Biomonitoring and exposure predictors of 29 dioxin, furan, and dl-PCB congeners in newborn meconium from Spain.

Prenatal exposure to persistent organic pollutants (POPs) is a matter of great concern due to the vulnerability of the foetus. Seventeen polychlorinated dibenzo-p-dioxins and dibenzofurans (PCCD/Fs) and 12 dioxin-like polychlorinated biphenyls (dl-PCBs) were measured in meconium samples from 50 Spanish newborns using gas chromatography coupled to high-resolution mass spectrometry (GC-HRMS). Median concentrations (wet weight) of PCDD/Fs and dl-PCBs were 0.017 pg toxic equivalents (TEQ)/g and 0.0017 pg TEQ/g, respectively. Highly significant correlations were observed between some congeners of dl-PCBs and octachlorodibenzo-p-dioxin (OCDD), suggesting their similar sources and kinetic behaviour. Neonatal weight and gestational age were demographic parameters that influenced dl-PCB levels in meconium. Multiple regression analysis showed that consumption of ultra-processed foods contributed to the levels of several dl-PCBs in meconium. Our study concludes that meconium may be employed as a human matrix for assessing prenatal exposure to POPs and provides, for the first time, information about predictors of exposure and biomonitoring of dioxins and furans in biological meconium samples.