ABSTRACT
OBJECTIVE: To observe the levels of four hydroxylated metabolites of polycyclic aromatic hydrocarbons(PAHs)in the urine of coke workers and its influencing factors.To explore the feasibility of using PAHs as biomarkers for exposure of coke oven emissions(COEs).METHODS: A cross-sectional survey was used to compare 261 coke oven workers in a coke oven plant as exposure group with 111 workers without COEs exposure in an oxygen making plant as control group.Ultra high liquid chromatography-mass spectrometry was used to detect four hydroxylated metabolites of PAHs,including1-hydroxypyrene(OHP),1-hydroxynaphthalene(OHN),2-OHN and 3-hydroxyphenanthrene,in urine of these two groups.RESULTS: The levels of four hydroxylated metabolites of PAHs in urine in exposure group were higher than that of the control group(P<0.01).The levels of urinary 1-OHP,1-OHN,2-OHN were followed by the sequence of bottomoven,side-oven,and top-oven subgroups among the exposure group(P<0.05).The multiple linear regression results indicated that the levels of urinary 1-OHP,1-OHN,2-OHN were correlated with COEs exposure(P<0.05),after adjusting the confounding factors of gender,age,length of service,smoking status and alcohol drinking status.The levels of urinary 1-OHP,1-OHN,2-OHN of the exposure group increased with the increase of COEs exposure levels showing a dose-effect relationship(P<0.01).The levels of 1-OHN and 2-OHN were associated with smoking apart from COEs exposure(P<0.01).CONCLUSION: The urinary 1-OHP can be used as a reliable biomarker for the evaluation of internal exposure to COEs.The 1-OHN and 2-OHN can be used as adjuvant biomarkers.
ABSTRACT
OBJECTIVE: To compare and analyze the risk of formaldehyde hazards in a plywood manufacturing factory using two risk assessment methods,and to evaluate the occupational health risk. METHODS: Occupational health investigation and formaldehyde detection for workplaces were carried out in a plywood manufacturing factory in Shandong province. The risk ratings of different posts were assessed by US Environmental Protection Agency( EPA) inhalation risk( EPA assessment model) and Singapore Semi-quantitative Assessment Model( MOM assessment model). The risk classification results of the 2 risk assessment methods were compared and analyzed. RESULTS: The concentration of airborne formaldehyde on the positions of shaving,woods feeding,gluing,hot milling,hot pressing,sanding and reprocessing were 0. 25,0. 13,1. 47,0. 72,0. 92 and 0. 58 mg/m~3,respectively. By the EPA assessment model,all of the positions were evaluated as high carcinogenic risk. Through the MOM assessment model,the feeding position was evaluated as medium risk,the positions of shaving,hot milling,hot pressing sanding and reprocessing were high risk,and the position of gluing was higher risk. CONCLUSION: It suggests that there is a high formaldehyde exposure in several posts in the plywood production processing. EPA assessment model is a suitable for occupational health risk assessment for formaldehyde exposure.
ABSTRACT
OBJECTIVE: To establish the cell model using human leukemia cell line HL-60 for exposure of coke oven emissions( COE) in vitro and to explore the mechanism of COE-induced acute toxicity in HL-60 cells. METHODS: HL-60 cells were collected in their logarithmic growth phase and cultured in medium that had final concentrations of COE in 2. 5,5. 0,10. 0 and 20. 0 mg / L for 24 hours. Cell survival rate was examined by CCK-8 assay. The cytotoxicity was evaluated using lactate dehydrogenase release assay. Reactive oxygen species( ROS) production was determined by the 2',7'-dichlorofluorescein diacetate and nitroblue tetrazolium method. The activation of nuclear factor-κB( NF-κB) pathway was evaluated by western blot. RESULTS: With the increasing exposure concentrations of COE,the cytotoxicity of HL-60 cells increased( P < 0. 01),the cell survival rate decreased( P < 0. 01),intracellular ROS decreased( P < 0. 01),whereas extracellular ROS increased( P < 0. 01). These changes had a dose-effect relationship. The levels of phospho-nuclear factor-kappa B p65 and phospho-inhibitor of kappa Bα were higher in all the COE-treated cells compared with untreated cells( P < 0. 05),with no dose-effect relationship. CONCLUSION: COE could cause acute toxicity in HL-60 cells in a doseeffect relationship. The mechanism may be related to the COE-induced in-balanced ROS release and removal,leading to the activation of NF-κB pathway. HL-60 cells can be used as a common cell line for COE hematotoxicity analysis.
