[The cell nuclear damage probably induces chronic refractory diseases]

The cell nuclear damage is mainly caused by the radiation and various carcinogenic compounds, the essence of the damage is molecular adhesion fracture and chemical modification. After nuclear damage, the cells whose nuclei may be abnormal in morphology, structure and function, then become a kind of morbid cells or defective cells. The cell nuclear damage can affect gene expression and regulation, leading to dysfunctions or abnormalities of transcription and protein synthesis, which results in aging and induces various chronic refractory diseases, such as hypertension, atherosclerosis, diabetes, Alzheimer's disease, autoimmune diseases, and so on. The cell nuclear damage can also affect the state of cell differentiation and lead to restart of genes related to division and proliferation, thus inducing cancer. The cancer cells are derived from the cells with nuclear abnormalities, and the biological behavior or characteristics of cancer cells (shedding and metastasis, immune tolerance, uncontrolled, loss of contact inhibition, etc.) are derived from cells with nuclear abnormalities. This article reviewed the chronic refractory diseases caused by nuclear damage and their mechanisms, which provided a new idea for occupational health and toxicology research, as well as a new method and strategy for occupational disease prevention and treatment.

[Comparative analysis of work-related musculoskeletal disorders catalogues]

Work-related musculoskeletal disorders (WMSDs) refer to musculoskeletal disorders caused by work or work as the main cause, which are characterized by high prevalence and heavy burden of disease as a global problem. The classification and catalog of occupational diseases is of great significance for guiding the prevention and control of occupational diseases and safeguarding the rights and interests of workers. The types of WMSDs included in the list of occupational diseases vary greatly from country to country, and the regulations on specific pathogenic factors are also inconsistent. By sorting out and analyzing the lists and characteristics of WMSDs at home and abroad, and using the International Statistical Classification of Diseases and Related Health Problems (ICD-10) in occupational health to standardize of WMSDs in various countries, which would lay the foundation for future multi-country WMSDs occupational health registration and disease burden research, and provide a reference for China to revise the WMSDs list.

[Relationship between pesticide exposure and lipid metabolism in population]

Objective: To investigate the effect of pesticides and herbicides on lipid metabolism. Methods: In November 2020, Based on the data of the national health and Nutrition Survey (NHANES) (2011-2014) , select the population aged 20~65 who have demographic information, pesticide use and data of four lipid metabolism indicators [total cholesterol (TC) , triglyceride (TG) , high density lipoprotein cholesterol (HDLC) and low density lipoprotein cholesterol (LDLC) ] (n=3039) . The subjects were divided into insecticide group (320 people) and non insecticide group (2719) according to the use of insecticides, and herbicide group (156 people) and non herbicide group according to the use of herbicides. Results: Among the 3039 subjects, the males and female were 1509 (49.7%) and 1530 (50.3%) respectively. The males age was (39.7±12.0) years and the females age was (40.2±12.0) years The concentration of HDLC in the NHANES (55.4±15.0) mg/dl was lower than that of (58.2±14.2) mg/dL in the non herbicide group (P<0.05) (b=-0.044, P<0.05) . The results showed that the use of herbicides was related to the decrease of HDLC and the increase of LDLC and LDLC/HDLC in female population (b=-0.050, 0.062, 0.067, all P<0.05) . Conclusion: Herbicide exposure can cause the change of lipid metabolism, and the effect on female population is more obvious.

[Pisussion on noise exposure level measurement and risk assessment of typical posts in coal-fired power plants]

Objective: To study the group noise exposure level of typical coal-fired power plants and explore the establishment of risk assessment methods for noise exposed posts. Methods: In April 2020, 295 typical workers in 11 coal-fired power plants were selected as the study subjects. The noise exposure dose of typical posts and the proportion of exposure groups under different exposure doses were analyzed, and the risk assessment based on the dose-response relationship was conducted. Results: The exposure level of typical noise posts in coal-fired power plants was (84.24±4.10) dB (A) , and the over-standard rate was 44.07% (130/295) . The highest noise over-standard rate in main posts were desulfurization inspectors (51.52%) , followed by steam turbine inspectors (47.92%) and belt inspectors (46.32%) . Taking 30 years as an example, the incidence rate of occupational noise deafness of noise-exposed posts in coal-fired power plants was 12.30%. The position with the highest incidence rate was belt inspector (13.21%) , followed by steam turbine inspector (12.97%) , desulfurization inspectors (12.42%) , boiler inspectors (11.59%) and chemical water inspectors (6.89%) . Conclusion: The risk of noise exposure in coal-fired power plants is relatively high. Comprehensive control measures are recommended to effectively reduce the risk of noise deafness.

