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On the use of small and cheaper sensors and devices for indicative citizen-based monitoring of respirable particulate matter Texte intégral
2015
Jovašević-Stojanović, Milena | Bartonova, Alena | Topalović, Dušan | Lazović, Ivan | Pokrić, Boris | Ristovski, Zoran
Respirable particulate matter present in outdoor and indoor environments is a health hazard. The particle concentrations can quickly change, with steep gradients on short temporal and spatial scales, and their chemical composition and physical properties vary considerably. Existing networks of aerosol particle measurements consist of limited number of monitoring stations, and mostly aim at assessment of compliance with air quality legislation regulating mass of particles of varying sizes. These networks can now be supplemented using small portable devices with low-cost sensors for assessment of particle mass that may provide higher temporal and spatial resolution if we understand the capabilities and characteristics of the data they provide. This paper overviews typical currently available devices and their characteristics. In addition it is presented original results of measurement and modelling in the aim of one low-cost PM monitor validation.
Afficher plus [+] Moins [-]Will technological modernization for power generation at an oil refinery diminish the risks from air pollution to the Atlantic Rainforest in Cubatão, SE Brazil? Texte intégral
2015
Nakazato, Ricardo K. | Rinaldi, Mirian C.S. | Domingos, Marisa
We assessed the level of atmospheric contamination by S, N and metals before, during and after the installation of a new thermoelectric plant that provides power to an oil refinery in Cubatão, SE Brazil. We measured the foliar accumulation in Lolium multiflorum “Lema” with the aim of evaluating risks to the Atlantic Rainforest that grows in the region. Al, Co, Cr, Cu, K, N, Ni, S, V and Zn were appropriate markers of the new air contamination profile associated with the modern technology. With the exception of V, the leaf contents of these elements significantly increased between the pre-operation to post-operation phases (Al, Co, N, K, S), or only during the transition phase (Zn, Cu, Cr, Ni), and returned to the previous levels after the total shutdown of the old system. Therefore, the expected environmental gain was not achieved with the installation of the new technology.
Afficher plus [+] Moins [-]Reconnaissance of contaminants in larval Pacific lamprey (Entosphenus tridentatus) tissues and habitats in the Columbia River Basin, Oregon and Washington, USA Texte intégral
2015
Nilsen, Elena B. | Hapke, Whitney B. | McIlraith, Brian | Markovchick, Dennis
Pacific lampreys (Entosphenus tridentatus) have resided in the Columbia River Basin for millennia and have great ecological and cultural importance. The role of habitat contamination in the recent decline of the species has rarely been studied and was the main objective of this effort. A wide range of contaminants (115 analytes) was measured in sediments and tissues at 27 sites across a large geographic area of diverse land use. This is the largest dataset of contaminants in habitats and tissues of Pacific lamprey in North America and the first study to compare contaminant bioburden during the larval life stage and the anadromous, adult portion of the life cycle. Bioaccumulation of pesticides, flame retardants, and mercury was observed at many sites. Based on available data, contaminants are accumulating in larval Pacific lamprey at levels that are likely detrimental to organism health and may be contributing to the decline of the species.
Afficher plus [+] Moins [-]Combined thermal and herbicide stress in functionally diverse coral symbionts Texte intégral
2015
van Dam, J.W. | Uthicke, S. | Beltran, V.H. | Mueller, J.F. | Negri, A.P.
Most reef building corals rely on symbiotic microalgae (genus Symbiodinium) to supply a substantial proportion of their energy requirements. Functional diversity of different Symbiodinium genotypes, endorsing the host with physiological advantages, has been widely reported. Yet, the influence of genotypic specificity on the symbiont's susceptibility to contaminants or cumulative stressors is unknown. Cultured Symbiodinium of presumed thermal-tolerant clade D tested especially vulnerable to the widespread herbicide diuron, suggesting important free-living populations may be at risk in areas subjected to terrestrial runoff. Co-exposure experiments where cultured Symbiodinium were exposed to diuron over a thermal stress gradient demonstrated how fast-growing clade C1 better maintained photosynthetic capability than clade D. The mixture toxicity model of Independent Action, considering combined thermal stress and herbicide contamination, revealed response additivity for inhibition of photosynthetic yield in both tested cultures, emphasizing the need to account for cumulative stressor impacts in ecological risk assessment and resource management.
