Objective To analyze the distribution characteristics of the single nucleotide polymorphism (SNP) site rs76206423 in the promoter region of the interleukin-2 receptor (IL-2R) β gene among Han males in a high radiation background area (HBRA) in Yangjiang City. Methods A total of 48 male participants from Tangkou Town, Yangxi County, Yangjiang City (HBRA group), and 51 male participants from Hengpo Town, Enping City (control group) were selected as the research subjects using the random number table method. Peripheral venous blood samples of participants from both groups were collected, and genomic DNA was extracted. The genotyping and allele frequency distribution of the rs76206423 (A/G) site in the IL-2R β promoter region was detected among the participants in both groups using the SNP detection method. The difference of allele frequencies between population in HBRA group and five area of East Asia, South Asia, Africa, Europe, and the Americas published in the Human Genome Project database from National Center for Biotechnology Information were analyzed. Results The allele frequencies of rs76206423 of population in both groups conformed to Hardy-Weinberg equilibrium (P>0.05). In the HBRA group, the AA genotype was predominant (64.6%), while the AG genotype was the most common in the control group (51.0%), with a significant difference (P<0.05). Population in both groups showed a predominance of the variant allele A (78.1% and 72.5%, respectively), with no significant difference (P>0.05). The frequency of the G allele of rs76206423 in the population in HBRA group was higher than those in South Asian, African, European, and American populations (all P<0.01), but showed no significant difference compared with East Asian populations (P>0.05). Conclusion In the Han male population from the HBRA in Yangjiang City, the rs76206423 site in the IL-2R β gene promoter region is predominantly composed of the wild-type A allele and AA genotype, indicating genetic stability and a relatively high degree of variation at this locus.

Objective To analyze the monitoring status of occupational hazard factors in key industry workplaces in a city of the Pearl River Delta area from 2019 to 2023. Methods A total of 1 548 enterprises in 12 key industries of the city were selected as the research subjects using the judgmental sampling method. Their monitoring data for dust, chemical factors, and noise, along with the occupational health management status of the enterprises were analyzed. Results Among the 1 548 enterprises, large and medium-sized enterprises accounted for 2.7% and 13.4%, while small and micro enterprises accounted for 83.9%. A total of 474 enterprises exceeded the national limit in the detection of occupational hazard factors, with an exceedance rate of 30.6%. The rates of workers exposed to occupational hazard factors, dust, chemical factors, and noise were 29.4%, 6.9%, 21.0%, and 13.0%, respectively, all showing a downward trend year by year (all P<0.05). The training rates for occupational health among enterprise managers, responsible persons, and workers were 84.1%, 84.2%, and 91.2%, respectively. The detection rates for abnormal occupational health examinations among workers exposed to dust, chemical factors, and noise were 0.2%, 0.3%, and 0.5%, respectively. The setting rates of warning signs and warning instructions among enterprises for dust, chemical toxins, and noise were 87.3%, 91.1%, and 89.5%, respectively. The setting rates for dust, toxic chemical, and noise control facilities were 72.4%, 75.4%, and 46.0%, with effectiveness rates of 70.5%, 56.6%, and 55.2%, respectively. The distribution rates of personal protective dust masks, gas masks, and noise earplugs/earmuffs were 91.9%, 83.8%, and 86.4%, with wearing rates of 80.8%, 70.5%, and 76.4%, respectively. The detection rates of exceeding national limits for dust, chemical factors, and noise in the work site of occupational hazard factors were15.2%, 1.0%, and 21.6%, respectively. The detection rates of exceeding national limits for dust, chemical factors, and noise in the workplace of occupational hazard factors were 2.4%, 2.5%, and 12.3%, respectively. The exceedance rate for noise in work site showed an upward trend year by year (P<0.01). Conclusion Occupational disease prevention and control work in the key industries of this city needs strengthening. It is essential to further enhance the regular monitoring and preventive measures of occupational hazard factors in enterprises, improve protective measures, strengthen the use of personal protective equipment, and enhance occupational health training and supervision, to effectively reduce the risk of occupational diseases and protect workers' occupational health rights.

