Objective To establish a method for simultaneous determination of four high-molecular-weight thiol derivatives (TDs) in workplace air by gas chromatography. Methods The four kinds of vapor-phase macromolecular TDs (1-pentanethiol, 1-hexanethiol, 1-benzyl mercaptan, and n-octanethiol) in the workplace air were collected using the GDH-1 air sampling tubes, desorbed with anhydrous ethanol, separated on a DB-FFAP capillary column, and determined by flame ionization detector. Results The quantitation range of the four TDs was 0.30-207.37 mg/L, with the correlation coefficients greater than 0.999 00. The minimum detection mass concentrations and minimum quantitation mass concentrations were 0.18-0.32 and 0.60-1.05 mg/m³, respectively (both calculated based on the 1.5 L sample and 3.0 mL desorption solvent). The mean desorption efficiencies ranged from 87.07% to 103.59%. The within-run and between-run relative standard deviations were 1.92%-8.22% and 1.89%-8.45%, respectively. The samples can be stored at room temperature or 4 ℃ for three days and up to 7 days at -18 ℃. Conclusion This method is suitable for the simultaneous determination of four vapor-phase TDs in workplace air.

ObjectiveTo understand the monitoring result of occupational hazard in the workplace of key industries in Guangdong Province from 2020 to 2023. Methods The data of occupational hazards in the workplace of 20 key industries in Guangdong Province from 2020 to 2023 were collected from the “Workplace Occupational Hazard Monitoring System” of the Chinese Disease Prevention and Control System subsystem. The monitoring result of occupational hazard factors, occupational health training, occupational health examination, occupational protection, detection of occupational hazardous agents such as dust, chemical substances and noise were analyzed. Results A total of 13 058 enterprises from key industries were recruited as the monitoring subjects in Guangdong Province. There were 290 large-, 1 342 medium-, 7 635 small-, and 3 791 micro-enterprises, with small and micro-enterprises accounting for 58.5% and 29.0% of the total, respectively. A total of 7 542 enterprises exceeded the national standard in the detection of occupational hazards, with a rate of 57.8%. A total of 1 942 517 workers from 13 058 enterprises were recruited, with 835 567 workers were exposed to occupational hazards, with a rate of 43.0%. The rate of occupational health training for enterprise leaders, occupational health management personnel, and workers was 71.9%, 73.8%, and 86.5%, respectively. The abnormal rate of occupational health examinations for workers exposed to noise, dust, and chemical agents was 2.0%, 0.6%, and 1.0%, respectively. The distribution rate of dust masks, anti-poisoning masks or face masks, and noise prevention earplugs or earmuffs was 83.3%, 71.3%, and 77.8%, respectively. The rate of installation of dust prevention facilities, anti-poisoning facilities, and noise prevention facilities was 85.6%, 81.2%, and 50.1%, respectively. The rate of exceeded the national standard of dust, noise in the worksites/types and workplaces showed a decreasing trend year by year (all P<0.01), while the rate of exceeded the national standard of chemical agents in worksites/types and workplaces showed an increasing trend year by year in various occupational hazards (all P<0.01). Conclusion Occupational hazards in the workplace of key industries in Guangdong Province are relatively common. The proportion of workers exposed to occupational hazards is relatively high. It is necessary to further improve the use of noise prevention facilities and protective equipment, strengthen occupational health training for enterprises throughout the province and regularly monitor occupational hazards to reduce the risk of occupational diseases.

ObjectiveTo establish a method for the determination of 1,1,1,2-tetrachloroethane (TeCA) and 1,1,2,2-TeCA in human urine using liquid-liquid extraction-gas chromatography. Methods The 5.0 mL urine sample was mixed with 2.0 g anhydrous sodium sulfate and 5.0 mL ethyl acetate, then vortexed mixing. The 1.0 mL extraction was separated by 100% dimethylpolysiloxane capillary gas chromatography column, detected by flame ionization detector, and quantified by an external standard method. Results The linear ranges of 1,1,1,2-TeCA and 1,1,2,2-TeCA were 0.250-50.750 mg/L, with both correlation coefficients of >0.999 9. The detection limit of 1,1,1,2-TeCA in urine was 0.020 mg/L, and the lower limit of quantification was 0.060 mg/L. The average recovery was 88.02%-101.32%, and the within-run and between-run relative standard deviations (RSDs) were 0.11%-0.47% and 0.39%-1.09%, respectively. The detection limit of 1,1,2,2-TeCA in urine was 0.050 mg/L, and the lower limit of quantification was 0.150 mg/L. The average recovery was 93.42%-101.32%, and the within-run and between-run RSDs were 0.28%-1.04% and 0.50%-1.03%, respectively. Both the 1,1,1,2-TeCA and 1,1,2,2-TeCA cannot be stored at room temperature. The 1,1,2,2-TeCA can be stored at 4 ℃ for at least three days. At -20 ℃, the 1,1,1,2-TeCA can only be stored for one day, while 1,1,2,2-TeCA can be stored for at least five days. Conclusion This method has high sensitivity, good specificity, simple sample pretreatment, and more intuitive and reliable results. It can be used to determine the level of 1,1,1,2-TeCA and 1,1,2,2-TeCA in urine of occupational population.