ABSTRACT
Objective@#To investigate the association between etheno-DNA adduct and the promoter of DNA methylation levels of cyclin dependent kinase inhibitor 2A (P16), Ras association domain family 1 (RASSF1A) and O-6-methylguanine-DNA methyltransferase (MGMT) in workers with occupational exposure to diesel engine exhaust (DEE).@*Methods@#We recruited 124 diesel engine testing workers as DEE exposure group and 112 water pump operator in the same area as control group in Henan province in 2012 using cluster sampling. The demographic data were obtained by questionnaire survey; urine after work and venous blood samples were collected from each subject. The urinary etheno-DNA adducts were detected using UPLC-MS/MS, including 1,N6-etheno-2'-deoxyadenosine (εdA) and 3,N4-etheno-2'-deoxycytidine(εdC). The DNA methylation levels of P16, RASSF1A, and MGMT were evaluated using bisulfite-pyrosequencing assay. The percentage of methylation was expressed as the 5-methylcytosine (5mC) over the sum of cytosines (%5mC). Spearman correlation and multiple linear regression were applied to analyze the association between etheno-DNA adducts and DNA methylation of P16, RASSF1A, and MGMT.@*Results@#The median (P25-P75) of urinary εdA level was 230.00 (98.04-470.91) pmol/g creatinine in DEE exposure group, and 102.10 (49.95-194.48) creatinine in control group. The level of εdA was higher in DEE exposure group than control group (P<0.001). DNA methylation levels of P16, RASSF1A and MGMT were 2.04±0.41, 2.19 (1.94-2.51), 2.22 (1.94-2.46)%5mC in exposure group, and 2.19±0.40, 2.41 (2.11-2.67), 2.44 (2.15-2.91)%5mC in control group. DNA methylation levels were lower in exposure group (P values were 0.005, 0.002 and 0.001, respectively). Spearman correlation analysis showed that DNA methylation levels of P16, RASSF1A, and MGMT were negative associated with urinary εdA level (r values were -0.155, -0.137, and -0.198, respectively, P<0.05). No significant correlation was observed between the εdC level and any measured DNA methylation levels (P>0.05) . Multiple linear regression confirmed the negative correlation between εdA and DNA methylation levels of P16, RASSF1A, and MGMT in non-smoking group (β (95%CI) was -0.068 (-0.132--0.003), -0.082 (-0.159--0.004) and -0.048 (-0.090--0.007), P values were 0.039, 0.039 and 0.024, respectively). Moreover, εdC was negative associated with DNA methylation level of MGMT in non-smoking group (β (95%CI) was -0.094 (-0.179--0.008), P=0.032).@*Conclusion@#DEE exposure could induce the increased of εdA and decreased of DNA methylation levels of P16, RASSF1A and MGMT.
ABSTRACT
<p><b>OBJECTIVE</b>To estimate the reference value for micronucleus frequency of peripheral blood lymphocytes in general Chinese population, and to guide the genotoxicity evaluation and risk analysis for populations exposed to environmental or occupational chemicals.</p><p><b>METHODS</b>A fulltext search was performed in CNKI with the key words of "micronucleus" and "human", and PubMed was searched with "cytokinesis-block micronucleus","CBMN","humans", and "adults", to obtain the articles published at home and abroad from 2001 to 2014 in which cytokinesis-block micronucleus (CBMN)assay was applied for micronucleus detection and populations not exposed to genotoxins were established as a control. Monte Carlo simulation was performed based on the micronucleus frequency, standard deviation, and sample size provided in these articles to calculate the micronucleus frequency for general population and to analyze the influence of sex, smoking, and drinking on micronucleus frequency.</p><p><b>RESULTS</b>A total of 23 articles were included in the final analysis. The minimum mean micronucleus frequency was 0.39‰, and the maximum mean micronucleus frequency was 25.3‰. There were 1623 subjects in the control group in total (range 22~178, mean 70.6). Monte Carlo simulation was performed 100 times, and the mode of micronucleus frequency was 0 or 1‰; the values of P0, P25, P50 , P75, and P95 were 0‰, 1‰, 2‰~3‰, 5‰~6‰, and 14‰~19‰, respectively; the mean value was 4.36‰(range 4.22‰~4.57‰). With the application of one-sided 95% range(x±1.64 s), the upper limit of the range of reference value was calculated to be 13.46‰~14.75‰.</p><p><b>CONCLUSION</b>The micronucleus frequency of peripheral blood lymphocytes in general Chinese population is 4.36‰, the interquartile range is 1‰~5‰ or 1‰~6‰, and the upper limit of reference value is 14.17‰. The factors of living area, sex, smoking, and drinking may influence micronucleus frequency.</p>
Subject(s)
Adult , Humans , Alcohol Drinking , DNA Damage , Environment , Lymphocytes , Pathology , Micronucleus Tests , Monte Carlo Method , Mutagens , Reference Values , Sex Factors , SmokingABSTRACT
Adverse outcome pathway (AOP) was a conceptual construct that integrated existing knowledge concerning the pathway of causal linkages between a molecular initiating event (MIE) and a final adverse effect at individual or population levels. The AOP methodology could be used as a basis for effects extrapolation and was an approach towards providing a framework for collecting and evaluating relevant chemical, biological and toxicological information. The framework would play an important role in risk assessment. We reviewed the concept of AOP, the development and assessment of the framework and the established models in toxicology researches. And the prospects and challenges of its application in toxicology were also introduced.
