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Objective To analyze the overall situation of regular monitoring of occupational hazards in enterprises in Guangdong Province in 2022. Methods Analysis and quality sampling from enterprises were conducted on the occupational hazard regular monitoring reports submitted by various occupational health institutions through the Guangdong Province Occupational Health Quality Control Platform for the year 2022. Results In 2022, a total of 40 129 enterprises in Guangdong Province conducted regular monitoring of occupational hazards, accounting for 5.9%. More than 4.85 million workers were enrolled, of which more than 1.99 million workers were exposed to occupational hazards, with an incidence of 41.1%. The incidence of exposure to chemicals, dust, and noise were 18.2%, 11.9%, and 23.5%, respectively. The incidence of exceeding national standard for chemical substances, dust and noise in enterprises were 2.7%, 3.3%, and 42.7%, respectively. The incidence of exceeding national standard for all occupational hazards increased with the scale of enterprises from micro, small, medium to large enterprises (29.1% vs 46.7% vs 61.3% vs 65.4%, all P<0.05). The top three key industries, with more enterprises exceeding national standard, were metal furniture manufacturing, wooden furniture manufacturing, and other metal daily necessities manufacturing. The concentration of 97 chemical hazardous agents such as silica dust and benzene in work site exceeded the national standard, but less than 1.0% chemical hazardous agents exceeded national standard in most of the chemical-exposed work site. The incidence of noise exceeding national standard was 45.4%, while the incidence of silica dust exceeding national standard was 17.3%. Conclusion The percentage of regular monitoring of occupational hazards in enterprises in Guangdong Province is relatively low. The main occupational hazard that exceeds the national standard was noise, indicating the need for special attention on noise protection in workplace.
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Objective To establish a method for the determination of thallium and its soluble compounds in workplace air using microporous filter membrane sampling and inductively coupled plasma mass spectrometry (ICP-MS). Methods Thallium and its soluble compounds in workplace air were collected using microporous filter membranes, digested with nitric acid, quantified using lutetium internal standard method, and detected by ICP-MS. Results The linear range of thallium was 0.00 to 600.00 μg/L, with the correlation coefficient of 1.000. The detection limit was 0.08 μg/L, and the lower limit of quantification was 0.26 μg/L. The minimum detection concentration and minimum quantitation concentration of thallium of 75.00 L workplace air were 1.0×10-5 and 3.0×10-5 mg/m3, respectively. The minimum detection concentration and minimum quantitation concentration of thallium of 480.00 L workplace air was 2.0×10-6 and 5.0×10-6 mg/m3, respectively. The recovery rate of spiking was 100.82%-103.44%, and the relative standard deviation within- and between-batches was 1.50%-3.32% and 1.32%-3.11%, respectively. The sample could be stored at room temperature for at least 14 days. Conclusion This method can be used for the detection of thallium and its soluble compounds in workplace air.
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Objective To establish a high performance liquid chromatography (HPLC) method for simultaneous determination of six aniline compounds (ADs) in workplace air. Methods GDH-1 air sampling tube was used to collect six co-existing ADs such as aniline, o-toluidine, N-methylaniline, m-methylaniline, p-methylaniline and N,N-dimethylaniline in the vapor and aerosol of workplace air. The samples were desorbed and eluted using a methanol solution containing 1.00% ammonia water, followed by separation on a C18 chromatographic column and detection using a diode array detector. Results The quantification range of the method was 0.19 -253.50 mg/L, with the correlation coefficient of 0.999 9 for all six ADs. The minimum detection range was 0.02-0.06 mg/m3, and the minimum quantitation range was 0.04-0.19 mg/m3 [both calculated for a 15.0 L sample with a desorption (elution) solution volume of 3.00 mL]. The average desorption and elution efficiencies were 92.15%-104.41% (silica gel) and 94.29%-104.29% (filter membrane). The intra-assay relative standard deviation (RSD) ranged from 0.90%-9.72% (silica gel) and 0.57%-6.96% (filter membrane). The inter-assay RSD ranged from 2.03%-9.78% (silica gel) and 2.50%-8.62% (filter membrane). The samples were stable at room temperature for seven days. Conclusion This method can be used for the simultaneous determination of six ADs in workplace air.
