[Research on quantitative evaluation of revise requirements of Specifications of Air Sampling for Hazardous Substances Monitoring in the Workplace (GBZ 159-2004)]

Objective: To conduct quantitative evaluation on the revise requirements of Specifications of Air Sampling for Hazardous Substances Monitoring in the Workplace (GBZ 159-2004) , clarify the problems and suggestions during its implementation for improvement, and provide a basis for the revision of the standard. Methods: From April to September 2021, stratified convenient sampling method was adopted and semi-open questionnaire was used to investigate the occupational health personnel in CDC, occupational prevention and control institutes, employers, third-party technical service institutions and universitie. The entropy weight of each index and the score based on entropy weight of GBZ 159 were calculated. Spearman rank correlation analysis was used to describe the correlation between the two indexes and radar chart was drawn for comprehensive evaluation. Results: A total of 151 questionnaires were received from the respondents, of which 147 were valid, with an effective recovery rate of 97.35%, involving 29 provinces, autonomous regions and municipalities. The median G scores of the necessity and urgency of GBZ 159 revision based on entropy weight were 2.84 and 3.17, respectively, and the difference was statistically significant (M=-25.50, P<0.001) . The trend of the score G of necessity and urgency based on entropy weight was basically the same for all secondary items (r(s)=0.9998, P<0.001) , and the score G of urgency based on entropy weight was higher than that of necessity. The highest score G of necessity and urgency based on entropy weight was "3.13 long time sampling", which were 7.56 and 8.23 respectively. This was followed by "3.12 short time sampling", which were 7.19 and 7.13 respectively. Conclusion: GBZ 159 has encountered some new problems and challenges in the implementation process, and some of its technical indicators have been out of line with the actual practice of occupational health at present. These are the two items that urgently needs to be revised and improved, such as "3.13 long time sampling" and "3.12 short time sampling" and other items need to be revised and improved.

[Study on the implementation effect evaluation of Specifications of Air Sampling for Hazardous Substances Monitoring in the Workplace (GBZ 159-2004)]

Systematically evaluate the implementation of Specifications of Air Sampling for Hazardous Substances Monitoring (GBZ 159-2004) , so as to provide technical basis for the future standard revision. The semi-structured interview method was used to interview the industry experts from centers for disease control and prevention, occupational disease prevention and control hospitals/institutes, employers, third-party technical service institutions and universities, and the induction method was used to refine the topics and relevant suggestions. Some technical indicators of GBZ 159 are not suitable for the current actual work of occupational health, and need to be revised and improved urgently. The revised GBZ 159 should comply with the current situation of China's industrial development and the development of occupational health testing equipment in the new era, and improve the relevant technical requirements of sampling quality control.

[Comparison and analysis research on occupational exposure limits of coal dust between China and foreign countries]

Objective: To study and compare the occupational exposure limits (OELs) of coal dust between China and foreign countries, understand the OEL of coal dust in China, and provide data and basis for revising the OEL of coal dust in China. Methods: In August 2023, by searching the official websites of limits setting institutions in relevant countries and regions at home and abroad, collecting and sorting out the OELs of coal dust issued by 10 limit setting institutions in 6 countries and the background information of the formulation, and conducting specific analysis on the classification, limit level and formulation principles of coal dust OEL in each country/institution. Results: In China and Japan, the total dust and respirable dust of coal dust OEL were established respectively, while in other countries, only the time-weighted average concentration (TWA) of respirable coal dust exposure was established. The TWA prescribed by China's Notional Health Commission, the United States Occupational Safety and Health Administration (OSHA) , the United States Mining Safety and Health Administration (MSHA) and the Australian Safety Work Bureau when the SiO(2) content was less than 5% were 5, 2.4, 2 and 3 mg/m(3) respectively. China GBZ 2.1-2019 sets the limit of 2.5 mg/m(3) for respirable coal dust with SiO(2) content less than 10%. The TWA set by the American Conference of Government Industrial Hygienists (ACGIH) and the South African Department of Mines and Energy (DME) for anthracite coal were 0.4 and 0.8 mg/m(3), respectively, and bituminous coal or lignite were 0.9 and 1.8 mg/m(3), respectively. The respirable coal dust TWA set by the National Institute for Occupational Safety and Health (NIOSH) in the United States was 1 mg/m(3), and the TWA set by the New Zealand Work Safety Authority was 3 mg/m(3). Conclusion: At present, the OEL of coal dust in China is at a relatively loose level, and it is suggested to further explore the possibility of revising coal dust OEL.

