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Joaquín L. Navarro - One of the best experts on this subject based on the ideXlab platform.
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First assessment of persistent organic pollutants in the Greater rhea (Rhea americana), a near-threatened flightless herbivorous bird of the Pampas grasslands
Environmental Science and Pollution Research, 2021Co-Authors: Alvina Lèche, Eric Gismondi, Mónica B. Martella, Joaquín L. NavarroAbstract:Persistent organic pollutants (POPs) are still globally distributed and can exert different effects on ecosystems. Little is known about the occurrence of these contaminants in terrestrial birds from South America. In this study, POPs were assessed for the first time in a flightless herbivorous species from the Pampas grasslands, the Greater rhea ( Rhea americana ). Concentrations of polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and organochlorine pesticides (OCPs) were determined in 18 samples of feathers from free-ranging and captive individuals inhabiting four sites with different land uses in central Argentina. Among the 16 POPs tested in those feathers, 6 PCBs (28, 52, 101, 138, 153, and 180) and 8 OCPs (α-HCH, β-HCH, γ-HCH, p,p′-DDE, p,p′-DDD, o,p′-DDT, p,p′-DDT, and HCB) were quantified. No PBDEs were detected. The total concentration of POPs was higher in populations living in an intensive crop production area (agriculture 159 ng g ^−1 and farm: 97.53 ng g^−1) compared with the population in an urban area (zoo 45.86 ng g^−1) and an agroecosystem with extensive rearing of livestock (cattle rearing 36.77 ng g^−1). PCBs were the most abundant pollutants in all the populations studied. Lower chlorinated CB 52 and CB 101 were the principal PCB congeners detected, representing at least 70% of the total quantified. All populations studied showed a DDE + DDD/DDT ratio > 1, indicating a historical application of this insecticide. This study provides a new contribution to the scarce data on POP concentrations in South American bird species. Further investigations are needed to evaluate their potential effects on the health of individuals and populations.
Alvina Lèche - One of the best experts on this subject based on the ideXlab platform.
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First assessment of persistent organic pollutants in the Greater rhea (Rhea americana), a near-threatened flightless herbivorous bird of the Pampas grasslands
Environmental Science and Pollution Research, 2021Co-Authors: Alvina Lèche, Eric Gismondi, Mónica B. Martella, Joaquín L. NavarroAbstract:Persistent organic pollutants (POPs) are still globally distributed and can exert different effects on ecosystems. Little is known about the occurrence of these contaminants in terrestrial birds from South America. In this study, POPs were assessed for the first time in a flightless herbivorous species from the Pampas grasslands, the Greater rhea ( Rhea americana ). Concentrations of polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and organochlorine pesticides (OCPs) were determined in 18 samples of feathers from free-ranging and captive individuals inhabiting four sites with different land uses in central Argentina. Among the 16 POPs tested in those feathers, 6 PCBs (28, 52, 101, 138, 153, and 180) and 8 OCPs (α-HCH, β-HCH, γ-HCH, p,p′-DDE, p,p′-DDD, o,p′-DDT, p,p′-DDT, and HCB) were quantified. No PBDEs were detected. The total concentration of POPs was higher in populations living in an intensive crop production area (agriculture 159 ng g ^−1 and farm: 97.53 ng g^−1) compared with the population in an urban area (zoo 45.86 ng g^−1) and an agroecosystem with extensive rearing of livestock (cattle rearing 36.77 ng g^−1). PCBs were the most abundant pollutants in all the populations studied. Lower chlorinated CB 52 and CB 101 were the principal PCB congeners detected, representing at least 70% of the total quantified. All populations studied showed a DDE + DDD/DDT ratio > 1, indicating a historical application of this insecticide. This study provides a new contribution to the scarce data on POP concentrations in South American bird species. Further investigations are needed to evaluate their potential effects on the health of individuals and populations.
Abid K. Al-agely - One of the best experts on this subject based on the ideXlab platform.
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DDE remediation and degradation.
Reviews of environmental contamination and toxicology, 2008Co-Authors: John E. Thomas, Abid K. Al-agelyAbstract:DDT and its metabolites, DDD and DDE, have been shown to be recalcitrant to degradation. The parent compound, DDT, was used extensively worldwide starting in 1939 and was banned in the United States in 1973. The daughter compound, DDE, may result from aerobic degradation, abiotic dehydrochlorination, or photochemical decomposition. DDE has also occurred as a contaminant in commercial-grade DDT. The p,p'-DDE isomer is more biologically active than the o,p-DDE, with a reported half-life of -5.7 years. However, when DDT was repeatedly applied to the soil, the DDE concentration may remain unchanged for more than 20 yr. Remediation of DDE-contaminated soil and water may be done by several techniques. Phytoremediation involves translocating DDT, DDD, and DDE from the soil into the plant, although some aquatic species (duckweed > elodea > parrot feather) can transform DDT into predominantly DDD with some DDE being formed. Of all the plants that can uptake DDE, Cucurbita pepo has been the most extensively studied, with translocation values approaching "hyperaccumulation" levels. Soil moisture, temperature, and plant density have all been documented as important factors in the uptake of DDE by Cucurbita pepo. Uptake may also be influenced positively by amendments such as biosurfactants, mycorrhizal inoculants, and low molecular weight organic acids (e.g., citric and oxalic acids). DDE microbial degradation by dehalogenases, dioxygenases, and hydrolases occurs under the proper conditions. Although several aerobic degradation pathways have been proposed, none has been fully verified. Very few aerobic pure cultures are capable of fully degrading DDE to CO2. Cometabolism of DDE by Pseudomonas sp., Alicaligens sp., and Terrabacter sp. grown on biphenyl has been reported; however, not all bacterial species that produce