The usage of vinyl chloride and trichloroethylene in China has been increasing year by year, and they have been detected in both drinking water and environmental water, making them important environmental pollutants. Based on the latest research results on the health effects of vinyl chloride and trichloroethylene, the newly issued, "Standards for Drinking Water Quality (GB5749-2022)" in China has adjusted the standard limit of vinyl chloride from 0.005 mg/L to 0.001 mg/L and the standard limit of trichloroethylene from 0.07 mg/L to 0.02 mg/L. This article analyzed and discussed the relevant technical contents for determining the above standard limits, including the levels and exposure conditions of vinyl chloride and trichloroethylene in the water environment, health effects, derivation of safety reference values, and determination of hygiene standard limits. Suggestions were also made for the implementation of this standard.
Humans ; Vinyl Chloride/analysis* ; Trichloroethylene/analysis* ; Drinking Water ; Environmental Pollutants ; China ; Water Pollutants, Chemical/analysis*

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

Objective: To understand the volatile organic components in the organic solvents used by enterprises in Baoan District, Shenzhen. Methods: From January to December 2020, a total of 541 organic solvent samples used by 86 companies were collected for volatile organic component analysis, and the main volatile components and high-risk occupational hazards in organic solvents used in different industries were analyzed. Results: A total of 201 volatile organic components were detected in 541 organic solvents. The top 5 components detected include xylene (29.76%, 116/541), toluene (21.81%, 118/541), methanol (20.70%, 112/541), n-hexane (14.79%, 80/541) and ethylbenzene (14.23%, 77/541). The detection rates of benzene, trichloroethylene, n-hexane, and 1, 2-dichloroethane, which were high-risk occupational hazards, were 2.40% (13/541), 3.70% (20/541), 14.79% (80/541), and 1.66% (9/541), respectively. The volatile components in organic solvents used in different industries was different. Benzene is more frequently detected in organic solvents used in the printing industry, trichloroethylene was more frequently detected in organic solvents used in the electronics industry, and n-hexane was more commonly found in organic solvents used in the electronics industry, printing and other industries, and 1, 2-dichloroethane has been more frequently detected in organic solvents used in the machinery industry. Conclusion: There are many types of organic solvents used by enterprises in Bao'an District, with complex components and differences in different industries.
Benzene/analysis* ; Hexanes ; Solvents ; Industry ; Trichloroethylene

OBJECTIVETo investigate the significance of monitoring procalcitonin (PCT) when applying antibiotics to trichlorethylene (TCE)-induced dermatitis.

METHODSOne hundred and two patients who were hospitalized and recovered from TCE-induced dermatitis in our hospital from 2006 to 2013 were enrolled as subjects. Based on whether the PCT level was monitored or not, we divided patients into regular group and PCT group. For the regular group, we applied antibiotic treatment and determined the course of treatment based on clinical symptoms, laboratory test results, medical imaging results, and bacterial culture. For the PCT group, in addition to the above treatments, antibiotic treatment was applied when the PCT level was not lower than 0.25 ng/ml and stopped when the PCT level was lower than 0.25 ng/ml. The distribution of bacterial infection sites, type of bacteria, type of antibiotics, average period of hospitalization, and course of antibiotic treatment were compared between the two groups.

RESULTSThere were no significant differences in the distribution of bacterial infection sites, type of bacteria, type of antibiotics, and average period of hospitalization between the two groups (P > 0.05). The course of antibiotic treatment for the PCT group was significantly shorter than that for the regular group (25.37 ± 11.66 vs 20.58 ± 7.53 d, P < 0.05).

CONCLUSIONUnder similar conditions of bacterial infection, antibiotic treatment of TCE-induced dermatitis based on the serum PCT level can significantly shorten the course of treatment and avoid the abuse of antibiotics.

Anti-Bacterial Agents ; therapeutic use ; Bacteria ; Bacterial Infections ; Calcitonin ; analysis ; Calcitonin Gene-Related Peptide ; Drug Eruptions ; drug therapy ; Hospitalization ; Humans ; Monitoring, Physiologic ; Protein Precursors ; analysis ; Trichloroethylene ; toxicity

Methanotrophs could degrade methane and various chlorinated hydrocarbons. The analysis on methane monooxygenase gene cluster sequence would help to understand its catalytic mechanism and enhance the application in pollutants biodegradation. The methanotrophs was enriched and isolated with methane as the sole carbon source in the nitrate mineral salt medium. Then, five chlorinated hydrocarbons were selected as cometabolic substrates to study the biodegradation. The phylogenetic tree of 16S rDNA using MEGE5.05 software was constructed to identify the methanotroph strain. The pmoCAB gene cluster encoding particulate methane monooxygenase (pMMO) was amplified by semi-nested PCR in segments. ExPASy was performed to analyze theoretical molecular weight of the three pMMO subunits. As a result, a strain of methanotroph was isolated. The phylogenetic analysis indicated that the strain belongs to a species of Methylocystis, and it was named as Methylocystis sp. JTC3. The degradation rate of trichloroethylene (TCE) reached 93.79% when its initial concentration was 15.64 μmol/L after 5 days. We obtained the pmoCAB gene cluster of 3 227 bp including pmoC gene of 771 bp, pmoA gene of 759 bp, pmoB gene of 1 260 bp and two noncoding sequences in the middle by semi-nested PCR, T-A cloning and sequencing. The theoretical molecular weight of their corresponding gamma, beta and alpha subunit were 29.1 kDa, 28.6 kDa and 45.6 kDa respectively analyzed using ExPASy tool. The pmoCAB gene cluster of JTC3 was highly identical with that of Methylocystis sp. strain M analyzed by Blast, and pmoA sequences is more conservative than pmoC and pmoB. Finally, Methylocystis sp. JTC3 could degrade TCE efficiently. And the detailed analysis of pmoCAB from Methylocystis sp. JTC3 laid a solid foundation to further study its active sites features and its selectivity to chlorinated hydrocarbon.
Methylocystaceae ; classification ; metabolism ; Multigene Family ; Oxygenases ; genetics ; Phylogeny ; Polymerase Chain Reaction ; RNA, Ribosomal, 16S ; genetics ; Sequence Analysis, DNA ; Trichloroethylene ; metabolism