[Introduction to carcinogenesis of nickel compounds in ILO criteria for Diagnosis and Exposure Standard for Occupational Diseases]

International Agency for Research on Cancer (IARC) classifies nickel compounds as Class Ⅰ carcinogens. International Labour Organization (ILO) also lists nickel compounds as carcinogenic factors of occupational cancer. At present, China is revising the Classification and Catalogue of Occupational Diseases, and cancer caused by nickel compounds may also be included in the statutory occupational diseases. The Diagnostic and Exposure Standards for Occupational Diseases published by ILO in 2022 discussed the pathogenic characteristics, occupational exposure, main health effects, diagnostic criteria and key preventive measures of nickel compounds in detail. This article mainly introduces its contents, in order to provid a basis for the formulation of relevant standards in China.

[41 cases of chronic obstructive pulmonary disease caused by occupational irritating chemicals]

Objective: To analyze the case characteristics of Chronic obstructive pulmonary disease caused by occupational irritant chemicals (OI-COPD). To provide basis for revising its diagnostic criteria. Methods: From June to December 2021, we investigated the information of OI-COPD patients confirmed by Shandong Institute of Occupational Health and Prevention of Occupational Diseases, Guangxi Zhuang Autonomous Region Institute of Occupational Disease Prevention and Control, Qingdao Central Hospital affiliated to Qingdao University and other diagnostic institutions in the past five years, a total of 41 cases. The basic information of OI-COPD cases, occupational risk factors exposure information, medical history, smoking history and clinical symptoms were analyzed retrospectively. The measurement data were tested for normal distribution, which was described by x±s, and compared between groups by t test; Those who do not conform to the normal distribution are described by the median [M (Q(1), Q(3)) ] and analyzed by nonparametric test; The counting data were expressed in frequency and rate (% ), and the comparison between groups was tested. Results: Of the 41 cases, 33 were male and 8 were female. The age of the patient diagnosed with OI-COPD was (49.5±10.3) years old, and the minimum age was 30 years old; Among them, 8 patients had a definite long-term smoking history (more than 5 years) ; The exposure duration of occupational risk factors was (18.6±10.3) years, of which 3 patients had exposure duration of less than 5 years; The occupational risk factors leading to OI-COPD include acids and acid-forming compounds, bases, aldehydes, nitrogen oxides, chlorine and its compounds, etc. The exposure level of occupational risk factors is related to the degree of COPD airflow restriction (χ(2)=6.17, P <0.05). 18 patients with diagnosis age <50 years old were diagnosed as early-onset COPD. The incidence of respiratory symptoms in the early diagnosis COPD group was lower than that in the non-early diagnosis COPD group, and the FEV1% pred was significantly higher than that in the non-early diagnosis COPD group. The difference was statistically significant (P<0.01 ) . Conclusion: The exposure level of occupational risk factors may be the risk factor affecting the degree of COPD airflow restriction. With the increase of the exposure level of COPD patients, the proportion of respiratory symptoms will also increase accordingly.

[Evaluation of the implementation of Diagnostic Criteria of Occupational Acute Neurotoxic Diseases Caused by Chemicals (GBZ 76-2002)]

