Urinary Trichloroacetic Acid Levels Research Articles

Urinary Malondialdehyde (MDA) and N-Acetyl-β-D-Glucosaminidase (NAG) Associated with Exposure to Trichloroethylene (TCE) in Underground Water.

Trichloroethylene (TCE) is commonly used in various industries. If wastewater in factories is not effectively treated, the inflow into and subsequent contamination of underground water is likely. Our study assessed the association of exposure to TCE in underground water with oxidative stress and renal tubule damage. We selected 579 residents from areas with underground water contaminated with TCE. Each participant was interviewed via a questionnaire. We also assessed their urinary trichloroacetic acid (TCA) levels by gas chromatography (GC)-FID. Urinary malondialdehyde (MDA) and N-acetyl-β-D-glucosaminidase (NAG) were taken as indicators of oxidative stress and renal tubule damage. We found about 73% of the residents to have consumed underground water. The average duration of consumption was 26 years, with an average of 1.6 L per day. Currently, only 1.5% of the residents still continuously consume underground water. The consumption of underground water positively correlated with heightened urinary TCA levels (r = 0.554). Heightened urinary TCA levels, in turn, were positively associated with NAG levels (r = 0.180) but negatively associated with MDA levels (r = −0.193). The results held even after we had segmented urinary TCA levels into three groups of different levels. The elimination of the source of heightened TCE levels from various industrial effluents is essential. Residents exposed to TCE-laden underground water should periodically undergo health inspections.

Urinary biomarkers of exposure to drinking water disinfection byproducts and ovarian reserve: A cross-sectional study in China

Experimental studies have demonstrated that disinfection byproducts (DBPs) can cause ovarian toxicity including inhibition of antral follicle growth and disruption of steroidogenesis, but there is a paucity of human evidence. We aimed to investigate whether urinary biomarkers of exposure to drinking water DBPs were associated with ovarian reserve. The present study included 956 women attending an infertility clinic in Wuhan, China from December 2018 to January 2020. Antral follicle count (AFC), ovarian volume (OV), anti-Mullerian hormone (AMH), and follicle-stimulating hormone (FSH) were measured as indicators of ovarian reserve. Urinary dichloroacetic acid (DCAA) and trichloroacetic acid (TCAA) were assessed as potential biomarkers of drinking water DBP exposures. Multivariate linear and Poisson regression models were applied to estimate the associations of urinary DCAA and TCAA concentrations with indicators of ovarian reserve. Elevated urinary DCAA and TCAA levels were monotonically associated with reduced total AFC (− 5.98%; 95% CI: − 10.30%, − 1.44% in DCAA and − 12.98%; 95% CI: − 17.00%, − 8.76% in TCAA comparing the extreme tertiles; both P for trends ≤ 0.01), and the former was only observed in right AFC but not in left AFC, whereas the latter was estimated for both right and left AFC. Moreover, elevated urinary TCAA levels were monotonically associated with decreased AMH (− 14.09%; 95% CI: − 24.79%, − 1.86% comparing the extreme tertiles; P for trend = 0.03). These negative associations were still observed for the exposure biomarkers modeled as continuous variables. Our findings suggest that exposure to drinking water DBPs may be associated with decreased ovarian reserve.

Urinary Biomarker of Prenatal Exposure to Disinfection Byproducts, Maternal Genetic Polymorphisms in CYP2E1 and GSTZ1, and Birth Outcomes.

The effects of disinfection byproducts (DBPs) on adverse birth outcomes remain unsettled. Maternal genetic variants in relation to DBP metabolism may modify this effect. Pregnant women during late pregnancy (n = 1306) were included from a Chinese cohort. Maternal urinary trichloroacetic acid (TCAA) was measured as a biomarker of DBP exposure. Maternal genotyping was conducted in cytochrome P450 2E1 (CYP2E1; rs2031920, rs3813867, and rs915906) and glutathione S-transferase zeta-1 (GSTZ1; rs7975). The associations between maternal urinary TCAA and birth outcomes and statistical interactions between maternal exposure and genetic polymorphisms were estimated. We found that maternal urinary TCAA levels were associated with decreased birth weight (P for trend = 0.003) and ponderal index (P for trend = 0.004). Interaction analyses showed that maternal urinary TCAA in association with decreased birth weight was observed only among subjects with CYP2E1 rs3813867 GC/CC versus GG (Pint = 0.07) and associations with decreased birth length, ponderal index, and gestational age were observed only among subjects with GSTZ1 rs7975 GA/AA versus GG (Pint = 0.07, 0.02, and 0.02, respectively). Our results suggested that prenatal DBP exposure was negatively associated with birth weight and ponderal index, and maternal genetic polymorphisms in CYP2E1 and GSTZ1 might modify these associations.

