Screening of human health risk to infants associated with the polychlorinated biphenyl (PCB) levels in human milk from Punjab Province, Pakistan.

This study assessed the polychlorinated biphenyl (PCB) levels in human milk and its associated health risk to infants from rural and urban settings of five districts of Punjab Province, Pakistan. The ∑34PCB concentrations ranged from 30.9 to 68.3 ng g-1 on lipid weight (l.w.) basis. The ∑8DL-PCB concentrations were ranged from 0.29 to 1.35 ng g-1 l.w., (mean 6.2 ± 8.7 ng g-1 l.w.), with toxicity equivalent to polychlorinated dibenzodioxins (PCDDs) ranging from 8.58 × 10-6 to 0.05 ng TEQ g-1 l.w. The spatial trend of PCB levels in human milk revealed higher bioaccumulative levels for urban mothers as compared with rural counterparts. The estimated daily intake (EDI) values of DL-PCBs to infants through trans-mammary transfer were considerably higher than tolerable daily intake limits established by WHO (i.e., 1-4 pg TEQ kg-1 bw) and other globally recognized organizations. Similarly, the hazard quotient values for TEQ ∑8DL-PCBs (range 1.21 to 79.87) were far above the benchmark value of 1 at all the sampling sites, indicating the high levels of adverse health risks to infants in the region through breast milk consumption. The ∑34PCB levels were found to be negatively correlated with mother' age (r = -0.31; p = 0.02), parity (r = - 0.85; p = 0.001), and infant' birth weight (r = - 0.73; p = 0.01). The present study suggests undertaking comprehensive public health risk assessment studies and firm regulatory measures to safeguard human health risks.

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

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.