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Effects of ozone on stomatal responses to environmental parameters (blue light, red light, CO2 and vapour pressure deficit) in three Populus deltoides × Populus nigra genotypes
2013
Dumont, Jenny | Spicher, Fabien | Montpied, Pierre | Dizengremel, Pierre | Jolivet, Yves | Le Thiec, Didier
The effect of ozone (O3) on stomatal regulation was studied in three Euramerican poplar genotypes (Populus deltoides × Populus nigra: Carpaccio, Cima and Robusta). The impact of O3 on stomatal conductance responses to variations in blue light, red light, CO2 concentration and vapour pressure deficit (VPD) was studied. Upon O3 exposure, a sluggish response of stomatal movements was observed, characterized by slower reactions to increases in blue light intensity, CO2 concentration and VPD, and lower amplitude of the response to variations in light intensity. That sluggish response should be taken into account in stomatal conductance models for phytotoxic ozone dose (PODY) calculations. The speed of the response to variations in environmental parameters appears as a determining factor of genotype-related sensitivity.
Mostrar más [+] Menos [-]Biomonitors of urban air pollution: Magnetic studies and SEM observations of corticolous foliose and microfoliose lichens and their suitability for magnetic monitoring
2013
Chaparro, Marcos A.E. | Lavornia, Juan M. | Chaparro, Mauro A.E. | Sinito, Ana M.
This study explored the suitability of available lichen species as air pollution biomonitors and assessed their potential for magnetic monitoring in cities. Several lichens on tree bark were collected in urban and industrial sites from Tandil city, as well as control sites. The results showed that magnetite-like minerals were the main magnetic carriers in all sites and samples. However, the concentration varied between clean and polluted sites. In addition, magnetic-grain size-distribution showed clear differences between sites. Observations by scanning electron microscopy showed different particles in a variety of shapes and grain sizes; moreover, the presence of iron oxides and several toxic elements was detected by energy dispersive spectroscopy analysis. Although eleven lichen species were identified that appeared suitable for use as air-pollution monitors, three of them, Parmotrema pilosum, Punctelia hipoleucites and Dirinaria picta, occurred more frequently in the area, thus constituting appropriate species for future monitoring in the study area.
Mostrar más [+] Menos [-]Unravelling remote sensing signatures of plants contaminated with gasoline and diesel: An approach using the red edge spectral feature
2013
Sanches, I.D. | Souza Filho, C.R. | Magalhães, L.A. | Quitério, G.C.M. | Alves, M.N. | Oliveira, W.J.
Pipeline systems used to transport petroleum products represent a potential source of soil pollution worldwide. The design of new techniques that may improve current monitoring of pipeline leakage is imperative. This paper assesses the remote detection of small leakages of liquid hydrocarbons indirectly, through the analysis of spectral features of contaminated plants. Leaf and canopy spectra of healthy plants were compared to spectra of plants contaminated with diesel and gasoline, at increasing rates of soil contamination. Contamination effects were observed both visually in the field and thorough changes in the spectral reflectance patterns of vegetation. Results indicate that the remote detection of small volumes of gasoline and diesel contaminations is feasible based on the red edge analysis of leaf and canopy spectra of plants. Brachiaria grass ranks as a favourable choice to be used as an indicator of HCs leakages along pipelines.
Mostrar más [+] Menos [-]Bioaccumulation of polybrominated diphenyl ethers and several alternative halogenated flame retardants in a small herbivorous food chain
2013
She, Ya-Zhe | Wu, Jiang-Ping | Zhang, Ying | Peng, Ying | Mo, Ling | Luo, Xiao-Jun | Mai, Bi-Xian
Little is known about the bioaccumulation behavior of polybrominated diphenyl ethers (PBDEs) and other halogenated flame retardants (HFRs) in plants and in herbivores. In the present study, PBDEs and several alternative HFRs (AHFRs) were examined in a small herbivorous food chain (paddy soils–rice plant–apple snails) from an electronic waste recycling site in South China. Mean concentrations of total PBDEs were 40.5, 1.81, and 5.54 ng/g dry weight in the soils, rice plant, and apple snails, respectively. Levels of total AHFRs in the samples were comparable to or even higher than those of PBDEs. The calculated plant to soil concentration ratios for most AHFRs (0.05–3.40) were higher than those for PBDEs (0.02–0.23), indicating the greater bioavailability of the AHFRs in the rice plant. All PBDE congeners and Dechlorane Plus (DP) isomers were biomagnified from the rice plant to apple snails, with mean biomagnification factors (BMFs) of 1.1–5.0.
Mostrar más [+] Menos [-]Ecotoxicological effects evoked in hydrophytes by leachates of invasive Acer negundo and autochthonous Alnus glutinosa fallen off leaves during their microbial decomposition
2013
Krevš, Alina | Darginavičienė, Jūratė | Gylytė, Brigita | Grigutytė, Reda | Jurkonienė, Sigita | Karitonas, Rolandas | Kučinskienė, Alė | Pakalnis, R. | Sadauskas, Kazys | Vitkus, Rimantas | Manusadžianas, Levonas
Throughout 90-day biodegradation under microaerobic conditions, invasive to Lithuania species boxelder maple (Acer negundo) leaves lost 1.5-fold more biomass than that of autochthonous black alder (Alnus glutinosa), releasing higher contents of Ntot, ammonium and generating higher BOD7. Boxelder maple leaf leachates were characterized by higher total bacterial numbers and colony numbers of heterotrophic and cellulose-decomposing bacteria than those of black alder. The higher toxicity of A. negundo aqueous extracts and leachates to charophyte cell (Nitellopsis obtusa), the inhabitant of clean lakes, were manifested at mortality and membrane depolarization levels, while the effect on H+-ATPase activity in membrane preparations from the same algae was stronger in case of A. glutinosa. Duckweed (Lemna minor), a bioindicator of eutrophic waters, was more sensitive to leaf leachates of A. glutinosa. Fallen leaves and leaf litter leachates from invasive and native species of trees, which enter water body, affect differently microbial biodestruction and aquatic vegetation in freshwater systems.
