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Effect of Pb toxicity on leaf growth, antioxidant enzyme activities, and photosynthesis in cuttings and seedlings of Jatropha curcas L 全文
2012
Shu, Xiao | Yin, LiYan | Zhang, QuanFa | Wang, Weibo
BACKGROUND: Cuttings and seedlings of Jatropha curcas L. were exposed to different regimes of lead (Pb) stress as Pb(NO3)2 at 0 (CK), 0.5, 1, 2, 3, and 4 mM kg−1 soil. OBJECTIVES: The effect of Pb treatment on the root length, tolerance index, photosynthetic pigments, photosynthetic activity, lipid peroxidation, and antioxidant enzyme was studied in a greenhouse pot experiment. RESULTS: The results showed that root lengths and tolerance index decreased with increase of Pb concentration, but tolerance index of cuttings was always lower than those of the seedlings. For cuttings, Pb treatment had a stimulating effect on chlorophyll content, carotenoid content, and superoxide dismutase (SOD) activity at low concentration and an inhibitory effect at higher concentration. For seedlings, SOD activity increased with increasing Pb concentration. In both seedlings and cuttings, Pb caused inhibition of leaf growth and photosynthesis, and induced the membrane damage which was more obvious in the cuttings. In comparison with the control, the dynamic tendency of catalase and perxidase activities in the leaves of Pb-stressed plants all ascended, and then declined. DISCUSSION: The increase in enzyme activities demonstrated that seedlings were more tolerant to Pb stress than cuttings. These results also indicate that the antioxidant system may play an important role in eliminating or alleviating the toxicity of Pb in J. curcas seedlings and cuttings. The accumulation of Pb increased in a concentration-dependent manner; however, its translocation from root to shoot was low. The cuttings accumulated significantly higher Pb in roots than seedlings.
显示更多 [+] 显示较少 [-]Characterization of particulate polycyclic aromatic hydrocarbons in the east of France urban areas 全文
2012
Delhomme, Olivier | Millet, Maurice
BACKGROUND: Air samples collected on three different urban sites in East of France (Strasbourg, Besançon, and Spicheren), from April 2006 to January 2007, were characterized to measure the concentrations of polycyclic aromatic hydrocarbons (PAHs) in the particulate phase (PM10) and to examine their seasonal variation, diurnal variations, and emission sources. RESULTS: The average concentrations of ΣPAHs were 12.6, 9.5, and 8.9 ng m−3 for the Strasbourg, Besançon, and Spicheren sites, respectively. Strong seasonal variations of individual PAH concentrations were found at the three sampling sites, with higher levels in the winter that gradually decreased to the lowest levels in the summer. The diurnal variations of PAH concentrations in summer presented highest concentrations during the morning (04:00–10:00) and the evening (16:00–22:00) times, indicating the important contribution from vehicle emissions, in the three sampling sites. Furthermore, the ratio of BaP/BeP suggests that the photochemical degradation of PAHs can suppress their concentrations in the midday/afternoon (10:00–16:00), time interval of highest global irradiance. In winter, concentrations of PAH were highest during the evening (16:00–22:00) time, suggesting that domestic heating can potentially be an important source for particulate PAH, for the three sampling sites. CONCLUSION: Diagnostic ratios were used to identify potential sources of PAHs. Results showed that vehicle emissions may be the major source of PAHs, especially in summer, with a prevalent contribution of diesel engines rather than gasoline engines at the three sites studied, independently of the seasons.
显示更多 [+] 显示较少 [-]Investigation of environmental contamination of mono-isopropylnaphthalene, di-isopropylnaphthalene and tri-isopropylnaphthalene in Hyogo in Japan 全文
2012
Suzuki, Motoharu | Matsumura, Chisato | Nakano, Takeshi | Imaishi, Hiromasa
Di-isopropylnaphthalene (DIPN) has highly persistent and bioaccumulative properties, and a large amount of DIPN is used as a PCB substitute in Japan. However, DIPN in the environment has not been thoroughly investigated. In addition, mono-isopropylnaphthalene (MIPN) and tri-isopropylnaphthalene (TIPN), which are the homologues of DIPN, have similar properties to DIPN. In this study, simultaneous analytical methods for MIPN, DIPN, and TIPN for air, environmental water, sediment, and biological samples were developed, and the resultant contamination caused by each in the environment was investigated. DIPN was detected at 1.1 ± 0.38 ng/m3 in air and between < 1.9 and 9.8 ng/L in river water, but MIPN and TIPN were not. In Lateolabrax japonicas (Japanese sea perch), TIPN was detected from only females at between 0.65 and 1.4 ng/g-wet. DIPN was detected from all perches at between 1.2 and 3.4 ng/g-wet. DIPN and TIPN isomer fingerprints in females were different from those in the reference standard stock solution ones. In sediments, MIPN, DIPN, and TIPN were detected at between < 0.16 and 8.6 ng/g-dry, between < 1.1 and 4400 ng/g-dry, and between < 0.83 and 500 ng/g-dry, respectively. The contamination trend of DIPN in the sediments was similar to that of PCBs.