Objective To establish a method to simultaneously determinate cobalt, nickel, arsenic, molybdenum, silver, cadmium and lead in blood and urine using inductively coupled plasma tandem mass spectrometry (ICP-MS/MS). Methods The blood samples were diluted 20 times with a mixed solution of nitric acid (0.10% V/V) and Triton X-100 (0.02% V/V). The urine samples were diluted 10 times with nitric acid (1.00% V/V). Yttrium-89, rhodium-103, and lutetium-175 were used as internal standards to decrease matrix interference, and either On-Mass mode or Mass-Shift mode was used to decrease mass spectrometry interference, with detection by ICP-MS/MS. Results The linear ranges of the seven elements were 0.100-10.000 μg/L, with the correlation coefficient >0.999 9. The detection limits for the seven elements in the blood and urine were 0.003-0.021 and 0.003-0.031 μg/L, respectively, and the minimum quantification limits were 0.009-0.064 and 0.009-0.094 μg/L, respectively. The recovery rates were 96.64%-102.90% and 96.34%-104.50% for the blood and urine, respectively. The within-run relative standard deviations (RSDs) were 0.32%-2.33% and 0.25%-2.31%, and the between-run RSDs were 1.07%-3.81% and 1.30%-3.62% for blood and urine, respectively. The samples were stable at 4 ℃ for at least 14 days. Conclusion ICP-MS/MS is a simple, sensitive, and accurate method for rapid detection of seven heavy metal elements in the blood and urine of occupational hazard-exposed workers.

Metabolomics, including targeted metabolomics and non-targeted metabolomics, is a method to study endogenous small molecule metabolites in organisms. The process of metabolomics analysis generally includes sample collection and pre-treatment, sample detection, data preprocessing, metabolite identification, data statistical analysis, and others. At present, metabolomics technology has been applied to study toxicological mechanism of occupational hazards, early detection and diagnosis of occupational diseases, screening biomarkers of occupational exposure, and others. The application of metabolomics technology to explore the relationship between workers' metabolites and exposure to occupational hazardous, assess the potential impact of occupational exposure on workers' health, and search for ideal biomarkers or therapeutic targets is conducive to early warning and monitoring of occupational health hazards, and assistance in the early diagnosis and prognosis of occupational diseases.In the future, further research is needed in the field of occupational health using metabolomics to establish more complete and standardized workflows and experimental methods, combine big data technology to explore potential biomarkers, utilize metabolic information to provide precise occupational health services, and use artificial intelligence models for data mining and disease diagnosis in metabolomics.

Objective To analyze the problems and differences in workplace on-site sampling and testing skills in external quality assessment in laboratory among occupational health technical service institutions. Methods A total of 108 occupational health technical service institutions nationwide, participated in the external quality assessment in laboratory of the on-site individual sampling operation skills for silica dust (hereinafter refer to as "silica dust sampling assessment") and on-site detection operation skills for carbon monoxide (hereinafter refer to as " carbon monoxide sampling assessment") in 2023, were selected as the research subjects. The result of the assessment was analyzed. Results The qualification rate of the institutions for the silica dust sampling assessment was 98.1%. The unqualified rate of institutions in the Pearl River Delta region was lower than that in non-Pearl River Delta regions (0.0% vs 11.1%, P<0.017). The excellence rate was higher in public institutions than that in private enterprises (73.5% vs 40.0%, P<0.017). The unqualified rate of institutions with permit was lower than that of institutions without permit (0.0% vs 13.3%, P<0.05). The qualification rate of the institutions for the carbon monoxide sampling assessment was 79.4%. The proportion of the institutes, whose results of carbon monoxide standard gas (gas bag) deviation was >±20.0% was higher in private enterprises than that in public institutions (32.8% vs 7.1%, P<0.017). In terms of the normativity of on-site individual sampling for silica dust, the rates of conducting air tightness checks before sampling, correct disassembly and installation and correct placement direction of dust sampling heads, and correct flow for calibration based on the provided dust sampling heads were low, at 53.7%, 33.3%, and 14.8%, respectively. In terms of the normativity of on-site detection of carbon monoxide, the accuracy rate of converting results by on-site detection individuals was low, at only 57.8%. ConclusionIt is necessary to further strengthen the training of theoretical knowledge and practical skills of individuals in occupational health technical service institutions in Guangdong Province, especially to enhance the capacity of occupational health technical services in non-Pearl River Delta regions of the province.

Biotoxins, which include bacterial, fungal, marine, plant, and animal toxins, are widespread in living and occupational environments, posing potential threats to human health. Rapid detection of biotoxins in blood is crucial for preventing health hazards and enabling timely disease diagnosis and treatment. Biosensors and immunoassay technologies have critical advantages in the rapid detection of biotoxins in blood. Common biosensors, such as surface plasmon resonance biosensors and fluorescent biosensors, enhance sensitivity and reduce detection limits through signal amplification. Common immunoassay methods, such as colloidal gold immunochromatography, fluorescence immunochromatography, and chemiluminescence immunoassay, improve detection efficacy and sensitivity through specific antibody-antigen binding and nanotechnology. However, current rapid detection technologies of bitoxins in blood face challenges such as matrix interference and insufficient specificity, and they fall short in high-throughput detection of multiple toxins simultaneously. Future developments should focus on improving sample pretreatment, innovating signal amplification methods, enhancing specificity on recognition of elements, and designing portable detection devices and high-throughput platforms for simultaneous toxin analysis. These advancements aim to improve the sensitivity and reliability of detection methods, providing more accurate and convenient solutions for biotoxin detection in blood.

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.

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.

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.