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 investigate the use of earplugs among noise-exposed workers (Homo sapiens) in Bao'an District, Shenzhen, measure the personal attenuation rating (PAR) of earplugs when wearing earplugs, (Homo sapiens), analyze factors influencing the protective effect of earplugs, and evaluate the role of targeted wearing interventions in improving protective efficacy.Methods:From December 2022 to January 2023, 220 workers in noise-exposed positions from 3 enterprises in Bao'an District, Shenzhen were selected as subjects using the convenience sampling method. The Personal Attenuation Rating (PAR) values of workers wearing earplugs were measured using a fit testing system. Combined with the results of a questionnaire survey, the individual differences in workers' baseline PAR were described. A multivariate logistic regression model was used to analyze the influencing factors for earplugs to achieve the protective effect. One-on-one wearing interventions were implemented for workers who failed to achieve the protective effect, and repeated PAR tests were conducted. The changes in PAR of 120 workers before and after the intervention were compared.Results:The median baseline PAR for 220 workers was 7 (0, 14) dB, and the intervention rate was 54.55% (120/220). There were differences in the baseline PAR of workers with different length of service, earplugs wearing time and experience, daily noise exposure time and intensity, training and the comfort of earplug use ( P<0.05). The results of multivariate regression analysis showed that workers The comfort with earplugs wearing ( OR=2.81, 95% CI: 1.49~5.33, P<0.01) and training ( OR=6.60, 95% CI: 1.70~25.63, P<0.05) were the influencing factors of achieving the protective requirement. The median PAR was increased to 13 (11, 16) dB after intervention. Conclusion:The baseline protective effect of earplugs worn by workers is significantly influenced by comfort and enterprise training. One-on-one interventions can effectively improve the protective efficacy of those who fail to meet the requirements.

Objective:To Exploring the protective effect of hearing protectors worn by noise workers in the petrochemical industry and the factors affecting the protective effect of hearing protectors.Methods:From June 2021 to July 2023, 929 petrochemical workers were selected as the research subjects through cluster sampling. The noise exposure of workers and the usage of two types of hearing protectors were surveyed through questionnaire surveys and on-site occupational hygiene surveys. The protective effect of hearing protectors were evaluated by testing the PAR of workers. If the noise exposure value of workers minus the PAR value was less than 85 dB (A) , it was considered passed. Otherwise, it was considered not passed. The passing rate of the protective effect test of hearing protectors was analyzed through chi square test and the influencing factors for the effectiveness of workers hearing protectors in test were explored through single factor analysis and logistic regression models.Results:Among the research subjects, 80.5% of workers (748/929) had noise exposure levels greater than 85 dB (A) . The passing rate (80.9%) of the earmuff is greater than that of the earplug (52.6%) , and the median of PAR of the earmuff is 22 (16, 25) , which is greater than that of the earplug 15 (3, 22) dB dB, with a statistically significant difference ( P<0.001) . Univariate analysis and logistic regression models showed that length of service, exposure level to noise, and wearing comfort were the influencing factors of earplug protection effect ( P<0.05) , while wearing comfort was the influencing factor of earmuff protection effect ( P<0.05) . Conclusion:This study indicates that the protective effect of hearing protectors on workers in the petrochemical enterprise is poor, and the protective effect of earmuffs is greater than that of earplugs. Working experience, noise exposure level, and wearing comfort are the influencing factors of earplug protection effect, while wearing comfort is the influencing factor of earplug protection effect.

In workplaces where formaldehyde, hydrochloric acid and water vapor coexist, dichloromethyl ether can be produced. Dichloromethyl ether has strong carcinogenicity. Its target organ is the lungs, and the common tissue type of lung cancer is small cell lung cancer. This paper analyzes the cause of a case of occupational tumor (lung cancer caused by dichloromethyl ether) in the electroplating industry. Through the use of on-site occupational health investigation method, engineering analysis method and detection and inspection method, the occupational disease diagnosis is diagnosed in combination with the patient's occupational contact history, clinical symptoms and workplace occupational disease hazard factors. According to GBZ 94-2017 "Diagnosis of Occupational Tumor", the patient in this case was clearly diagnosed with primary lung cancer and was diagnosed as an occupational tumor (lung cancer caused by dichloromethyl ether) .

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.