Afficher plus [+] Moins [-]Canopy-level stomatal narrowing in adult Fagus sylvatica under O3 stress – Means of preventing enhanced O3 uptake under high O3 exposure? Texte intégral
2015
Matyssek, R. | Baumgarten, M. | Hummel, U. | Häberle, K.-H. | Kitao, M. | Wieser, G.
Spatio-temporally consistent O3 doses are demonstrated in adult Fagus sylvatica from the Kranzberg Forest free-air fumigation experiment, covering cross-canopy and whole-seasonal scopes through sap flow measurement. Given O3-driven closure of stomata, we hypothesized enhanced whole-tree level O3 influx to be prevented under enhanced O3 exposure. Although foliage transpiration rate was lowered under twice-ambient O3 around noon by 30% along with canopy conductance, the hypothesis was falsified, as O3 influx was raised by 25%. Nevertheless, the twice-ambient/ambient ratio of O3 uptake was smaller by about 20% than that of O3 exposure, suggesting stomatal limitation of uptake. The O3 response was traceable from leaves across branches to the canopy, where peak transpiration rates resembled those of shade rather than sun branches. Rainy/overcast-day and nightly O3 uptake is quantified and discussed. Whole-seasonal canopy-level validation of modelled with sap flow-derived O3 flux becomes available in assessing O3 risk for forest trees.
Afficher plus [+] Moins [-]Hexabromocyclododecane flame retardant in Antarctica: Research stations as sources Texte intégral
2015
Chen, Da | Hale, Robert C. | La Guardia, Mark J. | Luellen, Drew | Kim, Stacy | Geisz, Heidi N.
Historical persistent organic pollutants (POPs) are banned from Antarctica under international treaty; but contemporary-use POPs can enter as additives within polymer and textile products. Over their useful lives these products may release additives in-situ. Indeed, we observed 226 and 109 ng/g dry weight (dw) of the total concentrations of α-, β- and γ-hexabromocyclododecane (HBCD) in indoor dust from McMurdo Station (U.S.) and Scott Station (New Zealand), respectively. Sewage sludge collected from wastewater treatment facilities at these stations exhibited ∑HBCD of 45 and 69 ng/g dw, respectively. Contaminants originally within the bases may exit to the local outdoor environment via wastewaters. Near McMurdo, maximum ∑HBCD levels in surficial marine sediments and aquatic biota (invertebrates and fish) were 2350 ng/g (total organic carbon basis) and 554 ng/g lipid weight, respectively. Levels declined with distance from McMurdo. Our results illustrate that Antarctic research stations serve as local HBCD sources to the pristine Antarctic environment.
Afficher plus [+] Moins [-]Parametric retrieval model for estimating aerosol size distribution via the AERONET, LAGOS station Texte intégral
2015
Emetere, Moses Eterigho | Akinyemi, Marvel Lola | Akin-Ojo, Omololu
The size characteristics of atmospheric aerosol over the tropical region of Lagos, Southern Nigeria were investigated using two years of continuous spectral aerosol optical depth measurements via the AERONET station for four major bands i.e. blue, green, red and infrared. Lagos lies within the latitude of 6.465°N and longitude of 3.406°E. Few systems of dispersion model was derived upon specified conditions to solve challenges on aerosols size distribution within the Stokes regime. The dispersion model was adopted to derive an aerosol size distribution (ASD) model which is in perfect agreement with existing model. The parametric nature of the formulated ASD model shows the independence of each band to determine the ASD over an area. The turbulence flow of particulates over the area was analyzed using the unified number (Un). A comparative study via the aid of the Davis automatic weather station was carried out on the Reynolds number, Knudsen number and the Unified number. The Reynolds and Unified number were more accurate to describe the atmospheric fields of the location. The aerosols loading trend in January to March (JFM) and August to October (ASO) shows a yearly 15% retention of aerosols in the atmosphere. The effect of the yearly aerosol retention can be seen to partly influence the aerosol loadings between October and February.
