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921.
Affum HA Oduro-Afriyie K Nartey VK Adomako D Nyarko BJ 《Environmental monitoring and assessment》2008,137(1-3):15-24
Lichens collected in an unpolluted forest (background) in November 2004, transplanted at 41 sampling sites along the Madina-Tetteh
Quarshie road, retrieved in February 2005 and analysed were found to contain higher concentrations of Manganese (Mn), Vanadium
(V), lead, Cadmium (Cd), Chromium (Cr) and Nickel (Ni) than in the background area. Observations showed that of all the heavy
metals studied, Manganese concentrations were highest at all sampling points with maximum values around a traffic light, an
intersection and car fitting/mechanic workshops. Significant correlations were found between Ni and Mn, Mn and Cr and Mn and
V. Statistical analysis also revealed a relatively even dispersion of the studied elements on the eastern side of the road
than on the western side. 相似文献
922.
Schaefer CE do Amaral EF de Mendonça BA Oliveira H Lani JL Costa LM Fernandes Filho EI 《Environmental monitoring and assessment》2008,140(1-3):279-289
The relationships between soils attributes, soil carbon stocks and vegetation carbon stocks are poorly know in Amazonia, even
at regional scale. In this paper, we used the large and reliable soil database from Western Amazonia obtained from the RADAMBRASIL
project and recent estimates of vegetation biomass to investigate some environmental relationships, quantifying C stocks of
intact ecosystem in Western Amazonia. The results allowed separating the western Amazonia into 6 sectors, called pedo-zones:
Roraima, Rio Negro Basin, Tertiary Plateaux of the Amazon, Javari-Juruá-Purus lowland, Acre Basin and Rondonia uplands. The
highest C stock for the whole soil is observed in the Acre and in the Rio Negro sectors. In the former, this is due to the
high nutrient status and high clay activity, whereas in the latter, it is attributed to a downward carbon movement attributed
to widespread podzolization and arenization, forming spodic horizons. The youthful nature of shallow soils of the Javari-Juruá-Purus
lowlands, associated with high Al, results in a high phytomass C/soil C ratio. A similar trend was observed for the shallow
soils from the Roraima and Rondonia highlands. A consistent east–west decline in biomass carbon in the Rio Negro Basin sector
is associated with increasing rainfall and higher sand amounts. It is related to lesser C protection and greater C loss of
sandy soils, subjected to active chemical leaching and widespread podzolization. Also, these soils possess lower cation exchangeable
capacity and lower water retention capacity. Zones where deeply weathered Latosols dominate have a overall pattern of high
C sequestration, and greater than the shallower soils from the upper Amazon, west of Madeira and Negro rivers. This was attributed
to deeper incorporation of carbon in these clayey and highly pedo-bioturbated soils. The results highlight the urgent need
for refining soil data at an appropriate scale for C stocks calculations purposes in Amazonia. There is a risk of misinterpreting
C stocks in Amazonia when such great pedological variability is not taken into account. 相似文献
923.
May TW Fairchild JF Petty JD Walther MJ Lucero J Delvaux M Manring J Armbruster M 《Environmental monitoring and assessment》2008,137(1-3):213-232
The Solomon River Basin is located in north-central Kansas in an area underlain by marine geologic shales. Selenium is an
indigenous constituent of these shales and is readily leached into the surrounding groundwater. Portions of the Basin are
irrigated primarily through the pumping of selenium-contaminated groundwater from wells onto fields in agricultural production.
Water, sediment, macroinvertebrates, and fish were collected from various sites in the Basin in 1998 and analyzed for selenium.
Selenium concentrations were analyzed spatially and temporally and compared to reported selenium toxic effect thresholds for
specific ecosystem components: water, sediments, food-chain organisms, and wholebody fish. A selenium aquatic hazard assessment
for the Basin was determined based on protocol established by Lemly. Throughout the Basin, water, macroinvertebrate, and whole
fish samples exceeded levels suspected of causing reproductive impairment in fish. Population structures of several fish species
implied that successful reproduction was occurring; however, the influence of immigration of fish from low-selenium habitats
could not be discounted. Site-specific fish reproduction studies are needed to determine the true impact of selenium on fishery
resources in the Basin.
The U.S. Government’s right to retain a non-exclusive, royalty free license in and to any copyright is acknowledged. 相似文献
924.
