The ubiquitous spread of polybrominated diphenyl ethers (PBDEs) has led to concerns regarding the metabolites of these congeners, in particular hydroxylated PBDEs. There are limited studies regarding the biological interactions of these chemicals, yet there is some concern they may be more toxic than their parent compounds. In this study three hydroxylated PBDEs were assessed for toxicity in embryonic zebrafish: 3-OH-BDE 47, 5-OH-BDE 47, and 6-OH-BDE 47. All three congeners induced developmental arrest in a concentration-dependent manner; however, 6-OH-BDE 47 induced adverse effects at lower concentrations than the other congeners. Furthermore, all three induced cell death; however apoptosis was not observed. In short-term exposures (24-28 hours post fertilization), all hydroxylated PBDEs generated oxidative stress in the region corresponding to the cell death at 5 and 10 ppm. To further investigate the short-term effects that may be responsible for the developmental arrest observed in this study, gene regulation was assessed for embryos exposed to 0.625 ppm 6-OH-BDE 47 from 24 to 28 hpf. Genes involved in stress response, thyroid hormone regulation, and neurodevelopment were significantly upregulated compared to controls; however, genes related to oxidative stress were either unaffected or downregulated. This study suggests that hydroxylated PBDEs disrupt development, and may induce oxidative stress and potentially disrupt the cholinergic system and thyroid hormone homeostasis.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/j.taap.2012.04.017 | DOI Listing |
Sci Total Environ
January 2025
University of Hohenheim, Institute of Food Chemistry, Department of Food Chemistry (170b), D-70599 Stuttgart, Germany. Electronic address:
Methoxylated polybrominated diphenyl ethers (MeO-BDEs) are a class of environmentally relevant halogenated natural products. The two most relevant isomers, 2'-MeO-BDE 68 and 6-MeO-BDE 47, were repeatedly detected at levels comparable with persistent organic pollutants in marine environmental and food samples. MeO-BDEs were suspected to be biosynthesized by bromoperoxidases through the merging of two bromophenol units, three of which (2,4-dibromophenol, 2,6-dibromophenol and 2,4,6-tribromophenol) are abundant in marine environments, followed by O-methylation to give MeO-BDEs.
View Article and Find Full Text PDFEnviron Int
December 2024
Shenzhen Key Laboratory of Ecological Remediation and Carbon Sequestration, Guangdong Provincial Engineering Technology Research Center for Urban Water Cycle and Water Environment Safety, Institute of Environment and Ecology, Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, PR China; State Environmental Protection Key Laboratory of Microorganism Application and Risk Control, School of Environment, Tsinghua University, Beijing 100084, PR China. Electronic address:
The nano zero-valent iron (nZVI) activated persulfate (PS) is recognized as a promising approach to degrade 2,2',4,4'-tetrabromodiphenyl ether (BDE-47), which is ubiquitous in the soil at electronic waste sites. However, all the reported studies were performed in liquids, gaps in the real behaviour and microbial contribution to the degradation of BDE-47 in soil media need to be urgently filled. The removal efficiency of BDE-47 is low using traditional nZVI as activator because of its aggregation and corrosion.
View Article and Find Full Text PDFChemosphere
October 2024
Guangdong Provincial Key Laboratory of Marine Disaster Prediction and Prevention, Guangdong Provincial Key Laboratory of Marine Biotechnology, Institute of Marine Sciences, Shantou University, Shantou, 515063, China. Electronic address:
Despite their ban, polybrominated diphenyl ethers (PBDEs) are frequently detected in various environmental compartments including marine and coastal ecosystems due to their persistence, bio-accumulative, high production volumes, and widespread use. One of the major concerns from PBDEs is the transformation products, such as hydroxylated polybrominated diphenyl ethers (OH-BDEs), which are more bioactive than the parent compounds. For example, 6-hydroxy-2,2',4',4-tetrabromodiphenyl ether (6-OH-BDE-47) is a typical metabolite of PBDEs and cause endocrine system disruption, developmental toxicity, and neurotoxicity in different species.
View Article and Find Full Text PDFSci Total Environ
December 2024
MOE Key Laboratory of Resources and Environmental Systems Optimization, College of Environmental Science and Engineering, North China Electric Power University, Beijing 102206, China. Electronic address:
As a widely used brominated flame retardant, the widespread presence of decabromodiphenyl ether (BDE-209) in the natural environment and the toxicity risks it poses are well established, but the recoverability of BDE-209-induced individual injuries remains unknown. Therefore, a 7-day depuration experiment following a 4-day exposure of zebrafish to BDE-209 was conducted to confirm the recoverability and its mode of action. Oxidative stress after depuration was significantly reduced compared with BDE-209 exposure as indicated by the decreased expression level of oxidative stress-related genes and the reduced MDA, Gpx, and GST in zebrafish, indicating a gradual recovery of antioxidant activity.
View Article and Find Full Text PDFWater Res
October 2024
Department of Environmental Science and Engineering, Nanjing Agricultural University, Nanjing, 210095, China. Electronic address:
This study investigated the expediated transformation of halophenols in the presence of nitrite (NO) under slightly acidic conditions in ice, whereas such transformation was negligible in liquid water at 4 °C. We proposed that this phenomenon was attributed to the freeze-concentration effect, incurring a pH drop and the aggregation of NO and halophenols within the liquid-like grain boundary layer amid ice crystals. Within this micro-environment, NO underwent protonation to generate reactive nitrous acid (HNO) and nitrosonium ions (NO) that facilitate the nitration and oxidation of halophenols.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!