Objective To obtain the protective performance parameters of barium sulfate mortar against positron nuclide γ-rays, provide reference data for precise shielding calculations, and guide the design, evaluation, and construction of radiation shielding. Methods The FLUKA program was used to build a model for simulating the dose equivalent rate variation around points of interest under the irradiation of the most commonly used positron nuclide ¹⁸F with changes in the thicknesses of lead and barium sulfate mortar. The transmission curves of lead and barium sulfate mortar were fitted, and the half-value layer (HVL) and lead equivalence of barium sulfate mortar were calculated based on the fitted curves. Results The ambient dose equivalent rate coefficient of positron nuclide ¹⁸F was 1.339 4×10⁻¹ μSv·m²/MBq·h and the HVL for lead was 4.037 mm, with deviations of 0.043% and 1.53% compared to the values provided in the AAPM Report No. 108, respectively. The HVLs for γ-rays produced by ¹⁸F, using barium sulfate mortar with apparent densities of 4.20, 4.00, and 3.90 g/cm³ mixed with 35.2-grade cement in a 4∶1 mass ratio, were 2.914, 2.969, and 3.079 cm, respectively. The lead equivalences were 0.1385, 0.1360, and 0.1311 mmPb/mm, respectively. Conclusion The three types of barium sulfate mortar can provide good protection against γ-rays in positron imaging locations. As the apparent density of barium sulfate increases, its protective effect improves slightly but remains significantly better than common construction materials like concrete and solid bricks.

Objective:To evaluate the current situation of the protective effect of hearing protection device (HPD) worn by manufacturing workers and discuss their possible influencing factors.Methods:A total of 3634 noisy workers were surveyed and tested. The study conducted surveys of workers on the use of HPD. The 3M TM E-A-R Fit TM binaural verification system was used to measure the personal attenuation device (PAR) of workers wearing HPD. Results:The M ( Q1, Q3) of baseline PAR obtained by 3634 workers was 12 (2, 19) dB. There was a statistically significant difference in baseline PAR among the three types of HPDs ( H=336.39, P<0.01) . After pairwise comparison, it was found that the baseline PAR of workers wearing foam earplugs and earmuffs was higher than that of pre-molded earplugs ( P<0.01) . There were differences in baseline PAR among workers in different industries ( Z=359.73, P<0.01) . Education level, age of using HPD, types of HPDs, noise exposure intensity, with or without knowledge of correct methods, and comfort evaluation were the main factors affecting baseline PAR ( P<0.05) . There were 1536 workers (43.4%) failed the baseline PAR test. After the intervention, the median PAR increased significantly from 1 (0, 6) dB (baseline) to 18 (14, 22) dB (after the intervention) ( P<0.01) . The follow-up test found that the follow-up PAR of 328 workers was higher than the baseline PAR of the initial test, and the follow-up PAR was higher than the post-intervention PAR of the initial test ( P<0.01) . Conclusion:Under the conditions of this study, the protective effect of HPD was affected by factors such as incorrect understanding of wearing methods, exposure to high-intensity noise, low education level, a short period of time of HPD use and low comfort of hearing protectors. The protective effect could be improved through training, optimizing the wearing of hearing protector models, and follow-up interventions. Enterprises should use suitability verification to ensure the correct selection and wearing of noisy workers.

Objective:To evaluate the current situation of the protective effect of hearing protection device (HPD) worn by manufacturing workers and discuss their possible influencing factors.Methods:A total of 3634 noisy workers were surveyed and tested. The study conducted surveys of workers on the use of HPD. The 3M TM E-A-R Fit TM binaural verification system was used to measure the personal attenuation device (PAR) of workers wearing HPD. Results:The M ( Q1, Q3) of baseline PAR obtained by 3634 workers was 12 (2, 19) dB. There was a statistically significant difference in baseline PAR among the three types of HPDs ( H=336.39, P<0.01) . After pairwise comparison, it was found that the baseline PAR of workers wearing foam earplugs and earmuffs was higher than that of pre-molded earplugs ( P<0.01) . There were differences in baseline PAR among workers in different industries ( Z=359.73, P<0.01) . Education level, age of using HPD, types of HPDs, noise exposure intensity, with or without knowledge of correct methods, and comfort evaluation were the main factors affecting baseline PAR ( P<0.05) . There were 1536 workers (43.4%) failed the baseline PAR test. After the intervention, the median PAR increased significantly from 1 (0, 6) dB (baseline) to 18 (14, 22) dB (after the intervention) ( P<0.01) . The follow-up test found that the follow-up PAR of 328 workers was higher than the baseline PAR of the initial test, and the follow-up PAR was higher than the post-intervention PAR of the initial test ( P<0.01) . Conclusion:Under the conditions of this study, the protective effect of HPD was affected by factors such as incorrect understanding of wearing methods, exposure to high-intensity noise, low education level, a short period of time of HPD use and low comfort of hearing protectors. The protective effect could be improved through training, optimizing the wearing of hearing protector models, and follow-up interventions. Enterprises should use suitability verification to ensure the correct selection and wearing of noisy workers.