Effect modification of CPY2E1 and GSTZ1 genetic polymorphisms on associations between prenatal disinfection by-products exposure and birth outcomes

BackgroundPrenatal disinfection by-products (DBPs) exposure is linked with adverse birth outcomes. Genetic susceptibility to DBP metabolism may modify the exposure-outcome associations. ObjectTo investigate whether CYP2E1 and GSTZ1 genetic polymorphisms modified the associations of prenatal DBP exposures with adverse birth outcomes. MethodsTwo biomarkers of DBP exposures including trihalomethanes (THMs) in blood and trichloroacetic acid (TCAA) in urine were determined among 426 pregnant women from a Chinese cohort study. CYP2E1 (rs2031920, rs3813867, and rs915906) and GSTZ1 (rs7975) polymorphisms in cord blood were genotyped. Statistical interactions between prenatal DBP exposures and newborns CYP2E1 and GSTZ1 polymorphisms on birth outcomes (birth weight, birth length, and gestational age) were examined by multivariable linear regression with adjustment for potential confounders. ResultsWe found that newborns CYP2E1 genetic polymorphisms (rs2031920 and rs3813867) modified the associations of maternal blood THMs or urinary TCAA levels with birth outcomes. However, these interactions were nonsignificant after Bonferroni correction for multiple comparisons, except for the interaction between maternal blood BrTHMs [sum of dibromochloromethane (DBCM), bromodichloromethane (BDCM), and bromoform (TBM)] and newborns CYP2E1 gene rs2031920 polymorphisms on birth weight (P for interaction = 0.003). ConclusionNewborns genetic variations of CYP2E1 rs2031920 may modify the impacts of prenatal BrTHM exposure on birth weight. This finding needs to be further confirmed.

Trichloroethylene (TCE) in underground water and its relationship with urinary malondialdehyde (MDA) and N-Acetyl-β-D-Glucosaminidase (NAG)

Background/objective: Trichloroethylene (TCE) is commonly used in various industries. If wastewater in factories is not effectively treated, the inflow to and subsequent contamination of underground water is likely. Our study assessed the association of exposure to TCE in underground water with oxidative stress and renal function. Materials and Methods: We selected 579 residents from areas with underground water contaminated with TCE. Each participant was interviewed via questionnaire. We also assessed their urinary trichloroacetic acid (TCA) levels by gas chromatography (GC)-FID. Urinary malondialdehyde (MDA) and N-Acetyl-β-D-Glucosaminidase (NAG) were taken as indicators of oxidative stress and renal tubule damage. Results: We found about 73% of the residents to have consumed underground water. The average duration of consumption was 26 years with an average of 1.6 liters per day. Presently, only 1.5% of the residents still continuously consume underground water. The consumption of underground water was positively correlated with heightened urinary TCA levels (r=0.554). Heightened urinary TCA levels, in turn, were positively associated with NAG levels (r=0.180) but negatively associated with MDA levels (r=-0.193). The results held even after we had segmented urinary TCA levels into three groups of different levels. Conclusion: The elimination of the source of heightened TCE levels from various industrial effluents is essential. Residents exposed to TCE-laden underground water should periodically undergo health inspections.

The compromise of dynamic disulfide/thiol homeostasis as a biomarker of oxidative stress in trichloroethylene exposure.

In this study, we aimed to investigate disulfide/thiol homeostasis in trichloroethylene (TCE) exposure. The study was carried out in 30 nonsmoker TCE-exposed workers with a variety of occupations. Additionally, 30 healthy nonsmoker volunteers were recruited as the control group. TCE exposure was determined by measuring urinary trichloroacetic acid (TCA) concentration. Median urinary TCA levels of exposed workers (20.5 mg/L) were significantly higher than control subjects (5 mg/L). Thiol and disulfide concentrations were determined using a novel automated method. Disulfide/thiol ratio was significantly higher in the exposed group (p < 0.001). Thiol/disulfide homeostasis was found to be disturbed in TCE-exposed workers. We predict that in TCE-exposed workers this disturbance can be a therapeutic target, and the efficiency of the treatment can easily be monitored by the novel method we used.