Objective: To investigate the implementation of Diagnostic Criteria of Occupational Acute Neurotoxic Diseases Caused by Chemicals (GBZ 76-2002) for accumulating basis of standard revision. Methods: In February 2020, 85 experts in occupational diseases and neurology from 39 medical and health institutions were selected as the respondents. The modified Delphi method was used to establish the standard evaluation index system and special group was organized for discussing the pre-survey and completing the questionnaire survey. Questionnaire survey was performed to investigate the grasp of the standards, application and modification suggestions of respondents. Results: The respondents' mastery of standard-related knowledge mainly came from work experience (84.7%, 72/85) , standard learning (81.2%, 69/85) and training (75.3%, 64/85) . Among the institutions in which the respondents worked, 98.8% (84/85) could carry out CT examinations, 96.5% (82/85) could carry out nerve conduction velocity and electromyography examinations, 89.4% (76/85) could carry out EEG examinations, 80% (68/85) could carry out evoked potential examinations and 72.9% (62/85) could carry out MRI examinations. Among the toxicants diagnosed as occupational acute toxic myelopathy, 10.6% (9/85) were organic phosphorus and 9.4% (8/85) were asphyxiating gas; Among the toxicants diagnosed as delayed peripheral neuropathy, pesticides accounted for 25.9% (22/85) and asphyxiating gases accounted for 12.9% (11/85) . 85.9% (73/85) of the respondents believed that the basis for the classification of acute toxic encephalopathy needed to supplement objective evidence; 80.0% (68/85) of the respondents thought that the diagnosis and classification of peripheral neuropathy should be refined according to the abnormal indexes of neuroelectromyography. Conclusion: The applicability of the criteria needs to be improved because the current criteria has a long application cycle without enough objective investigation bases in classification criteria index.

[Research on the relevant characteristics of occupational disease diagnostic criteria in China from the perspective of social network analysis]

Objective: To analyze the normative references in occupational disease diagnostic criteria and explore the relevant characteristics of occupational disease diagnostic criteria in China, aiming to provide the basis for improving the system of occupational disease diagnostic criteria. Methods: From January to March 2021, the text and normative references of occupational disease diagnostic criteria were retrieved, and the database was established with Excel 2013, and the data were analyzed with SPSS 22.0 software and Ucinet 6.0 software. The distributions of normative references were statistically analyzed by frequency analysis. The network density and centrality of occupational disease diagnostic criteria were analyzed by social network analysis. The network topology of relevant relationship network of occupational disease diagnostic criteria was drawn. Results: Among 115 occupational disease diagnostic criteria, 105 criteria cited 146 normative references, a total of 431 times. The normative documents cited more frequently were GB/T 16180 (91 times), GBZ 76 (37 times) and GBZ 73 (23 times). The number of normative references in GBZ 188 and GBZ/T 238 was large, 87 and 13 respectively. The results of social network analysis showed that the network density was 0.0281. The relative degree centrality was 3.089, and the top three criteria were GB/T 16180 (55.152), GBZ 188 (53.333) and GBZ 76 (23.636). The closeness centrality was 7.773 and the top three criteria were GB/T 16180 (8.735), GBZ 188 (8.730) and GBZ 76 (8.333). The betweenness centrality was 0.824 and the top three criteria were GBZ 188 (38.836), GB/T 16180 (38.301) and GBZ/T 238 (10.407). And GB/T 16180, GBZ 188, GBZ 76, GBZ 73 and GBZ 59 were at the core of the network topology of relationship network of occupational disease diagnostic criteria. Conclusion: The network density of occupational disease diagnostic criteria in China is low, and the relevant relationship is not close. GB/T 16180, GBZ 188, and GBZ 76 are node standards and should be the focus of the next standard implementation tracking.

[Anatomical characteristics of profunda artery perforator flap in the posteromedial femoral region and its application in the reconstruction of oral and maxillofacial defects]

