How to Control the Airborne Contamination in Laboratory Analyses of Microplastics?

Abstract: Numerous studies have quantified microplastics in biological and environmental samples in recent years, but contamination by airborne microplastic particles during laboratory analysis remains an unsettling possibility. We designed and tested a protocol to minimize airborne contamination during the screening of samples in laboratory conditions in order to increase the level of certainty that microplastics counted really comes from samples. Despite the care and default measures in laboratory routine, some airborne contamination in blanks was found (3.8%) at the beginning of sample screenings. After introducing more stringent procedures on our airborne contamination control protocol (ACC Protocol), a highly significant (p<0.0001) reduction was registered (1.1%). Thus, we prove that the use of a more stringent protocol should be an essential part of future studies quantifying microplastics in any samples. This study concludes that a protocol with simple, low-cost, but stringent measures can reduce airborne microplastic contamination, being applicable to any laboratory setting.

Liquid preparation of diatomaceous earth against the lesser mealworm, Alphitobius diaperinus (Panzer, 1797) (Coleoptera: Tenebrionidae)

The lesser mealworm (LMW) is the most important pest in poultry production. Insects are associated to avian pathogens, mainly Salmonella. Its control is based on chemical insecticide, with limited efficacy in population reduction. Also, insect populations are resistant to the main active ingredients used. Diatomaceous earth (DE) is a mineral dust that has activity against the LMW when used in dust application. No information is available about DE liquid preparation against this insect. Thus, bioassays were conducted aiming to develop a strategy for DE liquid preparation to this insect control. In laboratory the ideal concentration for poultry house experiment was estimated and the effect of insect contact with poultry litter or chicken feed after application was checked. In the poultry house, DE liquid preparation (10% in water, 1 L·m­2) was applied on the dirt soil of a cleaned and empty poultry house. In the control poultry house, a chemical insecticide was used (cypermethrin 15 g + chlorpyriphos 25 g + piperonyl butoxide 15 g) (1 L·m­2). DE at all concentrations was efficient mainly when insects were dried for 24 h before contact with a substrate. In poultry house, both treatments obtained similar results at 15 days after treatment (94% of reduction of insect population). At 45 days after treatment, the insect population with DE treatment increased 39% while the insect population remained 17% smaller than the initial population with a chemical insecticide. DE liquid preparation has potential to be used as a safe treatment in LMW population management, as a shock treatment.

Comparative study on establishing an immune tolerance model for allergic conjunctivitis in mice with different methods / 国际眼科杂志(Guoji Yanke Zazhi)

AIM:To establish an immune tolerance model for allergic conjunctivitis in newborn mice with different methods and observe the impact of environmental factors on allergic conjunctivitis in early life.METHOD: A total of 50 Balb/c newborn mice were randomly divided into blank control group, ovalbumin(OVA)+subcutaneous injection group, OVA+nebulized inhalation group, OVA+gastric group, ragweed pollen(RW)+subcutaneous injection group, RW+nebulized inhalation group, RW+gastric group, house dust mite(HDM)+subcutaneous injection group, HDM+nebulized inhalation group, HDM+intragastric group(n=5 animals/group). Except for the blank control group, mice in each group were individually exposed to the corresponding antigens to induce immune tolerance early in life and stimulated with the corresponding antigens in adulthood. The ocular surface was visualized by anterior segment photography. The relative expression level of conjunctival RANTES and IL-17 mRNA was measured by RT-qPCR and serum IL-17 concentration was measured by ELISA.RESULTS: Compared with the blank control group, the relative expression level of conjunctiva IL-17 mRNA in RW+gastric group was the highest, and it was the lowest in RW+subcutaneous group(all P&#x003C;0.05). The relative expression level of conjunctiva RANTES mRNA was the highest in RW+gastric group(P&#x003C;0.001). Compared with the blank control group, the serum concentration of IL-17 was increased in all treatment groups except OVA+nebulizer group and RW+subcutaneous group(P&#x003C;0.05).CONCLUSION: The immune tolerance of allergic conjunctivitis induced by subcutaneous injection of antigen was the most suitable method in the early life of mice.

