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Quality of roof-harvested rainwater – Comparison of different roofing materials Full text
2012
Lee, Ju Young | Bak, Gippeum | Han, Mooyoung
The objective of the study reported in this paper was to assess the quality of harvested rainwater on the basis of the roofing materials used and the presence of lichens/mosses on the roofing surface. Four pilot structures with different roofing materials (i.e., wooden shingle tiles, concrete tiles, clay tiles [Gi-Wa] and galvanized steel) were installed in a field. The galvanized steel was found to be the most suitable for rainwater harvesting applications, with their resulting physical and chemical water quality parameters meeting the Korean guidelines for drinking water quality (e.g., pH (5.8–8.5), TSS <500 mg/L, NO₃ ⁻ < 10 mg/L, SO₄ ²⁻ < 200 mg/L, Al < 0.2 mg/L, Cu < 1 mg/L, Fe < 0.3 mg/L, Pb < 0.05 mg/L, Zn < 1 mg/L, and E. coli (No detection)). In the galvanized steel case, the relatively high water quality was probably due to ultraviolet light and the high temperature effectively disinfecting the harvested rainwater. It was also found that the presence of lichens and mosses may adversely affect the physical, chemical and microbiological quality of rainwater.
Show more [+] Less [-]Reduced soil water availability did not protect two competing grassland species from the negative effects of increasing background ozone Full text
2012
Wagg, Serena | Mills, Gina | Hayes, Felicity | Wilkinson, Sally | Cooper, David | Davies, William J.
Two common (semi-) natural temperate grassland species, Dactylis glomerata and Ranunculus acris, were grown in competition and exposed to two watering regimes: well-watered (WW, 20–40% v/v) and reduced-watered (RW, 7.5–20% v/v) in combination with eight ozone treatments ranging from pre-industrial to predicted 2100 background levels. For both species there was a significant increase in leaf damage with increasing background ozone concentration. RW had no protective effect against increasing levels of ozone-induced senescence/injury. In high ozone, based on measurements of stomatal conductance, we propose that ozone influx into the leaves was not prevented in the RW treatment, in D. glomerata because stomata were a) more widely open than those in less polluted plants and b) were less responsive to drought. Total seasonal above ground biomass was not significantly altered by increased ozone; however, ozone significantly reduced root biomass in both species to differing amounts depending on watering regime.
Show more [+] Less [-]Exploratory study using proton induced X-ray emission analysis and histopathological techniques to determine the toxic burden of environmental pollutants Full text
2012
The aim of this novel research was to determine the toxic burden of increased elements in water resources on the inhabitant wild animals (squirrels, turtles, bats), using particle induced x-ray emission (PIXE) and histopathological approaches. PIXE analysis of skin, muscle, lung, liver and kidney revealed significant increase in Al, Cl, Fe, Mg, Mn, Si and V. Moreover, data clearly reflect a significant (P < 0.001) deposition of toxic elements (Al, Cl, Fe and K) in the lung producing interstitial/proliferative pneumonitis, intra-alveolar hemorrhages, and thickening of alveolar capillary walls. The results obtained from the liver samples emphasized that majority of the animals were intoxicated with Cl, Mg, S, Si and V, which have produced profound deterioration and swelling of the hepatocytes. Likewise, histopathology of the kidney sections spotlighted severe nephritis and degenerative changes, which could be associated with the elevated amount of Al, Cl and Mg. This data undoubtedly provide relevant information on the heavy burden of toxic elements and their pathological outcomes in wild animals and highlight their potential risks for human exposure. Thus, the information provided is critical for developing effective strategies in dealing with health hazards associated with elemental exposures.