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Objective To establish a rapid qualitative analysis method for volatile organic components in chemicals. Methods Headspace gas chromatography-mass spectrometry was used to qualitatively determine 19 volatile organic components, including benzene, 1,2-dichloroethane, and n-hexane, in chemicals. Different sample amounts, heating temperatures, heating times, and sample volumes were analyzed to assess their effects on detection results and optimize sampling conditions. Results Based on the set chromatography, the optimal sampling process of this method was as follows： 5.0 g sample in a 20.0 mL headspace bottle, incubated at 40 ℃ for 30 minutes in a constant-temperature drying incubator, and a 1.00 mL headspace gas injection. The within-run and between-run relative standard deviations of all components ranged from 0.00% to 21.05% and 0.00% to 33.33%, respectively. The samples stored in sealed glass containers were stable at room temperature for at least 60 days. Conclusion This method offers simplicity, good reproducibility, and stability, making it suitable for rapid qualitative analysis of volatile organic components in chemicals.
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Objective To establish an infrared spectrophotometric method for determination of mineral oil mist in workplace air. Methods The mineral oil mist in workplace air was sampled with glass fiber filter membrane and eluted with carbon tetrachloride. Petroleum-like standard solution of carbon tetrachloride was used as the calibration standard, and quantitative analysis was performed using infrared spectrophotometric oil analyzer. Results The sampling efficiency of the glass fiber filter membrane ranged from 94.8% to 99.2%, and the extraction efficiency ranged from 95.6% to 104.2%. The linear range of mineral oil mist was 1.00-120.00 mg/L, with a correlation coefficient of 0.999 4. The detection limit was 0.52 mg/L, and the quantification limit was 1.74 mg/L. The average recovery rate ranged from 98.8% to 104.1%. The within- and between- run relative standard deviations were 2.2%-6.4% and 2.3%-5.2%, respectively. The samples were stable at room temperature for seven days. This method could be used for air sampling of mineral oil mist in workplaces where mineral oil is used. Conclusion The method is sensitive, accurate, and efficient, which is suitable for determining the concentration of mineral oil mist in workplace air.
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Objective: To establish a solvent desorption-gas chromatography method for the determination of 1,1,2,2-tetrachloroethane and 1,1,1,2-tetrachloroethane in workplace air. Methods: The 1,1,2,2-tetrachloroethane and 1,1,1,2-tetrachloroethane in workplace air were collected using activated carbon tubes, desorbed with carbon disulfide, and separated and detected by gas chromatography. The quantifications were based on standard curves. Results: The linear ranges of 1,1,2,2-tetrachloroethane and 1,1,1,2-tetrachloroethane were 0.98-395.50 and 0.87-395.50 mg/L, respectively, with the correlation coefficient of 0.999 95. The detection limits were 0.29 and 0.26 mg/L, respectively. The average of desorption efficiency was 92.04%-104.67%. The within- and between-run relative standard deviations were 1.42%-2.09% and 1.63%-6.09%, respectively. The sampling efficiency was more than 98.00%. The samples could be stored at room temperature for at least 14 days. Conclusion: This method can be used in detection of 1,1,2,2-tetrachloroethane and 1,1,1,2-tetrachloroethane in workplace air.
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Objective: To establish a solvent desorption-gas chromatography method for determination of dimethyl carbonate (DMC) in workplace air. Methods: The air samples were collected using activated carbon tubes, desorbed by carbon disulfide, separated by dimethylpolysiloxane capillary columns, and detected by a flame ionization detector. Results: The linear range of DMC was 2.14 to 1.07×104 mg/L, and the correlation coefficient was greater than 0.999. The detection limit was 0.14 mg/L, the lower limit of quantification was 0.47 mg/L, the minimum detection concentration was 0.10 mg/m3, and the minimum quantification concentration was 0.32 mg/m3 (based on 1.5 L workplace air). The average desorption efficiency of the method was 96.2% to 102.0%. Both the within-run and between-run relative standard deviations were 0.9% to 2.3%. The samples could be stored for at least seven days at four celsius degree. Conclusion: This method shows high desorption efficiency, high sensitivity, good precision and is simple in using. It can be used for the determination of DMC in workplace air.