Objective:To investigate the fit of dust-exposed workers wearing KN95 masks in a city of Guangdong Province, and to discuss the intervention effect of nose pads and elastic adjustment clasps on the fit of KN95 masks.Methods:In January 2024, 145 dust-exposed workers from a stone processing enterprise in a city of Guangdong Province were selected as study subjects by convenience sampling, and 4 types of KN95 masks commonly used by dust-exposed workers were selected as test masks. The head and face dimensions of the study subjects were measured using a right-angle gauge and a curved-angle gauge, and the fit factor (FF) of the KN95 masks was tested using the quantitative fit test for respiratory protective equipment, and the intervention of adding nose pads or elastic adjustment clasps was given to those who failed the first fit test. The paired t-test was used to compare the changes of workers' FF before and after the intervention. Results:The coverage rate of the study population in the facial subsection of the Chinese Han population was 71.0% (103/145). Before intervention, the overall passing rate of the fit test of 4 types of KN95 masks was 16.6% (24/145), and the passing rate of 4 types of masks had statistical significance ( χ2=19.73, P<0.001). After intervention, the overall passing rate of the fit test of masks was 33.9% (41/121), and the geometric mean of the total FF after intervention increased from 15.9 to 62.7 ( t=-13.53, P<0.001), among which 88.4% (107/121) workers' FF improved after intervention, and 11.6% (14/121) of workers had reduced FF. Conclusion:Dust-exposed workers in a city of Guangdong Province have a low coverage rate of facial subsection among Chinese Han population, and the passing rate of KN95 mask fit test is low. Interventions using additional nose pads or elastic adjustment clasps can partially improve the fit of the mask, and it is still necessary to continue to explore interventions to improve the fit of mask wearers.

Objective:To understand the current status of the actual protective effect of respiratory protective equipment (RPE) for workers exposed to trichloroethylene (TCE), and to explore the factors affecting the actual protective effect.Methods:From July to December 2023, a total of 75 workers occupationally exposed to TCE from 21 hardware and electronics manufacturing facilities in a province were selected as research objects by convenient sampling method. Workplace protection factor (WPF) was used as an index to evaluate the actual protective effect of workers' RPE. The concentration of TCE inside and outside the RPE was detected to calculate WPE, and the temperature, humidity and wind speed near the working place were measured, as well as the forced vital capacity, respiratory rate, heart rate and other indicators of the worker were measured. The log-transformed WPF value (lgWPF) followed a normal distribution. One-sample t-test was used to compare the difference between the mean lgWPF and the log value of the assigned protection factor (APF) of the half mask (lgAPF=1). Multiple linear regression model was used to investigate the influencing factors of lgWPF. Results:The lgWPF of 75 TCE-exposed workers ranged from 0.40 to 1.32 (0.84±0.22). The mean of lgWPF was lower than that of lgAPF, and the difference was statistically significant ( t=-6.37, P<0.001). After adjusting for confounding factors, the results of multiple linear regression showed that humidity, forced vital capacity and respiratory rate were negatively correlated with lgWPF ( β=-0.008, -0.079, -0.021, P<0.05) . Conclusion:The actual protective efficacy of RPE among workers exposed to TCE is suboptimal. High humidity, elevated forced vital capacity, and increased respiratory rate may be contributing factors to the diminished protective performance of RPE.

