OBJECTIVETo investigate the characteristics of exposure to iron oxide nanoparticles in workplace.

METHODSThe real-time particle number (NC), surface area (SAC), and mass (MC) concentrations of nanoparticles were measured in various locations of a selected workplace manufacturing iron oxide nanoparticles. The collected particles were analyzed for morphology and elemental composition.

RESULTSThe average NCs and SACs in milling site (16,566 pt/cm3, 106.082 µm2/cm3), packaging site (12,386 pt/cm3, 89.861 µm2/cm3), shipping site (13,808 pt/cm3, 102.071 µm2/cm3), and product storage room (17,192 pt/cm, 115.044 µm2/cm3) of the yellow powder (α-Fe2O3 . nH2O) were all significantly higher than the workplace background concentrations (11,420 pt/cm3, 85.026 µm2/cm3) (all P<0.05). The NC was highly correlated with the SAC (r= 0.784), while both NC and SAC were loosely correlated with the MC (r1=0.323, r2=0.331). Scanning electron microscopy revealed a spindle-like shape of the iron oxide nanoparticle; the chemical composition of the collected particles contained 19.33 weight percent iron (Fe).

CONCLUSIONThe milling site and product storage room of the yellow powder are exposed to a higher concentration of nanoparticles, which are mainly composed of iron oxide nanoparticles. The NC is highly correlated with the SAC.

Hepatocellular carcinoma (HCC) has an insidious onset, and most HCC patients have reached the intermediate-advanced stage when they were diagnosed, which lead to missing the opportunity for radical treatment and suffering a poor prognosis. Conversion therapy is an important tool to improve the prognosis of patients with unresectable HCC by creating resectable opportunities. With the new targeted agents, anti-vascular agents, immune agents and multi-dimensional treatment regimens bringing high objective response rate and long duration of remission in HCC treatment, conversion therapy has emerged as a hot spot in the clinical research of HCC. In the era of targeted therapy combined with immunotherapy, the connotation of conversion therapy for HCC continues to expand, with strategies constantly being updated. As such, conversion therapy for HCC has entered a rapid development period, but still faces many challenges. Combined with clinical experience and the latest research progress, based on the efficacy of systematic therapy with targeted combined immunotherapy as the core and combined local therapy in advanced HCC, the authors summarize the definition and expansion of conversion therapy and the conversion therapy strategies in oncology.

Biomonitoring can be applied to assess internal exposure and environmental exposure by exposure markers with providing internal exposure to biological characterization and individual exposure information, which is a key tool to evaluate the risk exposure to disease by biological alternation information. With the development of high throughput, broad spectrum and high efficiency screening and detection technology, biomonitoring is defined as traditional biological monitoring (targeted monitoring) and non targeted monitoring analysis (exposomic approaches). An exposomic approach differs from traditional biomonitoring in that it can theoretically include all exposures of potential health significance, whether they are derived from exogenous sources. Both traditional and nontraditional biomonitoring methods should be used to understand the complexity of exposures faced throughout the lifespan. Through hybrid approaches, emerging techniques and the integration of bioinformatics, and developing the detection methods for low abundance chemicals, improving the differentiation ability between endogenous and exogenous chemical, the health outcomes and exposures can be widely recognized and characterized, which can finally contribute to improving the precise prevention and intervention for diseases under the new exposomic model.

OBJECTIVETo develop a method for determination of 2, 4-dichlorophenoxyacetic acid (2, 4-D) in the air of workplace by high-performance liquid chromatography.

METHODS2, 4-D was collected by ultrafine glass filters, desorbed by methanol, separated by a C18 column, and detected by a UV detector. Identification and quantification of 2, 4-D were performed by retention time and peak areas, respectively.

RESULTSThe linear range of the test was 2∼200 µg/ml; the elution efficiency was 94.6%- 95.9%; the limit of detection (S/N = 3) was 0.034 µg/ml (injection volume of 20 µl eluant); the lower limit of quantification (S/N = 10) was 0.11 µg/ml; the minimum detectable concentration was 0.011 mg/m(3); the minimum quantifiable concentration was 0.037 mg/m(3) (with sampled air volume of 45 L).

