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Dried blood spots (DBS) collected from infants shortly after birth for the newborn screening program (NSP) in the United States are valuable resources for the assessment of exposure to environmental chemicals in newborns. The NSP was debuted as a public health program in the United States in the 1960s; and the DBS samples collected over a period of time can be used in tracking temporal trends in exposure to environmental chemicals by newborns. In this study, polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) were measured in DBS samples collected from newborns in Upstate New York from 1997 to 2011 by gas chromatography–high resolution mass spectrometry (GC–HRMS). Twelve PCBs and two OCPs were found in DBS samples at a detection rate above 50% ( n =51). The mean whole blood concentration of ΣPCBs (sum of 12 congeners) over the 15-year period was 1.06 ng/mL, followed by p , p′ -DDE (0.421 ng/mL) and HCB (0.065 ng/mL). The measured concentrations of PCBs and p , p′ -DDE in infants׳ blood were comparable to those reported in cord blood, suggesting maternal/trans-placental transfer of these compounds from mothers to fetuses. The concentrations of ΣPCBs and p , p′ -DDE in blood samples of infants decreased significantly between 1997 and 2001, and no significant reduction was found thereafter. This observation is consistent with the trends reported for these chemicals in other human tissues in the United States. [ABSTRACT FROM AUTHOR]

Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) are persistent organic pollutants which may alter prenatal development, potentially through epigenetic modifications. Prior studies examining PFOS/PFOA and DNA methylation have relatively few subjects (n < 200) and inconsistent results. We examined relations of PFOA/PFOS with DNA methylation among 597 neonates in the Upstate KIDS cohort study. PFOA/PFOS were quantified in newborn dried blood spots (DBS) using high-performance liquid chromatography/tandem mass spectrometry. DNA methylation was measured using the Infinium MethylationEPIC BeadChip with DNA extracted from DBS. Robust linear regression was used to examine the associations of PFOA/PFOS with DNA methylation at individual CpG sites. Covariates included sample plate, estimated cell type, epigenetically derived ancestry, infant sex and plurality, indicators of maternal socioeconomic status, and prior pregnancy loss. In supplemental analysis, we restricted the analysis to 2242 CpG sites previously identified as Correlated Regions of Systemic Interindividual Variation (CoRSIVs) which include metastable epialleles. At FDR<0.05, PFOA concentration >90th percentile was related to DNA methylation at cg15557840, near SCRT2, SRXN1 ; PFOS>90th percentile was related to 2 CpG sites in a sex-specific manner (cg19039925 in GVIN1 in boys and cg05754408 in ZNF26 in girls). When analysis was restricted to CoRSIVs, log-scaled, continuous PFOS concentration was related to DNA methylation at cg03278866 within PTBP1. In conclusion, there was limited evidence of an association between high concentrations of PFOA/PFOS and DNA methylation in newborn DBS in the Upstate KIDS cohort. These findings merit replication in populations with a higher median concentration of PFOA/PFOS. • PFOS and PFOA were measured in newborn dried blood spots (DBS). • DNA was extracted from DBS to study methylation. • High PFOA/PFOS (>90th percentile) is related to DNA methylation at select CpG sites. • Findings are limited and need replication in cohorts with higher PFOA/PFOS exposure. [ABSTRACT FROM AUTHOR]