically stable Eu3+- and Tb3+-functionalized MOF materials Eu@MOF-808-TDA and Tb@MOF-808-TDA via thiodiglycolic acid (TDA) intermediates by the postsynthetic modification method. Among them, Tb@MOF-808-TDA was applied to construct numerical recognition systems of multiples of three and four by the combination of fluorescent signals, hierarchical cluster analysis, and logical gates. In addition, Tb@MOF-808-TDA exhibits good selectivity and sensitivity for the detection of Al3+ and UO22+. The detection limit is calculated to be 0.085 ppm for Al3+ and 0.082 ppm for UO22+ in aqueous solutions, which is lower than or close to that of latest reported Ln-MOFs. Moreover, the probe shows excellent hydrolytic stability and luminescence stability in the pH range of 4-11, further providing solid evidence for the practical application of Tb@MOF-808-TDA. More importantly, a mixed matrix hydrogel PVA-Tb@MOF-808-TDA was prepared to achieve the visual detection of Al3+, which broadens the potential in real-world sensing applications.

Improvement of protective facilities in vinyl chloride units on liver injury status of occupational exposed group

To comprehensively evaluate the effectiveness of improvement of protective facilities in a vinyl chloride monomer(VCM) on promotion toward health status of occupational exposed group and safety production at poly-vinyl chloride(PVC) by comparing the liver function indicators and inspection result before and after the improvement, and to analyze the possible influential factors. The information collection concerning facilities improvement in 2013 and 2016, identification toward critical controlling points, data or detection result from occupational on-site survey and physical examination were originated in July 2020, and 227 VCM exposed workers and 179 others without chemical reagents exposure history from production factory with calcium carbide process in Tianjin City were selected as objects. The effectiveness toward improvement of protective facilities in critical controlling points that occupational exposed workers usually involve in were evaluated through comparison toward VCM concentration result, thiodiglycolic acid(TDGA) content in urine, indicators on liver function and biochemistry and liver ultrasound. At the mean time, both binary Logistic regression analysis was used to screen the possible factors that contributed to abnormal symptoms and single dependent variable general linear regression model was used to find out the mutual interaction among influential factors. Prior to improvement on protective facilities, the C_(TWA)of VCM exposed by all 8 positions in G had exceeded 1 to 2 folds of occupational exposure limit(OEL=10 mg/m~3) and the position of synthetic operator and field sampling man were ones exposed to 1, 2-DCE with the range from 50% to 1 OEL, others hazard factors were found to meet relative OELs. Next, the content of TDGA in urine of exposed group was found to correlate strongly to the average concentration of VCM(r=0.79, P&lt;0.05), and result of TDGA content, alanine aminotransferase(ALT), γ-glutamyl transpeptidase(GGT) and abnormal rate toward liver ultrasound test in exposed group were much higher than ones in control group with significant differences(P&lt;0.05 or P&lt;0.001). By contrast, after the improvement, the exposure level toward all identified hazard factors were declined to meet OEL levels with significant differences in TDGA content, and result of ALT, GGT and abnormal rates toward symptoms in liver ultrasound test such as liver calcification with thickened liver echo, peripheral fibrosis of the liver, multiple hepatic cysts were markedly lower than ones before improvement and still were higher than ones in control group(P&lt;0.05 or P&lt;0.001). Further, parameters of gender, length of employment, weekly contact time, VCM exposed level, TDGA content were all important contributing factors to abnormal symptoms in liver ultrasound test before and after improvement on protective facilities(P&lt;0.05 or P&lt;0.001), in which a significant interaction effect between gender and length of employment(F=4.028, P=0.044), weekly contact time and TDGA content(F=2.183, P=0.046) in urine were found in contribution analysis to abnormal symptoms in liver ultrasound test(P&lt;0.05). The improvement measure carried out in VCM facilities by this PVC production factories with calcium carbide process effectively reduced the ambient concentration of hazard factors mainly led by VCM, but workers might still be at risk of liver injury even under VCM exposure at relative lower level, which may referred to factors of long weekly contact time, long length of employment and high fat diet.

SYNTHESIS AND CHARACTERISATION OF SOME NEW TIN METAL COMPLEXES [SnX2L 1-10] WITH MACROCYCLIC LIGANDS: PHOTOELECTRON STUDY and HOMO-LUMO GAP

Thirty tin (II) metal complexes of the type [SnX2L 1-10] (where X= Cl or Br or I; L= macrocyclic ligands (L1 to L10) derived from thiodiglycolic acid and different aliphatic diamines were created and characterized using elemental analysis, X-ray photoelectron (XPS), Infrared, and molar conductivity spectra. An octahedral geometry was found for these compounds. Frontier molecular orbitals (FMO) analysis has been done to obtain the HOMO-LUMO gap.

