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Flouride contamination of water is recognised as a serious challenge facing humanity. Consumption of water that contains excessive amounts of fluoride can result in fluorosis. Consequently, concerted efforts have been made to develop cheap, effective and green techniques/materials to remove fluoride from water, particularly potable water. Bone char prepared from bovine, swine, and equine bones has been used extensively in this regard, and is the most promising, cheap and green material for treating drinking water with high fluoride concentration, particularly in developing countries. However, research on bone char prepared from bones of animals in the wild, as well as those from domestic and semi-wild animals treated with antibiotics to enhance growth, has been scanty. Such research is important as the use of antibiotics may alter the composition of bones, and thus their potential as a green adsorbent to remove fluoride may be impaired. Furthermore, little attempt has been made so far to package char bones for easy application domestically, particularly in rural communities. Significance: * Contamination of water by fluoride is a major problem globally. * Various techniques and materials have been employed for water defluoridation, including the use of bone char, which has several advantages. * Bone char prepared from bones of animals in the wild and those from domestic and semi-wild animals treated with antibiotics to enhance growth should be further investigated. * Cheaper and less elaborate processes and packaging are required to scale down the use of bone char at domestic level. [ABSTRACT FROM AUTHOR]

Abstract: Polybrominated diphenyl ethers (PBDEs) are a group of organobromine compounds that are used as flame retardants in many commonly used products. Their presence has been confirmed in various environmental [...]

Aspalathus linearis (Burm. F.) R. Dahlg., commonly referred to as Rooibos tea, grows naturally in nutrient-poor, sandy, acidic soils (pH 3-5.3) with high aluminum concentration ranging from 110 to 275 µg Al[g.sup.-1] in the Cederberg's mountainous areas in South Africa. Earlier studies found significant differences in Al concentration in organs of A. linearis, with roots having higher amounts (1262-4078 µg Al[g.sup.-1,] suggesting that the plant is capable of accumulating excess Al in acidic soils. Identification of the mineralogical constituents of organs of A. linearis using X-ray diffraction (XRD) analysis revealed the presence of an Al-Si complex (aluminosilicate or hydroxyaluminosilicate (HAS) species) in the shoot and root, possibly to internally ameliorate Al toxicity. In addition, A. linearis has specialized cluster roots that exude Al-chelating organic acid ligands such as citric, malic, and malonic acids. Organic acids can bind strongly to Al in the plant and rhizosphere to reverse its phytotoxic effects to the plants. Field and glasshouse studies revealed significant differences in pH between rhizosphere and nonrhizosphere soils of A. linearis and also showed that roots of the plant release OH- and HC[O.sub.3]- anions to raise rhizosphere pH possibly to immobilize Al through complexation. Furthermore, A. linearis is easily infected by arbuscular mycorrhizae (AM) fungi, but mycorrhizal associations are known to inhibit transport of metallic cations into plant roots. These features of A. linearis are perceived as good indicators for bioremediation; and the plant could, therefore, be a suitable candidate for phytoremediation technologies such as phytoaccumulation, phytostabilization, and phytodegradation. The environmental and economic implications of the potential of A. linearis to bioremediate Al- contaminated soils are briefly discussed. Furthermore, this review briefly highlights future studies investigating the utilization of the shoot of A. linearis as adsorbent for the removal of trace and (or) heavy metal from aqueous solutions. Key words: A. linearis, Al-tolerant, Al-chelating ligands, mechanisms, organic acids, phytoremediation. L'Aspalathus linearis (Burm. F.) R. Dahlg., communement appele the Rooibos, vient naturellement dans les sols acides (pH 3-5.3), sablonneux et pauvres en nutriments, avec des teneurs en Al allant de 110 a 275 µg Al[g.sup.-1], dans les regions montagneuses du sud de l'Afrique. Des etudes antecedentes ont montre des differences significatives de la teneur en Al dans les organes de l'A.linearis, avec de plus fortes teneurs dans les racines (1262 a 4078 µg Al[g.sup.-1], suggere une capacite de la plante a accumuler des exces d'Al en sols acides. L'Identification des constituants mineralogiques des organes de l'A. linearis, par analyse de diffraction des rayons X, revele la presence du complexe Al-Si (speciation en aluminosilicate ou hydroxyaluminosilicate) dans la tige et les racines, possiblement destinee a reduire la toxicite interne de l'Al. De plus, l'A. linearis possede des racines regroupees exsudant des ligands d acides organiques chelateurs d Al, comme les acides citriques, maliques et moloniques. Les acides organiques peuvent lier fortement l Al dans la plante et la rhizosphere et renverser ses effets toxiques. Des etudes en serre et sur le terrain revelent des differences significatives du pH entre les sols de rhizosphere et de non-rhizosphere de l'A. linearis et montrent que les racines de la plante relachent des anions OH- et HC[O.sub.3]- augmentant le pH de la rhizosphere et possiblement immobilisant ainsi l'A, par complexation. De plus, l'A. linearis forme facilement des mycorhizes arbusculaires (MA), mais on sait que les associations mycorhiziennes inhibent le transfert des cations metalliques dans la racine des plantes. On considere ces caracteristiques de l A. linearis comme de bons indicateurs pour la bioremediation et consequemment, cette plante pourrait s averer utile pour les technologies de phytoremediation telles que la phytoaccumulation, la phytostabilisation et la phytodegradation. On discute brievement du potentiel environnemental et economique de l'A. linearis pour la bioremediation des sols contamines a l'Al. De plus, cette revue souligne brievement l'interet d'etudes futures sur l'utilisation de la tige de l'A. linearis comme adsorbant pour l'elimination des elements traces et lourds de solutions aqueuses. [Traduit par la Redaction] Mots-cles: A. linearis, tolerance a l'Al, ligands chelateurs de Al, mecanismes, acides organiques, phytoremediation., 1. Introduction Aluminum (Al) toxicity is a major limiting factor for the growth of agriculturally important plant species in acidic soils, which make up about 40% of the Earth's arable [...]