Mostrar más [+] Menos [-]Dechlorination of PCBs in the rhizosphere of switchgrass and poplar
2013
Meggo, Richard E. | Schnoor, Jerald L. | Hu, Dingfei
Polychlorinated biphenyl (PCB) congeners (PCB 52, 77, and 153) singly and in mixture were spiked and aged in soil microcosms and subsequently planted with switchgrass (Panicum virgatum) or poplar (Populus deltoids x nigra DN34). The planted reactors showed significantly greater reductions in PCB parent compounds when compared to unplanted systems after 32 weeks. There was evidence of reductive dechlorination in both planted and unplanted systems, but the planted microcosms with fully developed roots and rhizospheres showed greater biotransformation than the unplanted reactors. These dechlorination products accounted for approximately all of the molar mass of parent compound lost. Based on the transformation products, reductive dechlorination pathways are proposed for rhizospheric biotransformation of PCB 52, 77, and 153. This is the first report of rhizosphere biotransformation pathways for reductive dechlorination in marginally aerobic, intermittently flooded soil as evidenced by a mass balance on transformation products.
Mostrar más [+] Menos [-]Comparative effects of several cyclodextrins on the extraction of PAHs from an aged contaminated soil
2013
The objective of the present study was to characterise the polycyclic aromatic hydrocarbons (PAHs) content of an aged contaminated soil and to propose remediation techniques using cyclodextrins (CDs). Four CDs solutions were tested as soil decontamination tool and proved more efficient in extracting PAHs than when an aqueous solution was used; especially two chemically modified CDs resulted in higher extraction percentages than natural β-CD. The highest extraction percentages were obtained for 3-ring PAHs, because of the appropriate size and shape of these compounds relative to those of the hydrophobic cavities of the CDs studied. A detailed mechanistic interpretation of the chemical modification of CDs on the extraction of the different PAHs has been performed, and connected with the role that the different hydrophobicities of the PAHs play in the extraction behaviour observed for the 16 PAHs, limiting their accessibility and the remaining risk of those PAHs not extractable by CDs.
Mostrar más [+] Menos [-]The effects of low-level prenatal lead exposure on birth outcomes
2013
Xie, Xin | Ding, Guodong | Cui, Chang | Chen, Limei | Gao, Yu | Zhou, Yijun | Shi, Rong | Tian, Ying
Exposure to lead early in life may be a risk factor for fetal growth, but little is known about the effects of low-level prenatal lead exposure on birth outcomes. We measured maternal and cord blood lead levels and examined their associations with birth outcomes. Mother–infant pairs (n = 252) were recruited from a rural area located on the south coast of Laizhou Bay between 2010 and 2011. The median levels of maternal and cord blood lead were 3.20 and 2.52 μg/dL, respectively. Increasing maternal blood lead exposure was associated with decreasing birth weight (β = −148.99; 95% CI, −286.33 to −11.66), and a significant negative relationship was found between cord blood lead levels and birth length (β = −0.84; 95% CI, −1.52 to −0.16). Low-level prenatal lead exposure may adversely affect fetal growth. These results may be important for public health and have implications regarding the recommended blood lead levels.
Mostrar más [+] Menos [-]Impact of arsenic on uptake and bio-accumulation of antimony by arsenic hyperaccumulator Pteris vittata
2013
Müller, K. | Daus, B. | Mattusch, J. | Vetterlein, D. | Merbach, I. | Wennrich, R.
Individual uptake of As and Sb species in Pteris vittata have been investigated, but little information is available how uptake is affected if both metalloids are simultaneously present in different amounts. We investigated the uptake of antimony and its speciation in Pteris vittata cultivated in quartz substrate with, versus without, co-contamination with arsenic and a contaminated soil for 7 weeks. Applying HPLC-ICP-MS technique Sb(V), Sb(III), As(III), and As(V) could be identified as main species in aqueous extracts of roots and fronds with up to 230 mg kg−1 of total Sb in the roots. Adding increasing amounts of As to the quartz substrate resulted in increasing uptake of Sb. In contrast to As, which is readily transferred to the fronds, Sb is primarily accumulated in the roots with Sb(V) being the dominant species (>90% of Sb). The addition of As doesn't result in enhanced translocation of Sb into the fronds.
Mostrar más [+] Menos [-]Key factors affecting liver PBDE concentrations in sparrowhawks (Accipiter nisus)
2013
Crosse, John D. | Shore, Richard F. | Jones, K. C. (Kevin C.) | Pereira, M Glória
High PBDE concentrations have been detected in the eggs of the sexually dimorphic Eurasian sparrowhawk (Accipiter nisus) but little is known about contamination levels in adult birds and how this may vary with age and sex. We characterised liver PBDE concentrations in 59 sparrowhawks that had died in central Britain between 1998 and 2009 and determined how concentrations varied with sex, age, body condition and breeding status. Five BDE congeners (99 > 153 > 47 > 100 > 154) predominated and ΣPBDE concentrations were 10–15 fold and 2–3 fold higher in starved than non-starved adult and juvenile sparrowhawks, respectively. This was likely due to a combination of remobilisation of residues from other tissues and liver wastage. Liver ΣPBDE concentrations did not vary with sex but were greater in adults than juveniles, suggestive of accumulation with age. Overall, liver ΣPBDE concentrations ranged from 43.4 to 68,040 ng/g lipid weight, amongst the highest concentrations reported in birds anywhere.
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