[Screening of candidate genes related to low-dose ionizing radiation based on transcriptome-proteome correlation research techniques]

Objective: To identify the related genes of low-dose ionizing radiation on basis of association analysis of transcriptome and proteome data, and provide new clues for the molecular mechanism of low-dose radiation (LDR) effect. Methods: In March 2018, healthy human peripheral blood was used as materials for transcriptome sequencing and proteome analysis after exposure to radiation at 150 mGy (treatment group) and no radiation (control group) , with three samples in each group. The total RNA and protein were extracted and then correlation analysis of transcriptomic and proteomic were performed to determine LDR effect-related genes, and after that, the biological process and molecular function were analyzed. Results: A total of 486 genes and 266 proteins were identified differentially expressed between treatment group and control group, respectively. Twelve genes and related proteins were found correlated (P<0.05) . The overall correlation between quantitative protein and gene was low (r_s=0.0034) , the differential gene with the same change trend was positively correlated with protein expression (r_s=0.6786) , and the differential gene with the opposite change trend was negatively correlated with protein expression (r_s=-0.1000) . Seven differentially expressed genes (DEGs) showed the same trend as proteins, among which FBXO7 and SNCA were up-regulated as well as ORM1, ORM2, HIST1H4J, HBZ and LYZ were down-regulated. Five DEGs showed the opposite trend as proteins, including SLC4A1, BCAM, C4B_2, KEL, TGM2 up-regulated in transcription level and down-regulated in protein expression level. These DEGs were involved in various biological processes such as immune system regulation, signal transduction, enzyme activity regulation, transmembrane transport, defense, transcription and DNA repair, which indicated their important roles in response to LDR in human peripheral blood. Conclusion: Twelve candidate genes related to LDR effect and their corresponding expressed proteins are screened by the correlation research of transcriptome and proteome data, which provides new clues for the further study of the mechanism of LDR effect.

[Metabolomics study of urine with Benzene, Toluene and Xylene combined exposure based on ultra performance liquid chromatography-quadrupole time-of-flight mass spectrometry]

Objective: To study the effects of combined occupational exposure of benzene, toluene, and xylene on human metabolism at an overall level, and to screen biomarkers related to the combined occupational exposure of benzene, toluene, and xylene, and to explore the mechanism of early health effects preliminarily caused by combined occupational exposure of benzene, toluene, and xylene by identification of biomarkers and retrieval of metabolic pathways. Methods: A shoe-making company was selected as the research site. Twenty subjects for the exposed group and the control group were selected separately, and urine of the subjects was collected. The metabolic profiles of the samples were collected by liquid chromatography time-of-flight mass spectrometry, and professional metabolomics and multivariate statistical analysis software were used to establish PCA and OPLS-DA analysis models to screen potential biomarkers and identify biomarkers. Finally, based on the dynamic changes and trends of potential biomarkers between groups, the mechanism of body damage caused by benzene, toluene, and xylene was initially explored. Results: Urine metabolomics analysis showed that the metabolic profile of urine samples of the benzene, toluene, and xylene combined exposure group was different from that of the control group. 27 potential biomarkers that were closely related to the combined exposure of benzene, toluene, and xylene were screened and identified. These potential biomarkers were enriched in 16 metabolic pathways, of which 3 pathways were significantly enriched (P<0.05) , respectively, lysine metabolism, amino sugar metabolism, and nucleotide sugar metabolism. Conclusion: The metabonomics method can well reflect the changes in the metabolome of urine samples in the occupational population after the combined exposure of benzene, toluene, and xylene, which will help us better evaluate the risk of combined exposure of benzene, toluene, and xylene and prevent and control their health risks.