Brominated flame retardants (BFRs) are a relatively new generation of chemicals used as flame retardants in many types of consumer products. The most commonly used BFRs include tetrabromobisphenol A, polybromodiphenyl ethers, polybromobiphenyls, and hexabromocyclododecanes. Perhaps as a result of their widespread use and their lipophilicity, these compounds have become ubiquitous in the environment. This review summarizes BFR concentrations determined in different environmental media. The main sources of BFRs and the exposure pathways through consumption of contaminated food, ingestion, and inhalation of dust are reviewed. The distribution patterns in the abiotic and biotic environment as well as their toxicity are discussed with a view to provide a better understanding of these emerging environmental pollutants. In addition, it is envisaged that this review will heighten the importance of identifying emerging issues and data gaps, and generate a future research agenda on BFRs. Key words: brominated flame retardants, concentrations, sources, distribution patterns, toxicity. Les retardateurs de flamme a base de brome ' RFBs ' constituent une generation relativement nouvelle de produits chimiques utilises comme retardateurs de flammes dans plusieurs types de produits de consommation. Les RFBs les plus communement utilises incluent le tetrabromo-bisphenol A, des ethers de polybromodiphenyl, des polybromobiphenyls et des hexabromocyclododecanes. Il est possible que suite aleur usage generalise et leur lipophylie, ces produits soient devenus ubiquistes dans l'environnement. On resume ici les teneurs en RFBs decelees dans differents milieux environnementaux. On passe en revue les principales sources de RFBs ainsi que les cheminements d'exposition par la consommation d'aliments contamines, l'ingestion et l'inhalation de poussieres. Afin d'obtenir une meilleure comprehension de ces polluants environnementaux emergents, on discute les patrons de distribution dans le milieu abiotique et biotique ainsi que leur toxicite. De plus, on espere que cette revue soulignera l'importance d'identifier les consequences emergentes et les manques de donnees et generera un agenda futur sur les RFBs. Mots-cles : retardateurs de flamme a base de brome, teneurs, sources, patrons de distribution, toxicite. [Traduit par la Redaction], 1. Introduction New methods in agriculture and forestry, high demand in consumer products, use of chemicals in health programmes, and expansion of industrial processes have contributed to the dramatic increase [...]