Show more [+] Less [-]Ozone-induced stomatal sluggishness develops progressively in Siebold's beech (Fagus crenata) Full text
2012
Hoshika, Yasutomo | Watanabe, Makoto | Inada, Naoki | Koike, Takayoshi
We investigated the effects of ozone and leaf senescence on steady-state stomatal conductance and stomatal response to light variation. Measurements were carried out in a free-air ozone exposure experiment on a representative deciduous broadleaved tree species in Japan (Fagus crenata). Both steady-state and dynamic stomatal response to light variation varied intrinsically with season due to leaf senescence. Ozone induced the decrease in steady-state leaf gas exchange and the sluggish stomatal closure progressively. These findings suggest that ozone reduces the ability of plants to adapt to a fluctuating light environment under natural conditions, and therefore impairs plant growth and ability to control water loss.
Show more [+] Less [-]A multi-technique investigation of copper and zinc distribution, speciation and potential bioavailability in biosolids Full text
2012
Donner, E. | Ryan, C.G. | Howard, D.L. | Zarcinas, B. | Scheckel, K.G. | McGrath, S.P. | de Jonge, M.D. | Paterson, D. | Naidu, R. | Lombi, E.
The use of biosolids in agriculture continues to be debated, largely in relation to their metal contents. Our knowledge regarding the speciation and bioavailability of biosolids metals is still far from complete. In this study, a multi-technique approach was used to investigate copper and zinc speciation and partitioning in one contemporary and two historical biosolids used extensively in previous research and field trials. Using wet chemistry and synchrotron spectroscopy techniques it was shown that copper/zinc speciation in the biosolids was largely equivalent despite the biosolids being derived from different countries over a 50 year period. Furthermore, copper speciation was consistently dominated by sorption to organic matter whereas Zn partitioned mainly to iron oxides. These data suggest that the results of historical field trials are still relevant for modern biosolids and that further risk assessment studies should concentrate particularly on Cu as this metal is associated with the mineralisable biosolids fraction.
Show more [+] Less [-]Impacts of urbanization on carbon balance in terrestrial ecosystems of the Southern United States Full text
2012
Zhang, Chi | Tian, Hanqin | Chen, Guangsheng | Chappelka, Arthur | Xu, Xiaofeng | Ren, Wei | Hui, Dafeng | Liu, Mingliang | Lu, Chaoqun | Pan, Shufen | Lockaby, Graeme
Using a process-based Dynamic Land Ecosystem Model, we assessed carbon dynamics of urbanized/developed lands in the Southern United States during 1945–2007. The results indicated that approximately 1.72 (1.69–1.77) Pg (1P = 10¹⁵) carbon was stored in urban/developed lands, comparable to the storage of shrubland or cropland in the region. Urbanization resulted in a release of 0.21 Pg carbon to the atmosphere during 1945–2007. Pre-urbanization vegetation type and time since land conversion were two primary factors determining the extent of urbanization impacts on carbon dynamics. After a rapid decline of carbon storage during land conversion, an urban ecosystem gradually accumulates carbon and may compensate for the initial carbon loss in 70–100 years. The carbon sequestration rate of urban ecosystem diminishes with time, nearly disappearing in two centuries after land conversion. This study implied that it is important to take urbanization effect into account for assessing regional carbon balance.
Show more [+] Less [-]Release of native and mass labelled PCDD/PCDF from soil heated to simulate bushfires Full text
2012
Black, Robert R. | Meyer, Carl P. | Yates, Alan | Zwieten, Lukas van | Chittim, Brock G. | Gaus, Caroline | Mueller, Jochen F.
Soil is an important reservoir of PCDD/PCDF, which can be released when environmental conditions change. Fire is an extreme event that can increase the surface temperatures of soil substantially, yet little is known of the role soil plays in the emission of PCDD/PCDF. Soil containing native PCDD/PCDF was fortified with a mixture of mass labelled PCDD/PCDF and heated between 150°C and 400°C. Both native and mass labelled PCDD/PCDF were released from the soil beyond 200°C. Release of the mass labelled compounds was linearly related to temperature with up to 9 % found in the air stream at 400°C. The release of some native PCDD/PCDF was much greater. At 400°C, emission of 1,2,3,7,8-Cl₅DD was 300% compared to pre-experimental soil. Emission of PCDD/PCDF from soil during bushfires is a relevant process and may originate from both volatilization and formation via de novo or precursor pathways, or dechlorination.