Use of urinary trichloroacetic acid as an exposure biomarker of disinfection by-products in cancer studies

Urinary trichloroacetic acid (TCAA) has been proposed as a valid exposure biomarker for ingested disinfection by-products (DBP) for reproductive studies. However, it has never been used in epidemiologic studies on cancer. We investigate the performance of urinary TCAA as a biomarker of DBP exposure in the framework of an epidemiologic study on cancer.We conducted home visits to collect tap water, first morning void urine, and a 48h fluid intake diary among 120 controls from a case-control study of colorectal cancer in Barcelona, Spain. We measured urine TCAA and creatinine, and 9 haloacetic acids and 4 trihalomethanes (THM) in tap water. Lifetime THM exposure was estimated based on residential history since age 18 plus routine monitoring data. Robust linear regressions were used to estimate mean change in urinary TCAA adjusted by covariates.Among the studied group, mean age was 74 years (range 63–85) and 41 (34%) were females. Mean total tap water consumption was 2.2l/48h (standard error, 0.1l/48h). Geometric mean urine TCAA excretion rate was 17.3pmol/min [95%CI: 14.0–21.3], which increased 2% for a 10% increase in TCAA ingestion and decreased with total tap water consumption (−17%/l), water intake outside home (−32%), plasmatic volume (−64%/l), in smokers (−79%), and in users of non-steroidal anti-inflammatory drugs (−50%). Urinary TCAA levels were not associated with lifetime THM exposure.In conclusion, our findings support that urine TCAA is not a valid biomarker in case-control studies of adult cancer given that advanced age, comorbidites and medication use are prevalent and are determinants of urine TCAA levels, apart from ingested TCAA levels. In addition, low TCAA concentrations in drinking water limit the validity of urine TCAA as an exposure biomarker.

Occupational health risks among trichloroethylene-exposed workers in a clock manufacturing factory.

Trichloroethylene (TCE) is an important volatile organic compound once widely used in industry throughout the world. Occupational exposure to TCE can cause a number of health hazards such as allergic reactions and genetic damage. The purpose of this study was to evaluate occupational exposure to TCE, by analysis of the air in the breathing zone and of urine from workers employed in a clock manufacturing factory. A subjective symptom survey was conducted by using a self-administered questionnaire to evaluate the health hazards. Micronucleus (MN) frequency, based on the cytokinesis-block micronucleus assay (CBMN) in peripheral blood lymphocytes, (PBLs) was used as a biomarker for chromosome damage. A total of 244 participants, including 171 workers occupationally exposed to TCE and 73 non-exposed control employees, working mainly in office jobs in the same factory, were enrolled in this study. Analyses of airborne TCE concentrations in the workplace, and of urinary trichloroacetic acid (TCA) of the workers and controls, were performed by Gas Chromatography-Electron Capture Detector (GC-ECD) using the modified headspace technique. The average concentration of TCE in the workplace breathing zone was 27.83 ± 6.02 ppm. The average level of urinary TCA of the exposed workers and controls was 14.84 ± 1.62, 2.95 ± 0.28 mg/L. The frequency of MN/1000BN was 7.029 ± 0.39, significantly higher than for those in the control group (3.57 ± 0.31, p = 0.001). According to multiple linear regression analysis, the results indicated that urinary TCA levels correlated with the increased MN in exposed workers (r = 0.285, p < 0.001). The prevalence rate of subjective symptoms in the exposed group was 9.61-11.76 times higher than the rate of the non-exposed group (p < 0.001). It was found that skin (29.6%) and respiratory symptoms (21.1%) were the most frequent among the exposed workers.In conclusion, these results indicate that increased micronucleus frequency is associated with occupational trichloroethylene exposure. The use of TCE in the factory is threatening workers’ health.

0241 Association between the oxidative stress and renal function with exposure to TCE in underground water

ObjectivesOur study is to assess association between the oxidative stress and renal function with exposure to TCE in underground water.Method579 questionnaires and 180 urine specimens were voluntarily taken from 1165...

8-Hydroxydeoxyguanosine as a Useful Marker for Determining the Severity of Trichloroethylene Exposure

ABSTRACT The aim of this study was to determine 8-hydroxydeoxyguanosine (8-OH-dG) levels in trichloroethylene (TCE)-exposed workers. Oxidative stress biomarkers and biochemical parameters were monitored among 26 TCE-exposed workers and 78 age-matched control subjects. Levels of urinary 8-OH-dG were analyzed by liquid chromatography tandem mass spectrometry. Urinary 8-OH-dG levels were significantly higher for TCE-exposed group (p < .001). Spearman's correlation test revealed positive correlations between urinary trichloroacetic acid levels and age, urinary 8-OH-dG, urinary total oxidant status, and urinary total antioxidant status (p = .042, p < .001, p < .001, and p < .001, respectively). 8-OH-dG may be a useful marker to determine the extent of TCE exposure.