CONCLUSIONThis method is convenient and simple in sample collection and preparation, and satisfies all methodological requirements. Therefore, this method is useful for the determination of 2, 4-D in the air of workplace.

Objective To explore and validate suitable risk assessment methods for titanium dioxide though applying three risk assessment tools for nanomaterials based on the control banding (CB) approach.Methods A factory manufacturing titanium dioxide in Jinan city,Shandong province,was assessed using a quantitative exposure method and qualitative risk assessment methods in September,2014.A condensation particle counter equipment was used to monitor the number concentration of particles at packaging workshop and jet milling workshop.We employed three control banding tools,including CB nanotool,Stoffenmanager nano and the Guidance on working safely with nanomaterials and nanoproducts (GWSNN) to evaluate the two workshops,then compared the evaluation results.Results The increases of particle concentrations were generated directly by packaging and jet milling processes,the number concentration from (3.52± 1.46)× 104/cm3 to (14.70±8.86) ×104/cm3 at packaging workshop and from (0.97±0.25) ×104/cm3 to (1.26±0.35) ×104/cm3 at milling workshop (both P＜0.05).The number concentrations at packaging workshop were higher than those at jet milling workshop during both manufacturing and break times (both P＜0.05).The results of CB nanotool showed that the risk level of the packaging workshop was classified as high and the risk level of the jet milling workshop was classified asmedium.The results of Stoffenmanager nano showed that the risk level of the packaging workshop was classified as medium and the risk level of the jet milling workshop was classified as low.The results of GWSNN showed that the risk level of packaging workshop was classified as high and the risk level of jet milling workshop was classified as low.Conclusion The results of evaluation based on the three control banding tools are related and aligned with the results of quantitative monitoring,so they are all suitable to perform occupational health risk assessment on industrial scale production of titanium dioxideto some extent.

Objective To explore and validate suitable risk assessment methods for titanium dioxide though applying three risk assessment tools for nanomaterials based on the control banding (CB) approach.Methods A factory manufacturing titanium dioxide in Jinan city,Shandong province,was assessed using a quantitative exposure method and qualitative risk assessment methods in September,2014.A condensation particle counter equipment was used to monitor the number concentration of particles at packaging workshop and jet milling workshop.We employed three control banding tools,including CB nanotool,Stoffenmanager nano and the Guidance on working safely with nanomaterials and nanoproducts (GWSNN) to evaluate the two workshops,then compared the evaluation results.Results The increases of particle concentrations were generated directly by packaging and jet milling processes,the number concentration from (3.52± 1.46)× 104/cm3 to (14.70±8.86) ×104/cm3 at packaging workshop and from (0.97±0.25) ×104/cm3 to (1.26±0.35) ×104/cm3 at milling workshop (both P＜0.05).The number concentrations at packaging workshop were higher than those at jet milling workshop during both manufacturing and break times (both P＜0.05).The results of CB nanotool showed that the risk level of the packaging workshop was classified as high and the risk level of the jet milling workshop was classified asmedium.The results of Stoffenmanager nano showed that the risk level of the packaging workshop was classified as medium and the risk level of the jet milling workshop was classified as low.The results of GWSNN showed that the risk level of packaging workshop was classified as high and the risk level of jet milling workshop was classified as low.Conclusion The results of evaluation based on the three control banding tools are related and aligned with the results of quantitative monitoring,so they are all suitable to perform occupational health risk assessment on industrial scale production of titanium dioxideto some extent.

