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Bioaccumulation of perfluoroalkyl compounds in midge (Chironomus riparius) larvae exposed to sediment Texto completo
2014
Bertin, Delphine | Ferrari, Benoît J.D. | Labadie, Pierre | Sapin, Alexandre | Garric, Jeanne | Budzinski, Hélène | Houde, Magali | Babut, Marc
Midge larvae (Chironomus riparius) were exposed to sediments from a deposition sampled at a site along the Rhône River (France) downstream of an industrial site releasing various perfluorinated chemicals. This sediment is characterized by high concentrations of perfluoroundecanoic acid (PFUnA) and perfluorotridecanoic acid (PFTrDA) and a low perfluorooctane sulfonate (PFOS) concentration. Concentrations of 23 perfluoroalkyl compounds, including C4–C14 carboxylate acids, C4–C10 sulfonates, and seven precursors, were analyzed in overlying and pore water, sediment, and larvae. Midge larvae accumulated carboxylate acids (C11–C14), PFOS, and two precursors (perfluorooctane sulfonamide: FOSA and 6:2 fluorotelomer sulfonic acid, 6:2 FTSA). These substances accumulated mainly during the fourth instar larvae exponential growth phase. Accumulation of 6:2 FTSA, PFUnA, and PFOS occured via trophic and tegumentary routes. Other compounds mainly accumulated from food. Kinetics followed a partition model, from which uptake and elimination constants were derived.
Mostrar más [+] Menos [-]Exploitation of deep-sea resources: The urgent need to understand the role of high pressure in the toxicity of chemical pollutants to deep-sea organisms Texto completo
2014
Mestre, Nélia C. | Calado, Ricardo | Soares, Amadeu M.V.M.
The advent of industrial activities in the deep sea will inevitably expose deep-sea organisms to potentially toxic compounds. Although international regulations require environmental risk assessment prior to exploitation activities, toxicity tests remain focused on shallow-water model species. Moreover, current tests overlook potential synergies that may arise from the interaction of chemicals with natural stressors, such as the high pressures prevailing in the deep sea. As pressure affects chemical reactions and the physiology of marine organisms, it will certainly affect the toxicity of pollutants arising from the exploitation of deep-sea resources. We emphasize the need for environmental risk assessments based on information generated from ecotoxicological trials that mimic, as close as possible, the deep-sea environment, with emphasis to a key environmental factor – high hydrostatic pressure.
Mostrar más [+] Menos [-]Mapping polycyclic aromatic hydrocarbon and total toxicity equivalent soil concentrations by visible and near-infrared spectroscopy Texto completo
2014
Okparanma, Reuben N. | Coulon, Frederic | Mayr, Thomas | Mouazen, Abdul M.
In this study, we used data from spectroscopic models based on visible and near-infrared (vis-NIR; 350–2500 nm) diffuse reflectance spectroscopy to develop soil maps of polycyclic aromatic hydrocarbons (PAHs) and total toxicity equivalent concentrations (TTEC) of the PAH mixture. The TTEC maps were then used for hazard assessment of three petroleum release sites in the Niger Delta province of Nigeria (5.317°N, 6.467°E). As the paired t-test revealed, there were non-significant (p > 0.05) differences between soil maps of PAH and TTEC developed with chemically measured and vis-NIR-predicted data. Comparison maps of PAH showed a slight to moderate agreement between measured and predicted data (Kappa coefficient = 0.19–0.56). Using proposed generic assessment criteria, hazard assessment showed that the degree of action for site-specific risk assessment and/or remediation is similar for both measurement methods. This demonstrates that the vis-NIR method may be useful for monitoring hydrocarbon contamination in a petroleum release site.
Mostrar más [+] Menos [-]Relationship between site-specific nitrogen concentrations in mosses and measured wet bulk atmospheric nitrogen deposition across Europe Texto completo
2014
Harmens, Harry | Schnyder, Elvira | Thöni, Lotti | Cooper, David M. | Mills, Gina | Leblond, Sébastien | Mohr, Karsten | Poikolainen, Jarmo | Santamaria, Jesus | Skudnik, Mitja | Zechmeister, Harald G. | Lindroos, Antti-Jussi | Hanus-Illnar, Andrea
To assess the relationship between nitrogen concentrations in mosses and wet bulk nitrogen deposition or concentrations in precipitation, moss tissue and deposition were sampled within a distance of 1 km of each other in seven European countries. Relationships for various forms of nitrogen appeared to be asymptotic, with data for different countries being positioned at different locations along the asymptotic relationship and saturation occurring at a wet bulk nitrogen deposition of ca. 20 kg N ha−1 yr−1. The asymptotic behaviour was more pronounced for ammonium-N than nitrate-N, with high ammonium deposition at German sites being most influential in providing evidence of the asymptotic behaviour. Within countries, relationships were only significant for Finland and Switzerland and were more or less linear. The results confirm previous relationships described for modelled total deposition. Nitrogen concentration in mosses can be applied to identify areas at risk of high nitrogen deposition at European scale.
Mostrar más [+] Menos [-]Year-round grazing to counteract effects of atmospheric nitrogen deposition may aggravate these effects Texto completo
2014
van Dobben, H.F. | Wamelink, G.W.W. | Klimkowska, A. | Slim, P.A. | van Til, M.
