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

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

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

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*

Benzene ; analysis ; Chemical Industry ; Chromatography, Gas ; methods ; Humans ; Occupational Exposure ; analysis ; Toluene ; analysis ; Trichloroethylene ; analysis ; Xylenes ; analysis

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

Animals ; DNA Damage ; Dose-Response Relationship, Drug ; Isotope Labeling ; Male ; Phosphorus Radioisotopes ; analysis ; Rats ; Rats, Sprague-Dawley ; Trichloroethylene ; toxicity