Polybrominated diphenyl ethers (PBDE) as persistent contaminants : origin, behavior in the environment and analytical strategies

Flame retardants are substances mixed with numerous materials to inhibit the combustion process, reducing risks and damages caused by fires. Among these substances, polybrominated diphenyl ethers (PBDEs) have been widely used for decades due to their low cost and high efficiency. However, since they are mixed and not chemically bonded to the materials, PBDEs can be released over time being transported through numerous pathways until they reach soils and aquatic systems, where they can accumulate in sediments and biota. Due to their high chemical stability, an essential feature for flame retardants, they are considered persistent contaminants. Several studies report the presence of PBDEs in atmospheric and aquatic particulate matter, sediments, soils and biological matrices such as marine animals, tissues and human fluids. In Brazil, little is known about the use and commercialization of PBDEs, as well as their levels in different environmental compartments. Thus, this review provides an overview of the origin of PBDEs in the environment as well as information inherent to the understanding of the behavior and presence of this contaminants of recent interest in different environmental compartments. Finally, the manuscript also brings state-of-the-art analytical approaches used for environmental sampling, preservation, preparation and sample analysis

ÉTERES DIFENÍLICOS POLIBROMADOS (PBDE) COMO CONTAMINANTES PERSISTENTES: OCORRÊNCIA, COMPORTAMENTO NO AMBIENTE E ESTRATÉGIAS ANALÍTICAS

Flame retardants are substances mixed with numerous materials to inhibit the combustion process, reducing risks and damages caused by fires. Among these substances, polybrominated diphenyl ethers (PBDEs) have been widely used for decades due to their low cost and high efficiency. However, since they are mixed and not chemically bonded to the materials, PBDEs can be released over time being transported through numerous pathways until they reach soils and aquatic systems, where they can accumulate in sediments and biota. Due to their high chemical stability, an essential feature for flame retardants, they are considered persistent contaminants. Several studies report the presence of PBDEs in atmospheric and aquatic particulate matter, sediments, soils and biological matrices such as marine animals, tissues and human fluids. In Brazil, little is known about the use and commercialization of PBDEs, as well as their levels in different environmental compartments. Thus, this review provides an overview of the origin of PBDEs in the environment as well as information inherent to the understanding of the behavior and presence of this contaminants of recent interest in different environmental compartments. Finally, the manuscript also brings state-of-the-art analytical approaches used for environmental sampling, preservation, preparation and sample analysis

POLYBROMINATED DIPHENYL ETHERS (PBDE) AS PERSISTENT CONTAMINANTS: ORIGIN, BEHAVIOR IN THE ENVIRONMENT AND ANALYTICAL STRATEGIES

<p></p><p>Flame retardants are substances mixed with numerous materials to inhibit the combustion process, reducing risks and damages caused by fires. Among these substances, polybrominated diphenyl ethers (PBDEs) have been widely used for decades due to their low cost and high efficiency. However, since they are mixed and not chemically bonded to the materials, PBDEs can be released over time being transported through numerous pathways until they reach soils and aquatic systems, where they can accumulate in sediments and biota. Due to their high chemical stability, an essential feature for flame retardants, they are considered persistent contaminants. Several studies report the presence of PBDEs in atmospheric and aquatic particulate matter, sediments, soils and biological matrices such as marine animals, tissues and human fluids. In Brazil, little is known about the use and commercialization of PBDEs, as well as their levels in different environmental compartments. Thus, this review provides an overview of the origin of PBDEs in the environment as well as information inherent to the understanding of the behavior and presence of this contaminants of recent interest in different environmental compartments. Finally, the manuscript also brings state-of-the-art analytical approaches used for environmental sampling, preservation, preparation and sample analysis.</p><p></p

Microbial Ecology of the Dark Ocean above, at, and below the Seafloor†

Summary: The majority of life on Earth—notably, microbial life—occurs in places that do not receive sunlight, with the habitats of the oceans being the largest of these reservoirs. Sunlight penetrates only a few tens to hundreds of meters into the ocean, resulting in large-scale microbial ecosystems that function in the dark. Our knowledge of microbial processes in the dark ocean—the aphotic pelagic ocean, sediments, oceanic crust, hydrothermal vents, etc.—has increased substantially in recent decades. Studies that try to decipher the activity of microorganisms in the dark ocean, where we cannot easily observe them, are yielding paradigm-shifting discoveries that are fundamentally changing our understanding of the role of the dark ocean in the global Earth system and its biogeochemical cycles. New generations of researchers and experimental tools have emerged, in the last decade in particular, owing to dedicated research programs to explore the dark ocean biosphere. This review focuses on our current understanding of microbiology in the dark ocean, outlining salient features of various habitats and discussing known and still unexplored types of microbial metabolism and their consequences in global biogeochemical cycling. We also focus on patterns of microbial diversity in the dark ocean and on processes and communities that are characteristic of the different habitats