Chromatography, Gas ; methods ; Humans ; Tetrachloroethylene ; blood

Recently physiologically based pharmacokinetic (PB-PK) model has important role in industrial and environmental health. One of problem in application of PB-PK models is that they have uncertainties that is due to different input parameters according to authors. In order to develope a PB-PK model that hag good validity, the effect of several input parameters on simulation results was studies. Chemicals studied were perchloroethylene, toluene and styrene. Simulation of alveolar concentration, blood concentration and urinary metabolites was performed for three solvents, respectively. Input parameters discusses were physiological parameters, metabolic parameters and partition coefficient of chemicals. By comparing simulation results according to several pairs of parameters with experimental data, input parameters that showed best fit were decided.
Environmental Health ; Solvents ; Styrene ; Tetrachloroethylene ; Toluene ; Volatile Organic Compounds*

There are clear indoor air pollution sources of trichloroethylene and tetrachloroethylene. A large number of epidemiological evidence has confirmed their carcinogenic toxicity and non-carcinogenic toxicity. Several countries and international organizations have paid attention to indoor air trichloroethylene and tetrachloroethylene. It has been also assessed that there should be certain potential health risk of indoor air trichloroethylene and tetrachloroethylene in China. Based on the latest research results of health risk assessment of indoor air trichloroethylene and tetrachloroethylene, the "Standards for indoor air quality (GB/T 18883-2022)" added trichloroethylene and tetrachloroethylene as indicators. The index limit of trichloroethylene is 6 μg/m³ for an 8-hour average concentration. The index limit of tetrachloroethylene is 120 μg/m³ for an 8-hour average concentration. The technical contents related to the determination of the standard limits of trichloroethylene and tetrachloroethylene in indoor air were analyzed and discussed, including the sources, the exposure, the health effects, the determination of the limit values, and the recommendations for standard implementation. It also proposed recommendations for the implementation of"Standards for indoor air quality (GB/T 18883-2022)".
Humans ; Tetrachloroethylene/analysis* ; Air Pollution, Indoor ; Trichloroethylene/analysis* ; China

There are clear indoor air pollution sources of trichloroethylene and tetrachloroethylene. A large number of epidemiological evidence has confirmed their carcinogenic toxicity and non-carcinogenic toxicity. Several countries and international organizations have paid attention to indoor air trichloroethylene and tetrachloroethylene. It has been also assessed that there should be certain potential health risk of indoor air trichloroethylene and tetrachloroethylene in China. Based on the latest research results of health risk assessment of indoor air trichloroethylene and tetrachloroethylene, the "Standards for indoor air quality (GB/T 18883-2022)" added trichloroethylene and tetrachloroethylene as indicators. The index limit of trichloroethylene is 6 μg/m³ for an 8-hour average concentration. The index limit of tetrachloroethylene is 120 μg/m³ for an 8-hour average concentration. The technical contents related to the determination of the standard limits of trichloroethylene and tetrachloroethylene in indoor air were analyzed and discussed, including the sources, the exposure, the health effects, the determination of the limit values, and the recommendations for standard implementation. It also proposed recommendations for the implementation of"Standards for indoor air quality (GB/T 18883-2022)".
Humans ; Tetrachloroethylene/analysis* ; Air Pollution, Indoor ; Trichloroethylene/analysis* ; China

Tetrachloroethylene is widely used as a solvent for degreasing operations and for dry cleaning. Accidental overexposure of tetrachloroethylene produces central nervous system depression which may be followed by hepatic and renal damage. Renal changes are usually mild and reversible with removal of the offending agent. The relationship between exposure to tetrachloroethylene and chronic renal failure remains controversial. Acute or subacute tetrachloroethylene poisoning has been occasionally observed in dry cleaners and fatal cases have been rarely reported. We experienced a case of acute tetrachloroethylene poisoning complicated by acute renal failure. After ingestion of 200 mL tetrachloroethylene, a 32- year-old man was admitted to the clinic in semicoma. Under the conservative treatment, the clinical condition of the patient improved consideravely, but acute renal failure developed. After 5 times hemodialysis during the admission, he recovered completely from acute renal failure.
Acute Kidney Injury* ; Central Nervous System ; Depression ; Eating ; Humans ; Kidney Failure, Chronic ; Poisoning* ; Renal Dialysis ; Tetrachloroethylene*