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Objective: To investigate the specificity of endogenous metabolic profile in plasma of patients with occupational acute methyl acetate poisoning using non-targeted metabolomics. Methods: A total of six patients with occupational acute methyl acetate poisoning were selected as the poisoning group, while 10 healthy workers without occupational exposure history of chemical hazards in the same industry were selected as the control group using the judgment sampling method. Metabolites in patient plasma of the two groups were detected using ultra-high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry, and non-targeted metabolomics analysis was performed. Principal component analysis and partial least squares discriminant analysis were used to identify differential metabolites and analyze their metabolic pathways. Results: There were significant differences in metabolite profiles in patient plasma between poisoning group and control group. A total of 195 differentially expressed metabolites were screened in plasma of patients in poisoning group, including 119 upregulated and 76 downregulated metabolites. Lipid substances (lipids and lipid-like molecules) accounted for the highest proportion (21.5%). The differential metabolites of poisoning group were related to folate biosynthesis, amino acid metabolism, pyrimidine metabolism, sphingolipid biosynthesis and other metabolic pathways in plasma compared with the control group (all P<0.05). Conclusion: Occupational acute methyl acetate poisoning affects metabolism of the body. The folic acid biosynthesis, amino acid and lipid metabolism and other pathways may be involved in the occurrence and development of poisoning.
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Aromatic amine compounds are diverse, widely used, and highly toxic. They mainly exist in aerosol and vapor in workplace air. Occupational poisoning incidents caused by aromatic amine compounds occur from time to time. In China, occupational exposure limits have been established for only 11 aromatic amine compounds, with supporting detection methods developed only for four compounds： aniline, N-methylaniline, N,N-dimethylaniline, and p-nitroaniline. Most of the highly toxic and hazardous aromatic amine compounds do not have specific limit. Currently, regular sampling mediums for detecting aromatic amine compounds in the workplace air are absorbing solution, filter membrane, silica gel, and poly(styrene-divinylbenzene) resin. Regular detection methods are gas chromatography, liquid chromatography, fluorescence detection, and chromatography-mass spectrometry. However, these methods are mostly designed for detecting individual compounds or their specific forms, and there is a need to develop a detection method that can detect aromatic amine compounds existing in aerosol and vapor form simultaneously using a novel composite sampling tube.
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OBJECTIVE: To establish a method for simultaneous detection of 6 isomers of dimethylaniline(DMA) in workplace air by gas chromatography(GC). METHODS: The vapor and aerosol DMA in workplace air were collected by GDH-1 air sampling tube, and desorbed and eluted with absolute ethanol, then separated by a special capillary column for amines analysis, and finally detected by GC-flame ionization detector. RESULTS: The quantitative detection range of 6 isomers of DMA was 0.26-226.66 mg/L, with all the correlation coefficients greater than 0.999 00. The minimum detectable concentration was 0.01-0.02 mg/m~3, and the minimum quantification concentration was 0.04-0.05 mg/m~(3 )(15.00 L sample, 2.00 mL sample solution). The average desorption and elution efficiency was 92.48%-104.60%. The within-run relative standard deviations(RSD) was 0.31%-4.51%, and the between-run RSD was 1.23%-6.03%. The samples can be sealed and stored for more than 19 days at room temperature. CONCLUSION: The method is suitable for simultaneous detection of 6 isomers of DMA in workplace air.