Objective:To explore the self-conscious health status and related influencing factors of greenhouse agricultural workers in Beijing suburb, so as to provide scientific basis for developing strategies to improve and promote the occupational health conditions of those workers.Methods:According to the production characteristics and scale of the main agricultural districts or counties in the suburb of Beijing, 182 agricultural production personnel were randomly selected to investigate the general situation, occupational situation and self-conscious health status during June 2018 to December 2019. The relevant factors which may affect the self-conscious health conditions were also analyzed by statistical methods.Results:The detection or reported rate of self-conscious health problems was 51.6% (94/182) , among which 29.1% (53/182) workers reported musculoskeletal disorder diseases and 21.4% (39/182) workers reported nervous system diseases. And the self-conscious health status of greenhouse agricultural workers were statistically different in household registration, gender, marital status, working years, mixing or spraying pesticides, smoking or eating in the greenhouse ( P<0.05) . Moreover, gender, mixing or spraying pesticide, eating and smoking behavior in the workplace all had an impact on the risk of self-conscious health status of greenhouse agricultural workers ( P< 0.05) . Specifically, male is the protective factor to reduce the occurrence of self-conscious symptoms of greenhouse agricultural workers ( OR=0.447, 95% CI: 0.234~0.852) , while mixing or spraying pesticides and smoking or eating behaviors in the workplace are the risk factors ( OR=1.055, 2.524; 95% CI: 0.503~2.210, 1.107~5.755) . Conclusion:Reducing pesticide use from the source thus minimize related exposure opportunities, strengthening occupational health education thus foster good hygienic habits and improve individual protection consciousness are of great significance for the health protection of greenhouse agricultural workers in Beijing suburb.

To meet the requirement from the economy and society, China's emergency rescue has been developing towards specialization and professionalization. The working environment for emergency responders is special accompanying with tremendous challenges and uncertainties. To promote the research on occupational health and personal protection is an important guarantee for the workers in China to realize the goal of "decent work". This paper reviews the hazards that affect the occupational health of emergency rescue workers, the research progress of adverse outcomes caused from exposure to these hazards, and the related development issues of personal protection. In order to ensure the safety and health of emergency rescue workers, the direction of further research on occupational health of emergency rescue workers is put forward.

To meet the requirement from the economy and society, China's emergency rescue has been developing towards specialization and professionalization. The working environment for emergency responders is special accompanying with tremendous challenges and uncertainties. To promote the research on occupational health and personal protection is an important guarantee for the workers in China to realize the goal of "decent work". This paper reviews the hazards that affect the occupational health of emergency rescue workers, the research progress of adverse outcomes caused from exposure to these hazards, and the related development issues of personal protection. In order to ensure the safety and health of emergency rescue workers, the direction of further research on occupational health of emergency rescue workers is put forward.

Objective:To explore the self-conscious health status and related influencing factors of greenhouse agricultural workers in Beijing suburb, so as to provide scientific basis for developing strategies to improve and promote the occupational health conditions of those workers.Methods:According to the production characteristics and scale of the main agricultural districts or counties in the suburb of Beijing, 182 agricultural production personnel were randomly selected to investigate the general situation, occupational situation and self-conscious health status during June 2018 to December 2019. The relevant factors which may affect the self-conscious health conditions were also analyzed by statistical methods.Results:The detection or reported rate of self-conscious health problems was 51.6% (94/182) , among which 29.1% (53/182) workers reported musculoskeletal disorder diseases and 21.4% (39/182) workers reported nervous system diseases. And the self-conscious health status of greenhouse agricultural workers were statistically different in household registration, gender, marital status, working years, mixing or spraying pesticides, smoking or eating in the greenhouse ( P<0.05) . Moreover, gender, mixing or spraying pesticide, eating and smoking behavior in the workplace all had an impact on the risk of self-conscious health status of greenhouse agricultural workers ( P< 0.05) . Specifically, male is the protective factor to reduce the occurrence of self-conscious symptoms of greenhouse agricultural workers ( OR=0.447, 95% CI: 0.234~0.852) , while mixing or spraying pesticides and smoking or eating behaviors in the workplace are the risk factors ( OR=1.055, 2.524; 95% CI: 0.503~2.210, 1.107~5.755) . Conclusion:Reducing pesticide use from the source thus minimize related exposure opportunities, strengthening occupational health education thus foster good hygienic habits and improve individual protection consciousness are of great significance for the health protection of greenhouse agricultural workers in Beijing suburb.