The presence of brominated flame retardants (BFRs) in various environmental matrices, including humans, has been well documented. Increasing levels of these emerging contaminants in various environmental compartments suggest the wide application of these chemicals in products of everyday use. The release of BFRs from treated products is generally believed to be the major source of these contaminants into the environment, particularly in indoor environments. The sources and pathways through which BFRs enter the human system are evaluated in this paper. Human exposure via consumption of contaminated food and water, inhalation and ingestion of dust, as well as dermal absorption, are important pathways for these contaminants. Consumption of fatty foods especially fish, meat, dairy products as well as human milk constitute important routes for human exposure to these contaminants. Although brominated diphenyl ether (BDE) 209 has been found to be less bioaccumulative due to its high molecular weight, its dominance in indoor dust samples could be responsible for its detection in most human tissues investigated. BDE 47 is the most dominant polybrominated diphenyl ether (PBDE) congener found in human tissues. Regional differences in BFR levels in various environmental and biological matrices reflect their consumption patterns with higher levels mostly reported in the North American environments than in other regions of the world. Key words: brominated flame retardants, polybrominated diphenyl ethers, indoor dust, human breast milk, human. Il existe une bonne documentation sur la presence de retardants de flamme a base de brome (BFR) dans diverses matrices environnementales, incluant les humains. L'observation de l'augmentation des teneurs de ces contaminants en emergence dans differents compartiments de l'environnement suggere une importante utilisation de ces produits dans la vie de tous les jours. On croitgeeneralement que le relachement des BFRs a partir de produits traites constitue la principale source de ces contaminants pour l'environnement, particulierement a l'inteerieur des edifices. Dans ce travail, les auteurs evaluent les sources et les cheminements par lesquels les BFRs entrent dans le systeme humain. L'exposition humaine via la consommation d'eau ou de nourriture contamineies, l'inhalation et l'ingestion de poussieres ainsi que l'absorption dermique, constituent d'importants sentiers pour ces contaminants. La consommation de nourriture grasse surtout le poisson, la viande, les produits laitiers y compris le lait humain, constituent d'importants chemins d'exposition a ces contaminants pour les humains. Bien qu'on ait montrei que le BDE 209 soit moins susceptible d'eitre bioaccumulei, compte tenu de son poids moleculaire, sa dominance dans les echantillons de poussiere a l'inteirieur des edifices pourrait etre responsable de sa detection dans la plupart des tissus humains examinees. Le BDE 47 apparait comme le congeenere le plus important du PBDE dans les tissus humains. Les diffeirences reigionales des teneurs en BFRs dans divers environnements et matrices biologiques refletent les patrons de consommation, les teneurs rapportees eetant plus elevees dans les environnements nordameiricains que dans les autres reigions du monde. Mots-cles: retardants de flamme a base de brome, eethers de diphenyle polybromes, poussiere inteirieure, lait au sein humain, humain. [Traduit par la Redaction], 1.0 Introduction Brominated flame retardants (BFRs) are high volume industrial chemicals usually incorporated into a wide range of textiles and polymers used in several consumer products. These chemicals are extensively [...]

This study report the presence of polybrominated biphenyls (PBBs), polybrominated diphenyl ethers (PBDEs) and novel brominated flame-retardants (NBFRs) in muscle tissues of Labeo capensis (mudfish), Labeo umbratus (moggel), Cyprinus carpio (carp) and Clarias gariepinus (catfish) from Vaal River, South Africa. The concentrations (in ng g−1 wet weight (ww)) of these contaminants ranged from LOQ to 12.8 ng g−1 ww in catfish, with lowest concentrations found for mudfish ranging from −1 ww. This variation was attributed to species-specific ecological status such as feeding habit and trophic level with BDE209 and BB209 as a major congeners among PBDEs and PBBs, respectively, and decabromodiphenyl ethane (DBDPE) as a major flame retardants among the NBFRs. The hazard quotients of these contaminants were very low indicating that these contaminants do not pose health risk to South Africans via fish consumption. [ABSTRACT FROM AUTHOR]