| 1. |
- Rose, Melissa, et al.
(författare)
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PBDEs in 2-5 Year-Old Children from California and Associations with Diet and Indoor Environment
- 2010
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Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 44:7, s. 2648-2653
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Tidskriftsartikel (refereegranskat)abstract
- This study determined the body burden of PBDEs in 100 California children, and evaluated associations with sociodemographic, household, and dietary factors. In national and international comparisons, California dust, breast milk, and human serum samples contain higher concentrations of PBDEs. Higher levels in children suggest exposure pathways depend upon age. Plasma samples were analyzed for PBDEs using GC/MS. Circulating levels of PBDEs were 10-to 1000-fold higher than similar aged populations in Mexico and Europe, 5-times higher than similar aged children across the U.S., and 2- to 10-fold higher than U.S. adults. Increased levels of higher-brominated congeners were associated with the recent purchase of new upholstered furniture or mattresses and consumption of pork. Concentrations of lower-brominated congeners increased with frequency of poultry consumption. Lower maternal education was independently and significantly associated with higher levels of most congeners in the children.
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| 2. |
- Sethi, Sunjay, et al.
(författare)
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Comparative Analyses of the 12 Most Abundant PCB Congeners Detected in Human Maternal Serum for Activity at the Thyroid Hormone Receptor and Ryanodine Receptor
- 2019
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Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 53:7, s. 3948-3958
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Tidskriftsartikel (refereegranskat)abstract
- Polychlorinated biphenyls (PCBs) pose significant risk to the developing human brain; however, mechanisms of PCB developmental neurotoxicity (DNT) remain controversial. Two widely posited mechanisms are tested here using PCBs identified in pregnant women in the MARBLES cohort who are at increased risk for having a child with a neurodevelopmental disorder (NDD). As determined by gas chromatography-triple quadruple mass spectrometry, the mean PCB level in maternal serum was 2.22 ng/mL. The 12 most abundant PCBs were tested singly and as a mixture mimicking the congener profile in maternal serum for activity at the thyroid hormone receptor (THR) and ryanodine receptor (RyR). Neither the mixture nor the individual congeners (2 fM to 2 μM) exhibited agonistic or antagonistic activity in a THR reporter cell line. However, as determined by equilibrium binding of [3H]ryanodine to RyR1-enriched microsomes, the mixture and the individual congeners (50 nM to 50 μM) increased RyR activity by 2.4-19.2-fold. 4-Hydroxy (OH) and 4-sulfate metabolites of PCBs 11 and 52 had no TH activity; but 4-OH PCB 52 had higher potency than the parent congener toward RyR. These data support evidence implicating RyRs as targets in environmentally triggered NDDs and suggest that PCB effects on the THR are not a predominant mechanism driving PCB DNT. These findings provide scientific rationale regarding a point of departure for quantitative risk assessment of PCB DNT, and identify in vitro assays for screening other environmental pollutants for DNT potential.
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