A Ratiometric Fluorescent Sensor Based on Dye/Tb (III) Functionalized UiO-66 for Highly Sensitive Detection of TDGA.

Thiodiglycolic acid (TDGA) is a biomarker for monitoring vinyl chloride exposure. Exploring a facile, rapid and precise analysis technology to quantify TDGA is of great significance. In this research, we demonstrate a fluorescent sensor based on dual-emissive UiO-66 for TDGA detection. This ratiometric fluorescent material named C460@Tb-UiO-66-(COOH)2 was designed and synthesized by introducing organic dye 7-diethylamino-4-methylcoumarin (C460) and Tb3+ into UiO-66-(COOH)2. The as-obtained C460@Tb-UiO-66-(COOH)2 samples showed highly selective recognition, excellent anti-interference and rapid response characteristics for the recognition of TDGA. The detection limit is 0.518 mg·mL−1, which is much lower than the threshold of 20 mg·mL−1 for a healthy person. In addition, the mechanism of TDGA-induced fluorescence quenching is discussed in detail. This sensor is expected to detect TDGA content in human urine.

Two SiO44--Templated Ln23Ni20 Clusters with Magnetic Cooling and Stability.

Assembling and studying high-nuclearity 3d-4f metal clusters represent a pregnant and challenging research hotspot. Based on anionic template and ligand-controlled hydrolytic methods, two heterometallic metal clusters, formulated as [Gd23Ni20(DTA)20(CO3)4(CH3COO)6(SiO4)4(CH3CH2OH)2(μ3-OH)33(μ2-OH)4(H2O)16]·Cl2·30H2O and [Eu23Ni20(DTA)20(CO3)4(CH3COO)6(SiO4)4(CH3CH2OH)2(μ3-OH)33(μ2-OH)4(H2O)16]·Cl2·46H2O (abbreviated as Gd23Ni20, Eu23Ni20, H2DTA = thiodiglycolic acid), are successfully obtained, which both feature similar double-shell-shaped structures with a Ni20 building unit encapsulating a Ln23 aggregation. The structural analysis illustrates that the SiO44- anion, serving as the anionic template in this work, is reported for the second time in 3d-4f metal clusters. In terms of the magnetic properties, large amounts of Gd3+ and Ni2+ ions contribute to the MCE of compound Gd23Ni20, along with 38.15 J kg-1 K-1 at ΔH = 7.0 T for 2.0 K. It is worth mentioning that compound Gd23Ni20 exhibits an excellent magnetic entropy change at low fields (-ΔSm = 19.10 J kg-1 K-1 at 2.0 K for ΔH = 2.0 T). In addition, Gd23Ni20 exhibits preferable solvent and thermal stability.

A novel core-shell nanomaterial ratiometric fluorescent probe for detecting urinary TDGA as a biomarker for VCM exposure

Thiodiglycolic acid (TDGA) is regarded as a sensitive biomarker for biological monitoring of VCM exposure. A simple, fast and reliable TDGA analysis method is of great significance to human health and the ecological environment. In this work, a novel core-shell nanomaterial based on p-type semiconductor@MOFs (Eu-CBO@Uio-66) is first prepared by in-situ growth and post-synthesis modification (PSM) as a ratiometric fluorescent probe for detecting TDGA, which shows a high sensitivity with a detection limit down to 51.1 μg L−1 (about 0.34 μM), relatively broad linear range (0–700 mg/L), fast response to TDGA within 2 min. As a result, after dispersing the resulting composite material in a solution containing TDGA, the blue emission of Eu-CBO@Uio-66 at 466 nm remains unchanged, while the red emission of Eu3+ center at 615 nm is significantly quenched, even in coexistence with other potentially analytes in the urine, so that the peak height ratio of the two emissions could be employed for determining TDGA. In addition, the significant ratiometric luminescence response caused by TDGA makes Eu-CBO@Uio-66 undergo a significant color transition from red to blue under UV-lamp, which is beneficial for visual analysis with the naked eye.