HSP90α exacerbates house dust mite-induced asthmatic airway inflammation by upregulating endoplasmic reticulum stress in bronchial epithelial cells / 南方医科大学学报

OBJECTIVE@#To explore the role of heat shock protein 90α (HSP90α) and endoplasmic reticulum (ER) stress pathway in allergic airway inflammation induced by house dust mite (HDM) in bronchial epithelial cells.@*METHODS@#A HDM- induced asthmatic cell model was established in human bronchial epithelial (HBE) cells by exposure to a concentration gradient (200, 400 and 800 U/mL) of HDM for 24 h. To test the effect of siHSP90α and HSP90 inhibitor 17-AAG on HDM-induced asthmatic inflammation, HBE cells were transfected with siHSP90α (50 nmol, 12 h) or pretreated with 17-AAG (900 nmol, 6 h) prior to HDM exposure (800 U/mL) for 24 h, and the changes in the expression of HSP90α and ER stress markers were assessed. We also tested the effect of nasal drip of 17-AAG, HDM, or their combination on airway inflammation and ER stress in C57BL/6 mice.@*RESULTS@#In HBE cells, HDM exposure significantly up-regulated the expression of HSP90α protein (P=0.011) and ER stress markers XBP-1 (P=0.044), ATF-6α (P=0.030) and GRP-78 (P=0.027). Knocking down HSP90α and treatment with 17-AAG both significantly inhibited HDM-induced upregulation of XBP-1 (P=0.008). In C57BL/6 mice, treatment with 17-AAG obviously improved HDM-induced airway inflammation and significantly reduced the number of inflammatory cells in the airway (P=0.014) and lowered the levels of IL-4 (P=0.030) and IL-5 (P=0.035) in alveolar lavage fluid. Immunohistochemical staining showed that the expressions of XBP-1 and GRP-78 in airway epithelial cells decreased significantly after the treatment of 17-AAG.@*CONCLUSIONS@#HSP90α promotes HDM-induced airway allergic inflammation possibly by upregulating ER stress pathway in bronchial epithelial cells.

Investigation on diagnosis of pneumoconiosis in non-coal mining industry in Jiangsu Province / 中华劳动卫生职业病杂志

Objective: To understand the incidence of pneumoconiosis in the non-coal mining industry in Jiangsu Province, and provide reference for the prevention and control of pneumoconiosis in the non-coal mining industry. Methods: The data of 7019 newly diagnosed pneumoconiosis patients in non-coal mining industry in Jiangsu Province from January 1956 to December 2019 were collected through the Jiangsu Province Pneumoconiosis Follow-up Network Report System, including the gender of the pneumoconiosis patients, the name of the employer and the location, the industry classification of the employer, the duration of dust exposure in dust exposure, the name of occupational pneumoconiosis disease, the date of diagnosis of pneumoconiosis, etc. The collected case data of patients with pneumoconiosis were entered into the statistical software, and the characteristics of the patients' diagnosis time, region and industry were analyzed. Results: The number of confirmed pneumoconiosis patients in the non-coal mining industry in Jiangsu Province was mostly in 2007 (395 cases) , concentrated in Wuxi City (40.96%, 2875/7019) and Suzhou City (27.72%, 1946/7019) . The industries to which the patients belonged were mainly non-metallic mining and dressing (60.95%, 4278/7019) , and the most common type of pneumoconiosis was silicosis (96.40%, 6766/7019) . The patients were mainly stageⅠpneumoconiosis (61.33%, 4305/7019) . There were statistically significant differences in the mean age of diagnosis and the average duration of dust exposure among patients with different pneumoconiosis stages (P<0.01) . The differences in the average diagnosis age and the average duration of dust exposure of patients with different types of pneumoconiosis were statistically significant (P<0.05) , the mean age of diagnosis and the average duration of dust exposure of electric welders were the smallest, which were (44.92±7.74) years old and (17.38±10.15) years, respectively. Conclusion: The regional and industry distribution characteristics of new pneumoconiosis patients in the non-coal mining industry in Jiangsu Province are obvious, and attention should be paid to the treatment of pneumoconiosis patients with young diagnosed age and short duration of dust exposure, as well as the personal protection and health protection of front-line workers such as electric welders who are exposed to productive dust in a short period of time.