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OBJECTIVE: To establish a method of determination of difluorochloromethane in workplace air by direct sampling gas chromatography. METHODS: Difluorochloromethane in workplace air was collected with aluminum plastic composite film airbag and then directly injected. Difluorochloromethane was separated by DB-1 capillary column and detected with hydrogen flame ionization detector. RESULTS: Good linearity was obtained in the range of 1.50-15 042.90 mg/m~3 with the correlation coefficient of 0.999 96. The limit of detection was 1.26 mg/m~3 and the limit of quantitation was 3.78 mg/m~3. The minimum detection concentration was 1.26 mg/m~3 and the minimum quantification concentration was 3.78 mg/m~3. The standard recovery was 98.34%-99.19%. The within-run relative standard deviation(RSD) and the between-run RSD were 1.82%-3.72% and 2.17%-4.17%, respectively. The samples can be stored at room temperature for at least 7 days. CONCLUSION: This method is suitable for difluorochloromethane detection in workplace air.
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OBJECTIVE: To establish a method for simultaneous determination of chlorobenzene, p-dichlorobenzene and o-dichlorobenzene in workplace air by portable gas chromatography-mass spectrometry(GC-MS). METHODS: The portable GC-MS heat tracing sampling probe was used for sampling. Samples were separated with LTM DB-5 MS rapid chromatographic column. The qualitative analysis was based on retention times and characteristic ions, and the quantification was based on standard curves. RESULTS: The linear correlation coefficient of this method was higher than 0.999 6. The minimum detectable concentrations were 0.03, 0.03 and 0.06 mg/m~3, and the minimum quantification concentrations were 0.10, 0.10 and 0.20 mg/m~3. The recovery rates were 84.68%-92.61%, 86.27%-93.92% and 82.31%-92.36% respectively for three chlorobenzenes compounds. The within-run relative standard deviations(RSD) were 8.51%-9.34%, 7.93%-9.19%, 5.47%-7.48% respectively for three chlorobenzenes compounds, the between-run RSD were 7.29%-9.73%, 8.08%-10.04% and 5.19%-5.98% respectively for three chlorobenzenes compounds. CONCLUSION: The portable GC-MS could be used for qualitative and quantitative detection of three chlorobenzenes compounds in workplace air.
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OBJECTIVE: To establish a method for simultaneous detection of 2-aminopyridine, 3-aminopyridine and 4-aminopyridine in workplace air by solvent eluting-gas chromatography. METHODS: 2-aminopyridine, 3-Aminopyridine and 4-aminopyridine in workplace air were collected by glass fiber filter paper dipped with sulfuric acid solution, and eluted using sodium hydroxide solution. After that, the eluent was separated by capillary column, and finally detected using the nitrogen and phosphorus detector. RESULTS: The quantitative determination ranges of 2-aminopyridine, 3-aminopyridine and 4-aminopyridine were 0.30-800.00, 0.80-800.00 and 2.00-800.00 mg/L respectively, with the correlative coefficients greater than 0.999 9. The minimum detectable concentrations were 4.67, 8.00 and 40.00 μg/m~3 respectively, and the minimum quantification concentrations were 14.00, 28.00 and 133.33 μg/m~3(45.00 L sample, 3.00 mL eluent) respectively. The average elution efficiencies were 79.63%-98.61%, 83.80%-101.42% and 81.60%-100.29% respectively. The within-run relative standard deviations(RSD) were 1.13%-3.65%, 1.47%-4.00% and 1.94%-5.15% respectively, and the between-run RSD were 1.77%-5.30%, 2.06%-4.65% and 2.59%-6.46% respectively. Samples were stable at room temperature for at least 14 days. CONCLUSION: This method is appropriate to be applied for simultaneous detection of 2-aminopyridine, 3-aminopyridine and 4-aminopyridine in workplace air.