Integrative omics analysis reveals the protective role of vitamin C on perfluorooctanoic acid-induced hepatoxicity

IntroductionPerfluorooctanoic acid (PFOA) is a compound used as an industrial surfactant in chemical processes worldwide. Population and cross-sectional studies have demonstrated positive correlations between PFOA levels and human health problems. ObjectivesMany studies have focused on the hepatotoxicity and liver problems caused by PFOA, with little attention to remediation of these problems. As an antioxidant, vitamin C is frequently utilized as a supplement for hepatic detoxification. MethodsIn this study, we use a mouse model to study the possible role of vitamin C in reducing PFOA-induced liver damage. Based on comparative transcriptomic and metabolomic analysis, we elucidate the mechanisms underlying the protective effect of vitamin C. ResultsOur results show that vitamin C supplementation reduces signs of PFOA-induced liver damage including total cholesterol and triglyceride levels increase, liver damage markers aspartate, transaminase, and alanine aminotransferase elevation, and liver enlargement. Further, we show that the protective role of vitamin C is associated with signaling networks control, suppressing linoleic acid metabolism, reducing thiodiglycolic acid, and elevating glutathione in the liver. ConclusionThe findings in this study demonstrate, for the first time, the utility of vitamin C for preventing PFOA-induced hepatotoxicity.

Liver fibrosis associated with potential vinyl chloride and ethylene dichloride exposure from the petrochemical industry

BackgroundThe understanding of the relationship between exposure to carcinogenic vinyl chloride (VCM) and ethylene dichloride (EDC) and liver fibrosis is limited. ObjectiveThis study aimed to investigate the associations between the urinary metabolite levels of VCM and EDC and the risk of liver fibrosis in residents living near a petrochemical complex. MethodsOur study comprised 447 adult residents of two townships with questionnaire survey and health examination near the largest petrochemical complex in central Taiwan. The urinary levels of thiodiglycolic acid (TdGA), the metabolite of VCM and EDC, were detected in study subjects. We utilized fibrosis-4 (FIB-4) as the noninvasive liver fibrosis index. Adjusted linear model was applied to evaluate the associations between the distance from the complex and the urinary TdGA levels. Adjusted logistic regression model was applied to evaluate the associations between the urinary TdGA levels and the risk of liver fibrosis. ResultsThe study subjects living in the closer township had significant higher urinary TdGA levels than those living in the more distant township (269.6 ± 200.7 vs. 199.2 ± 164.7 μg/g creatinine) (p < 0.001). It showed that urinary TdGA levels were decreased 0.53-fold when the distances from the complex were increased 1-fold after adjusting for confounding factors. It demonstrated that the study subjects with the highest TdGA levels (>343.3 μg/g creatinine) had a higher risk of FIB-4>1.29 (OR = 2.09; 95% CI: 1.17, 3.78), and those with higher TdGA levels (232.7 to 343.3 μg/g creatinine) had a marginally higher risk of FIB-4>1.29 (OR = 1.65; 95% CI: 0.94, 2.90). ConclusionThe residents living closer to the VCM/PVC plant in the petrochemical complex had higher urinary TdGA levels, which were associated with an increased risk of fibrosis. This confirmed that the EDC and VCM potentially emitted from the petrochemical industry may have an impact on the liver health of nearby residents.

Liver Fibrosis Associated with Potential Vinyl Chloride and Ethylene Dichloride Exposure from the Petrochemical Industry

Background & Aims: The understanding of the relationship between exposure to carcinogenic vinyl chloride (VCM) and ethylene dichloride (EDC) and liver fibrosis is limited. This study aimed to investigate the associations between the urinary metabolite levels of VCM and EDC and the risk of fibrosis in residents living near a petrochemical complex. Approach & Results: Our study comprised 447 adult residents of two townships with questionnaire survey and health examination near the largest petrochemical complex in Taiwan. The urinary levels of thiodiglycolic acid (TdGA), the metabolite of VCM and EDC, were detected in study subjects. We utilized fibrosis-4 (FIB-4) as the liver fibrosis index. Adjusted generalized linear and logistic regression models were applied to evaluate the associations between those exposure and the risk of fibrosis. The subjects living in the closer township had significantly higher TdGA levels than those living in the more distant (269.6 ±200.7 vs. 199.2±164.7 μg/g creatinine). It showed that TdGA levels were 6.51 μg/g creatinine lower 1 km away from the emission source of the complex after adjusting for confounding factors. It demonstrated that the subjects with the highest TdGA levels (>343.3 μg/g creatinine) had a significantly higher risk of abnormal FIB-4 (OR=2.09; 95% CI: 1.17, 3.77), and those with higher TdGA levels (232.7 to 343.3 μg/g creatinine) had a marginally higher risk of abnormal FIB-4 (OR=1.65; 95% CI: 0.94, 2.90). Conclusion: The residents living closer to the VCM/PVC plant in the complex had higher urinary TdGA levels, which were significantly associated with the risk of fibrosis. This confirmed that the EDC and VCM potentially emitted from the petrochemical industry may have an impact on the liver health of nearby residents. Funding Statement: This research was funded by a grant from the Changhua County Public Health Bureau in Taiwan (grant number 1040723). The study was also funded by the Ministry of Science and Technology in Taiwan (grant number MOST 107-3017-F-002-003, MOST 108-3017-F-002-001) and Featured Areas Research Center Program within the framework of the Higher Education Sprout Project by the Ministry of Education in Taiwan (grant numbers NTU-107L9003, NTU380 108L9003). Declaration of Interests: The authors declare no competing interests. Ethics Approval Statement: This study was approved by the Research Ethics Committee of the National Health Research Institutes in Taiwan, and written informed consent forms were signed by each subject.