Subject(s)
Research Design , Risk Assessment , Toxicology , MethodsABSTRACT
<p><b>OBJECTIVE</b>To systematically evaluate the environmental exposure information of coke oven workers, we investigated the concentration and size distribution characteristics of the particle matter (PM) in the top working area of coke oven.</p><p><b>METHODS</b>The aerodynamic particle sizer spectrometer was employed to collect the concentration and size distribution information of PM at a top working area. The PM was divided into PM ≤ 1.0 µm, 1.0 µm < PM ≤ 2.5 µm, 2.5 µm < PM ≤ 5.0 µm, 5.0 µm < PM ≤ 10.0 µm and PM>10.0 µm based on their aerodynamic diameters. The number concentration, surface area concentration, and mass concentration were analyzed between different groups. We also conducted the correlation analysis on these parameters among groups.</p><p><b>RESULTS</b>We found the number and surface area concentration of top area particulate was negatively correlated with particle size, but mass concentration curve showed bimodal type with higher point at PM = 1.0 µm and PM = 5.0 µm. The average number concentration of total particulate matter in the top working area was 661.27 number/cm³, surface area concentration was 523.92 µm²/cm³, and mass concentration was 0.12 mg/m³. The most number of particulate matter is not more than 1 µm (PM(1.0)), and its number concentration and surface area concentration accounted for 96.85% and 67.01% of the total particles respectively. In the correlation analysis, different particle size correlated with the total particulate matter differently. And the characteristic parameters of PM2.5 cannot fully reflect the total information of particles.</p><p><b>CONCLUSION</b>The main particulate matter pollutants in the top working area of coke oven is PM1.0, and it with PM(5.0) can account for a large proportion in the mass concentration of PM. It suggest that PM1.0 and PM(5.0) should be considered for occupational health surveillance on the particulate matter in the top area of coke oven.</p>
Subject(s)
Humans , Air Pollutants, Occupational , Coke , Occupational Exposure , Particle Size , Particulate Matter , WorkplaceABSTRACT
<p><b>OBJECTIVE</b>To investigate the cell proliferation and genome stability in workers with occupational exposure to diesel exhaust (DE).</p><p><b>METHODS</b>In 2012, 117 DE-exposed workers and 106 control workers were recruited by cluster sampling in this study. The demographic data were obtained by questionnaire survey. The airborne fine particle and enriched polycyclic aromatic hydrocarbons (PAHs) at different workplaces were collected and analyzed. The concentrations of main PAHs monohydroxy metabolites in the urine were determined by high performance liquid chromatography-mass spectrometry (LC-MS), which could reflect the internal exposure level of DE. The cell proliferation capacity and genome stability in the periphery lymphocytes of workers were evaluated by cytokinesis-block micronucleus (CBMN) cytome assay.</p><p><b>RESULTS</b>The concentrations (median (P5-P95)) of total PAHs monohydroxy metabolites in the urine of exposed group and control group were 12.96 (4.73-28.10), 4.76 (0.90-15.00) µg/L, respectively, and the exposed group was higher than that of controls (Z = -8.77, P < 0.001). The nuclear division index (NDI) of exposed group and control group was 1.68±0.13, 1.85±0.16, respectively, and the NDI of exposed group showed significantly decreased (t = 8.86, P < 0.001), while the genome instability index calculated by micronucleus, nuclear bridges and nuclear buds, of exposed group and control group was 13.27±6.26, 4.83±3.38, respectively, and the exposed group had statistically significant increase (Z = -10.08, P < 0.001). The tertiles of total PAHs monohydroxy metabolites in the urine were categorized into low, medium and high groups (<5.96, 5.96-12.46, >12.46 µg/L). With the NDI decreased, 1.81±0.17, 1.79±0.17, 1.68±0.14 (F = 13.14, P < 0.001), genome instability index began to increase 5.80±4.15, 9.97±7.14, 11.99±6.61 (/1 000), respectively (χ(2) = 36.74, P < 0.001). With the increase of total PAHs monohydroxy metabolites level in corresponding groups. In addition, the NDI was negatively correlated with the frequencies of micronucleus, nuclear bridges, nuclear buds and genome instability index, respectively, and the difference was statistically significant (P < 0.001).</p><p><b>CONCLUSIONS</b>DE exposure lead to inhibition of cell proliferation capacity and increase genome instability in the peripheral lymphocytes of occupational-exposed population, providing important clues and evidence for early biomarkers monitoring.</p>
