Quantification of polychlorinated biphenyl contamination using human placenta as biomarker from Punjab Province, Pakistan

Abstract

The present study biomonitored the placental polychlorinated biphenyl (PCB) concentrations in women from Punjab Province, Pakistan, that provides the pioneer data for occurrence and body burden of PCBs in placental tissues from South Asian women. The ∑₃₄PCB concentrations in placental tissues were ranged from 20.2 to 115.98 ng/g lipid weight (lip. wt.), with predominance of tetra-PCB (54.67%). The levels of ∑₈DL-PCBs and ∑₆-indicator PCBs were ranged from 2.03 to 27.64 ng/g (lip. wt.) and 1.71 to 30.8 ng/g (lip. wt.), respectively. The WHO-TEQ2005 values for DL-PCBs were ranged from 1.18 × 10^-5 to 0.067 ng/g (lip. wt.), with highest value evaluated for CB-126. The estimated daily intake (EDI) for DL-PCBs was ranged from 9.27 × 10^-8 to 5.25 × 10^-4 pg WHO-TEQ/kg body weight (bw), which was within the tolerable daily intake (TDI) values established by international organizations. The spatial distribution patterns of Σ₃₄PCB concentrations from study area have shown relative higher concentrations in samples from urban and industrial cities than rural areas, and industrial and urban releases along with e-waste handling were recognized as vital PCB sources in the environment. In order to ascertain the transplacental transfer of PCBs, the fetal growth parameters were correlated with the ∑₃₄PCB concentrations in placental tissues. The relationship between ∑₃₄PCB concentrations in placental tissues and infant's anthropometric measures through multiple linear regression showed a negative correlation of infant's body weight (R² = 0.0728), crown to heel length (R² = 0.068), head circumference (R² = 0.0342), chest circumference (R² = 0.0001), and mid arm circumference (R² = 0.0096) that noticeably highlights the inhibited fetal anthropometric development associated with maternal PCB bioaccumulation. Hence, an immediate elimination of ongoing PCB addition in the studied area has been emphasized and further investigations are suggested to appropriately manage the public and neonatal health risks in the region.

Keywords: Dioxin-like PCBs; Neonatal health; PCBs; Placental transfer.