| Objective:Coke oven emissions is a kind of mixed pollutants produced in the process of coke production.Polycyclic aromatic hydrocarbons（PAHs）are the main occupational hazard factors leading to cancer and other health damage.Lung cancer caused by coke oven emissions is also one of the definitive occupational tumors.Long-term exposure to coke oven emissions can cause a series of occupational injuries,including lung cancer.Therefore,it is particularly important to carry out occupational health risk assessment for coke oven workers to help them identify risks and give early health hazard identification and assessment.At the same time,the occupational biological exposure limit is the main basis for the guidance of occupational exposure to chemical toxins and the main goal of risk assessment work.Compared with the concentration of environmental pollutants,the biological limit can better reflect the exposure of workers,because it can reflect the actual exposure of workers,so it is more accurate and intuitive.1-hydroxypyrene is an active metabolite of PAHs after exposure,which is metabolized by kidney and excreted in urine,and can be used as a marker of internal PAHs exposure.Urinary 1-hydroxypyrene（1-OHP）,as an exposure marker for coke oven workers,can effectively reflect the exposure level of PAHs in coke oven workers.However,there is no occupational limit of 1-OHP in China at present.There is also no international standard on the monitoring the 1-OHP in urines.Therefore,the guiding value of urinary1-hydroxypyrene is proposed to provide basis for the occupational protection of coke oven workers.Based on the above background,this study assessed the carcinogenic risk level of occupational PAHs exposure based on the environmental monitoring data of different types of work in coke oven operation,combined with the health risk assessment model of environmental pollutants widely used in the world,and the physiological and pharmacodynamic model in toxicology.By the epidemiological study on coke oven workers;we evaluated the baseline dose analysis of exposure markers and early oxidative damage markers.Combined with literature evidence,we systematically analyzed the biological limits of PAHs metabolites in urine,which can be used to guide the biological monitoring and health risk assessment of occupational population with PAHs exposure.Methods:The 473 male workers in a coking plant in East China and the103 male workers in an oxygen plant in the same area were selected.We collected workers’occupational history information and post-shift urine samples.Environmental samples were taken at different working sites in coking plants,and the fine particulate matter and polycyclic aromatic hydrocarbons were detected by weighing method and high-performance liquid chromatography.The concentrations of 1-hydroxypyrene and8-hydroxy 2 deoxyguanosine in urines were determined by gas chromatography-mass spectrometry.The carcinogenic risk of PAHs in different positions was compared and analyzed using the carcinogenic model of lifetime exposure and Air Q+software.Expose-related dose estimation model（ERDEM）was used to simulate the physiological and pharmacokinetics（PBPK）of human exposure to PAHs,and the carcinogenic risk of workers at different positions was assessed by the calculated internal dose.Epidemiological literature was collected with genotoxicity as the endpoint.At the same time,BMD model was used to model the baseline dose of urinary 1-hydroxypyrene and oxidative damage.Based on the comprehensive analysis of literature,a systematic reference threshold analysis of the biological monitoring limit of 1-hydroxypyrene in urine was carried out.Results:1.The median concentration of fine particles in the environment of the coking plant was 200.2μg/m3,and the median concentration of PAHs was 783.83ng/m3.From the perspective of PAH exposure,from high to low,they are furnace cover/riser foreman,coke transporter,coke pushing car driver,coal filling car driver,coke extinguishing car driver,furnace door repairman,coke blocking car driver,furnace operator,switch control.2.The assessment results of lifetime exposure model show that the furnace cover/riser position has the highest carcinogenic risk,with a risk value of 5.8*10-4,followed by the positions from highest to lowest,which are coke transporter,coal filling car driver,coke pushing car driver,coke extinguishing car driver,furnace door repairman,furnace operator,coke blocking car driver,switch control.The corresponding carcinogenic risks were 4.8*10-4,3.7*10-4,1.0*10-4,5.4*10-5,5.2*10-5,4.6*10-5,3.3*10-5,2.0*10-5,respectively.The carcinogenic risk of control workers was 5.8*10-7,and the carcinogenic risk of coke oven workers was much higher than that of oxygen workers.3.The results of Air Q+model shown that there are 336.54 carcinogenic cases of furnace cover/riser per 100000 man-years,280.33 carcinogenic cases of coke transporter per 100000 man-years,212.04carcinogenic cases of coal filling car driver per 100000 man-years,63.41 carcinogenic cases of coke pushing car driver per 100000 man-years,31 carcinogenic cases of coke extinguishing car driver per 100000 man-years,30.03 carcinogenic cases of furnace door repairman per 100000 man-years,26.67 carcinogenic cases in the positions of manufacturers per 100000 man-years,18.84 carcinogenic cases in the positions of drivers of coke per 100000 man-years,11.5 carcinogenic cases in the positions of switch control per 100000 man-years,and 0.33 carcinogenic cases in the control workers per 100000 man-years during the same period.4.The simulation results of physiologic and pharmacological metabolic dynamics model showed that the concentration of benzo[a]pyrene in the venous blood of furnace cover/riser,coke transporter,coal filling car driver,coke pushing car driver,coke extinguishing car driver,furnace door repairman,furnace operator,coke blocking car driver,switch control was 47ng/L,36ng/L,26.8ng/L,8.1ng/L,3.9ng/L,3.8ng/L,3.4ng/L,2.4ng/L,1.5ng/L,respectively.According to this calculation,the highest carcinogenic risk under internal exposure is the position of furnace cover/riser,and the lowest is the position of switch control.5.Urinary 1-hydroxypyrene level of coke oven workers was 0.68μmol/mol creatinine,and that of control workers was 0.03μmol/mol creatinine,the difference was statistically significant（P<0.001）;Urinary8-hydroxydeoxyguanosine level of coke oven workers was 0.81μmol/mol creatinine,while that of control workers was 0.56μmol/mol creatinine,and the difference was statistically significant（P<0.001）.Urinary 8-hydroxydeoxyguanosine level of coke oven workers was 0.81μmol/mol creatinine,while that of control workers was 0.56μmol/mol creatinine,and the difference was statistically significant（P<0.001）.6.On the basis of an analysis of the literature,an unobserved level of genotoxic effects（NOGEL）with gene damage as the endpoint was found,corresponding to a level of0.99μmol/mol creatinine of urinary 1-hydroxypyrene.7.After baseline dose modeling of urine 1-hydroxypyrene and urine 8-hydroxy 2 deoxyguanosine,the corresponding lower baseline dose level of urine 1-hydroxypyrene was calculated to be 1.06758μmol/mol creatinine.Conclusions:1.The occupational health risks of coke oven workers are relatively high,and they are closely related to their working positions,so it is necessary to pay attention to their health protection.2.Both Air Q+model and the physiologic and pharmacological metabolic dynamics model found that coke oven workers had a higher carcinogenic risk.3.Combined with literature and reference dose analysis,the recommended guideline value of urine 1-hydroxypyrene for coke oven workers is 1.0μmol/mol creatinine... |
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