Environmental Health Section, Biological & Medical Research Department, King Faisal Specialist Hospital & Research Centre, PO Box: 3354, Riyadh, Saudi Arabia.
Sci Total Environ. 2013 Feb 1;444:565-78. doi: 10.1016/j.scitotenv.2012.12.021. Epub 2013 Jan 9.
Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous environmental contaminants that are known to induce oxidative stress. There have been several reports about the link between PAH exposure and complications in pregnancy. This cross-sectional study was conducted to: (1) measure the levels of benzo(a)anthracene (BaA), chrysene (Ch), benzo(b)fluoranthene (BbF), benzo(a)pyrene (BaP), and dibenzo(a,h)anthracene (DBahA) in placentas and maternal and -umbilical cord blood obtained at delivery from 1578 women between June 2005 and 2006 in the area of Al-Kharj, Saudi Arabia; (2) assess their influence on various anthropometric measures of birth outcome taking into consideration the carcinogenic properties of these PAHs; and (3) determine the degree of PAH-related oxidative DNA damage and birth outcome. Among the five tested PAHs, only BaP was carcinogenic; therefore, the levels of the other four probable or possible carcinogenic PAHs (BaA, Ch, BaF, and DBahA) were summed as ∑4-PAHs. Levels of 1-hydroxypyrene (1-HP) were determined in maternal urine samples as a biomarker of PAH internal dose. Urinary cotinine (COT) was measured as an index of smoking. The following markers of oxidative stress were selected: malondialdehyde (MDA) in cord (C-MDA) and maternal (M-MDA) serum and 8-hydroxy-2-deoxyguanosine (8-OHdG) in maternal urine. None of the tested PAHs was found in maternal or cord blood. However, all five PAH compounds were detected in placentas; Ch was the highest (6.582 μg/kg dry wt.), and BaA was the lowest (0.236 μg/kg dry wt.). The mean concentration of urinary 1-HP found in this study was 0.216 ± 0.856 μg/g Cr. After adjusting for gestational age and other confounding variables, regression models revealed an inverse relationship between placental weight, cord length and placental BaP. A similar trend was observed between cord length and ∑4-PAHs in placental tissues. Urinary 1-HP, though, cannot be used as an unequivocal biomarker of PAH exposure, but it can be an appropriate indicator of exposure to environmental tobacco smoke (ETS). The data demonstrate that ETS exposure (as measured by urinary COT) may adversely affect birth outcome as shown by reduced head circumference, birth weight, and birth length, as well as increased cephalization index. The positive relationship between 8-OHdG levels and 1-HP in urine provides evidence of an oxidative stress mechanism. Although this study provides no direct evidence of an association between PAH exposure and DNA damage, increased oxidative stress in the form of lipid peroxidation significantly affected various birth measures. Therefore, there is a need for studies regarding PAH exposure and its associated biological effects to determine the extent of potential fetal damage as well as possible long-term effects, such as cancer.
多环芳烃（PAHs）是普遍存在的环境污染物，已知会诱导氧化应激。已经有一些关于 PAH 暴露与妊娠并发症之间联系的报告。这项横断面研究旨在：（1）测量 2005 年 6 月至 2006 年期间在沙特阿拉伯阿尔卡尔吉地区分娩的 1578 名女性的胎盘和母体及脐带血中苯并（a）蒽（BaA）、屈（Ch）、苯并（b）荧蒽（BbF）、苯并（a）芘（BaP）和二苯并（a，h）蒽（DBahA）的水平；（2）考虑到这些 PAHs 的致癌特性，评估它们对各种出生结局的各种人体测量指标的影响；（3）确定与 PAH 相关的氧化 DNA 损伤和出生结局的程度。在测试的五种 PAHs 中，只有 BaP 具有致癌性；因此，将其他四种可能或可能致癌的 PAHs（BaA、Ch、BaF 和 DBahA）的水平相加作为∑4-PAHs。在母体尿液样本中测定 1-羟基芘（1-HP）作为 PAH 内部剂量的生物标志物。尿可替宁（COT）被测量为吸烟的指标。选择了以下氧化应激标志物：脐带（C-MDA）和母体（M-MDA）血清中的丙二醛（MDA）和母体尿液中的 8-羟基-2-脱氧鸟苷（8-OHdG）。在母体或脐带血中均未发现测试的 PAHs。然而，所有五种 PAH 化合物都在胎盘组织中检测到；Ch 最高（6.582μg/kg 干重），BaA 最低（0.236μg/kg 干重）。本研究中发现的尿液 1-HP 的平均浓度为 0.216±0.856μg/g Cr。在调整了胎龄和其他混杂变量后，回归模型显示胎盘重量、脐带长度和胎盘 BaP 之间存在负相关关系。在胎盘组织中也观察到类似的趋势，即脐带长度与∑4-PAHs 之间存在负相关关系。尿液 1-HP 虽然不能作为 PAH 暴露的明确生物标志物，但可以作为环境烟草烟雾（ETS）暴露的合适指标。数据表明，ETS 暴露（以尿 COT 测量）可能会通过降低头围、出生体重和出生长度以及增加头化指数，对出生结局产生不利影响。尿液中 8-OHdG 水平与 1-HP 的正相关关系提供了氧化应激机制的证据。尽管这项研究没有直接证据表明 PAH 暴露与 DNA 损伤之间存在关联，但以脂质过氧化形式出现的氧化应激显著影响了各种出生指标。因此，需要研究 PAH 暴露及其相关的生物学效应，以确定潜在胎儿损伤的程度以及可能的长期影响，如癌症。
