Placental levels of polycyclic aromatic hydrocarbons and its association with preterm birth and redox status (GSH/MDA)

Abstract

Placental levels of polycyclic aromatic hydrocarbons and its association with preterm birth and redox status (GSH/MDA)Background: Earlier researches have shown association between prenatal environmental exposures specifically to polycyclic aromatic hydrocarbons (PAHs) and adverse health outcomes; however inconsistency lies in reported results and limited focus on women from developing nation India, which is ranked first for preterm birth. Thus, there is a mounting need to assess the presence of PAHs in human tissues and its further impact on adverse pregnancy outcomes. Method: Present study is a part of an ongoing cross-sectional study, collecting 166 placenta tissue samples immediately after delivery from North Indian pregnant women. A well structured questionnaire enclosing socio-demographic characteristics of women and sources of environmental and occupational exposures to PAHs were filled by researchers via face to face interviews. Processing of biochemical parameters (malondialdehyde and reduced glutathione) were done instantly after collection of placenta tissues, followed by extraction of 16 USEPA priority PAHs that were analyzed with the help of GC-MS. Results and conclusion: Benzo(a)pyrene (23.93%) and Chrysene (17.06%) were the most dominant PAHs detected, among all measured PAHs. In addition, high molecular weight PAHs were found to be in more prevalence in placenta tissue samples than low molecular weight congeners. Results of student’s t-test indicated that most PAHs (except acenaphthylene) were higher in mothers delivering preterm infants with significantly higher levels of benzo(b)fluoranthene, dibenzo(ah)anthracene and ∑16PAHs. Concomitantly, significantly enhanced levels of MDA and decreased levels of GSH were recorded among cases (preterm infants, n=80) than controls (fullterm infants, n=86). Multivariable regression analysis showed significant negative association of naphthalene, acenaphthene, benzo(b)fluoranthene with GSH and positive association of benzo(a)anthracene with MDA, explains that PAHs possibly by altering the redox status during pregnancy induce preterm birth. These findings shed light on adverse effect of PAHs on reproductive aged women.