During pregnancy, lipophilic xenobiotics stored in maternal adipose tissue can be mobilized and enter her blood circulation and reach the placenta. This study measured residues of oestrogen-mimicking organochlorine pesticides (OCs) in 150 placenta samples from women in Southern Spain. OCs were extracted from placenta by solideliquid technique and purified by preparative liquid chromatography. Gas chromatography/electron-capture detection and mass spectrometry were used to identify and quantify p,p´-DDT and congeners/metabolites, endosulphan and congeners/metabolites, lindane, aldrin/dieldrin/endrin, hexachlorobenzene, methoxychlor and mirex. A mean of eight pesticides per placenta were detected (range, 3-15 pesticides). Endosulphan-ether, endosulphan-diol, endosulphan-I, p,p´-DDE, o,p´-DDD, p,p´-DDT, o,p´-DDT and lindane were detected in ≥50% of samples; p,p´-DDE was the most frequent (96.03%), followed by endosulphan-diol (76.86%) and lindane (74.17%). Presence of more pesticides was significantly associated with lower birth weight. Mean concentration of p,p´-DDE was 2.37±2.80 ng/g of placenta or 76.62±104.85 ng/g of lipid. Higher maternal body mass index was significantly associated with higher endosulphan concentrations in placenta, and greater maternal weight gain was significantly associated with higher p,p-DDE concentrations. Prenatal exposure to OC xenoestrogens may be a causative factor in adverse reproductive health trends, and further studies are required to identify and describe pathways of this exposure to enhance preventive measures.