显示更多 [+] 显示较少 [-]Biodegradability and ecotoxicitiy of tramadol, ranitidine, and their photoderivatives in the aquatic environment 全文
2012
Bergheim, Marlies | Gieré, Reto | Kümmerer, Klaus
PURPOSE: This study was designed to assess the fate and the overall potential impacts of the widely prescribed drugs ranitidine and tramadol after their introduction into the aquatic environment. METHODS: The probability to detect these two drugs in the aquatic environment was studied by analyzing their abiotic and biotic degradation properties. For this purpose, samples were irradiated with different light sources, and three widely used biodegradability tests from the OECD series, the closed bottle test (OECD 301 D), the manometric respirometry test (OECD 301 F) and the Zahn–Wellens test (OECD 302 B), were conducted. The ecotoxicity of the photolytically formed transformation products was assessed by performing the bacterial growth inhibition test (EN ISO 10712). Furthermore, quantitative structure–activity relationship analysis and a risk analysis based on the calculation of the predicted environmental concentrations have also been conducted to assess the environmental risk potential of the transformation products. The possible formation of stable products by microbial or photolytical transformation has been investigated with DOC and LC-MS analytics. RESULTS: In the present study, neither ranitidine, nor tramadol, nor their photoderivatives were found to be readily or inherently biodegradable according to test guidelines. The photolytic transformation was faster under a UV lamp compared to the reaction under an Xe lamp with a spectrum that mimics sunlight. No chronic toxicity against bacteria was found for ranitidine or its photolytic decomposition products, but a low toxicity was detected for the resulting mixture of the photolytic transformation products of tramadol. CONCLUSIONS: The study demonstrates that transformation products may have a higher environmental risk potential than the respective parent compounds.
显示更多 [+] 显示较少 [-]Characterization of PM10 atmospheric aerosol at urban and urban background sites in Fuzhou city, China 全文
2012
Xu, Lingling | Chen, Xiaoqiu | Chen, Jinsheng | Zhang, Fuwang | He, Chi | Du, Ke | Wang, Yang
BACKGROUND: PM10 aerosol samples were simultaneously collected at two urban and one urban background sites in Fuzhou city during two sampling campaigns in summer and winter. PM10 mass concentrations and chemical compositions were determined. METHODS: Water-soluble inorganic ions (Cl−, NO 3 − , SO 4 2− , NH 4 + , K+, Na+, Ca2+, and Mg2+), carbonaceous species (elemental carbon and organic carbon), and elements (Al, Si, Mg, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, As, Se, Br, and Pb) were detected using ion chromatography, thermal/optical reflectance, and proton-induced X-ray emission methods, respectively. RESULTS: PM10 mass concentrations, as well as most of the chemical components, were significantly increased from urban background to urban sites, which were due to enhanced anthropogenic activities in urban areas. Elements, carbonaceous species, and most of the ions were more uniformly distributed at different types of sites in winter, whereas secondary ion SO 4 2− , NO 3 − , and NH 4 + showed more evident urban-background contrast in this season. The chemical mass closure indicated that mineral dust, organic matters, and sulfate were the most abundant components in PM10. The sum of individually measured components accounted for 86.9–97.7% of the total measured PM10 concentration, and the discrepancy was larger in urban area than in urban background area. CONCLUSION: According to the principal component analysis–multivariate linear regression model, mineral dust, secondary inorganic ions, sea salt, and motor vehicle were mainly responsible for the PM10 particles in Fuzhou atmosphere, and contributed 19.9%, 53.3%, 21.3%, and 5.5% of PM10, respectively.
