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921.
A spatial risk assessment methodology to support the remediation of contaminated land 总被引:4,自引:0,他引:4
When soil and groundwater contaminations occur over large areas, remediation measures should be spatially prioritized on the basis of the risk posed to human health and in compliance with technological and budget constraints. Within this scope, the application of human health risk assessment algorithms in a spatially resolved environment raises a number of methodological and technical complexities. In this paper, a methodology is proposed and applied in a case study to support the entire formulation process of remediation plans, encompassing hazard assessment, exposure assessment, risk characterisation, uncertainty assessment and allocation of risk reduction measures. In the hazard assessment, it supports the selection of Contaminants of Concern (CoC) with regard to both their average concentrations and peak concentrations, i.e. hot spots. In the exposure assessment, it provides a zoning of the site based on the geostatistical mapping of contaminant. In the risk characterisation, it generates vector maps of Risk Factors on the basis of the risk posed by multiple substances and allows the interrogation of most relevant CoC and exposure pathways for each zone of the site. It also supports the Monte Carlo based probabilistic estimation of the Risk Factors and generates maps of the associated uncertainty. In the risk reduction phase, it supports the formulation of remediation plans based on the stepwise spatial allocation of remediation interventions and the on-time simulation of risk reduction performances. The application of this methodology is fully supported by an easy-to-use and customized Geographical Information System and does not require high expertise for interpretation. The proposed methodology is the core module of a Decision Support System (DSS) that was implemented in the DESYRE software aimed at supporting the risk-based remediation of megasites. 相似文献
922.
Hugo D. Silva Ludimila A. C. Wosnjuk Sônia F. O. Santos Cesar A. S. T. Vilanova-Costa Flávia C. Pereira Elisângela P. Silveira-Lacerda Marco T. A. Garcíazapata Carlos E. Anunciação 《Food and environmental virology》2010,2(1):35-40
Adenoviruses are a highly important public health issue, since they are among the most persistent and ubiquitous viruses present
in water and associated with a variety of clinical manifestations. The aim of this study was to use molecular techniques for
the detection of adenovirus in public and recreational water supplies in Goiania, Brazil. From December 2007 to November 2008,
54 water samples were collected in 5 different sites in 2 lakes and 2 rivers of the city. The samples were filtered in a positively
charged nylon membrane, and the DNA was extracted using the phenol–chloroform–isoamyl alcohol method. Semi-nested PCR was
used to detect adenovirus DNA, and sequence analysis of the semi-nested PCR products was performed to identify the recovered
viruses. Adenovirus DNA was detected in 43% (24 of 54) of samples collected. Considering all examined sites, MP1 presented
the highest occurrence of adenovirus (6 positive from 10 collected samples), followed by MP2 (3 positive from 6 collected
samples), JL (10 positive from 21 collected samples), VB (3 positive from 9 collected samples), and BB (2 positive from 8
collected samples), respectively. The methodology employed proved to be feasible, fast, low-cost, and suitable to be used
as screening approach on adenovirus detection in water for public sanitation companies. 相似文献
923.
Evaluation of the e ectiveness of horizontal subsurface flow constructed
wetlands for di erent media
Two media bed (gravel and Filtralite NR) were tested in a mesocosm to evaluate the removal of organic matter (as chemical oxygen
demand (COD)), ammonia (NH4-N), nitrite, nitrate and solid matter (as total suspended solids (TSS)) for a synthetic wastewater
(acetate-based) and a domestic wastewater. The use of Filtralite allowed average removal rates (6–16.8 g COD/(m2 day), 0.8–1.1
g NH4-N/(m2 day) and 3.1 g TSS/(m2 day)) and removal e ciencies (65%–93%, 57%–85% and 78% for COD, NH4-N and TSS,
respectively), higher than that observed in the experiments with gravel. The applied loads of COD, ammonia, nitrate and TSS seem
to influence the respective removal rates but only for the treatment of domestic wastewater with higher correlation coe cients for
Filtralite. Regardless the type of media bed and the type of wastewater, nitrate was completely removed for nitrogen loading rates up to
1.3 g NO3-N/(m2 day). There was no evidence of the influence of nitrate loads on the removal of organic matter. 相似文献
924.