biphenyl dioxygenase degraded DDE. Arsenic and copper inhibit DDE degradation by aerobic microorganisms. Similarly, metal chelates such as EDTA inhibit the breakdown of DDE by the extracellular lignolytic enzymes produced by white rot fungi. The addition of adjutants such as sodium ion, surfactants, and cellulose increased the rate of DDT aerobic or anaerobic degradation but did little to enhance the rate of DDE disappearance under anaerobic conditions. Only in the past decade has it been demonstrated that DDE can undergo reductive dechlorination under methanogenic and sulfidogenic conditions to form the degradation product DDMU, 1-chloro-2,2'-bis-(4'-chlorophenyl)ethane. The only pure culture reported to degrade DDE under anaerobic conditions was the denitrifier Alcaligens denitrificans. The degradation of DDE by this bacterium was enhanced by glucose, whereas biphenyl fumes had no effect. Abiotic remediation by DDE volatilization was enhanced by flooding and irrigation and deepplowing inhibited the volatilization. The use of zero-valent iron and surfactants in flooded soils enhanced DDT degradation but did not significantly alter the rate of DDE removal. Other catalysts (palladized magnesium, palladium on carbon, and nickel/aluminum alloys) degraded DDT and its metabolites, including DDE. However, these systems are often biphasic or involve explosive gases or both. Safer abiotic alternatives use UV light with titanium oxide or visible light with methylene green to degrade DDT, DDD, and DDE in aqueous or mixed solvent systems. Remediation and degradation of DDE in soil and water by phytoextraction, aerobic and anaerobic microorganisms, or abiotic methods can be accomplished. However, success has been limited, and great care must be taken that the method does not transfer the contaminants to another locale (by volatilization, deep plowing, erosion, or runoff) or to another species (by ingestion of accumulating plants or contaminated water). Although the remediation of DDT-, DDD-, and DDE-contaminated soil and water is beset with myriad problems, there remain many open avenues of research.
Chunyang Liao - One of the best experts on this subject based on the ideXlab platform.
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historical record and fluxes of ddts at the palos verdes shelf superfund site california
Science of The Total Environment, 2017Co-Authors: Chunyang Liao, Allison Taylor, William F Kenney, Daniel SchlenkAbstract:Abstract Marine sediments at many locations in the world are contaminated with a wide range of persistent organic pollutants. The Palos Verdes Shelf (PVS) is located in the ocean off the coast of Los Angeles, California and has been listed as a Superfund site by the US EPA since 1997, because of heavy contamination of DDTs and PCBs. However, little is known about the historical trend in the deposition of DDTs as a result of decades-long discharge of wastewater effluents. In this study, sediment cores were taken from the PVS site and determined for DDT and its metabolites including DDE and DDD (denoted as DDTs). Individual DDTs were found in the majority (95%) of the samples analyzed. The highest ∑ DDT concentrations were found in three cores along the 60-meter isobath with geometric means of 31300, 7490, and 5010 ng/g dw and medians of 82400, 17300, and 5200 ng/g dw, respectively. Among DDT congeners, p,p′-DDE, o,p′-DDE and p,p′-DDD were predominant, contributing to approximately 54%, 27%, and 14% of the ΣDDTs in sediment. The vertical profiles of concentrations of contaminants in the sediment cores were examined. For most of the cores, a steady increase in the concentrations of DDTs during 1940s to 1980s was observed, while the concentrations declined gradually toward the surficial layers. On the basis of the mass flux of DDTs calculated and the area of the PVS Superfund site, we estimated the total deposition amount of DDTs in sediment and the deposition amount of ΣDDTs in this region during 1947–1971 was 132 tons, which was fairly close to what was reported in earlier studies for industrial wastewater discharge in the PVS site (870–1450 tons). Our findings suggest that the elevated levels of DDTs in sediment from the PVS site are linked to the discharge of these contaminants between the 1940s–1980s.
Eric Gismondi - One of the best experts on this subject based on the ideXlab platform.
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First assessment of persistent organic pollutants in the Greater rhea (Rhea americana), a near-threatened flightless herbivorous bird of the Pampas grasslands
Environmental Science and Pollution Research, 2021Co-Authors: Alvina Lèche, Eric Gismondi, Mónica B. Martella, Joaquín L. NavarroAbstract:Persistent organic pollutants (POPs) are still globally distributed and can exert different effects on ecosystems. Little is known about the occurrence of these contaminants in terrestrial birds from South America. In this study, POPs were assessed for the first time in a flightless herbivorous species from the Pampas grasslands, the Greater rhea ( Rhea americana ). Concentrations of polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and organochlorine pesticides (OCPs) were determined in 18 samples of feathers from free-ranging and captive individuals inhabiting four sites with different land uses in central Argentina. Among the 16 POPs tested in those feathers, 6 PCBs (28, 52, 101, 138, 153, and 180) and 8 OCPs (α-HCH, β-HCH, γ-HCH, p,p′-DDE, p,p′-DDD, o,p′-DDT, p,p′-DDT, and HCB) were quantified. No PBDEs were detected. The total concentration of POPs was higher in populations living in an intensive crop production area (agriculture 159 ng g ^−1 and farm: 97.53 ng g^−1) compared with the population in an urban area (zoo 45.86 ng g^−1) and an agroecosystem with extensive rearing of livestock (cattle rearing 36.77 ng g^−1). PCBs were the most abundant pollutants in all the populations studied. Lower chlorinated CB 52 and CB 101 were the principal PCB congeners detected, representing at least 70% of the total quantified. All populations studied showed a DDE + DDD/DDT ratio > 1, indicating a historical application of this insecticide. This study provides a new contribution to the scarce data on POP concentrations in South American bird species. Further investigations are needed to evaluate their potential effects on the health of individuals and populations.