显示更多 [+] 显示较少 [-]Distribution and sources of polycyclic aromatic hydrocarbons (PAHs) in sediment from the upper reach of Huaihe River, East China 全文
2012
Feng, Jinglan | Zhai, Mengxiao | Sun, Jianhui | Liu, Qun
INTRODUCTION: To assess the status of polycyclic aromatic hydrocarbons (PAHs) contamination in sediments from the upper reach of Huaihe River, East China, 16 surface sediment samples were collected in March 2007 and analyzed for 16 USEPA priority PAHs. RESULTS AND DISCUSSION: The results indicated that the total concentrations of 16 PAHs (∑PAHs) were 95.2–877.5 μg kg−1 dry weight (dw) with a mean value of 370.8 μg kg−1 dw for the main stream, 85.7–935.2 μg kg−1 dw with a mean concentration of 480.7 μg kg−1 dw for tributaries, and 144.8–303.2 μg kg−1 dw with an average concentration of 224.0 μg kg−1 dw for lakes. PAHs pollution was closely related to sewage input and industrial activities. Furthermore, the distribution of PAHs in sediments from the main stream indicated that the input of tributaries was an important factor for Huaihe River. In comparison to a worldwide survey of sedimentary PAHs concentrations, PAHs pollution in Huaihe River sediments was ranked as low to moderate. The dominant compounds in surface sediment samples were four-ring and five-ring PAH compounds. CONCLUSION: Selected PAH ratios suggested that PAHs mainly came from the contamination of pyrogenic processes, such as coal and biomass combustion. Risk assessment indicated that PAHs in sedimentary environment in the upper reach of Huaihe River may cause mild toxic effects but would not cause immediate biological effects.
显示更多 [+] 显示较少 [-]Impact of two different humic substances on selected coccal green algae and cyanobacteria—changes in growth and photosynthetic performance 全文
2012
Bährs, Hanno | Steinberg, Christian E. W.
BACKGROUND, AIM AND SCOPE: There is growing evidence to show that dissolved humic substances, HSs, can directly interact with freshwater organisms, such as phototrophic organisms, cladocerans, amphipods and fish. The responses are—at least in part—transcriptionally controlled. These interactions can lead to stress symptoms in the exposed organisms. In phototrophs, stress symptoms include a reduction in photosynthetic oxygen release and antioxidative stress. Besides the direct effects, HSs also cause indirect effects that provoke different physiological adaptations in the phototrophs. MATERIALS AND METHODS: The HS-influenced photosynthetic performance and stress response of two different green algae, Pseudokirchneriella subcapitata (Koršikov) Hindák and Monoraphidium braunii (Nägeli in Kützing) Komárková-Legnerová, and two cyanobacterial species, Synechocystis sp. (PCC 6803, Institut Pasteur) and Microcystis aeruginosa (PCC 7806, Institut Pasteur), were tested. Two humic preparations were applied, the synthetic HS1500 and HuminFeed®, HF, which had previously been proven effective in bioassays with invertebrates and a water mould. RESULTS AND DISCUSSION: When the algae were grown near light saturation, most of the tested species were positively affected by HSs in growth rate or chlorophyll content. Cell sizes decreased with increasing HS concentrations for all eukaryotic phototrophs, except for the cyanobacteria. After 4 to 5 days of cultivation at the highest HS exposure, there was a decrease in total dry weight due to reduced cell sizes in contrast to an increase in cell numbers. With the exception of Synechocystis, the dry weight per cell ratio decreased with increasing HS concentration. The efficiency of utilizing absorbed light quanta increased with increasing HS concentrations; the maximum quantum yield of photosystem II (ΦPSIImax) was higher in all of the tested species, with the exception of M. aeruginosa, after exposure to HS. CONCLUSION: The applied humic preparations did not interact directly with PSII, but changed the physiological state of the algae, especially the photosynthetic performance. Neither the green algae nor the cyanobacteria were inhibited in growth or negatively affected in their photosynthetic performance. The exposure to lower concentrations of HS stimulated better growth of the phototrophs. The tested humic preparations obviously did not have the potency to act as xenobiotic stressors; furthermore, there was no sign of herbicide potency.