Six new lanthanide metal–organic frameworks as luminescent sensors for the detection of 1-N, TDGA, UA, and HA in urine

The hydrothermal reaction of Ln(NO3)3·6H2O with H2tyia (H2tyia = 5-(triazol-1-yl) isophthalic acid) afforded the lanthanide organic frameworks (Ln-MOFs), [Eu2(tyia)3(H2O)3]n (1) and {[Ln2(tyia)3·(H2O)3]· 3H2O}n (Ln = Tb 2, Dy 3, Sm 4, Gd 5, and Nd 6). Compounds were characterized by routine methods: PXRD, elemental analysis, solid-state luminescence properties analysis, TGA, FT-IR, and single-crystal X-ray crystallography. In this work, the luminescent properties of 2, 4, 5, and 6 and the responsiveness of various chemical components contained in urine were investigated. These MOFs detect 1-naphthol (1-N), urinary thiodiglycolic acid (TDGA), uric acid (UA), and hippuric acid (HA), which are the final metabolites of carbaryl, vinyl chloride monomers, purine, and toluene, respectively. These new Ln-MOFs offer the potential for biomarkers or metabolic sensors and show excellent selective and sensitive luminescence detection of 1-N, TDGA, UA, and HA.

Reduced adiponectin:leptin ratio associated with inhalation exposure to vinyl chloride monomer

The hepatic toxicity of vinyl chloride monomer (VCM) has often been reported, but few studies have assessed insulin resistance or adipose tissue dysfunction. We analyzed the chronic health effects of moderate exposure to VCM on factory workers in Taiwan. Data were collected from personal air samples, urine samples, and immunohistochemical (IHC) examinations of 122 recruited voluntary participants. Air samples were analyzed to assess personal levels of exposure to VCM and ethylene dichloride (EDC). Urine samples were collected from each worker before they started and after they finished their daily shift. Urinary thiodiglycolic acid (TDGA) levels were analyzed using high-performance liquid chromatography-tandem mass spectrometry (HPLC/MS/MS). IHC examinations included liver function and serum adipokine level tests for insulin resistance. Consequently, the participants included for the final analysis were 113. After confounders had been adjusted for, the airborne VCM concentration significantly (P = 0.043) correlated with pre-shift urinary TDGA levels (β = 0.194). A multivariate analysis showed a significant (P = 0.013) inverse correlation between the adiponectin:leptin ratio and the airborne VCM concentration (β = −0.283), which means that exposure to VCM might increase the risk of insulin resistance and adiponectin abnormalities. We hypothesized that pre-shift urinary TDGA levels can be used as exposure biomarkers for the exposure of workers to VCM.

Does Urinary Thiodiglycolic Acid Increase the Risk of Non-Alcoholic Fatty Liver Disease in Children Living Near a Petrochemical Complex?

Does Urinary Thiodiglycolic Acid Increase the Risk of Non-Alcoholic Fatty Liver Disease in Children Living Near a Petrochemical Complex?

