Internal Exposure Dose And Cancer Risk Assessment Of Polycyclic Aromatic Hydrocarbons(PAHs) In Human Body

Owing to widespread distribution in the environment and highly mutagenic and carcinogenic features of some PAH species, PAHs have attracted many scientist attentions. Studies estimating internal exposure and demands on health become more and more important.Physiologically based pharmacokinetic(PBPK)model is mathematical description aims at developing mathematical method to describe the mechanism of chemical absorption, distribution, metabolism and excretion and then obtaining the internal doses. Dealing with PAHs,the model is associated with the multiple-path particle dosimetrymodel for particles. The incremental lifetime cancer riskmodel and Monte Carlo method are used for dose-response simulation and uncertaintyanalysis.(1)The PAHs absorption amount of children is different from that of adults; the former is larger than the later.(2)The highest BaPeq concentrations are observed in fatty tissues and accumulate differently in tissue compartments of various physiological and biochemical parameters.(3)The activity levels have positive impacts on the internal exposure levels:because of the physiological parameters; children have2times higher exposure level than adult in the same condition; the level of adults in light work is more than3times higher than in rest and the level of children playing is approximately3times higher than in rest.(4)The average intake per day per unit bodyweight of children is4times more than that of adults; the metabolic level of child(1.245ng/kgBwt) is much higher than adult(0.1951ng/kgBwt).(5)The value of incremental lifetime cancer risk(ILCR) of adults in rest is0.951×10-6, which may cause lifetime lose(LL) of59.12min; ILCR with light work is4.787×10-6and LL is297.56min. Considering the whole life exposure from childhood, the ILCR value is5.831×10-6and the LL value is362.46min.(6)The best fit of the forecast frequency is Beta distribution with the mean value of0.56, which indicates the importance of the randomness.(7)Dose and the cancer slope factor are the most important causes of uncertainty.Long-term exposure to low concentrations of PAHs will cause the accumulation of carcinogens and then threat human life and health. Children have much largerdoses than adults. The increase of activity levels causes the increase of doses.