Excessive nitrogen input in natural ecosystems is a major threat to biodiversity. A coastal dune area near Amsterdam in the Netherlands suffers from high atmospheric nitrogen deposition affecting sensitive habitats such as fixed coastal dunes with herbaceous vegetation (‘grey dunes’). To mitigate its effect year round grazing was applied from 2007 until 2012. In winter, when natural food supply is low, the cattle received supplementary hay that caused additional inputs of nitrogen. Estimates based on nitrogen contents of hay, as well as of manure, showed the input through winter feeding (c. 3–14 kg N ha−1.y−1) is in the same order of magnitude as both the actual deposition (c. 17 kg N ha−1.y−1) and the critical load for a number of herbaceous habitat types (10–15 kg N ha−1.y−1). Locally, the effect of winter feeding adds to the effect of nitrogen redistribution within the area caused by the cattle's terrain usage. We conclude that winter feeding may aggravate effects of atmospheric nitrogen deposition.
Mostrar más [+] Menos [-]Exposure to polycyclic aromatic hydrocarbons in urban environments: Health risk assessment by age groups Texto completo
2014
Amarillo, Ana C. | Tavera Busso, Iván | Carreras, Hebe
A detailed investigation was conducted into the concentration of polycyclic aromatic hydrocarbons (PAHs) associated with PM10 particles collected during 2012 in an urban area in Cordoba, Argentina. Their composition was studied and the lifetime lung cancer risk resulting from exposure to total and individual PAHs was estimated. Samples of PM10 were collected daily on fiber glass filters with PAHs being extracted with methylene chloride and analyzed by HPLC. Mean PAH concentrations were higher during autumn and winter. In contrast, during warm months, high ambient temperature and wind speed contributed to a decrease in the PAH ambient concentrations. The PAH levels found in the present study were within the range of those reported in other polluted urban areas. However risk factors calculated for exposure to individual and cumulative PAHs exceeded the carcinogenic benchmark level of 1 × 10−6 early in childhood, implying that these PAH concentrations represent a serious risk to public health.
Mostrar más [+] Menos [-]Effets des pollutions atmosphériques sur les cultures et la forêt Texto completo
2014
Castell, Jean-François | Environnement et Grandes Cultures (EGC) ; Institut National de la Recherche Agronomique (INRA)-AgroParisTech | Société Météorologique de France. Paris, FRA.
Effets des pollutions atmosphériques sur les cultures et la forêt. Journée scientifique sur la pollution atmosphérique et les impacts sanitaires
Mostrar más [+] Menos [-]Reprint of On the link between biomagnetic monitoring and leaf-deposited dust load of urban trees: Relationships and spatial variability of different particle size fractions Texto completo
2014
Hofman, Jelle | Wuyts, Karen | Van Wittenberghe, Shari | Brackx, Melanka | Samson, Roeland
Biomagnetic monitoring of urban tree leaves has proven to be a good estimator of ambient particulate matter. We evaluated its relevancy by determining leaf area normalised weight (mg m−2) and SIRM (A) of leaf-deposited particles within three different size fractions (>10 μm, 3–10 μm and 0.2–3 μm) and the SIRM of the leaf-encapsulated particles. Results showed that throughout the in-leaf season, the trees accumulated on average 747 mg m−2 of dust on their leaves, of which 74 mg m−2 was within the 0.2–10 μm (∼PM10) size range and 40 mg m−2 within the 0.2–3 μm (∼PM3) size range. A significant correlation between the SIRM and weight of the surface-deposited particles confirms the potential of biomagnetic monitoring as a proxy for the amount of leaf-deposited particles. Spatial variation of both SIRM and weight throughout the street canyon suggests traffic and wind as key factors for respectively the source and distribution of urban particulates.
Mostrar más [+] Menos [-]Bioaccumulation and trophic transfer of perfluorinated compounds in a eutrophic freshwater food web Texto completo
2014
Xu, Jian | Guo, Chang-Sheng | Zhang, Yuan | Meng, Wei
In this study, the bioaccumulation of perfluorinated compounds from a food web in Taihu Lake in China was investigated. The organisms included egret bird species, carnivorous fish, omnivorous fish, herbivorous fish, zooplankton, phytoplankton, zoobenthos and white shrimp. Isotope analysis by δ13C and δ15N indicated that the carnivorous fish and egret were the top predators in the studied web, occupying trophic levels intermediate between 3.66 and 4.61, while plankton was at the lowest trophic level. Perfluorinated carboxylates (PFCAs) with 9–12 carbons were significantly biomagnified, with trophic magnification factors (TMFs) ranging from 2.1 to 3.7. The TMF of perfluorooctane sulfonate (PFOS) (2.9) was generally comparable to or lower than those of the PFCAs in the same food web. All hazard ratio (HR) values reported for PFOS and perfluorooctanoate (PFOA) were less than unity, suggesting that the detected levels would not cause any immediate health effects to the people in Taihu Lake region through the consumption of shrimps and fish.
Mostrar más [+] Menos [-]Modeling stomatal conductance and ozone uptake of Fagus crenata grown under different nitrogen loads Texto completo
2014
Azuchi, Fumika | Kinose, Yoshiyuki | Matsumura, Tomoe | Kanomata, Tomoaki | Uehara, Yui | Kobayashi, Ayumi | Yamaguchi, Masahiro | Izuta, Takeshi
A multiplicative stomatal conductance model was constructed to estimate stomatal O3 uptake of Fagus crenata exposed to O3 under different N loads to the soil. Our stomatal conductance model included environmental functions such as the stomatal responses of F. crenata to diurnal changes, chronic O3 stress (AOT0), acute O3 stress (O3 concentration), and nitrogen load to soil. The model could explain 62% of the variability in stomatal conductance. We suggest therefore that stomatal closure induced by O3 and N load-induced soil acidification must be taken into account in developing a stomatal conductance model for estimating stomatal O3 uptake for future risk assessment of O3 impact on Japanese forest tree species such as F. crenata.
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