Urinary thiodiglycolic acid is associated with increased risk of non-alcoholic fatty liver disease in children living near a petrochemical complex

BackgroundOccupational and experimental studies have revealed that high vinyl chloride monomer (VCM) exposure is associated with non-alcoholic fatty liver disease (NAFLD). Epidemiological study reported that children living near a petrochemical complex have elevated exposure levels of urinary thiodiglycolic acid (TDGA), a potential VCM biomarker. However, no studies on the association of urinary TDGA exposure with NAFLD in children are available. AimTo assess the association of pediatric NAFLD with urinary TDGA exposure in school-aged children living near a petrochemical complex. Materials and methodsIn total, 261 school-aged children (aged 6–13 years) living near a petrochemical complex were recruited during October 2013 to September 2014. First morning spot urine was sampled for analyzing urinary TDGA through liquid chromatography-tandem mass spectrometry. Ultrasonography and serum alanine aminotransferase (ALT) were examined in each participant. NAFLD was diagnosed as recommended by the North American and European Society of Pediatric Gastroenterology, Hepatology and Nutrition (NASPGHAN and ESPGHAN). Risk for NAFLD with urinary TDGA exposure in children was evaluated using a multivariate logistic regression model. ResultsThe percentage of children with NAFLDNASPGHAN and NAFLDESPGHAN were 9.6% and 11.5%, respectively. Median levels (μg/g creatinine) of urinary TDGA of children with NAFLDNASPGHAN (vs non-NAFLDNASPGHAN) and NAFLDESPGHAN (vs non-NAFLDESPGHAN) were 118.0 (vs 96.6) and 113.1 (vs 96.5), respectively. Participants in the highest urinary TDGA quartile (Q4: ≥160.0 μg/g creatinine) had a significantly increased risk (odds ratio [OR] = 4.95; 95% confidence interval [CI] = 1.15–21.38; P = 0.032) and dose-response trend (Ptrend = 0.045) for NAFLDNASPGHAN compared with those in the lowest urinary TDGA quartile (Q1: <35.4 μg/g creatinine) after adjustment for age, gender, BMI, triglycerides, HOMA-IR and distance of elementary schools from the petrochemical complex. Participants in the Q4 had borderline significantly increased risk (OR = 3.45; 95% CI = 0.89–13.42; P = 0.074) correlated with NAFLDESPGHAN compared with those in the Q1 after adjustment for confounders. ConclusionOur findings support the hypothesis that children exposed to higher urinary TDGA levels significantly increased pediatric NAFLD risk. Serum ALT levels can be a useful predictor for screening children's NAFLD in field studies. Large and longitudinal studies are warranted to elucidate the association.

Association between urinary thiodiglycolic acid level and hepatic function or fibrosis index in school-aged children living near a petrochemical complex

The effect of exposure to vinyl chloride monomer (VCM) on susceptibility to hepatotoxicity in children is unknown, although experimental studies have demonstrated a significantly increased risk of hepatocellular carcinoma in rodents exposed to VCM in early life. Epidemiological studies have revealed a high prevalence of liver fibrosis and abnormal liver function in workers exposed to high VCM levels. We aimed to assess the association among urinary thiodiglycolic acid (TDGA) level, abnormal liver function, and hepatic fibrosis in school-aged children living near a petrochemical complex. A total of 303 school-aged (6–13 years) children within 10 km nearly a petrochemical complex was recruited in central Taiwan. First-morning urine and blood samples were collected from each subject, and urinary TDGA level was analyzed through liquid chromatography–tandem mass spectrometry. Liver function was determined by serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels. Hepatic fibrosis was assessed using the AST to platelet ratio index (APRI) and fibrosis-4 score (FIB-4). Risk of hepatotoxicity induced by TDGA exposure was estimated using multivariate logistic regression. The median (range, subclinically abnormal %) AST and ALT levels of all subjects were 26.0 (17.0–99.0, 25.7%) and 15.0 (7.0–211.0, 5.9%) IU/L, respectively. Children in the highest urinary TDGA quartile (≥160.0 μg/g creatinine) exhibited significantly elevated median AST levels compared with those in the lowest quartiles (<35.4 μg/g creatinine, p = 0.033). After adjustment for potential confounding factors, children in the highest quartiles (Q4) of TDGA level had significantly increased odds ratio (OR) of subclinically abnormal AST (OR = 3.86; 95% confidence interval: 1.54–9.67) compared with those in the lowest quartile. A dose-response trend (p = 0.004) was observed. Our findings support the hypothesis that elevated urinary TDGA level in children living near petrochemical complex is associated with susceptibility to hepatotoxicity.