Distribution and exposure assessment of phthalic acid esters （PAEs） in indoor dust of Shanghai / 上海预防医学

Objective To characterize the distribution and assess the exposure to phthalic acid esters （PAEs） in the indoor dust of Shanghai City. Methods Samples were collected from 33 sampling sites， including homes， hotels， offices and public places， in Shanghai in 2018， 2019， and 2020. The samples were pretreated by 100 sieves， extracted and concentrated， and then analyzed by gas chromatography-mass spectrometry in selected ion mode （SIM）. Results Results on the characteristics of PAEs in indoor dust in different places showed that concentrations of PAEs were in a range of <0.01-2 464 mg·kg-1.The average concentration of 16 PAEs was 613 mg·kg-1. Bis（2-ethylhexyl） phthalate （DEHP）， di-iso-butyl phthalate （DiBP）， di-n-butyl phthalate （DBP） and di-n-octyl phthalate （DnOP） were the main components of PAEs in indoor dust， accounting for approximately 99.5% of 16 PAEs. The intake of DEHP， DBP， DEP and BBP was lower than the tolerable daily intake （TDI） and reference doses （RfD） set by EU CSTEE and U.S. EPA. Conclusion Average daily dose （ADD） via indoor dust is estimated， and the order of intake through different pathways is hand-oral intake>skin contact>respiratory inhalation. Exposure risk of PAEs in children is greater than that in adults.

Distribution and exposure assessment of phthalic acid esters （PAEs） in indoor dust of Shanghai / 上海预防医学

Objective To characterize the distribution and assess the exposure to phthalic acid esters （PAEs） in the indoor dust of Shanghai City. Methods Samples were collected from 33 sampling sites， including homes， hotels， offices and public places， in Shanghai in 2018， 2019， and 2020. The samples were pretreated by 100 sieves， extracted and concentrated， and then analyzed by gas chromatography-mass spectrometry in selected ion mode （SIM）. Results Results on the characteristics of PAEs in indoor dust in different places showed that concentrations of PAEs were in a range of <0.01-2 464 mg·kg-1.The average concentration of 16 PAEs was 613 mg·kg-1. Bis（2-ethylhexyl） phthalate （DEHP）， di-iso-butyl phthalate （DiBP）， di-n-butyl phthalate （DBP） and di-n-octyl phthalate （DnOP） were the main components of PAEs in indoor dust， accounting for approximately 99.5% of 16 PAEs. The intake of DEHP， DBP， DEP and BBP was lower than the tolerable daily intake （TDI） and reference doses （RfD） set by EU CSTEE and U.S. EPA. Conclusion Average daily dose （ADD） via indoor dust is estimated， and the order of intake through different pathways is hand-oral intake>skin contact>respiratory inhalation. Exposure risk of PAEs in children is greater than that in adults.

Dificuldade auditiva autorreferida e exposição ocupacional a agentes otoagressores: um estudo de base populacional / Self-reported hearing impairment and occupational exposure to hazardous noise and ototoxic agents: a population-based study / Dificultad auditiva autoinformada y exposición ocupacional a agentes otoagresores: un estudio de base poblacional

O objetivo deste estudo foi estimar a associação entre dificuldade auditiva autorreferida e exposição ocupacional a agentes otoagressores em trabalhadores brasileiros. Trata-se de um estudo transversal realizado com dados da Pesquisa Nacional de Saúde (PNS-2013). A variável dependente foi a dificuldade auditiva autorreferida, e foram analisadas três exposições principais: ruído, poeira industrial e substâncias químicas. Realizou-se análise de regressão logística, estimando-se as odds ratio (OR) brutas e ajustadas, com intervalos de 95% de confiança (IC95%). As variáveis principais de exposição foram ajustadas entre si e pelas covariáveis sexo, idade, ambiente de trabalho, tempo de trabalho e hipertensão arterial. Participaram deste estudo 36.442 trabalhadores. Maior prevalência de dificuldade auditiva foi observada em indivíduos expostos à poeira industrial (9,9%) (p < 0,001). Além disso, quanto maior a idade do trabalhador e tempo de trabalho, maior foi a prevalência do desfecho (p < 0,001). Na análise ajustada, trabalhadores expostos a ruído apresentaram 1,65 vez mais chance de referir dificuldade auditiva, quando comparados aos indivíduos não expostos (p < 0,001). O mesmo ocorreu com trabalhadores expostos à poeira industrial (OR = 1,36) (p = 0,012). Não foi observada associação entre o desfecho e a variável exposição a substâncias químicas (p = 0,120). Observou-se associação entre dificuldade auditiva e exposição ocupacional a ruído e à poeira industrial em trabalhadores brasileiros. Reforçam-se a importância do aprimoramento de políticas públicas em saúde auditiva e o desenvolvimento de ações voltadas à prevenção e ao monitoramento auditivo em ambiente ocupacional.