Cozzi F Adami G Barbieri P Reisenhofer E Bovenzi M 《Environmental monitoring and assessment》2008,144(1-3):389-401
The aim of this study was to measure the concentration of some metals (Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Ti) in PM(10) samples collected in one urban and one industrial site and to assess that PM(10) total mass measurement may be not sufficient as air quality index due to its complex composition. Metals were determined by inductively coupled plasma-atomic emission spectroscopy (ICP-AES) and differential pulsed anodic stripping voltammetry (DPASV). The measured concentrations were used to calculate the content of metals in the PM(10) total mass, and to estimate the enrichment factors and the correlations between PM(10), metal concentrations and meteorological data for the two sites. The mean PM10 concentration during the sampling period in the urban site exceeded the annual European Union (EU) standard (40 microg/m(3)) and, for some sampling days, the daily EU standard (50 microg/m(3)) was also exceeded. In opposite, both EU standards were never exceeded in the industrial site. The overall metal content was nearly double in the industrial site compared to the urban one, and the mean Ni concentration exceeded the EU annual limit value (10 ng/m(3)). The metals with the highest enrichment factor were Cd, Cu, Ni and Pb for both sites, suggesting a dominant anthropogenic source for these metals. Metal concentrations were very low and typical of rural background during Christmas holidays, when factories were closed. PM(10) total mass measurement is not a sufficient air quality index since the metal content of PM(10) is not related to its total mass, especially in sites with industrial activities. This measurement should be associated with the analysis of toxic metals. 相似文献
925.
Maria P. Papadopoulou Emmanouil A. Varouchakis George P. Karatzas 《Environmental Modeling and Assessment》2010,15(5):319-328
Karst aquifers are characterized by spatial heterogeneity due to the presence of highly permeable channels and conduits in
low-permeable fractured rocks (matrix block). Recent studies have reported a close relationship between surface and subsurface
water in karstic regions due to the water flow through a complicated network of paths formed by fracture intersections. Subsurface
flow in karstified aquifers ranges between conduit flow, in large passages with relatively high flow velocities, and diffuse
flow, in the matrix block where Darcy’s law is still valid. In this paper, we present the simulation of a complex karstified
aquifer system in Crete, Greece, where the presence of main faults drastically affects the regional flow. A discrete fracture
approach in conjunction with an equivalent porous medium approach was adopted to simulate the mixed flow in the area of interest.
The simulation results have shown that the length and the orientation of the dominant faults, primarily during the rainy season,
affect the flow field. 相似文献
926.
Alam R Munna G Chowdhury MA Sarkar MS Ahmed M Rahman MT Jesmin F Toimoor MA 《Environmental monitoring and assessment》2012,184(1):573-580
In rural areas in Bangladesh, groundwater is the principal source of water supply. This underground water is available in
considerable amount in shallow aquifers. It is free from pathogenic microorganisms and hence water-borne diseases. In plain
lands, other than hilly areas, water supply to 97% rural population comes from tube-wells, which is regarded to be a phenomenal
achievement in preserving public health. Besides, a dependable water supply system all throughout the country is offset by
two factors: (a) high salinity in surface plus groundwater in coastal areas; (b) want of suitable groundwater aquifers in
hilly areas and the high cost of setting up tube-wells due to deep underground water table and stony layers. However, presence
of arsenic in underground water now poses a serious threat to the success once made in water supply by setting up of manually
operated tube-wells in the village areas—the achievement is now on the brink of total collapse. In about 61 districts out
of 64, presence of arsenic exceeds a quantity of 0.05 mg/1, a permissible limit as per Bangladeshi water quality standard.
Harvesting rainwater can be a pragmatic solution to this problem, which is common in many places in Sylhet especially in the
hilly areas on the north eastern part of the city. This can be an alternative source of drinking water because of availability
of rainwater from March to October. Heavy rain occurs from end of May till mid September, which is commonly known as the rainy
season. This paper focuses on the possibility of harvesting rainwater in rural communities and thickly populated urban areas
of Sylhet. It also demonstrates the scopes of harvesting rainwater using simple and low-cost technology. With setting up of
a carefully planned rainwater storage tank, a family can have all of its drinking water from rain. Planned use of rainwater
through rainwater harvesting in the roof catchments may fulfill the entire annual domestic water demand of a family in the
rural areas of Bangladesh. 相似文献
927.
The main objective of this work was to assess the potential use of goose barnacle Pollicipes pollicipes as biomonitor of metal contamination in northwest (NW) coast of Portugal. The concentrations of Cd, Cr, Cu, Fe, Mn, Ni and Zn were determined in coastal seawaters and tissues of P. pollicipes, which allowed establishing correlations between metals in coastal seawaters and P. pollicipes and calculating metal bioaccumulation factors (BAFs). The results of this study showed that P. pollicipes soft tissues can be used for monitoring metal contamination in these coastal seawaters: (1) there were significant correlations (p?0.05) between metals in soft tissues and their concentrations in seawaters, except for Zn (p?>?0.05); (2) soft tissues were sensitive to spatial variations of metal bioavailabilities and their concentrations ranged 0.70-2.22?mg?Cd?kg(-1), 0.49-1.40?mg?Cr?kg(-1), 1.37-2.07?mg?Ni?kg(-1), 2.4-3.3?mg?Cu?kg(-1), 5-59?mg?Mn?kg(-1), 134-578?mg?Fe?kg(-1)and 728-1,854?mg?Zn?kg(-1); (3) mean logarithmic bioaccumulation factors (log BAF) of Fe, Cd and Zn were higher, 5.57, 5.47 and 4.41, respectively, than mean log BAFs of Cr, Mn, Cu and Ni, 4.18, 4.14, 3.98 and 3.51, respectively. In contrary, P. pollicipes shell plates were not considered ideal material to monitor metal bioavailabilities in these coastal seawaters. Regarding the very high concentrations of Zn obtained in the coastal seawaters and P. pollicipes soft tissues, the NW coast of Portugal should be classified as "Class III/IV - Remarkably/Highly Polluted". 相似文献
928.