Association between Liver Function, Hepatic Fibrosis Index and Urinary Thiodiglycolic Acid in School-Aged Children Living near a Petrochemical Complex

Background/AimWhether children are susceptible to hepatotoxicity when exposed to vinyl chloride monomer (VCM) is unknown. Epidemiological studies revealed high prevalence of liver fibrosis and abnormal liver function in high VCM/PVC exposed workers, and previous study indicated that using urinary thiodiglycolic acid (TDGA) as a biomarker of VCM metabolites is reliable in children living near VCM/PVC factories. We aim to assess the association among urinary TDGA levels, liver function, and hepatic fibrosis in school-aged children.Methods 303 school-aged children (aged &amp;#8805;6-&amp;lt;13 years) were recruited in central Taiwan. First morning urine and blood samples were collected in each participants, and urinary TDGA levels were analyzed by LC/MS-MS. Liver function was determined by subclinical abnormal serum aspirate aminotransferase (AST) and alanine aminotransferase (ALT). Hepatic fibrosis was assessed by AST to platelet ratio index (APRI), and fibrosis-4 score (FIB-4).Results Median levels of all subjects urinary TDGA (range), AST/ALT (range; subclinically abnormal rate) were 95.2 &amp;#956;g/g-creatinine, 26.0 IU/L (17.0-99.0; 26%)/15.0 IU/L (7.0-211.0; 6%), respectively. Third quartile of urinary TDGA levels in children (Q3: &amp;#8805; 95.2 - &amp;lt;160.0 &amp;#956;g/g-creatinine) and highest quartile (Q4: &amp;#8805; 160.0 &amp;#956;g/g-creatinine) had significantly increased the odds ratio (OR) (Q3: OR&amp;#61; 3.54, 95% confidence interval (CI): 1.35-9.30; Q4: OR&amp;#61; 5.26, 95% CI: 1.93-14.31) of subclinically abnormal AST compared with those in the lowest quartile after adjustment for elementary schools, age, sex, BMI, annual family income, physical activity, and passive smoking. A trend for a dose-response (p for trend&amp;#61; 0.001) was also observed.ConclusionsOur findings supported the hypothesis that urinary TDGA levels in children living near VCM/PVC industries are associated with susceptibility to hepatotoxicity.

Association between Hepatic Index and Urinary Thiodiglycolic Acid in Residents Living near to a Big Petrochemical Complex

Background/Aim No.6 Naphtha Cracking Complex in Taiwan is producing vinyl chloride monomer (VCM) and polyvinyl chloride (PVC) by Ethylene dichloride (EDC), which might release trace level of VCM an...

Feasibility of using urinary TDGA as a biomarker for VCM exposures

Thiodiglycolic acid (TDGA) is a major metabolite of vinyl chloride monomer (VCM), and it has been suggested as an exposure biomarker for VCM. The validity of this biomarker when the level of VCM is less than 5 ppm, however, is questionable. The objective of this article is to evaluate the feasibility of using urinary TDGA as a biomarker of VCM exposure in a community health risk assessment setting where the concentration of VCM in air is typically very low (likely below 1 ppm). To achieve this objective, we examine the fraction of urinary TDGA associated with different levels of VCM exposures of three studies from different countries, using estimations of the TDGA metabolite predicted by a PBPK model. It is demonstrated that differences in background TDGA have considerable effect on the adequacy of TDGA as a biomarker of VCM. We conclude that, in a community health assessment setting, TDGA should not be used as an exposure biomarker for VCM without having a proper control group, and a PBPK model can be used first to determine whether or not the amount of TDGA in urine is of concern.

Quantitative determination of acidic hydrolysis products of Chemical Weapons Convention related chemicals from aqueous and soil samples using ion-pair solid-phase extraction and in situ butylation.

Chemical warfare agents such as organophosphorus nerve agents, mustard agents, and psychotomimetic agent like 3-quinuclidinylbenzilate degrade in the environment and form acidic degradation products, the analysis of which is difficult under normal analytical conditions. In the present work, a simultaneous extraction and derivatization method in which the analytes are butylated followed by gas chromatography and mass spectrometric identification of the analytes from aqueous and soil samples was carried out. The extraction was carried out using ion-pair solid-phase extraction with tetrabutylammonium hydroxide followed by gas chromatography with mass spectrometry in the electron ionization mode. Various parameters such as optimum concentration of the ion-pair reagent, pH of the sample, extraction solvent, and type of ion-pair reagent were optimized. The method was validated for various parameters such as linearity, accuracy, precision, and limit of detection and quantification. The method was observed to be linear from 1 to 1000ng/mL range in selected ion monitoring mode. The extraction recoveries were in the range of 85-110% from the matrixes with the limit of quantification for alkyl phosphonic acids at 1ng/mL, thiodiglycolic acid at 20ng/mL, and benzilic acid at 50ng/mL with intra- and interday precisions below 15%. The developed method was applied for the samples prepared in the scenario of challenging inspection.