Tetrachloroethylene is a chlorinated solvent that is primarily used in dry cleaning and degreasing operations. Although the hepatotoxicity caused by tetrachloroethylene has been well documented in literature, it is rarely considered as a cause of acute liver failure. We report a case of a 39-yr-old man who was admitted to our hospital for acute liver failure due to tetrachloroethylene exposure. Histological examination of the liver revealed massive hepatic necrosis, prominently, in zone 3 of the hepatic lobules. The patient underwent supportive treatment along with 3 sessions of plasmapheresis, and consequently, he presented a favorable outcome. Repeat liver biopsy performed 6 months after the patient's discharge showed architectural distortion with postnecrotic cirrhosis. Physicians should be aware of the possibility of acute liver failure induced by tetrachloroethylene. Early plasmapheresis can be effective for individuals with sufficient capacity for hepatocyte regeneration.
Adult ; Carcinogens/*toxicity ; Humans ; Liver Cirrhosis/pathology ; Liver Failure, Acute/chemically induced/*diagnosis/pathology ; Male ; *Occupational Exposure ; Plasmapheresis ; Tetrachloroethylene/*toxicity

OBJECTIVETo investigate the biodegradation of tetrachloroethylene (PCE) by acclimated anaerobic sludge using different co-substrates, i.e., glucose, acetate, and lactate as electron donors.

METHODSHP-6890 gas chromatograph (GC) in combination with auto-sampler was used to analyze the concentration of PCE and its intermediates. Results PCE could be degraded by reductive dechlorination and the degradation reaction conformed to the first-order kinetic equation. The rate constants are k(lactate) > k(glucose) > k(acetate). The PCE degradation rate was the highest in the presence of lactate as an electron donor.

CONCLUSIONLactate is the most suitable electron donor for PCE degradation and the electron donors supplied by co-metabolic substrates are not the limiting factors for PCE degradation.

Acetates ; metabolism ; Anaerobiosis ; Bacteria, Anaerobic ; metabolism ; Biodegradation, Environmental ; Bioreactors ; Glucose ; metabolism ; Kinetics ; Lactic Acid ; metabolism ; Oxidation-Reduction ; Sewage ; microbiology ; Tetrachloroethylene ; metabolism

This review summarizes the epidemiology of cancer of the female reproductive system and associated lifestyle factors. It also assesses the available evidence for occupational factors associated with these cancers. Cervical, endometrial, and ovarian cancers are relatively common, and cause significant cancer morbidity and mortality worldwide, whereas vulvar, vaginal, fallopian tube cancers, and choriocarcinomas are very rare. As several lifestyle factors are known to play a major role in the etiology of these cancers, very few published studies have investigated possible relationships with occupational factors. Some occupational exposures have been associated with increased risks of these cancers, but apart from the available evidence on the relationships between asbestos fibers and ovarian cancer, and tetrachloroethylene and cervical cancer, the data is rather scarce. Given the multifactorial nature of cancers of the female reproductive system, it is of the utmost importance to conduct occupational studies that will gather detailed data on potential individual confounding factors, in particular reproductive history and other factors that influence the body's hormonal environment, together with information on socio-economic status and lifestyle factors, including physical activity from multiple sources. Studies on the mechanisms of carcinogenesis in the female reproductive organs are also needed in order to elucidate the possible role of chemical exposures in the development of these cancers.
Asbestos ; Choriocarcinoma ; Endometrial Neoplasms ; Fallopian Tube Neoplasms ; Female ; Humans ; Life Style ; Motor Activity ; Occupational Exposure ; Ovarian Neoplasms ; Pregnancy ; Reproductive History ; Tetrachloroethylene ; Uterine Cervical Neoplasms ; Vaginal Neoplasms

OBJECTIVETo explore the different concentrations of trichloroethylene (TCE) or perchloroethylene (PCE) induced cultured normal human epidermal keratinocyte (KC) lipid peroxidation and protective effect of Vitamin E on it.

METHODSKC derived from 3 or more donors were pooled together and cultured with K-SFM. Neutral Red Uptake Assay was used to determine the IC50 of TCE or PCE, and then different concentrations of TCE or PCE were administered for culturing KC; 0.5 mmol/L TCE or 0.2 mmol/L PCE and different concentrations of Vitamin E were used to determine the protective effect of Vitamin E. After 4 hours' culture, kits were used to determine cellular MDA, SOD and ROS level.