This study's objective was to estimate the association between self-reported hearing impairment and occupational exposure to hazardous noise and ototoxic agents in Brazilian workers. This was a cross-sectional study with data from the Brazilian National Health Survey (PNS-2013). The dependent variable was self-reported hearing impairment, and three principal exposures were analyzed: noise, industrial dust, and chemical substances. Logistic regression was performed, estimating crude and adjusted odds ratios (OR) with 95% confidence intervals (95%CI). The principal exposure variables were adjusted for each other and by covariables sex, age, workplace, time on the job, and hypertension. 36,442 workers participated in the study. Higher prevalence of hearing impairment was seen in workers exposed to industrial dust (9.9%) (p < 0.001). The older the worker and the longer the time on the job, the higher the prevalence of hearing impairment (p < 0.001). In the adjusted analysis, workers exposed to noise showed 1.65 higher odds of reporting difficulty hearing, when compared to unexposed individuals (p < 0.001). The same was true for workers exposed to industrial dust (OR = 1.36) (p = 0.012). No association was observed between the outcome and exposure to chemical substances (p = 0.120). There was an association between hearing impairment and occupational exposure to noise and industrial dust in Brazilian workers. This emphasizes the importance of strengthening public policies for hearing health and the development of measures for prevention and auditory monitoring in the workplace.

El objetivo de este estudio fue estimar la asociación entre dificultad auditiva autoinformada y la exposición ocupacional a agentes otoagresores en trabajadores brasileños. Se trata de un estudio transversal, realizado con datos de la Encuesta Nacional de Salud (PNS-2013). La variable dependiente fue la dificultad auditiva autoinformada y se analizaron tres exposiciones principales: ruido, polvo industrial y substancias químicas. Se realizó un análisis de regresión logística, estimándose las odds ratio (OR) brutas y ajustadas, con intervalos de un 95% de confianza (IC95%). Las variables principales de exposición fueron ajustadas entre sí y por las covariables: sexo, edad, ambiente de trabajo, tiempo de trabajo e hipertensión arterial. Participaron en este estudio 36.442 trabajadores. La mayor prevalencia de dificultad auditiva se observó en individuos expuestos al polvo industrial (9,9%) (p < 0,001). Asimismo, cuanto mayor era la edad del trabajador y tiempo de trabajo, mayor fue la prevalencia del desenlace (p < 0,001). En el análisis ajustado, los trabajadores expuestos a ruido presentaron 1,65 veces más oportunidad de informar de dificultad auditiva, cuando se comparan con los individuos no expuestos (p < 0,001). Lo mismo sucedió con trabajadores expuestos a polvo industrial (OR = 1,36) (p = 0,012). No se observó una asociación entre el desenlace y la variable exposición a sustancias químicas (p = 0,120). Se observó una asociación entre dificultad auditiva y exposición ocupacional a ruido y polvo industrial en trabajadores brasileños. Se refuerza la importancia del perfeccionamiento de políticas públicas en salud auditiva y desarrollo de acciones dirigidas a la prevención y monitoreo auditivo en el entorno laboral.

Occupational health risk assessment of dust in cement production enterprises / 预防医学

Objective@#To evaluate the occupational health risk of key posts exposed to cement dust in four cement production enterprises, and to provide reference for cement pneumoconiosis prevention and control. @*Methods@#Four Chinese typical cement enterprises and key posts exposed to cement dust were selected to carry out occupational health investigation and detection, and three risk assessment methods were used to assess their occupational health risk levels, including semi-quantitative comprehensive index method, semi-quantitative contact ratio method and risk rating method of International Mining and Metal Commission ( ICMM ). Meanwhile, the differences and consistencies among different assessment methods were compared. @*Results@#Dust free silica content ranged from ( 4.70±2.01 ) % to ( 5.63±2.48 ) %,and the total and respirable dust concentrations exposed by bagged cement loaders and cement baggers exceeded Chinese permissible concentration-time weighted average（ PC-TWA ）. The results of semi-quantitative comprehensive index method showed that all the types of work were at high risk of total and respirable dust, while the results of the other two assessment methods showed that bagged cement loaders and cement baggers were at a extremely high or intolerable risk. There were no significant differences among three risk assessment methods whether in terms of total dust or respirable dust ( P>0.05 ). ICMM risk rating method and contact ratio method showed highly positive correlation in term of respirable dust ( rs=0.894, P=0.016 ), but not in term of total dust ( rs=0.733, P=0.097 ). However, the correlations of comprehensive index method with the other two methods were unable to conduct.@*Conclusion@#Bagged cement loaders and cement baggers are at high occupational health risk levels. Moreover, semi-quantitative contact ratio method and ICMM risk rating method have high positive correlation in term of respirable dust, the applicability of comprehensive index method still needs further study.