Afficher plus [+] Moins [-]Are imported consumer products an important diffuse source of PFASs to the Norwegian environment? Texte intégral
2015
Vestergren, Robin | Herzke, Dorte | Wang, Thanh | Cousins, Ian T.
The aim of this study was to measure perfluoroalkyl substances in a selection of imported consumer products (n = 45) and estimate population normalized emission rates during the use phase. 6:2 and 8:2 fluorotelomer alcohol (FTOH) were found in the highest concentrations ranging from <MDL to 374 and 163 μg m−2 respectively. Concentrations of FTOHs were approximately 2–3 orders of magnitude higher than those of perfluoroalkyl carboxylic acids (PFCAs). Although perfluorooctane sulfonate (PFOS) was detected in one carpet sample at 1.7 μg m−2, the majority of samples complied with regulatory limits for PFOS in the EU. Population normalized emission rates of perfluorooctanoic acid, 6:2 FTOH and 8:2 FTOH from imported consumer products were estimated to be 6.6, 2130 and 197 μg year−1 capita−1 respectively for the “intermediate” emission scenario. The results from this study suggest that emissions from imported products would have a small impact on the environmental concentrations of perfluoroalkyl acids on a regional scale.
Afficher plus [+] Moins [-]Are levels of perfluoroalkyl substances in soil related to urbanization in rapidly developing coastal areas in North China? Texte intégral
2015
Meng, Jing | Wang, Tieyu | Wang, Pei | Zhang, Yueqing | Li, Qifeng | Lü, Yonglong | Giesy, John P.
Concentrations of 13 perfluoroalkyl substances (PFASs) were quantified in 79 surface soil samples from 17 coastal cities in three provinces and one municipality along the Bohai and Yellow Seas. The ∑PFASs concentrations ranged from less than limitation of quantification (LOQ) to 13.97 ng/g dry weight (dw), with a mean of 0.98 ng/g dw. The highest concentration was observed along the Xiaoqing River from Shandong province, followed by that from the Haihe River in Tianjin (10.62 ng/g dw). Among four regions, ∑PFASs concentrations decreased in the order of Tianjin, Shandong, Liaoning and Hebei, which was consistent with levels of urbanization. Fluorine chemical industries allocated in Shandong and Liaoning played important roles in terms of point emission and contamination of PFASs, dominated by perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS). Intensive anthropogenic activities involved in urbanization possibly resulted in increasing releases of PFASs from industrial and domestic sources.
Afficher plus [+] Moins [-]Persistent and emerging micro-organic contaminants in Chalk groundwater of England and France Texte intégral
2015
Lapworth, D.J. | Baran, N. | Stuart, M.E. | Manamsa, K. | Talbot, J.
The Chalk aquifer of Northern Europe is an internationally important source of drinking water and sustains baseflow for surface water ecosystems. The areal distribution of microorganic (MO) contaminants, particularly non-regulated emerging MOs, in this aquifer is poorly understood. This study presents results from a reconnaissance survey of MOs in Chalk groundwater, including pharmaceuticals, personal care products and pesticides and their transformation products, conducted across the major Chalk aquifers of England and France. Data from a total of 345 sites collected during 2011 were included in this study to provide a representative baseline assessment of MO occurrence in groundwater. A suite of 42 MOs were analysed for at each site including industrial compounds (n=16), pesticides (n=14) and pharmaceuticals, personal care and lifestyle products (n=12). Occurrence data is evaluated in relation to land use, aquifer exposure, well depth and depth to groundwater to provide an understanding of vulnerable groundwater settings.
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