Subject(s)
Humans , Biomarkers , Cell Proliferation , Chromatography, Liquid , Genomic Instability , Lymphocytes , Micronucleus Tests , Occupational Exposure , Particulate Matter , Polycyclic Aromatic Hydrocarbons , Surveys and Questionnaires , Vehicle Emissions , WorkplaceABSTRACT
<p><b>BACKGROUND</b>Chronic exposure to n-hexane can lead to peripheral neuropathy that no effective treatment regimen could be applied presently. This study investigated whether myelin protein zero (P0) protein and its antibody could be used to distinguish n-hexane intoxication and protect workers from peripheral neuropathy.</p><p><b>METHODS</b>We compared P0 protein and its antibody among three levels of n-hexane-exposed groups, which included 18 patients with n-hexane-induced peripheral neuropathy as case group, 120 n-hexane-exposed workers as n-hexaneexposed control group, and 147 non-hexane-exposed participants used as control group. ELISA method was applied to detect P0 protein and its antibody.</p><p><b>RESULTS</b>P0 protein in serum was significantly higher in the case group and n-hexane-exposed control group in comparison with the control group (P < 0.01). Compared with the n-hexane-exposed control group, the case group also had significant increase of P0 protein (P < 0.01). After 6 months therapy, P0 protein was observed to decrease significantly in the case group (P < 0.01). The P0 antibody in serum was significantly higher in the n-hexane-exposed control group than in the control group (P < 0.01), but not significantly different between cases and controls.</p><p><b>CONCLUSIONS</b>P0 antibodies in serum may be a short-term effect biomarker for n-hexane exposure. P0 protein in serum may be an early effective biomarker for peripheral nerve neuropathy and its biological limit value needs investigation in the future study.</p>
Subject(s)
Adult , Female , Humans , Male , Young Adult , Antibodies , Blood , Allergy and Immunology , Cross-Sectional Studies , Hexanes , Toxicity , Myelin P0 Protein , Blood , Allergy and Immunology , Peripheral Nervous System Diseases , Blood , Allergy and ImmunologyABSTRACT
<p><b>OBJECTIVE</b>The aim of this study was to investigate the use of the lesion-specific endonucleases-modified comet assay for analysis of DNA oxidation in cell lines.</p><p><b>METHODS</b>DNA breaks and oxidative damage were evaluated by normal alkaline and formamidopyrimidine-DNA-glycosylase (FPG) modified comet assays. Cytotoxicity were assessed by MTT method. The human bronchial epithelial cell (16HBE) were treated with benzo (a) pyrene (B(a)P), methyl methanesulfonate (MMS), colchicine (COL) and vincristine (VCR) respectively, and the dose is 20 µmol/L, 25 mg/ml, 5 mg/L and 0.5 mg/L for 24 h, respectively. Oxidative damage was also detected by levels of reactive oxygen species in treated cells.</p><p><b>RESULTS</b>Four genotoxicants give higher cytotoxicity and no significant changes on parameters of comet assay treated by enzyme buffer. Cell survival rate were (59.69 ± 2.60) %, (54.33 ± 2.81) %, (53.11 ± 4.00) %, (51.43 ± 3.92) % in four groups, respectively. There was the direct DNA damage induced by test genotoxicants presented by tail length, Olive tail moment (TM) and tail DNA (%) in the comet assay. The presence of FPG in the assays increased DNA migration in treated groups when compared to those without it, and the difference was statistically significant which indicated that the clastogen and aneugen could induce oxidative damage in DNA strand. In the three parameters, the Olive TM was changed most obviously after genotoxicants treatment. In the contrast group, the Olive TM of B(a) P,MMS, COL,VCR in the contrast groups were 22.99 ± 17.33, 31.65 ± 18.86, 19.86 ± 9.56 and 17.02 ± 9.39, respectively, after dealing with the FPG, the Olive TM were 34.50 ± 17.29, 43.80 ± 10.06, 33.10 ± 12.38, 28.60 ± 10.53, increased by 58.94%, 38.48%, 66.86% and 68.21%, respectively (t value was 3.91, 3.89, 6.66 and 3.87, respectively, and all P < 0.05), and the correlation between Olive TM and reactive oxygen species was better than other parameters (r = 0.77, P < 0.05).