Occupational health examination results of dust exposed workers in Binhai New Area of Tianjin in 2019 / 公共卫生与预防医学

Objective To investigate the occupational health status of dust exposed workers in Binhai New Area of Tianjin, and to provide a scientific basis for the formulation of occupational disease prevention strategies. Methods On-duty physical examination data of dust exposed workers in Binhai New Area in 2019 were collected, and data processing and statistical analysis were conducted by Excel 2016 and SPSS22.0. Results A total of 20 898 dust exposed workers were included in the physical examination in 2019. Among them, 158 were abandoned in the examination of posterior-anterior high kV chest X-ray or digital radiography (DR) chest X-ray, 14 were abandoned in the examination of lung function, and a total of 20 726 were included in the final examination. Thirty-seven cases (0.18%) were found to be suspected of pneumoconiosis, 51 cases (0.25%) were found to be contraband, and 15 cases (0.072%) were found to be pneumoconiosis. The detection rate of abnormal chest radiograph was 4.73%, and the detection rate of abnormal lung function was 6.99%. Conclusion The detection rates of abnormal chest X-ray and pulmonary function of dust exposed workers in this area are rising with the increase of exposure time. Attention should be paid to the prevention of occupational pneumoconiosis by promoting the publicity and education of dust workers in large enterprises, strengthening the management of occupational health in collective enterprises, especially for older workers with long working years.

The epidemiological characteristics of welders' pneumoconiosis in Tianjin in 2001-2020 / 公共卫生与预防医学

Objective To analyze the epidemiological characteristics of welders' pneumoconiosis cases reported from 2001 to 2020 in Tianjin, and to provide a scientific basis for formulating prevention and control strategies for welders' pneumoconiosis. Methods A database was established based on the data of all welders' pneumoconiosis cases reported in Tianjin from 2001 to 2020，and SPSS 24.0 software was used for statistical analysis. Results (1) From 2001 to 2020，there were 376 cases of welders' pneumoconiosis reported in Tianjin，with 356 new cases (91.05%). There were fewer progressed and death cases, which were 13 and 7 cases, respectively; (2) The number of new cases showed a trend of increasing firstly and then decreasing with the reporting year. The dust-exposure years were concentrated from 1970 to 1989，with the number of cases accounting for 69.94% of the total; (3) The median dust-exposure year of welders' pneumoconiosis new cases from 2001 to 2020 was 25.92 years. The median diagnosis age was 54.30 years old，which increased with the reporting year（F=20.23，5.13，P0.05）; (5) The main industries were general and professional equipment manufacturing industry and ferrous metal smelting and rolling processing industry. Conclusion The incidence of new cases of welder pneumoconiosis in Tianjin is relatively low and has significantly decreased in recent five years. The age of diagnosis and length of service for dust exposure are on the rise, indicating that the incidence of pneumoconiosis among welders has been effectively controlled. However, the impact of welding fumes on workers' health cannot be ignored. The control and engineering governance should be strengthened to reduce the impact of welding fumes on workers' health, and to achieve the goal of ultimately eliminating welders' pneumoconiosis.

Investigation and analysis of occupational hazards in dust related enterprises in Tianjin / 公共卫生与预防医学

Objective To understand the occupational hazards of dust related enterprises in Tianjin, and to provide a scientific basis for formulating regulatory policies and effectively curbing the high incidence of pneumoconiosis. Methods The basic situation of the enterprise, the occupational health management status, and the occupational health status of the workers were described and analyzed. Results Most of the enterprises exposed to dust in Tianjin were small and micro enterprises, manufacturing enterprises and private enterprises. The reporting rate of occupational hazard items was uneven (P < 0.01). As the scale of the enterprise decreased, the comprehensive training rate of occupational health, the training rate of enterprise leaders, the training rate of occupational health management personnel, the comprehensive implementation rate of occupational hazard detection and the detection rate decreased accordingly (P < 0.01). Conclusion Tianjin should focus on the supervision of small and micro enterprises, strengthen the occupational health training of small and micro enterprises, and implement hierarchical and effective supervision for enterprises of different sizes in different regions. Meanwhile, enterprises should bear the main responsibility of occupational health, so as to ensure the continuity of occupational health management measures such as occupational hazard detection and occupational health inspection.