显示更多 [+] 显示较少 [-]Plasma esterases in the tegu lizard Tupinambis merianae (Reptilia, Teiidae): impact of developmental stage, sex, and organophosphorus in vitro exposure 全文
2012
Basso, Agustín | Attademo, Andrés M. | Lajmanovich, Rafael C. | Peltzer, Paola M. | Junges, Celina | Cabagna, Mariana C. | Fiorenza, Gabriela S. | Sanchez-Hernandez, Juan Carlos
PURPOSE: In this study, we determined normal serum butyrylcholinesterase (BChE) and carboxylesterase (CbE) activities in Tupinambis merianae in order to obtain reference values for organophosphorus pesticide monitoring. METHODS: Forty-two T. merianae individuals were grouped by sex and size to identify potential differences in their enzyme levels to allow for proper representation of normal values for females, males, juveniles, and hatchlings. Mean CbE was determined using two model substrates: alpha-naphtylacetate (α-NA) and p-nitrophenyl valerate (4-NPV). BChE and CbE sensitivity to malaoxon (Mx) was also evaluated as well as the possibility of BChE reactivation with pyridine-2-aldoxime methochloride (2-PAM). RESULTS: Mean adult females’ BChE was significantly higher than adult males, juveniles, and hatchlings. No significant differences were found between groups regarding CbE. CbE (4-NPV) activity showed slightly negative correlation with lizard snout–vent length, while BChE and CbE (α-NA) showed no correlation with body size. Apparent IC50 values for BChE and CbE (α-NA) suggested different sensitivities among groups. CbE (4-NPV) could not be inhibited. All Mx-inhibited groups treated with 2-PAM in a final concentration of 2.8 mM showed clear signs of reactivation. CONCLUSIONS: In conclusion, the results demonstrate that (1) plasma esterase activity did not vary with age and sex, except for BChE activity, and (2) because biological and environmental variables could be confounding factors in the response of plasma cholinesterases, complementary biomarkers like CbE inhibition and oxime-induced reactivation of esterases are strongly recommended.
显示更多 [+] 显示较少 [-]Source apportionment of ultrafine and fine particle concentrations in Brisbane, Australia 全文
2012
Friend, Adrian J. | Ayoko, G. A. (Godwin A.) | Jayaratne, E Rohan | Jamriska, Milan | Hopke, Philip K. | Morawska, L. (Lidia)
PURPOSE: To investigate the significance of sources around measurement sites, assist the development of control strategies for the important sources and mitigate the adverse effects of air pollution due to particle size. METHODS: In this study, sampling was conducted at two sites located in urban/industrial and residential areas situated at roadsides along the Brisbane Urban Corridor. Ultrafine and fine particle measurements obtained at the two sites in June–July 2002 were analysed by positive matrix factorization. RESULTS: Six sources were present, including local traffic, two traffic sources, biomass burning and two currently unidentified sources. Secondary particles had a significant impact at site 1, while nitrates, peak traffic hours and main roads located close to the source also affected the results for both sites. CONCLUSIONS: This significant traffic corridor exemplifies the type of sources present in heavily trafficked locations and future attempts to control pollution in this type of environment could focus on the sources that were identified.
显示更多 [+] 显示较少 [-]Development of a country-specific CO₂ emission factor for domestic anthracite in Korea, 2007–2009 全文
2012
Lee, Jeongwoo | Kim, Jinsu | Kim, Seungjin | Im, Gikyo | Lee, Seehyung | Jeon, Eui-Chan
INTRODUCTION: Korea has been making efforts to reduce greenhouse gas (GHG) emissions, including a voluntary commitment to the target of a 30% reduction, based on business-as-usual of the total GHG emission volume, by 2020; 2006 IPCC Guidelines provided default values, applying country-specific emission factors was recommended when estimating national greenhouse gas emissions. RESULTS AND DISCUSSION: This study focused on anthracite produced in Korea in order to provide basic data for developing country-specific emission factor. This study has estimated CO₂ emission factors to use worksheet of which five steps consisted according to the fuel analysis method. CONCLUSION: As a result, the average of net colorific value for 3 years (2007∼2009) was 4,519 kcal/kg, and the CO₂ emission factor was calculated to be 111,446 kg/TJ, which is about 11.8% lower than the 2006 IPCC guidelines default value, and about 7.9% higher than the US EPA emission factor.
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