Impact Of Smoking On The Concentrations Of Urinary10Metabolites Of Polycyclic Aromatic Hydrocarbons In Coke Oven Workers

Polycyclic aromatic hydrocarbons(PAHs) are a group of organic compounds that arecommonly found in the human living and working environment. Many studies have shownthat polycyclic aromatic hydrocarbons are associated with many cancers, cardiopulmonarydiseases, and obstructive pulmonary diseases. Coke oven emissions(COEs) are a group ofmixture produced when carbon is not completely burning in the progress of coking, containa mount of PAHs, Benzene, toluene, ethylbenzene and xylene, Benzene soluble matter, SO2,and CO2. Polycyclic aromatic hydrocarbons are the major component of the COEs.Polycyclic aromatic hydrocarbons also exist in the smoke produced when from burningtobacco. COEs and tobacco smoke are the important sources of PAHs we expose.Therefore, the smokers exposed to COEs in coke oven workers particularly need ourattention. Polycyclic aromatic hydrocarbons can enter the body through respiratory tract,skin. Once entered the body, PAHs are metabolized into monohydroxy polycyclic aromatichydrocarbons by a variety of enzymes, and then excreted via urine.Since urinary1-hydroxypyrene(1-PYR) has been found, it is considered as the bestbiomarker of evaluating PAHs exposure due to its high concentration in urine and itseasiness to detect. More and more biomarkers have come into our attentions with thedevelopment of detection technologies, such as1-hydroxynaphthalene(1-NAP),2-hydroxynaphthalene(2-NAP), and metabolites of fluorene and phenanthrene. These are good response of PAHs exposure levels, and were gradually used to evaluate occupationalPAHs exposure and PAHs exposure of smoke.Recently, people began to pay attention to whether tobacco somke can affect theconcentrations of urinary monohydroxy polycyclic aromatic hydrocarbons (OH-PAHs) incoke oven workers. However, findings are not consistent across studies. St.Hellen observedthe dose-response relationship between smoking amount and urinary OH-PAHs innon-occupational groups, while Pestch et.al have shown that the concentration of urinaryOH-PAHs are higher among smokers comparing to non-smokers within workers that wereexposed to vapours and aerosols of bitumen. However, other studies have also the differentresult. Bo Chen and Rossella found that the differences of urinary OH-PAHs betweensmokers and nonsmokers were not statistically significant., while Bo Chen did not findstatistically significant result in Coke oven workers. Only, Zhao ZH and Szaniszlo haveshowed the dose-response relationship between smoking amount and urinary1-PYR incoking sites workers.But they were lack of conviction because of only a few samples. Therewere limited data on coke oven workers that can prove the impact of smoking.This study recruited1401male coke oven workers from one Coking plant and dividedthem into four groups according to their workplaces and the different concentrations ofPAHs in the environment, namely Offices, Adjunct workplaces, Bottom and side, Top. Wecarried out occupational health examination for every worker from the four groups,collected their urine, and then detected the concentrations of the ten OH-PAHs in urinesamples with gas chromatography-mass spectrometry(GC-MS). We considered the currentsmokers as the smokers groups, and then compare the concentrations of the ten OH-PAHsbetween smokers and nonsmokers in each workplace group, so as to explore the impact ofsmoking on workers’ health.Our results showed that the concentrations of the ten OH-PAHs are different in t fourdifferent areas, the levels of OH-PAHs in the top were higher than the other groups. Among the ten OH-PAHs, we found significant positive correlations between each urinaryOH-PAHs and PAHs in workplaces environment(P<0.01) except4-hydroxyphenanthrene(4-PHE)(P=0.08). Comparing the ten OH-PAHs levels betweensmokers and nonsmokers, we found that the levels of1-NAP among smokers are higherthan nonsmokers with statistically significant(P<0.001) result in offices, adjunct workplaces,bottom and side groups. The ratios of the levels of OH-PAHs among smokers to that ofnonsmokers were1.68,1.58, and1.35, respectively. The levels of2-NAP among smokerswere higher in all four areas(P<0.01), and the ratios are2.83,2.24,1.85, and1.74,respectively. However, the levels of1-PYR had no statistically significant differencesbetween the four areas. In our study the concentrations of1-NAP and2-NAP had positivecorrelations with smoking amount in four groups(P<0.01), while this positive correlationwas only ovserved in the offices group for2-FLU(P=0.045), and no statistically significantcorrelations were observed for the levels of1-PYR among all four groups.In conclusion, the concentrations of urinary1-NAP and2-NAP have statisticallysignificant differences between smokers and nonsmokers in coke oven workers from thefour areas, but the1-PYR don’t show any statistically significant differences. The levels of1-NAP and2-NAP have significant positive correlations with smoking amount in the fourareas. This positive correlation was only observed in the offices group for2-FLU and nostatistically significant correlation was observed for the levels of1-PYR in each of the fourgroups.There are a number of strengths in this study. Firstly, so far there have been no studiesevaluated whether or not smoke affects the concentrations of urinary OH-PAHs in cokeoven workers from different workplaces with different levels of PAHs exposure. Secondly,we detected10urinary OH-PAHs to assess the impact of smoking on human health, whichprovided accurate assessment. However, there are some limitations in the study, such as, wedidn’t consider the impact of cooking on concentrations of urinary OH-PAHs, and we also did not consider the impact of diet on concentrations of urinary OH-PAHs.