RESULTSTreatment of KC with different concentrations of TCE or PCE showed significant dose-related variations in lipid peroxidation, with the higher concentration, higher level of MDA, ROS and lower activity of SOD displayed in this study. Vitamin E 10 - 200 mmol/L dose-dependently attenuated MDA and ROS level, and increased SOD activities.

CONCLUSIONTCE or PCE can induce the lipid peroxidation in cultured KC and Vitamin E protects it from TCE- or PCE-induced peroxidation.

Antioxidants ; pharmacology ; Cells, Cultured ; Dose-Response Relationship, Drug ; Humans ; Keratinocytes ; drug effects ; metabolism ; Lipid Peroxidation ; drug effects ; Malondialdehyde ; metabolism ; Reactive Oxygen Species ; metabolism ; Superoxide Dismutase ; metabolism ; Tetrachloroethylene ; toxicity ; Trichloroethylene ; toxicity ; Vitamin E ; pharmacology

Chlorinated solvents are recognized as well-known drinking water contaminants and potent teratogens for developing embryos. Among theses compounds, tetrachloroethylene was studied to evaluate the teratogenic effects in detail. This study was also undertaken to understand the teratogenetic mechanisms by assessing the relationship between the physiological impairments and cellular degeneration including apoptosis induced by tetrachloroethylene, and the cardiovascular malformations. Fertilized white leghorn eggs (n=530) were incubated for 90~96 hours up to Hamburger-Hamilton stage 27~28. To the experimental group, tetrachloroethylene was dissolved in mineral oil at concentrations of 40 micrometer and 50 micrometer and was injected into the chorioallantoic membrane. One half of the control was injected with saline and the other half with mineral oil. The experimental animals are studied for ECG changes, and light and electron microscopic observation. Two silver thread electrodes were used to record the ECG. ECG changes were recorded for 6~30 minutes after tetrachloroethylene injections. In parallel studies, blood velocity through the dorsal aorta was measured by a pulse Doppler velocity meter with 20 MHz probe. The specimens were stained with hematoxylin and eosin for light microscopic study and the Hitachi H-800 EM was used for transmission electron microscopic evaluation. The embryos underwent formalin fixation on day 14, and the presence of malformations was observed by a microscopy. The results obtained are as follows: Repeated injections of 40~50 micrometer tetrachloroethylene appeared to have a strong influence on the formation of cardiovascular malformations. Various types of cardiac malformations were observed in the experimental group compared to control group, that were statistically significant (p<0.01) and many embryos also died. The malformations observed were large ventricular septal defect, endocardial cushion defect, double outlet right ventricle and truncus arteriosus associated with single ventricle. Large ventricular septal defect was most common type of cardiovascular abnormalities. Arrythymias including ventricular fibrillations were evident on ECG 6~30 minutes after the injections. Blood flow through the dorsal aorta was markedly decreased in concordance with the ECG changes. A large amount of individual cell death suggesting apoptosis was seen on light microscopic evaluation and the electron microscope revealed cellular degeneration of the embryonic myocardium. We concluded that tetrachloroethylene, like other chloride compounds has potent teratogenic effects. The cardiac malformations were probably caused by decreased blood flow due to physiofunctional changes and cellular necrosis associated with apoptosis. By including birds and mammals in further experiments, we hope to elucidate an embry-ological clue into how early cardiovascular malformations are caused.
Animals ; Aorta ; Apoptosis ; Birds ; Cardiovascular Abnormalities ; Cell Death ; Chick Embryo* ; Chorioallantoic Membrane ; Double Outlet Right Ventricle ; Drinking Water ; Eggs ; Electrocardiography ; Electrodes ; Embryonic Structures ; Endocardial Cushion Defects ; Eosine Yellowish-(YS) ; Formaldehyde ; Heart Septal Defects, Ventricular ; Hematoxylin ; Hope ; Mammals ; Microscopy ; Mineral Oil ; Myocardium ; Necrosis ; Ovum ; Silver ; Solvents ; Teratogens ; Tetrachloroethylene* ; Truncus Arteriosus ; Ventricular Fibrillation