Assessment Of Human Exposure And Health Risks From Polycyclic Aromatic Hydrocarbons And Their Hydroxyl Metabolites:Paired Serum And Urine Samples

Polycyclic aromatic hydrocarbons(PAHs)are a kind of persistent organic pollutants(POPs)which are composed of two or more benzene rings of carbon and hydrogen.PAHs are ubiquitous environmental pollutants,which are mainly generated by incomplete combustion of organic materials(such as coal,oil,gasoline,and wood),and the emissions from human activities are dominant.Studies have shown that many PAHs are toxic,mutagenic and carcinogenic.At the beginning,people often use the concentration of PAHs in air,water,food and other media to evaluate the human exposure to PAHs,which is called external exposure assessment.Although environmental monitoring will indicate the current level of PAHs in the environment and the possibility of exposure,biological monitoring will help to integrate the exposure from all sources,and can well estimate the risk of a single PAH poison or mixture.Although hydroxyl polycyclic aromatic hydrocarbons(OH-PAHs)in urine have been widely used to estimate human exposure to PAHs,1-OH-Pyr in particular,no study has examined the difference between using OH-PAHs in urine and PAHs in blood for such an assessment.Comparatively,the chemical concentration in blood is more stable than that in urine.In this study,the difference survey of serum PAHs and urine OH-PAH samples from 480 participants from a typical city in southern China was conducted to compare the differences among different influencing factors,and health risk assessment was also conducted to explore the differences between the two.The median serum concentration of PAHs was 4.01 ng/ml,which was lower than that of OH-PAHs in urine(8.33 ng/m L).However,pyrene in serum was significantly higher than its metabolite 1-hydroxypyrene in urine,likely because pyrene is difficult to metabolize.There was no significant correlation between maternal PAH isomers in serum and their urine metabolites except that phenanthrene was negatively correlated with its urine metabolites.Significant regional differences in serum PAHs were observed,but there were no significant differences in gender,age and BMI.However,urine concentrations of OH-PAHs differed significantly between regions,gender groups and BMI groups,except for age groups.The non-carcinogenic risks of pyrene based on both pyrene in serum and 1-hydroxypyrene in urine were found to be lower than one unit,indicating non-carcinogenic risk of pyrene can be ignored.However,the carcinogenic risks cannot be ignored since more than 20% of the participants exceeded the acceptable cancer risk level of 10?6.Overall,human exposure and health risks assessed using pyrene in serum were generally higher than 1-hydroxypyrene in urine.And the human exposure and health risks of pyrene estimated using urinary 1-hydroxypyrene were only 13.6% of those assessed using pyrene in serum,indicating that the risks may be underestimated when only considering urinary 1-hydroxypyrene.