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OBJECTIVE: To observe the sub-acute toxicity of 1-bromopropane(1-BP) oral exposure for 28 days in SD rats. METHODS: Specific pathogen free adult female SD rats were randomly assigned to the control and exposed group, 8 rats in each group. The 1-BP was suspended in corn oil and administered by gavages in a dose of 800 mg/kg body weight to rats in the exposed group, once a day, 5 days per week for 4 weeks. The rats in the control group were given equal volume of corn oil. After the last exposure, blood and urine of rats were collected for 1-BP level detection and hematological examination. Brain, heart, lung, liver, kidney and spleen of rats were collected for gross pathological examination and histopathological examination. RESULTS: The rats of exposed group showed unstable standing, weakness of hind limbs, limping and lying down from the 3 rd week of exposure. From the 1 st to 4 th week of exposure, mean body weight of rats in the exposed group were significantly lower than those of the control group(P<0.05). In the exposed group, the level of 1-BP in urine was higher than that in blood(P<0.05), and that there was positive correlation between them(Spearman correlation coefficient=0.954, P<0.01). In the control group, 1-BP was not detected. The absolute weights of brain and lung tissue in the exposure group decreased(P<0.05), meanwhile the organ coefficients of heart, liver, spleen and kidney were significantly increased compared with the control group(P<0.05). The number of red blood cells, hemoglobin concentration, hematocrit, the mean hemoglobin concentration, the total serum cholesterol and triglycerides were decreased(P<0.05). No pathological change related to 1-BP exposure was observed in the main organs of the rats in the exposed group. CONCLUSION: The sub-acute oral toxicity of 1-BP is mainly neurotoxicity and hematotoxicity. The 1-BP level in urine may reflect its exposure.
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Objective@#To develop a solvent desorption-gas chromatography method for simultaneous determination of methyl methacrylate (MMA) , ethyl methacrylate (EMA) , n-propyl methacrylate (PMA) and butyl methacrylate (BMA) in workplace air.@*Methods@#MMA, EMA, PMA and BMA in workplace air were captured by charcoal tubes and desorbed with carbon disulfide, separated through capillary chromatographic column, and then analyzed by gas chromatography-flame ionization detector.@*Results@#The linear ranges of MMA, EMA, PMA and BMA were 0-8 305.00 mg/L, 0-9 080.50 mg/L, 0-8 899.00 mg/L and 0-8 371.00 mg/L respectively, and the related coefficients were between 0.999 96-0.999 98. The relative standard deviations (RSD) within the group were 0.56%-1.71%, 0.45%-1.65%, 0.51%-1.49% and 0.45%-1.50% respectively, and the RSD between the group were 1.14%-2.79%, 0.79%-2.13%, 0.93%-2.30% and 1.09%-2.84% respectively. The average desorption efficiencies were 95.76%-99.58%, 97.82%-102.28%, 98.55%-102.28%and 98.70%-102.40% respectively. The minimum quantification concentrations were 0.12 mg/m3, 0.10 mg/m3, 0.07 mg/m3 and 0.07 mg/m3 respectively (3.00 L sample) . The samples could be stored at room temperature for at least 7 days.@*Conclusion@#This method could be used for monitoring of MMA, EMA, PMA and BMA in workplace air.
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OBJECTIVE: To establish a method for simultaneously detecting methyl methacrylate, ethyl methacrylate, n-propyl methacrylate and butyl methacrylate in workplace air by a portable gas chromatography-mass spectrometer(GC-MS) technique. METHODS: The portable GC-MS hand-held probe was used for sampling and detection. Samples were separated with DB-5 rapid chromatographic column in order to maintain retention time and characteristics of the ions, and quantified by standard curve method. RESULTS: The linear correlation of this method was higher than 0.999 0. The minimum detection concentration was 0.03-0.06 mg/m~3, and the minimum quantitation concentration was 0.10-0.20 mg/m~3. The standard recovery rate was 82.22%-91.24%. The within-run and the between-run relative standard deviation were 7.67%-14.63% and 10.40%-13.79% respectively. CONCLUSION: The portable GC-MS technique could be used for qualitative and quantitative detection of above-mentioned four methylacrylate compounds in workplace air.
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OBJECTIVE: To establish a method for detecting dichloromethane,trichloromethane and 1,2-dichloroethane in blood by gas chromatography-mass spectrometry. METHODS: Using static headspace analysis, three halogenated hydrocarbons in blood samples were separated by DB-5 MS elastic capillary column and detected by gas chromatographymass spectrometry. RESULTS: There was a good linear relationship in the selected range of dichloromethane,trichloromethane and 1,2-dichloroethane in blood. The linear correlation coefficient was greater than 0. 999 8. The detection limit and the lower limit of quantitation was 0. 19-0. 28 and 0. 64-0. 93 μg/L,respectively. The average recovery rate was 95. 1%-106. 6%. The within-run and between-run relative standard deviation was 2. 9%-4. 9% and 5. 0%-7. 0%,respectively. The samples could be preserved at room temperature or 4 ℃ for 3 days and at-8 ℃ or below for7 days. CONCLUSION: With the features of high sensitivity,precision,accuracy,easy operation and less interference,this method is suitable for detecting dichloromethane,trichloromethane and 1,2-dichloroethane in the blood.
