Objective To establish a liquid chromatography method for the simultaneous determination of 13 aromatic amine compounds (AAs) in workplace air. Methods A total of 13 AAs in both vapor and aerosol phases were collected in workplace air using a new GDH-6 sampling tube. Samples were desorbed and eluted with methanol, separated using a Symmetry Shield™ RP₁₈ reversed-phase liquid chromatography column, and detected with a diode array detector. Quantification was performed using an external standard method. Results The linear range of the 13 AAs measured by this method was 0.02-373.60 μg/L with the correlation coefficients greater than 0.999 0. The minimum detection concentration was 0.09-14.37 μg/m³, and the minimum quantitative concentration was 0.31-47.90 μg/m³ (both calculated based on sampling 15.0 L of air and 3.0 mL of elution volume). The average desorption and elution efficiency ranged from 97.46% to 101.23%. The within-run relative standard deviation (RSD) was 0.10%-5.99%, and the between-run RSD was 0.17%-2.71%. Samples could be stably stored in sealed conditions at 2-8 ℃ for more than seven days. Conclusion This method is suitable for the simultaneous determination of 13 AAs in workplace air, including both vapor and aerosol phases.

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.

Acute Gelsemium poisoning is a systemic disease primarily affecting the central nervous system and respiratory symptoms caused by the ingestion of a substantial amount of Gelsemium within a short period. It manifests as sudden onset and rapid progression, primarily caused by accidental ingestion due to misidentification, and posing significant health risks. The compilation of the Technical Plan for Emergency Health Response to Acute Gelsemium Poisoning describes in detail the specialized practice and technical requirements in the process of handling acute Gelsemium poisoning, including accident investigation and management, laboratory testing and identification, in-hospital treatment, and health monitoring. The guidelines clarify key procedures and requirements such as personal protection, investigation elements, etiology determination, medical rescue, and health education. The key to acute Gelsemium poisoning investigation lies in promptly identifying the toxin through exposure history, clinical manifestations, and sample testing. Because there is no specific antidote for Gelsemium poisoning, immediate removal from exposure, rapid elimination of the toxin, and respiratory monitoring are critical on-site rescue measures. Visual identification of food or herbal materials, followed by laboratory testing to determine Gelsemium alkaloids in samples is a rapid effective screening method. These guidelines offer a scientific, objective, and practical framework to support effective emergency responses to acute Gelsemium poisoning incidences.

Objective To investigate the technical capacity and service quality of occupational health technical service institutions (hereinafter referred to as "occupational health institutions") in Guangdong Province. Methods All occupational health institutions in Guangdong Province that had valid occupational health service qualifications and within the validity period were included for analysis. Data on basic information, employed personnel, and results of professional technical capacity assessments across occupational health institutions were obtained through the Guangdong Provincial Occupational Health Technical Quality Control Center. Results A total of 99 institutions with 2 732 technical staff were included in this study. Occupational health institutions in Guangdong Province were mainly distributed in the Pearl River Delta region, accounting for 87.9% (87/99) of the total. The number of public and private health institutions was 23 and 76, accounted for 23.2% and 76.8% respectively. In terms of technical personnel, the percentage of individuals worked in public or private health institutions was 24.1% and 75.9%, respectively. Personnel titles were predominantly intermediate level and no title, accounting for 38.7% and 26.4%, respectively. Individuals with a bachelor′s degree or above accounted for 67.4%. Engineering and other professionals accounted for 35.4% and 30.5%, respectively. Private institutions undertook 97.3% of testing and evaluation workload related to occupational hazard in the province. The number of occupational health institutes acquiring category Ⅰ and Ⅱ service license were 97 and 13. Among institutions participating in inter-laboratory comparisons, the overall pass rates for quantitative items were 95.5% in public and 70.3% in private institutions, while the pass rates for qualitative items were 100.0% and 94.5%, respectively. Conclusion Occupational health institutions in Guangdong Province face issues such as imbalanced regional distribution, uneven development, and insufficient technical competence and testing capacity of professional personnel. Health authorities at all levels should continue to strengthen supervision and quality control to solidify the technical foundation and comprehensively enhance service capacity and quality.