</p><p><b>CONCLUSION</b>This study indicates that FPG-comet assay appears more specific for detecting oxidative DNA damage induced by genotoxicants exposure, and the application of comet assay will be expanded. The endonuclease modified comet assay will be used widely in the toxicology and molecular epidemiology study.</p>
Subject(s)
Humans , Cell Line , Comet Assay , Methods , DNA Damage , Endonucleases , Mutagens , Toxicity , Oxidation-Reduction , Oxidative Stress , Reactive Oxygen Species , MetabolismABSTRACT
OBJECTIVE To find the infla mmation bio markers induced by coke oven e missions (COE),we investigated the changes of T helper 17 (Th17 )cytokines in hu man bronchial epithelial (16HBE)cells.METHODS 16HBE cells were exposed to organic extracts of COE collected fro m co-king plant at the concentrations of 5,10 and 20 mg·L -1 for 24 h or 5 d to establish short-term and long-term cell models,respectively.Cell viability was measured by MTT assay and infla mmatory da mage was assessed by lactate dehydrogenase assay (LDH).The cytokines in culture supernatant sa mples was detected by co mmercial hu man Th17 cytokine panel kit.RESULTS COE Can induce infla mmation in COE 20 mg·L -1 group and no expression on IL-17 F and IL-1 β.The concentration of IL-10 was 1 .25 ± 0.54,1 .39 ±0.13 and (1 .90 ±0.73)pg·mL -1 in COE 5,10 and 20 mg·L -1 group showing good con-centration-effect relationship (r=0.98,P <0.05 ).IL-23 expression was found only higher at 10 and 20 mg·L -1 and the concentrations were 3.38 ±3.90 and (1 .74 ±2.00 )pg·mL -1 ,respectively.In 16HBE cells treated by COE for 5 d,elevated expression of IL-17A was found in COE 5 and 10 mg·L -1 group,and there was statistically sigificant difference between COE 10 mg·L -1 and DMSO group (P<0.05).Elevated concentration of IL-17F of 10.2 ±1 1 .78 and (6.79 ±7.84)pg·mL -1 was found in COE 5 and 10 mg·L -1 group.The concentration of IL-10 was 1 .71 ±0.02,1 .49 ±0.25 and (2.82 ± 0.33)pg·mL -1 in COE 5,10 and 20 mg·L -1 group,respectively.We found increased IL-1 βexpression with concentration of 2.72 ±0.62,2.25 ±0.33 and (0.93 ±0.21 )pg·mL -1 in COE 5,10 and 20 mg·L -1 group with negative dose-response relationship.We also found more elevated TNF-αlevels in the 5 d than in the 24 h model with no COE specific relationship.CONCLUSION COE induces expression changes of Th17 cytokines profile in 16HBE cells,including IL-23 and IL-1 βfor early and long-term infla mmation,respectively.IL-10 may be a candidate marker for population study on COE induced infla mmatory injury.
ABSTRACT
<p><b>OBJECTIVE</b>To investigate the role of myelin protein zero (P(0)) in 2,5-hexanedione (2,5-HD)-induced peripheral nerve injury, and the protective effect of Ginkgo biloba extract (Egb761) on 2,5-HD-induced toxic peripheral neuropathy.</p><p><b>METHODS</b>After 4 weeks of treatment with 2,5-HD at different doses (50, 100, 200, 400 mg/kg) in rats, changes in the levels of P(0) in rat sciatic nerves was investigated, and the effect of Egb761 on 2,5-HD-induced toxic peripheral neuropathy was studied.</p><p><b>RESULTS</b>The blood-nerve barrier (BNB) permeability of the sciatic nerve increased, and the expression of P(0) mRNA and P(0) protein decreased in a dose-dependent manner after treatment with 2,5-HD for 4 weeks. Pretreatment with Egb761 protected against BNB interruption, and inhibited P(0) mRNA and protein reduction during 2,5-HD treatment. Pretreatment with Egb761 significantly reduced loss of body weight (P<0.01) and mitigated gait abnormalities (2.85±0.22) induced by 400 mg/kg 2,5-HD (P<0.01). It also reduced the signs of neurotoxicity induced by 2,5-HD.</p><p><b>CONCLUSION</b>2,5-HD inhibited the expression of P(0) in a dose-dependent manner, and this may be an important mechanism by which toxic peripheral neuropathy is induced by 2,5-HD. Egb761 has a protective effect against 2,5-HD-induced peripheral neurotoxicity in rats.</p>