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OBJECTIVE: To establish a method for determination of N-methyl-2-pyrrolidone(NMP) in workplace air by solvent desorption-gas chromatography. METHODS: NMP in the workplace air was collected with activated carbon tube and desorbed with methanol ∶dichloromethane(5 ∶95, V/V). After desorption, it was separated by capillary column separation, and detected by flame ionization detector. RESULTS: The good linear concentration of NMP was 0.51-4 108.00 mg/L. The correlation coefficient was 0.999 9. The detection limit was 0.08 mg/L(calculated by 3 times of standard deviation). The average desorption efficiency was 101.68%-103.44%. The within-run and between-run relative standard deviations were 1.94%-3.97% and 0.97%-2.26%, respectively. The sample could be stored at room temperature for at least 14 days. CONCLUSION: The developed method is suitable for the determination of NMP in workplace air.
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OBJECTIVE: To establish a method for simultaneous determination of 1,1,1-trichloroethane(TCA) and 1,1,2-TCA in the workplace air by solvent desorption-gas chromatography. METHODS: The 1,1,1-TCA and 1,1,2-TCA in the workplace air were collected by activated carbon tube and desorbed with carbon disulfide. They were separated with DB-1(100.0% dimethyl polysiloxane) capillary column and detected by flame ionization detector. RESULTS: The good linear ranges of 1,1,1-TCA and 1,1,2-TCA were 1.340-1.338×10~4 and 1.440-1.442×10~4 mg/L, respectively. The correlation coefficients were greater than 0.999, with the detection limits of 0.100 and 0.140 mg/L, respectively. The average desorption efficiencies of 1,1,1-TCA and 1,1,2-TCA were 98.6%-99.6% and 94.9%-96.2%. The within-run and between-run relative standard deviations were 0.4%-0.9% and 0.5%-1.1%, respectively. The samples could be stored at room temperature for at least 14 days. CONCLUSION: This method has high desorption efficiency and sensitivity, good precision and simple operation, which is suitable for simultaneous detection of 1,1,1-TCA and 1,1,2-TCA in the workplace air.
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OBJECTIVE: To investigate the effect of 1,2-dichloroethane(1,2-DCE) acute inhalation exposure on the differential gene expression of phase Ⅰ metabolic enzymes. METHODS: The specific pathogen free SD rats were randomly divided into control group(16 rats), low-and high-dose groups(24 rats in each group, half males and half females). Low-and high-dose group were given daily 600, 1 800 mg/m~(3 ) of 1,2-DCE, and the control group given the fresh air by dynamic inhalation for 8 hours per day for consecutive 7 days. After the end of exposure, the relative mRNA expression of cytochrome P450 2 E1(CYP2 E1), alcohol dehydrogenase(ADH1) and acetaldehyde dehydrogenase 3 alpha 1(ALDH3α1) in the liver tissue was detected by real-time fluorescence quantitative polymerase chain reaction. RESULTS: The relative expression of CYP2 E1 in male high-dose group was higher than that in male low-dose group and female high-dose group(P<0.05). The relative expression of ADH1 in male low-and high-dose groups was higher than that in male control group(P<0.05). The relative expression of ADH1 in male high-dose group was higher than that in male low-dose group and female high-dose group(P<0.05). The relative expression of ALDH3α1 in high-dose group was higher than that in control group and low-dose group(P<0.05). CONCLUSION: High dose 1,2-DCE could increase the gene expression of phase Ⅰ metabolic enzymes in rat liver. The 1,2-DCE has more obvious effect in male rats than in female rats.