Adolescent ; Adult ; Female ; Humans ; Male ; Occupational Diseases ; etiology ; prevention & control ; Occupational Exposure ; analysis ; prevention & control ; Trichloroethylene ; poisoning ; Young Adult

OBJECTIVETo understand the demographic, occupational and clinic characteristics of occupational poisoning case due to trichloroethylene in Dongguan in recent years for the purpose of prevention.

METHODSUsing the trichloroethylene patients of poisoning diagnosed in the years between 2002 to 2009 as subjects, their age, sex, industry, job, working duration and exposure level were analysed.

RESULTSIn Dongguan between 2002 and 2009 altogether 82 cases were reported, among the 82 cases 8 patients were dead with case fatality rate of 9.8%. among them there were 12 cases of poisonings(8 females ,4 males); 9 cases were classified as mild poisonings and the rest serious ones, among the 12 cases 3 patients were dead with case fatality rate of 25.0%; Dermatitis caused by TCE there were 70 cases (37 males and 33 females), among the 70 cases 5 patients were dead with case fatality rate of 7.1%. 11 persons (91.7%) were engaged in the job of cleaning and 1 (8.3%) in water gun, and they performed the job only for 3 days in shortest and for 450 days in longest. The cases were distributed in the jobs as the following: 29 (41.4%), 12 (17.1%), 8 (11.4%), 5 (7.1%), 4 (5.7%), cases respectively in the job of cleaning, parts hanging, board washing, painting, gun water spraying; a job duration of 1-50 d (27.4 days in average).

CONCLUSIONIn summary the TCE poisonings in Dongguan were two types of poisoning, i.e., systematic poisonings and drug rash-like dermatitis, occupational TCE poisonings took place mainly in the cleaning workers. Dermatitis caused by TCE can cure but hard to prevent, we should strengthen the early examination of new works.

Adolescent ; Adult ; China ; epidemiology ; Dermatitis, Occupational ; epidemiology ; Female ; Humans ; Male ; Middle Aged ; Occupational Exposure ; analysis ; Trichloroethylene ; poisoning ; Young Adult

OBJECTIVETo screen and identify differential serum proteins which might be involved in dermatitis medicamentosa-like of trichloroethylene (DMLT).

METHODSThree groups of sera were collected from population exposed to trichloroethylene (TCE) (group I), patients suffering from DMLT (group II), and the healed cases (group III). After removing albumin and IgG in the three pools of sera, a comparative proteomic analysis was carried out. The images were analyzed using ImageMaster Platinum 2D 5.0 to screen the differentially expressed proteins. The protein spots were then subjected to matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) and tandem mass spectrometry sequencing of tryptic peptides for further identification.

RESULTSThe depletion of albumin and IgG greatly increased the number of protein spots to 300 ± 12.Five differential spots were identified, which were complement component C4b, apolipoprotein A-I, apolipoprotein C-III apolipoprotein C-II and transthyretin. Compared with group I, the expression levels of complement component C4b in group III and apolipoprotein C-II in group II were up-regulated (1.352 88-fold, 1.512 14-fold, respectively); compared with group I, the expression levels of apolipoprotein A-I, apolipoprotein C-III and transthyretin in group II were down-regulated (1.601 17-fold, 1.034 49-fold, 1.313 35-fold, respectively).

CONCLUSIONThe findings of this study show that most of the identified differential proteins are closely related to immunity and liver dysfunction, which provides some evidence on elucidating the mechanisms and screening of biomarkers of TCE intoxication.

Adolescent ; Adult ; Apolipoprotein A-I ; isolation & purification ; Apolipoprotein C-III ; isolation & purification ; Biomarkers ; analysis ; Blood Proteins ; chemistry ; isolation & purification ; Dermatitis, Occupational ; blood ; Drug Eruptions ; blood ; Environmental Exposure ; Female ; Humans ; Male ; Proteome ; analysis ; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization ; Trichloroethylene ; adverse effects ; Young Adult

Adhesives ; chemistry ; Benzene ; analysis ; Chromatography, Gas ; Hexanes ; analysis ; Toluene ; analysis ; Trichloroethylene ; analysis