Using placenta to evaluate the polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) exposure of fetus in a region with high prevalence of neural tube defects Jin Ma a , Xinghua Qiu a,n , Aiguo Ren b,nn , Lei Jin b , Tong Zhu a a State Key Joint Laboratory for Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering and Center for Environment and Health, Peking University, PR China b Institute of Reproductive and Child Health, Peking University Health Science Center and National Reference Laboratory on Reproductive and Child Health, Ministry of Health, PR China article info Article history: Received 3 July 2012 Received in revised form 3 September 2012 Accepted 4 September 2012 Available online 27 September 2012 Keywords: Polychlorinated biphenyls (PCBs) Polybrominated diphenyl ethers (PBDEs) Neural tube defects (NTDs) Placenta abstract Polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) are persistent organic pollutants suspected to have various toxic effects, including reproductive toxicity. The aim of this study was to determine the concentrations of PCBs and PBDEs in human placentas and to examine the potential association between in utero exposure to these pollutants and the risk of neural tube defects. Subjects were recruited from a birth defects surveillance program in a rural area of Shanxi Province, China, from 2005 to 2007. 80 placental samples from fetuses/neonates with neural tube defects and 50 samples from healthy newborn infants were analyzed for PCBs and PBDEs using electron-capture negative-ionization gas chromatographic mass spectrometry. The median concentrations were 0.89 and 0.54 ng/g lipid for the eight PCB congeners and six PBDE congeners detected, respectively. The median concentration of total PCBs was slightly higher in the case samples than in the controls (0.91 vs. 0.89 ng/g lipid), but the difference was not significant (P ¼0.46), as also found for the median concentration of total PBDEs (0.55 vs. 0.54 ng/g lipid, P ¼0.61). For both PCBs and PBDEs, when their placental concentration was above the median of all samples, it was associated with a non-significantly higher or equal risk of neural tube defects. Low levels of PCBs and PBDEs are not likely risk factors for neural tube defects in this population. & 2012 Elsevier Inc. All rights reserved. 1. Introduction Polychlorinated biphenyls (PCBs), once widely used as insula- tors in electrical equipment, are ubiquitous environmental pollu- tants. PCBs are persistent in the environment, accumulate in biota, and have various health effects in humans (Ross et al., 2000). Animal experiments demonstrated that PCBs have a variety of toxic effects on the nervous and reproductive systems (Grandjean and Landrigan, 2006). Especially, neonatal deficits have been reported in infants exposed prenatally to PCBs (Fein et al., 1984). Similar to PCBs in structure, polybrominated diphe- nyl ethers (PBDEs) belong to a group of emerging pollutants used worldwide as flame retardants (Hites, 2004). PBDEs have neuro- toxicity, thyroid toxicity, carcinogenicity, and reproductive toxi- city (McDonald, 2002). PCBs and PBDEs are lipid soluble and resistant to metabolism (Ross et al., 2000; Hites, 2004). They can cross the placenta, resulting in fetal exposure (Doucet et al., 2009), and can interact with and enhance developmental neurobehavioral defects when the exposure occurs during a critical stage of neonatal develop- ment (Eriksson et al., 2006). Effects on cell viability, DNA damage, chromosomal abnormalities, and DNA-protein crosslinks induced by BDE-47 combined with CB-153 have also been observed (He et al., 2010). Hence, we suspected that exposure to PCBs and PBDEs in utero could be associated with neural tube defects (NTDs), one of the most common human congenital malforma- tions (Copp et al., 2003). During mammalian embryo/fetus development, the placenta is responsible for nutrient and oxygen transport, lipophilic pollu- tants such as PCBs and PBDEs can accumulate in the placenta, and hence the level of pollutants in placenta is a biomarker of prenatal exposure of the embryo/fetus to these chemicals (Myren et al., 2007). Compared with pollutants in blood or urine samples, pollutants in the placenta could reflect the exposure of the fetus in utero throughout the pregnancy (Reichrtova et al., 1998). In addition, pollutants in the placenta are also biomarkers of Contents lists available at SciVerse ScienceDirect journal homepage: www.elsevier.com/locate/ecoenv Ecotoxicology and Environmental Safety 0147-6513/$ - see front matter & 2012 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.ecoenv.2012.09.005 n Corresponding author. Fax: þ86 10 62760755. nn Corresponding author. Fax: þ86 10 8280 1141. E-mail addresses: xhqiu@pku.edu.cn (X. Qiu), renag@bjmu.edu.cn (A. Ren). Ecotoxicology and Environmental Safety 86 (2012) 141–146