Objective: To investigate the anatomical basis for the preparation of the profunda artery perforator flap (PAPF) in the posteromedial femoral region and its application in the reconstruction of oral and maxillofacial defects. Methods: Six lower limbs of Chinese adult cadavers were micro-surgically dissected. CT angiography (CTA) data of bilateral lower limbs of 6 patients was also collected retrospectively. The number, external diameter, pedicle length, and distribution of perforators in the posteromedial femoral region were recorded from the specimens and CTA data. Meanwhile, 10 patients with oral squamous cell carcinoma in the Department of Oral and Maxillofacial Surgery, Affiliated Hospital of Stomatology, Nanjing Medical University from August 2018 to June 2021 were treated with the PAPF. At each follow-up, contour and function of recipient and donor site, as well as swallowing and speech function were evaluated. Results: A total of 19 profunda artery perforator were identified in 6 lower limb specimens. The outer diameter at the beginning of the source artery was (2.34±0.25) mm and the total length of the pedicle was (11.12±1.06) cm. CTA data analysis of 12 legs identified 15 perforators of profunda artery in the posteromedial region. Eleven perforators were septocutaneous, including 2 perforators with a common trunk, while the remaining 4 perforators were musculocutaneous. As for different patterns of perforators (septocutaneous perforators, musculocutaneous perforators and perforators with a common trunk), the longitudinal distance to the pubic tubercle was (19.95±2.43), (21.84±2.54) and (19.48±0.55) cm respectively. The horizontal distance to the posterior edge of gracilis was (3.54±1.10), (3.72±0.30) and (3.85±1.48) cm, respectively. The initial diameters of perforators was (2.4±0.4), (2.6±0.6) and 1.9 mm respectively. Ten cases of the profunda artery perforator flaps survived successfully after operation. The flap sizes ranged from 8 cm×6 cm to 12 cm×7 cm. The patients were evaluated at 1, 3 and 6 months, and with 6 months interval ever since. During the follow-up, the shape of the recipient site was ideal, and the swallowing and language functions were not significantly affected. There was only linear scar in the donor area, and the function of the thigh was basically normal. Conclusions: PAPF possessed a good anatomic stability, suitable vascular pedicle length and diameter, minor influence to the donor area, sufficient amount tissue with good quality. It is an ideal choice for head and neck reconstruction.

[Different treatment regimens for primary central nervous system lymphoma:based on SEER database]

Objectives: To explore the prognostic factors of primary central nervous system lymphoma(PCNSL) and to analyze the efficacy of different treatment methods. Methods: Clinical data of 4 812 patients with PCNSL in SEER database from January 1975 to December 2016 were retrospectively analyzed.Among them, 2 831 were male and 1 981 were female, the ratio of male to female was 1.4∶1.0.There were 2 236 cases(46.47%) under 60 years old, 1 718 cases(35.70%) aged 60 to 74 years old, and 858 cases(17.83%) aged 75 years old or above. Two thousand four hundred and seventeen cases(50.23%) had supratentorial tumors, 299 cases (6.21%) had infratentorial tumors, and 554 cases(11.51%) had multiple brain tumors, 1 542 cases (32.04%) were other or unspecified location.Three thousand five hundred and thirteen cases(73.00%) had diffuse large B-cell lymphoma (DLBCL), 234 cases(4.86%) had non DLBCL, 1 065 cases (22.13%) had other or unspecified types of tumor.The treatment included 2 011 cases (41.77%) of biopsy, 61 cases (1.27%) of subtotal resection(STR), 54 cases (1.12%) of gross total resection(GTR), 2 384 cases (49.54%) of biopsy and chemotherapy, 159 cases (3.30%) of STR and chemotherapy, 144 cases (3.00%) of GTR and chemotherapy.Univariate and multivariate Cox regression models were used to analyze the prognostic factors affecting the overall survival of the patients.Fine-Gray test and competitive risk model were used to analyze the prognostic factors affecting cancer-specific survival.Kaplan-Meier method and Log-rank test was used for survival analysis. Results: Univariate and multivariate Cox regression analyses showed that age, race, marital status, tumor site, pathological subtype, surgery, chemotherapy, combined with other malignant tumors, and HIV infection were the independent prognostic factors affecting the overall survival of PCNSL patients.The results of Fine-Gray test and competitive risk model analyses showed that age, race, marital status, tumor location, pathological subtype, surgical method, chemotherapy, combined with other malignant tumors, and HIV infection were independent prognostic factors affecting cancer-specific survival, while gender and radiotherapy had no significant correlation with cancer-specific survival.Compared with biopsy, PCNSL patients may benefit from surgical resection (STR:HR=0.805, 95%CI:0.656‒0.989, P=0.04; GTR:HR=0.521, 95%CI:0.414‒0.656, P<0.01).Kaplan-Meier survival analysis showed that the median survival time of biopsy+chemotherapy group was 28 months (95%CI:24.497‒31.503), 2 months (95%CI:1.756‒2.244) in the biopsy group, 2 months (95%CI:1.410-2.590) in the STR group, 19 months (95%CI:0‒39.311) in the biopsy+chemotherapy group, 67 months (95%CI:46.187-87.813) in the STR+chemotherapy group, 84 months (95%CI:57.448‒110.552) in the GTR+chemotherapy group.The median survival time of patients with different treatment methods was statistically significant (P<0.01). Conclusions: Surgical resection may improve the prognosis of some PCNSL patients.Patients who have access to receive GTR or STR combined with chemotherapy may have prolonged Cancer-specific survival.