Analysis of respiratory dust hazard in 20 coal mining enterprises of a mining group / 中国职业医学

OBJECTIVE: To analyze the hazardous status of respiratory dust in coal mining enterprises. METHODS: A total of 20 coal mining enterprises in a mining group were selected as the research subjects using a cluster random sampling method. Respiratory dust in the workplace was detected, and the incidence of pneumoconiosis was investigated. RESULTS: The dust types in the workplace of these 20 coal mining enterprises were mainly coal dust and silica dust. The posts with serious coal dust hazard were coal mining and tunneling posts. The M(P_0-P_(100)) of the exposure concentration of time weighted average(C_(TWA)) were 2.38(0.19-14.21) and 2.73(0.49-9.57) mg/m~3. The over-standard rate was 49.2% and 50.0%, respectively, that was higher than the post of gangue selection(all P<0.05 or all P<0.017). The results of short time exposure concentration of short term(C_(STE)) and the over-standard rate were higher in the coal mining and tunneling posts than those of gangue selection and boiler room post(all P<0.05 or all P<0.008). The most serious post with silica dust hazard was the tunneling post, and the M(P_0-P_(100))of C_(TWA) was 1.30(0.38-8.50) mg/m~3, and the over-standard rate was 85.7%. The detection results and over-standard rate of C_(STEL) were higher in the coal mining and tunneling posts than that of boiler room post(all P<0.01). The coal dust over-standard rate of C_(TWA) in workplaces of coal mining enterprises increased from 2015 to 2018(P<0.05). However, there was no significant difference in the over-standard rate of silica dust C_(TWA) in different years(P>0.05). From 2015 to 2018, the incidence of pneumoconiosis was 0.3%, 0.3%, 0.2% and 0.3% respectively, and the patients were all from coal mining and tunneling posts. CONCLUSION: The supervision, management and treatment of respiratory dust hazard in coal mining and tunneling posts should be strengthened to protect the health of workers.

Prediction of occupational coal workers′ pneumoconiosis incidence by a multi-layer perceptron neural network model / 中国职业医学

OBJECTIVE: To construct and verify the incidence prediction model of occupational coal workers′ pneumoconiosis(CWP) in coal mine workers exposed to dust(hereinafter referred to as ″dust exposure″) based on a multi-layer perceptron(MLP) neural network, and explore its application value in predicting CWP incidence. METHODS: A total of 17 023 dust exposed workers in a coal mining group in Hebei Province from 1970 to 2017 were selected as the research subjects by a typical sampling method. Among them, 839 patients were confirmed as CWP and 16 185 workers did not suffered from CWP. The MLP neural network model was established with the incidence of CWP as the target output variable, and the type of work, age, beginning year of dust exposure, observation year(i.e. incubation period) and cumulative dust exposure as the input variable. The receiver operating characteristic(ROC) curve was used to evaluate the predictive ability of the built model. The established model was used to predict the high-risk group and key monitoring group population of CWP in dust-exposed workers in the following 10 years. RESULTS: There were 44 synapses in the hidden layer of the established MLP neural network model. The area under ROC curve was 0.91. The accuracy, sensitivity and specificity of the model were 92.7%, 74.8% and 93.6%, respectively. In the validation samples, the accuracy, sensitivity and specificity were 92.1%, 70.5% and 93.2%, respectively. The MLP neural network model was used to predict 1 534 workers with high risk of CWP in the following 10 years, and the individuals were located. The number of workers in need of actively monitored was 7 599. Among them, it is predicted that the incidence of CWP in different types of dust exposed workers in the following 10 years from high to low is tunneling worker, coal miner, mixing worker and auxiliary worker(P<0.01). The earlier the dust exposure began, the higher the risk of CWP(P<0.01). CONCLUSION: The MLP neural network model based on the type of work, age, beginning year of dust exposure, incubation period and cumulative dust exposure has a good performance in predicting the incidence of CWP in coal mine dust exposure workers, and can provide a reference for early preventive management measures to prevent and cure CWP.