Objective To improve the national standardized method for determining biphenyl in workplace air, which was based on activated carbon tube sampling, carbon disulfide desorption, and gas chromatography, by developing a method using GDX-502 tubes for sampling, toluene for desorption, and gas chromatography. Methods Workplace air samples were collected using GDX-502 sampling tubes and desorbed with toluene, followed by determination with gas chromatography. Results The improved method demonstrated good linearity for biphenyl concentrations ranging from 0.33 to 330.00 mg/L, with a correlation coefficient of 0.999 9. The detection limit and lower limit of quantification were 0.06 and 0.21 mg/L, and the minimum detection concentration and minimum quantification concentration were 0.04 and 0.14 mg/m³ (based on 1.5 L air sample volume), respectively. The average desorption efficiency ranged from 96.6% to 101.1%. The within-run and between-run relative standard deviations were 0.6%-1.4% and 1.4%-3.3%, respectively, with 100.0% sampling efficiency. Samples remained stable for at least 14 days at room temperature. Conclusion The improved method for biphenyl detection demonstrates rapid and accurate performance, with the advantages of low detection limits and high sampling and desorption efficiency.

Objective To summarize the key precautions in the determination of nitrogen oxides (nitric oxide and nitrogen dioxide) in the workplace air and to explore potential optimization items in the national standard analytical method. Methods According to GBZ/T 160.29-2004 Methods for Determination of Inorganic Nitrogen Compounds in the Air Workplace, comparative experiments were conducted to evaluate and optimize critical technical parameters of the standardized method, including the oxidation efficiency of oxidation tubes and the preparation and storage of absorption solutions. The application details of the standard method were refined. Results The concentrations of nitrogen oxides (nitric oxide and nitrogen dioxide) were expressed as nitrogen dioxide equivalents. During calibration, the flow calibrator should be connected to the upstream of the air sampler, and the sampling system should undergo an air tightness check. Each batch of oxidation tubes should be validated before use. Before sampling, both end caps should be removed and the tube should be equilibrated for one hour in a clean environment with 30.00%-70.00% relative humidity. The prepared absorption stock solution in this method can be stored at 4 ℃ for up to 96 days. Commercial porous plate absorption tubes must be batch-validated before use. The sampling flow rate during sampling should be consistent with that specified in the standard method. After sampling, collected samples should be sealed in 10.00 mL amber glass bottles with screw caps and stored at 4 ℃ for up to 120 hours. Conclusion This study summarizes precautions for the sampling, detection, and calculation of nitrogen oxides (nitric oxide and nitrogen dioxide)in workplace air to strengthen quality control. Experimental optimizations of oxidation tube conditioning, absorption stock solution preparation and preservation, and sample storage conditions and durations may provide references for diversifying and simplifying the detection process, which facilitate the practical application in actual work.

Objective To develop a solvent desorption-gas chromatography method for quantifying malononitrile in workplace air. Methods Malononitrile in workplace air was collected using a silica gel tube and desorbed with methanol. Separation was performed using DB-FFAP capillary column, and detection was performed by hydrogen flame ionization detector. Results The linear ranges of malononitrile were 4.00-600.00 mg/L, with the correlation coefficient of 0.999 92. The detection limit was 0.54 mg/L. The minimum detection concentration was 0.36 mg/m³ (based on a collected air volume of 1.5 L). The average desorption efficiency was 95.0%-101.0%. The within-run and between-run relative standard deviations were 0.9%-5.3% and 1.0%-6.8%, respectively. The sampling efficiency was 100.0%. The samples were stable at 4 ℃ for at least 14 days. Conclusion The solvent desorption-gas chromatography method established in this study for the determination of malononitrile in workplace air is simple to use, with high accuracy and good precision, and is suitable for the determination of malononitrile in workplace air.

Dust and chemical substances are widely present occupational hazards in workplaces. Long-term exposure to dust and chemical substances can pose serious threats to workers′ health. Owing to their advantages in real-time detection, rapid response, and high accuracy, online monitoring technologies enable continuous measurement and analysis of the concentration and composition of dust and chemical substances in workplaces. These technologies provide timely and effective data support for the prevention and control of occupational diseases and have become an important protective tool in the field of occupational hazard. Current online monitoring technologies for workplace dust mainly include the tapered element oscillating microbalance method, light scattering method, β-ray method, triboelectric charging, video exposure monitoring, and ultrasonic methods. Online monitoring devices for workplace chemical substances are still in the early stages of development. However, this equipment has been partially applied in environmental monitoring, covering methods such as spectral analysis, electrochemical sensors, cataluminescence sensors, and intelligent sensing systems. In the future, the development of online dust monitoring technology should focus on overcoming technical bottlenecks to improve detection accuracy and exploring the synergistic effects of different technologies to compensate for the limitations of single methods. Meanwhile, online monitoring technologies for chemical substances should aim to develop integrated detection systems that combine high precision, real-time performance, low cost, and stability.

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.