[Investigation and analysis of occupational hazards and control measures in waste incineration power generation enterprises]

Objective: To investigate occupational hazards in waste incineration power generation enterprises. Methods: From May 2016 to September 2018, four garbage incineration power generation enterprises in different regions and scales were selected as the survey objects. Investigated and analyzed the types of occupational hazards, workplace distribution and occupational disease prevention facilities and the concentration (intensity) of major types of work and workplace occupational hazards were also improved Line detection and analysis. Results: Silica dust could be seen in slag tank, slag sorting and crusher operation position. The concentration of silica dust in each workplace fluctuates within 0.3-1.1 mg/m(3). Both the concentration of silica dust in the workplace and the time weighted average allowable concentration (C-TWA) of dust exposure of dust exposed workers were detected, but none of them exceeds the requirements of the national occupational exposure limit. Carbon monoxide, ammonia, nitrogen dioxide, hydrogen sulfide, non methane total hydrocarbon, formaldehyde, hydrogen fluoride, hydrogen cyanide, hydrochloric acid, sodium hydroxide and ozone were detected, but all meet the requirements of national occupational exposure limit. The 8-hour equivalent a sound level (L(ex·8h)) over 85 dB (A) mainly includes boiler, steam turbine, electrical inspector and auxiliary value of water treatment. Conclusion: The occupational hazards of waste incineration power generation enterprises are serious. Occupational health management and occupational health monitoring to reduce their occupational hazards to workers.

[Determination of seven urinary metabolites of benzene, toluene and xylene by ultra-high performance liquid chromatography-triple quadrupole mass spectrometry]

Objective: To develop a method using ultra-high performance liquid chromatography-triple quadrupole mass spectrometry to determine the urinary metabolites of benzene, toluene and xylene. The selected metabolites are S-phenylmercapturic acid (S-PMA) , trans, trans-muconic acid (t, t-MA) , 8-hydroxy-2 deoxyguanosine (8-OHdG) , hippuric acid (HA) , 2-methylhippuric acid (2-MHA) , 3-methylhippuric acid (3-MHA) and 4-methylhippuric acid (4-MHA) . Methods: The urine sample was pretreated using methanol to precipitate the proteins. HSS T3 chromatographic column was used to separate the metabolites. The mass spectrometric acquisition was carried out using multiple reaction monitoring (MRM) after ionization with ESI source. External standard method was used for quantification. Results: All the standard curves showed good linear relation, and r of the seven metabolites was all above 0.999. The detection limits and quantitative limits of the seven metabolites were 0.01-500 ng/ml and 0.02-1 000 ng/ml (based on the actual dilution ratio) , respectively. The average spiked recoveries of four loadings ranged from 85.8% to 109.9%. The intra-day and inter-day precisions were 0.2%-4.5% and 0.6%-9.5%, respectively. The samples can be kept for at least 14 days at both 4 ℃ and -20 ℃. Conclusion: This method is simple, rapid and highly sensitive with low cost, and its accuracy, precision and stability can meet the daily test requirements. It can be applied for the determination of urinary S-PMA, t, t-MA, 8-OHdG, HA, 2-MHA, 3-MHA and 4-MHA for the occupational population exposed to benzene, toluene and xylene.

[Determination of Cortisol in Saliva by Liquid Chromatography Tandem Mass Spectrometry]

Objective: To establish a liquid chromatography tandem mass spectrometry method to determine the cortisol in saliva. Methods: Take 0.5 ml saliva sample into a 2 ml centrifuge tube, add excess sodium chloride and 1ml acetonitrile to it, then vortex for 3 min, centrifuge for 10 min at 15 000 r/min, and take 800 μl of the upper layer to another centrifuge tube. Finally, the sample was concentrated by a vacuum concentrator and brought to 200 μl with the initial mobile phase. Then, the sample was analyzed by liquid chromatography tandem mass spectrometry. The target compound was quantified by external standard curve method. Results: The linear range of the method was 0.02-5.00 ng/ml, r=0.999 9, the method limit of the detection was 0.002 ng/ml, the method limit of quantitative was 0.02 ng/ml, and the spiked recoveries were 89.60%-98.60%. The intra-assay precision was 1.90%-3.30%, and the inter-assay precision was 4.20%-9.00%; samples could be stored at -20 °C for at least 14 days. The determination of cortisol could not be interfered by other endogenous substances in the sample. Conclusion: The method is simple in pretreatment, high sensitivity, good reproducibility and good recovery, and it is suitable for the quantitative analysis of cortisol in saliva for normal and occupationally stressed populations.