Urinary trichloroacetic acid levels and semen quality: A hospital-based cross-sectional study in Wuhan, China

Toxicological studies indicate an association between exposure to disinfection by-products (DBPs) and impaired male reproductive health in animals. However, epidemiological evidence in humans is still limited. We conducted a hospital-based cross-sectional study to investigate the effect of exposure to DBPs on semen quality in humans. Between May 2008 and July 2008, we recruited 418 male partners in sub-fertile couples seeking infertility medical instruction or assisted reproduction services from the Tongji Hospital in Wuhan, China. Major semen parameters analyzed included sperm concentration, motility, and morphology. Exposure to DBPs was estimated by their urinary creatinine-adjusted trichloroacetic (TCAA) concentrations that were measured with the gas chromatography/electron capture detection method. We used linear regression to assess the relationship between exposure to DBPs and semen quality. According to the World Health Organization criteria (<20 million/mL for sperm concentration and <50% motile for sperm motility) and threshold value recommended by Guzick (<9% for sperm morphology), there were 265 men with all parameters at or above the reference values, 33 men below the reference sperm concentration, 151 men below the reference sperm motility, and 6 men below the reference sperm morphology. The mean (median) urinary creatinine-adjusted TCAA concentration was 9.2 (5.1) μg/g creatinine. Linear regression analyses indicated no significant association of sperm concentration, sperm count, and sperm morphology with urinary TCAA levels. Compared with those in the lowest quartile of creatinine-adjusted urinary TCAA concentrations, subjects in the second and third quartiles had a decrease of 5.1% (95% CI: 0.6%, 9.7%) and 4.7% (95% CI: 0.2%, 9.2%) in percent motility, respectively. However, these associations were not significant after adjustment for age, abstinence time, and smoking status. The present study provides suggestive but inconclusive evidence of the relationship between decreased sperm motility and increased urinary TCAA levels. The effect of exposure to DBPs on human male reproductive health in Chinese populations still warrants further investigations.

Trichloroacetic acid as a biomarker of exposure to disinfection by-products in drinking water: a human exposure trial in Adelaide, Australia.

We addressed the need for a biomarker of ingestion exposure to drinking water disinfection by-products by performing a human exposure trial. We evaluated urinary excretion of trichloroacetic acid (TCAA) as an exposure biomarker using 10 volunteers who normally consume their domestic tap water. We recruited the volunteers at a water quality research laboratory in Adelaide, Australia. Participants maintained a detailed consumption and exposure diary over the 5-week study. We also analyzed tap water and first morning urine (FMU) samples for TCAA, and tap water for chloral hydrate (CH). We documented both interindividual and intraindividual variability in TCAA ingestion and urinary excretion, and both were substantial. With a TCAA-free bottled water intervention, we used creatinine-adjusted urinary TCAA levels to estimate urinary TCAA excretion half-lives for three of the participants. We observed correspondence over time between estimated TCAA excretion, calculated from TCAA + CH ingestion levels, and measured TCAA urinary excretion. This study demonstrates the merits and feasibility of using TCAA in FMU as an exposure biomarker, and reveals remaining concerns about possible alternate sources of TCAA exposure for individuals with low drinking water ingestion exposure.

Urinary concentrations of trichloroacetic acid in Danish workers exposed to trichloroethylene, 1947-1985

Since 1947, the National Labour Inspection Service in Denmark has relied upon urinary measurements of trichloroacetic acid (TCA) in surveys of the occupational exposure to trichloroethylene (TCE). We examined the paper files relating to 2397 TCA measurements to extract information about the year, the company, the work process and the worker. We used multiple regression models to analyze the effects of various factors on the urinary concentration of TCA. The regression analyses showed that (1) a four-fold decrease in TCA concentrations occurred from 1947 to 1985; (2) the highest concentrations were observed in the iron and metal, chemical, and dry cleaning industries; (3) TCA levels were two times higher among men compared with women in the iron and metal and dry cleaning industries; (4) TCA concentrations were higher among younger compared with older workers; and (5) persons working in an area in which TCE was used, but not working with TCE themselves, also showed urinary TCA levels indicative of exposure. Calendar year, type of industry, degree of contact with TCE, sex and age were predictors of TCA concentration in the urine of Danish workers.