Objective:To observe the current status of the use of personal protective equipment (PPE) by the dust working population, and to analyze the factors affecting its use, so as to provide a reference basis for proposing scientific intervention methods.Methods:From October to December 2023, random sampling method was used to conduct a self-designed Questionnaire on the Use of Personal Protective Equipment by the Dust Working Population. A total of 1216 dust workers were randomly selected from each city in Guangdong Province, and their mask wearing status was evaluated. The Wilcoxon rank sum test was used for comparison between measurement data sets, and the Chi-square test or Fisher exact probability method was used for counting data. A binary logistic regression model was used to analyze the factors affecting the use of PPE in dust workers.Results:The correct rate of wearing PPE in dust working group was 66.12% (804/1216). In univariate analysis, there were statistical significances in different knowledge score, wearing PPE to reduce exposure to dust particles, wearing occupational health protective equipment such as masks was uncomfortable, wearing occupational health protective equipment such as masks reduced work efficiency, attending pre-employment occupational health examination, attending occupational health examination on a regular basis, receiving occupational health training during work in the enterprise, being urged or reminded by workmates, supervisors, or family members to use PPE, the correct use of PPE when workers or shift leaders were exposed to dust particles, second-hand smoke inhalation, smoking, and alcohol consumption ( P<0.05). Multiple logistic regression results showed that gender ( OR=2.00, 95% CI: 1.48-2.72), knowledge score ( OR=1.18, 95% CI: 1.11-1.26), neutral attitude towards the discomfort of wearing occupational health protective equipment such as masks during work ( OR=1.64, 95% CI: 1.18-2.27), and participation in pre-job occupational health examination ( OR=0.23, 95% CI: 0.10-0.54) were the main influencing factors on the use of PPE to be worn correctly ( P<0.05) . Conclusion:The rate of correct wearing of PPE for dust working population still needs to be improved. Factors such as gender, knowledge score, neutral attitude towards the discomfort of wearing masks during work, and participation in pre-job occupational health examination may be the influencing factors on the use of PPE for dust working population.

Objective:To analyze the correct use of personal protective equipment (PPE) among noise-exposed workers and its influencing factors, providing reference information for noise intervention efforts.Methods:In September 2023, a stratified sampling method was employed. Based on the 2022 gross domestic product (GDP) rankings of cities in Guangdong Province, 21 prefecture-level cities were divided into economically developed and less developed groups. Two cities were randomly selected from each group, and 16 to 17 enterprises were randomly chosen from each city as study sites. Twenty workers were included from each enterprise as study subjects. A total of 1200 questionnaires were distributed and collected, and 1099 were valid, with an effective recovery rate of 91.6%. The correctness of hearing protector usage was evaluated according to the GB/T 23466-2009 "Guidelines for the Selection of Hearing Protectors", and the personal attenuation rating values of the workers' hearing protectors were measured. A self-designed Questionnaire on the Use of Hearing Protectors by Noise-Exposed Workers was used to investigate PPE-related usage. Multivariate logistic regression analysis was conducted to identify factors influencing the correct use of PPE.Results:A total of 429 (39.0%) noise-exposed workers were able to use PPE correctly during work. Multivariate logistic regression analysis showed that age, working hours, gender, occupational noise protection knowledge score, whether PPE was checked after use, and the frequency of peer supervision on PPE usage were significant factors influencing the effective use of PPE ( P<0.05) . Conclusion:The correct use of PPE by noise-exposed workers still needs to be improved. The level of occupational health education in enterprises should be enhanced to promote the correct use of PPE by noise-exposed workers.

Objective:To understand the occupational injury situation of front-line workers in metallurgical and shipbuilding and repairing industry, and explore the risk factors of occupational injury.Methods:From September 2023 to March 2024, using cluster sampling method, front-line workers from 2 metallurgical enterprises in Shaoguan and Jinan City and 2 shipbuilding and repairing enterprises in Jiangmen and Shenzhen City were selected as the investigation objects. 6248 questionnaires were distributed and collected, and 6178 were effective questionnaires, with a effective recovery rate of 98.88%. The basic information, living habits, working system, protection and occupational injury of workers were investigated, and the data of occupational injury in factories was collected. The types, jobs and main causes of occupational injuries in different industries were analyzed, and the influencing factors of occupational injuries were analyzed by univariate and multi-factor logistic regression.Results:The incidence of occupational injury was 3.13% (128/4086) in metallurgical industry and 4.02% (84/2092) in shipbuilding and repairing industry. The top three occupational injuries in the metallurgical industry were furnace worker (17.19%, 22/128), steel rolling worker (14.84%, 19/128), maintenance worker (10.16%, 13/128), and the top three injury types were mechanical injury (24.22%, 31/128), height fall (20.31%, 26/128) and object strikes (17.97%, 23/128). The top three occupational injuries in shipbuilding and repairing industry were welder (20.24%, 17/84), riveter (9.52%, 8/84) and crane (8.33%, 7/84). The top three injury types were hit by objects (34.52%, 29/84), hit by falling objects (22.62%, 19/84), and lifting injury (20.24%, 17/84). The injuries of workers in metallurgical industry and shipbuilding and repairing industry were mainly fractures, accounting for 32.03% (41/128) and 60.71% (51/84), respectively. The incidence of occupational injury was higher in males, with sleep disorder, high temperature exposure and chemical toxicity exposure ( P<0.05). There were significant differences in age, smoking degree, working age and emotional state between workers with occupational injury and those without occupational injury ( P<0.05). Multivariate analysis showed that male, age above 50 years old, moderate smoking, working years of 5-9 years, mild anxiety, poor health status and high temperature exposure were risk factors for occupational injury ( OR=25.57, 3.72, 14.27, 2.09, 1.50, 4.36, 0.66, P<0.05) . Conclusion:The incidence of occupational injury is higher in shipbuilding and repairing industry, and fracture is the main type of occupational injury. The occurrence of occupational injury is affected by gender, age, smoking, working age, emotional state, health status and high temperature exposure.