Investigation on skills of using dust mask in dust-exposed workers of civil metal ship manufacturing enterprises / 中国职业医学

OBJECTIVE: To analyze the skills of using dust mask in the dust-exposed workers in civil metal ship manufacturing enterprises. METHODS: A total of 123 dust-exposed workers in a civil metal ship manufacturing enterprise were selected as the research subjects using convenience sampling method. Dust Mask Using Situation and Maintenance Questionnaire was used to investigate the use of dust masks, and the tightness of using dust mask was measured by the tightness tester. RESULTS: The median, and the 0 th-100 th percentiles[M(P_0-P_(100))] of the dust mask use time in the workers was 3.0(1.0-3.0) months, and the M(P_0-P_(100)) of filter element use time was 1.0(0.5-2.0) workdays. The subjects did not disinfect the masks after use. Only 36.6%(45/123) of workers regularly cleaned dust masks during use. There was 62.6%(77/123) of workers who failed to correctly perform negative pressure air tightness check by themselves. A total of 112 workers carried out tightness test, and the pass rate of those who passed the tightness test for the first time was 62.5%(70/112). The median, and the 25 th and 75 th percentiles [M(P_(25), P_(75))] of fit factor(FF) in the 70 qualified workers was 835.0(503.0, 1 635.0). After retests, the overall tightness test pass rate was 66.1%(74/112), and the M(P_(25), P_(75)) of FF in the 74 qualified workers was 786.0(477.7, 1 532.2). The reasons for failure of tightness test were the mismatch of the mask and face size, wrong wearing methods and long beard. CONCLUSION: Some of the dust-exposed workers in the civil metal ship manufacturing enterprises did not use the dust mask correctly. The dust mask configuration and the use and maintenance training should be strengthened, and the tightness test should be carried out regularly to improve workers′ skills in using dust masks.

Analysis of surveillance results of key occupational diseases in Nanning City, 2015-2019 / 中国职业医学

OBJECTIVE: To analyze the distribution characteristics of surveillance results of key occupational diseases in Nanning City.METHODS: The occupational health monitoring data of key occupational diseases of Nanning City from 2015 to 2019 were collected using judgment sampling method and analyzed by descriptive epidemiology method. RESULTS: A total of 38 cases of key occupational diseases were reported in Nanning City during the past 5 years.The main diseases were occupational pneumoconiosis and occupational noise-induced deafness(ONID). The rate of occupational health examination was 40.06%, showing an increasing trend with the increase of years(P<0.01). The detection rate of occupational pneumoconiosis was higher than that of ONID(0.19% vs 0.01%, P<0.01). However, the abnormal detection rate of occupational health special examination in noise-exposed workers was higher than that in dust-exposed workers(10.98% vs 0.35%, P<0.01). The detection rate of pneumoconiosis-like changes in dust-exposed workers was the highest in private enterprises(P<0.01). The detection rate of binaural high frequency average hearing threshold ≥40 dB was highest in small and micro enterprises and private enterprises(all P<0.01). The detection rate of blood lead level >400 μg/L was 24.75%, and 98.80% of the abnormal workers were concentrated in medium-sized foreign-funded enterprises. The detection rates of abnormal leukocyte, neutrophil and platelet counts in benzene-exposed workers were 1.17%, 3.21% and 0.26% respectively. CONCLUSION: Among the key occupational disease risk factors in Nanning City, the number of workers exposed to dust and noise is relatively high, which results in serious consequences and harm. But the hazards of lead and benzene cannot be ignored. Emphasis should be placed on strengthening the supervision and management of key occupational diseases in small and medium-sized micro-enterprises and private enterprises.

Research advances on silica dust induced-autoimmune diseases and its mechanism / 中国职业医学

Silica dust is one of the main occupational hazards in various industries. In addition to causing occupational silicosis, silica dust can also stimulate innate and acquired immunity and induce autoimmune diseases(AID) such as systemic lupus erythematosus, rheumatoid arthritis, systemic sclerosis, and antineutrophil cytoplasmic antibody(ANCA)-associated vasculitis. Silica dust exposure can induce changes in the levels of autoantibodies in vivo, such as rheumatoid factor, antinuclear antibody, ANCA, anti-centromere antibody, anti-topoisomerase Ⅰ antibody, anti-desmoglein antibody, anti-centromere antigens-B antibody, anti-carbamylated protein antibody, anti-smooth muscle antibody and anti-glomerular basement membrane antibody. At present, the mechanism of autoimmune disorders induced by silica dust has not yet been fully elucidated. The current research suggests that it is related to cell apoptosis of alveolar macrophages, the disorder of the Fas/Fas ligand system, the imbalance of T cell proportion, and the dysregulation of T helper cell(Th) 1 and Th2 type cytokines homeostasis. Understanding the pathogenesis of autoimmune disorders induced by silica dust and exploring possible therapeutic targets will provide new ideas for the treatment of silicosis.