Large and mesoscale meteo-oceanographic patterns in local responses of biogeochemical concentrations
de Oliveira MM Pereira GC de Oliveira JL Ebecken NF 《Environmental monitoring and assessment》2012,184(11):6935-6956
Investigations surrounding the variability of productivity in upwelling regions are necessary for a better understanding the physical-biological coupling in these regions by monitoring systems of environmental impacts according to the needs of the regional coastal management. Using a spatial and temporal database from National Centers for Environmental Prediction (NCEP) and National Center for Atmospheric (NCAR) Research reanalysis, Quick Scatterometer vector wind, and surface stations from the Southeast coast of Brazil, we investigate the meteorological influences due to the large-scale systems in the variability of the nutrient and larvae concentration, and chlorophyll a, describing statistically relationships between them in upwelling regions. In addition, we used multivariate analysis, such as PCA and clustering to verify spatial and temporal variances and describe more clear the structure and composition of the ecosystem. Correlation matrix analyses were applied for different water masses present in the study area to identify the relations between physical and biogeochemical parameters in a region, where frequently upwelling occur. Statistical approaches and seasonal variability show that the period of November to March is more sensitive to nutrients (1.20?mg/m(3) for chlorophyll a, 2.20?μmol/l for total nitrogen and 5.5?ml/l for DO) and larvae concentrations (120 org/m(3) for most of the larvae, except for cirripedia that presented values around 370 org/m(3)) relating to the influence of large and mesoescale meteorological patterns. The spatial and temporal variables analyzed with multivariate approach show meaningful seasonality variance of the physical and biological samples, characterizing the principal components responsible for this variance in spring and summer (upwelling period), emphasizing the monitoring of species as crustaceans and mussels that are present in the local economy. Then, the spring and summer season are characterized by high productivity due to the occurrence of upwelling in this period. 相似文献
929.
José A. Murillo Pulgarín Luisa F. García Bermejo Armando Carrasquero Durán 《Environmental monitoring and assessment》2013,185(1):573-580
A flow injection analysis method based on ion chromatography and luminol chemiluminescence detection was used for the simultaneous determination of copper (II) and cobalt (II) trace levels in soils and sediments following microwave-assisted acid digestion. Detection was based on chemiluminescence (CL) of the luminol–perborate system in an alkaline medium, which is catalyzed by both transition metals. The concentration and pH of the eluent (oxalic acid) was found to affect CL intensities and retention times, both of which were inversely proportional to the oxalic acid concentration. The calibration curves for both metal ions were linear and allowed a limit of detection of 0.003 μg l?1 for cobalt (II) and 0.014 μg l?1 for cooper (II) to be calculated. The proposed method was successfully used to determine both metal ions in certified reference materials of stream and river sediments and soil samples. Based on the results, the determination is free of interferences from the usual concomitant ions. 相似文献
930.
Maria C. Dzul Philip M. Dixon Michael C. Quist Stephen J. Dinsmore Michael R. Bower Kevin P. Wilson D. Bailey Gaines 《Environmental monitoring and assessment》2013,185(1):405-414
We used variance components to assess allocation of sampling effort in a hierarchically nested sampling design for ongoing monitoring of early life history stages of the federally endangered Devils Hole pupfish (DHP) (Cyprinodon diabolis). Sampling design for larval DHP included surveys (5 days each spring 2007–2009), events, and plots. Each survey was comprised of three counting events, where DHP larvae on nine plots were counted plot by plot. Statistical analysis of larval abundance included three components: (1) evaluation of power from various sample size combinations, (2) comparison of power in fixed and random plot designs, and (3) assessment of yearly differences in the power of the survey. Results indicated that increasing the sample size at the lowest level of sampling represented the most realistic option to increase the survey’s power, fixed plot designs had greater power than random plot designs, and the power of the larval survey varied by year. This study provides an example of how monitoring efforts may benefit from coupling variance components estimation with power analysis to assess sampling design. 相似文献