Objective:To investigate the fit of dust-exposed workers wearing KN95 masks in a city of Guangdong Province, and to discuss the intervention effect of nose pads and elastic adjustment clasps on the fit of KN95 masks.Methods:In January 2024, 145 dust-exposed workers from a stone processing enterprise in a city of Guangdong Province were selected as study subjects by convenience sampling, and 4 types of KN95 masks commonly used by dust-exposed workers were selected as test masks. The head and face dimensions of the study subjects were measured using a right-angle gauge and a curved-angle gauge, and the fit factor (FF) of the KN95 masks was tested using the quantitative fit test for respiratory protective equipment, and the intervention of adding nose pads or elastic adjustment clasps was given to those who failed the first fit test. The paired t-test was used to compare the changes of workers' FF before and after the intervention. Results:The coverage rate of the study population in the facial subsection of the Chinese Han population was 71.0% (103/145). Before intervention, the overall passing rate of the fit test of 4 types of KN95 masks was 16.6% (24/145), and the passing rate of 4 types of masks had statistical significance ( χ2=19.73, P<0.001). After intervention, the overall passing rate of the fit test of masks was 33.9% (41/121), and the geometric mean of the total FF after intervention increased from 15.9 to 62.7 ( t=-13.53, P<0.001), among which 88.4% (107/121) workers' FF improved after intervention, and 11.6% (14/121) of workers had reduced FF. Conclusion:Dust-exposed workers in a city of Guangdong Province have a low coverage rate of facial subsection among Chinese Han population, and the passing rate of KN95 mask fit test is low. Interventions using additional nose pads or elastic adjustment clasps can partially improve the fit of the mask, and it is still necessary to continue to explore interventions to improve the fit of mask wearers.

Objective:To understand the current status of the actual protective effect of respiratory protective equipment (RPE) for workers exposed to trichloroethylene (TCE), and to explore the factors affecting the actual protective effect.Methods:From July to December 2023, a total of 75 workers occupationally exposed to TCE from 21 hardware and electronics manufacturing facilities in a province were selected as research objects by convenient sampling method. Workplace protection factor (WPF) was used as an index to evaluate the actual protective effect of workers' RPE. The concentration of TCE inside and outside the RPE was detected to calculate WPE, and the temperature, humidity and wind speed near the working place were measured, as well as the forced vital capacity, respiratory rate, heart rate and other indicators of the worker were measured. The log-transformed WPF value (lgWPF) followed a normal distribution. One-sample t-test was used to compare the difference between the mean lgWPF and the log value of the assigned protection factor (APF) of the half mask (lgAPF=1). Multiple linear regression model was used to investigate the influencing factors of lgWPF. Results:The lgWPF of 75 TCE-exposed workers ranged from 0.40 to 1.32 (0.84±0.22). The mean of lgWPF was lower than that of lgAPF, and the difference was statistically significant ( t=-6.37, P<0.001). After adjusting for confounding factors, the results of multiple linear regression showed that humidity, forced vital capacity and respiratory rate were negatively correlated with lgWPF ( β=-0.008, -0.079, -0.021, P<0.05) . Conclusion:The actual protective efficacy of RPE among workers exposed to TCE is suboptimal. High humidity, elevated forced vital capacity, and increased respiratory rate may be contributing factors to the diminished protective performance of RPE.