The Transmission Of Polycyclic Aromatic Hydrocarbons Between Mother And Fetus And Its Relationship With Pathological Pregnancy

Polycyclic aromatic hydrocarbons(PAHs)are typical environmental pollutants which are widely present in the environment,are hard to degrade,can migrate over long distances in a variety of environmental medias.PAHs are widely eoneerned because of their immunotoxicity,neurotoxicity,reproductive and developmental toxicity as well as their three effects(teratogenic,carcinogenic and mutagenic).The previous studies were focused on occupational exposure or the special populations,while non-special exposure groups were ignored.Our research aims to measure the concentrations of 16 kinds of US EPA priority PAHs in the maternal blood,placenta and umbilical cord blood samples from the non-special exposed population in Kunming and its surrounding areas,to analyse the differences among the PAHs concentrations from the three types of human tissues by the use of gene polymorphism of PAHs metabolic enzymes system in maternal,to discuss the transfer potential of PAHs from mother to fetus.The impacts of PAHs on the morbidity of pregnancy complications and the effects of complications of pregnancy on the metabolism and transport of PAHs in the maternal-fetal system were discussed by the comparison among the concentrations of PAHs in pathological group,healthy group and the case group of different diseases or the same diseases in different periods of the three kinds of tissues.The results were found that:(1)In Kunming and its surrounding areas,the PAHs in non-special exposed population mainly derived from pyrolysis sources,which is mainly composed of high molecular weight compounds with high healthy risks.(2)The ratio pairs containing multiple elements should be selected in the diagnosis method for source analysis of PAHs in human body,such as low molecular weight PAHs/high molecular weight PAHs.(3)The sources of PAHs in human body should be determined by direct or first exposure organs.(4)The healthy risks of PAHs can be indicated not only from their concentrations,but also related to their origin and principal components.(5)The placental barrier could not protect fetuses from the transfer of low molecular weight PAHs,so that low molecular weight PAHs can have transplacental transfer from mother to the fetus;(6)Healthy placenta may have a barrier function for high molecular weight PAHs that can also hold and store high molecular weight PAHs,and pathological pregnancy may affect the barrier function of the placenta;(7)Daily exposure of low doses PAHs may not be the main cause of the morbidity of pregnancy complications,but the gestational diabetes,hypertensive disorders complicating pregnancy,premature delivery and other pathological pregnancy may affect the placental barrier function,changing the distribution,transmission and metabolism and enrichment of PAHs in the maternal and fetal tissues,which should be widely concerned.