Show more [+] Less [-]A stomatal ozone flux–response relationship to assess ozone-induced yield loss of winter wheat in subtropical China Full text
2012
Feng, Zhaozhong | Tang, Haoye | Uddling, Johan | Pleijel, Håkan | Kobayashi, Kazuhiko | Zhu, Jianguo | Oue, Hiroki | Guo, Wenshan
Stomatal ozone flux and flux–response relationships were derived for winter wheat (Triticum aestivum L.) grown under fully open-air ozone fumigation. A stomatal conductance (gₛₜₒ) model developed for wheat in Europe was re-parameterized. Compared to European model parameterizations, the main changes were that the VPD and radiation response functions were made less and more restrictive, respectively, and that the temperature function was omitted. The re-parameterized gₛₜₒ model performed well with an r² value of 0.76. The slope and intercept of the regression between observed and predicted gₛₜₒ were not significantly different from 1 to 0, respectively. An ozone uptake threshold of 12 nmol m⁻² s⁻¹ was judged most reasonable for the wheat flux–response relationship in subtropical China. Judging from both flux- and concentration-based relationships, the cultivars investigated seem to be more sensitive to ozone than European cultivars. The new flux–response relationship can be applied to ozone risk assessment in subtropical regions.
Show more [+] Less [-]Biological effects of environmentally relevant concentrations of the pharmaceutical Triclosan in the marine mussel Perna perna (Linnaeus, 1758) Full text
2012
Cortez, Fernando Sanzi | Seabra Pereira, Camilo Dias | Santos, Aldo Ramos | Cesar, Augusto | Choueri, Rodrigo Brasil | Martini, Gisela de Assis | Bohrer-Morel, Maria Beatriz
Triclosan (5-Chloro-2-(2,4-dichlorophenoxy) phenol) is an antibacterial compound widely employed in pharmaceuticals and personal care products. Although this emerging compound has been detected in aquatic environments, scarce information is found on the effects of Triclosan to marine organisms. The aim of this study was to evaluate the toxicity of a concentration range of Triclosan through fertilization assay (reproductive success), embryo-larval development assay (early life stage) and physiological stress (Neutral Red Retention Time assay - NRRT) (adult stage) in the marine sentinel organism Perna perna. The mean inhibition concentrations for fertilization (IC₅₀ = 0.490 mg L⁻¹) and embryo-larval development (IC₅₀ = 0.135 mg L⁻¹) tests were above environmental relevant concentrations (ng L⁻¹) given by previous studies. Differently, significant reduction on NRRT results was found at 12 ng L⁻¹, demonstrating the current risk of the continuous introduction of Triclosan into aquatic environments, and the need of ecotoxicological studies oriented by the mechanism of action of the compound.
Show more [+] Less [-]The effects of the urban built environment on the spatial distribution of lead in residential soils Full text
2012
Schwarz, K. | Pickett, Steward T.A. | Lathrop, Richard G. | Weathers, Kathleen C. | Pouyat, Richard V. | Cadenasso, Mary L.
Lead contamination of urban residential soils is a public health concern. Consequently, there is a need to delineate hotspots in the landscape to identify risk and facilitate remediation. Land use is a good predictor of some environmental pollutants. However, in the case of soil lead, research has shown that land use is not a useful proxy. We hypothesize that soil lead is related to both individual landscape features at the parcel scale and the landscape context in which parcels are embedded. We sampled soil lead on 61 residential parcels in Baltimore, Maryland using field-portable x-ray fluorescence. Thirty percent of parcels had average lead concentrations that exceeded the USEPA limit of 400 ppm and 53% had at least one reading that exceeded 400 ppm. Results indicate that soil lead is strongly associated with housing age, distance to roadways, and on a parcel scale, distance to built structures.
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