[A bibliometric analysis of China's occupational health standard from 2001 to 2016]

Objective: To analyze the relevant literature on China's occupational health standard from 2001 to 2016, and to provide a basis for further improving China's occupational health standard system. Methods: Wanfang Data, CNKI, VIP, PubMed, Embase, and Web of Knowledge were used to retrieve relevant literature on China's occupational health standard from 2001 to 2016. Information of the literature was collected, and type of literature, time and region, first author's affiliation, and research funding were analyzed by bibliometrics. Results: The relevant literature on China's occupational health standard was concentrated domestically and in the health system, and the number of documents was highly correlated with socio-economic conditions. The literature was dominated by the research on onsite application of occupational health (53.08%) , while there was less research on occupational health standard (11.78%) . The number of published articles and funding intensity were significantly different between centers for disease control and prevention at different levels. Conclusion: It is suggested to accelerate the application of evidence-based medicine and systematic review in the development of occupational health standard, enhance the research ability of county/district-level disease control officers, assist them in summarizing and publishing their daily work experience, and give them appropriate funding, so as to promote the accumulation of knowledge in the field of occupational health.

Percutaneous manual aspiration thrombectomy followed by stenting for iliac vein compression syndrome with secondary acute isolated iliofemoral deep vein thrombosis: a prospective study of single-session endovascular protocol

OBJECTIVE

To evaluate the feasibility, safety, and effectiveness of single-session endovascular treatment with manual aspiration thrombectomy (MAT) as the first-line method of thrombus removal for iliac vein compression syndrome (IVCS) with secondary acute isolated iliofemoral deep vein thrombosis (DVT).

METHODS

This was a prospective clinical study. Twenty-six patients (19 women, 7 men, mean age 54 years) with left-sided acute iliac-common femoral DVT secondary to IVCS were enrolled. All patients presented with leg swelling or pains. Endovascular treatment, consisting of MAT, balloon angioplasty, and stent placement, was performed in the same setting. Overnight antegrade thrombolysis was performed in patients with residual thrombus after MAT. Patients were followed up by ultrasonography. The mean follow-up period was 17.8 months (12-25 months).

RESULTS

Single-session endovascular procedures were performed successfully in all patients. The mean procedure time was 67 minutes (ranging from 45 to 90 minutes). Complete thrombus removal, including almost 100% of removal in 24 patients and little residual thrombus (<5%) in two, was achieved after repeated MAT. Thrombolysis was used in these two patients. Complete symptomatic relief was achieved in 25 patients (96%) and partial relief in one. The hospital stay ranged from 2 to 4 days (mean 2.7 days). Recurrent thrombosis within the stent was observed in one case and recanalized with thrombolysis. The 1-year primary and secondary patency rate was 96% and 100%, respectively. No symptomatic pulmonary embolization, bleeding, and venous reflux were observed. Five patients complained about transitory low back pains during balloon angioplasty.

CONCLUSION

Single-session endovascular treatment with MAT as the first-line thrombus removal method is feasible, safe, and effective for IVCS with secondary acute isolated iliofemoral DVT. Although limited, our experience suggests that patients thought to be at high risk of bleeding may be candidates for the present single-session endovascular protocol.