Analysis on active surveillance results of occupational pneumoconiosis in Beijing in 2019 / 中国职业医学

OBJECTIVE: To analyze the active surveillance results of occupational pneumoconiosis(hereinafter referred to as “pneumoconiosis”) in Beijing in 2019. METHODS: A total of 2 634 dust exposed workers were recruited as the active surveillance subjects by judgment sampling method. The abnormalities and influencing factors of High kV or digital photography of posterior-anterior chest radiography(hereinafter referred to as “chest radiography”) and lung function were analyzed. RESULTS: The detection rate of abnormal chest radiograph and pulmonary dysfunction were 14.0%(368/2 634) and 6.6%(175/2 634), respectively. The multivariate logistic regression analysis showed that the risk of abnormal chest radiograph in dust-exposed workers increased with age(P<0.01). Mining and construction workers had higher risk of abnormal chest radiograph than manufacturers(all P<0.05). The risk of abnormal chest radiograph of dusk-exposed workers in state-owned and foreign enterprises was higher than that of workers in private enterprises(P<0.05). The risk of pulmonary dysfunction was increased with age and length of dust exposure(all P<0.05). Workers exposed to silica dust and aluminum dust had higher risks than those exposed to welding dust(all P<0.01). The risk of pulmonary dysfunction of workers in small and micro enterprises was higher than that of workers in large enterprises(all P<0.01). Mining workers had higher risks of pulmonary dysfunction than manufacturing workers(P<0.05). CONCLUSION: Age, length of dust exposure, dust type, industry type, enterprise scale and economic type were the influencing factors of lung injury of dust exposed workers. Therefore, the supervision of key population and industries should be strengthened to reduce the occurrence of pneumoconiosis.

Investigation on the current status of silica dust hazard in workplaces in Jiangxi Province / 中国职业医学

OBJECTIVE: To analyze the current status of silica dust hazard in workplaces of Jiangxi Province. METHODS: The level of silica dust in the air of workplaces, occupational health examination of the dust-exposed workers and diagnosis of occupational disease in 1 557 enterprises in Jiangxi Province were investigated and analyzed. RESULTS: The 1 557 enterprises were included in eight industries, and the main types of enterprises were non-coal mining, ceramic products manufacturing and stone processing industry(a total of 85.16%). There were 4 029 jobs/positions that were involved in exposure to silica dust in these workplaces. Among them, the exposure concentration of time weighted average(C_(TWA)) of total dust and respirable dust exceeded 21.52% and 20.55%, respectively. The posts where the total dust and respirable dust that exceed the standard were found in the quartz sand processing industry, non-ferrous metal smelting industry and stone processing industry, that were the top three among the eight industries(all P<0.01). Among the 828 posts with C_(TWA) of respiratory dust exceeding the standard, the C_(TWA) exceeding rate of mild-, moderate-and high-hazardous jobs were 3.87%(156/4 029), 1.66%(67/4 029) and 15.02%(605/4 029), respectively. Among 23 643 dust-exposed workers, the detection rates of occupational contraindications and suspected silicosis were 2.06% and 1.51%, and the prevalence of silicosis was 1.21%. CONCLUSION: Silica dust hazard in workplaces of quartz sand processing industry, non-ferrous metal smelting industry and stone processing industry are serious in Jiangxi Province. The supervision and management of occupational health should be further strengthened to guarantee the occupational health of workers.

Occupational dust exposure-related chronic obstructive pulmonary disease: a bibliometric and visual analysis / 中国职业医学

OBJECTIVE: To analyze the current status and research hotspots of occupational dust exposure-related chronic obstructive pulmonary diseases(COPD). METHODS: Publications were searched and collected from the CNKI, SinoMed, PubMed and EMBASE. The high frequency key words were visually analyzed using NoteExpress V3.0 and VOSviewer 1.6.10, and content analysis was used to analyze research hotspots. RESULTS: A total of 3 095 COPD publications related to occupational dust exposure were retrieved. The first paper on COPD was published in 1973 in Chinese literature, and the number of publications had been on the rise since 2006. A total of 410 journals and 980 research institutions had published relevant articles. The first paper on COPD was published in 1950 in English literature, with a peak in publication after 2014. A total of 523 journals and 109 countries or regions had published relevant articles. The results of keyword co-occurrence analysis showed that COPD studies related to dust exposure mainly focused on epidemiology, risk factors and clinical characteristics. CONCLUSION: The number of research papers on occupational dust exposure-related COPD has been on the rise. The research papers mainly focus on epidemiology, risk factors and clinical characteristics of COPD.