Search results for " Pollution"
showing 10 items of 1010 documents
Precise Indication of Air Pollution Sources
2002
The present paper is a report of an application of Mossbauer spectroscopy, X-ray diffractometry, thermogravimetric analysis and PIXE in the characterization of the particulate matter in atmospheric aerosols in Vitoria Metropolitan Region (VMR), Brazil. The main sources of particulate matter, natural, industrial and antropogenic (from human activities), have been studied to identify its contribution in the atmospheric particles. Through the years 1995 to 1999 samples of total suspended particles (TSP, O ⩽; 100 μm) were collected from six points within VMR and in two points the inhalable particles (PM10, O ⩽ 10 μm). In addition, a receptor modeling was used helping in a precise indication of …
Association between residential proximity to environmental pollution sources and childhood renal tumors
2016
FI=3.835 (año 2016), Q1 Background: Few risk factors for childhood renal tumors are well established. While a small fraction of cases might be attributable to susceptibility genes and congenital anomalies, the role of environmental factors needs to be assessed. Objectives: To explore the possible association between residential proximity to environmental pollution sources (industrial and urban areas, and agricultural crops) and childhood renal cancer, taking into account industrial groups and toxic substances released. Methods: We conducted a population-based case-control study of childhood renal cancer in Spain, including 213 incident cases gathered from the Spanish Registry of Childhood T…
Status of vulnerable Cystoseira populations along the Italian infralittoral fringe, and relationships with environmental and anthropogenic variables
2018
We analyzed the occurrence and status of infralittoral fringe populations of Cystoseira spp. (Fucales) at thirteen rocky sites around the Italian coastline, and explored the relationships with relevant environmental and anthropogenic variables. We found Cystoseira populations at 11 sites: most were scattered and comprised monospecific stands of C. compressa, and only 6 sites also supported sparse specimens of either C. amentacea var. stricta or C. brachycarpa. Coastal human population density, Chlorophyll a seawater concentrations, sea surface temperature, annual range of sea surface temperature and wave fetch explained most of the variation of the status of C. compressa. We hypothesize a g…
Upward and downward solar-induced chlorophyll fluorescence yield indices of four tree species as indicators of traffic pollution in Valencia
2013
Abstract: Passive steady-state chlorophyll fluorescence (Fs) provides a direct diagnosis of the functional status of vegetation photosynthesis. With the prospect of mapping Fs using remote sensing techniques, field measurements are mandatory to understand to which extent Fs allows detecting plant stress in different environments. Trees of four common species in Valencia were classified in either a low or a high local traffic exposure class based on their leaf magnetic value. Upward and downward hyperspectral fluorescence yield (FY) and indices based on the two Fs peaks (at 687 and 741 nm) were calculated. FY indices of P. canariensis and P. x acerifolia were significantly different between …
Chlorophyll a fluorescence, antioxidant enzymes and lipid peroxidation in tomato in response to ozone and benomyl
2001
Ozone is a widely distributed phytotoxic air pollutant and is known to reduce the yield of several important agricultural crops in Spain. However, benomyl has been found to lessen the adverse impact of ozone on plants. We studied the effects of ozone and benomyl on chlorophyll a fluorescence, antioxidant enzymes, and lipid peroxidation in tomato (Lycopersicon esculentum Mill. cv. Tiny Tim) grown in open-top chambers in the field. Our results indicate that benomyl prevented the peroxidation of membrane lipids and increased protection of PSII from ozone. There was also a significant reduction in the activity of the antioxidant enzyme superoxide dismutase in ozone-exposed plants that had not b…
Tobacco plants detect a decrease of environmental genotoxicity in Toulouse (France).
2003
Tobacco plants, heterozygous for two independent loci involved in the chlorophyll parenchyma differentiation, allow the genotoxic effects of the atmosphere of the industrial estate South of Toulouse to be estimated. Somatic spots of green cellular colonies on yellow-green background, were counted to calculate the cellular rates of reversion. Two experiments were carried out in 1981, and in 1997. A general decrease of genotoxic effects was observed. These observations were interpreted as being due to a general decrease of the air pollution evaluated by the development of the concentrations of three toxic gases before and after the implementation of cleanup devices. The results obtained demon…
A practical approach to improve the statistical performance of surface water monitoring networks
2019
The representativeness of aquatic ecosystem monitoring and the precision of the assessment results are of high importance when implementing the EU’s Water Framework Directive that aims to secure a good status of waterbodies in Europe. However, adapting monitoring designs to answer the objectives and allocating the sampling resources effectively are seldom practiced. Here, we present a practical solution how the sampling effort could be re-allocated without decreasing the precision and confidence of status class assignment. For demonstrating this, we used a large data set of 272 intensively monitored Finnish lake, coastal, and river waterbodies utilizing an existing framework for quantifying…
Influence of ground tire rubber on the transient loading response of a peat biofilter
2010
Abstract The effect of using ground tire rubber (GTR) as an adsorptive material in the removal of a 2:1:1 weight mixture of n-butyl acetate, toluene and m-xylene by using a peat biofilter under different intermittent conditions was investigated. The performance of two identical size biofilters, one packed with fibrous peat alone and the other with a 3:1 (vol) fibrous peat and GTR mixture, was examined for a period of four months. Partition coefficients of both materials were measured. Values of 53, 118 and 402 L kg −1 were determined for n-butyl acetate, toluene and m-xylene in peat, respectively; and values of 40, 609 and 3035 L kg −1 were measured for the same compounds in GTR. Intermitte…
Determination of phenoxy acid herbicides in drinking waters by HPLC and solid phase extraction
1998
Abstract An HPLC procedure for determining phenoxy acid herbicides in waters is described. A LichroSpher RP select B octadecyl-silane analytical column and spectrophotometric detection at 230 nm were used. Adequate retention was achieved with a mobile phase containing MeOH/phosphate buffer 10−2 M pH 2.5/PnOH (50/42/8, v/v). The herbicides were isolated from water samples by using a single solid phase extraction procedure with C18 solid-phase columns. An enrichment factor of 500 is achieved. The coefficients of variation of the method were generally lower than 2.7% at 0.4 μg L−1 herbicide concentration levels. Recoveries ranged between 93 and 118%. The results obtained indicate that the prop…
Improving the solid-phase extraction of “quat” pesticides from water samples
1998
A novel strategy, based on the addition of a cationic surfactant, for preventing the interferences associated with a diminution in the efficacy of solid-phase extraction (SPE) with silica cartridges of diquat, paraquat and difenzoquat in water is developed. Conditions for extraction are optimised with respect to pH, cationic surfactant and its concentration. Humic acids, anionic surfactants, inorganic salts and other organic contaminants like pesticides, phenols, polycyclic aromatic hydrocarbons and polychlorinated biphenyls produce the studied interferences. The best performance is shown in the improvement of the "quats" recovery from waters with high levels of humic acids and anionic surf…