Stefano?Antonio?GattoneEmail authorView authors OrcID profile Paolo?Giordani Tonio?Di?Battista Francesca?Fortuna 《Environmental and Ecological Statistics》2018,25(1):125-138
The implementation of an adaptive cluster sampling design often becomes logistically challenging because variation in the final sampling effort introduces uncertainty in survey planning. To overcome this drawback, an inexpensive and easy to measure auxiliary variable could be used in a two-phase survey strategy, called adaptive cluster double sampling (Félix-Medina and Thompson in Biometrika 91:877–891, 2004). In this paper, a two-phase sampling strategy is proposed which combines the idea of adaptive cluster double sampling with the principle of post-stratification. In the first-phase an adaptive cluster sample is selected by means of an inexpensive auxiliary variable. Networks from the first phase sampling are then post-stratified according to their size. In the second-phase, the network structure is used to select a subsample of units by means of stratified random sampling. The proposed sampling strategy employs stratification without requiring an a priori delineation of the strata. Indeed, the strata sizes are estimated in the course of the two-phase sampling process. Therefore, it is suitable for situations where stratification is suspected to be efficient but strata cannot be easily delineated in advance. In this framework, a new type of estimator for the population mean which mimics the stratified sampling mean estimator and an estimator of the sampling variance are proposed. The results of a simulation study confirm, as expected, that the use of post-stratification leads to gain in precision for the estimator. The proposed sampling strategy is applied for targeting an epiphytic lichen community Lobarion pulmonariae in a forest area of the Northern Apennines (N-Italy), characterized by several species of conservation concern. 相似文献
925.
Federico?AndreisEmail authorView authors OrcID profile Marco?Bonetti 《Environmental and Ecological Statistics》2018,25(1):139-154
We introduce a novel method to extract a sample from a finite population where units with desired characteristics are over-represented. The approach is both sequential and adaptive and allows, via suitable compositions of predictive and objective functions, to target specific subsets of the population. We consider the problem of estimation and conjecture the validity of a modified Horvitz–Thompson estimator capable to account for the imbalance induced by the targeting procedure. After discussing how to apply the method to the sampling of geographically distributed units, we investigate its potential via simulations. 相似文献
926.
The phylum Gastrotricha includes about 750 species of meiobenthic marine and freshwater species that are often widely distributed.
The microscopic size, short life cycle, low motility of adults, and the absence of larval stages normally required for dispersal
raise doubts about the putative cosmopolitan distribution of many of gastrotrich species. The phenomenon of cosmopolitanism
is acknowledged for all major meiobenthic taxa (“the meiofauna paradox”) and can be explained, at least in part, with the
existence of sibling species, so far identified primarily by molecular analysis. In this paper, we report the discovery of
sibling species in the marine chaetonotidan Xenotrichula intermedia using confocal laser scanning microscopy (CLSM). A total of 40 specimens collected from two geographically separate populations,
the Mediterranean (Adriatic Sea) and the Arabian Gulf (Kuwait), were investigated. Fifteen specimens of each population were
studied in vivo with a contrast interference microscope (DIC) in order to obtain the main morphometric parameters; ten other
animals (five in each population) were fixed and marked with fluorescent phalloidin for the observation of their muscular
systems under CLSM. The metrics and meristic data of the two populations fall within the range of measures recognized for
the species. Pairwise comparisons (t-test) in general did not reveal statistically significant differences between the traits of specimens belonging to the two
populations; moreover, multivariate analyses (cluster- and MDS analysis) were unable to separate clearly the Mediterranean
from the Arabian specimens. In contrast, an examination of their muscular systems revealed clear dissimilarities between the
two geographic groups. In particular, while the Italian specimens possessed incomplete circular bands and dorsoventrally orientated
muscles that are partially inserted into the basal lamina of the cuticle, in both splanchnic- and somatic positions, their
Arabian counterparts showed partial dorsoventral bands and complete circular muscles that surround the entire body of the
animal in the same corresponding positions. Additional differences in the position of helicoidal bands (present in a more
anterior location in the Italian specimens) are noted between Mediterranean and Arabian specimens. Since the investigated
animals share a similar interstitial habitat, a working hypothesis connects the differences in the musculature to possible
differences in the reproductive modality of specimens between the two populations. 相似文献
927.
Typically, studies of the disturbance effect on metapopulation dynamics are limited to understanding the effect of habitat loss although, recently, the spatial pattern of the disturbance has been shown to influence dynamics. In this study, we used a stochastic patch-dynamic model to investigate the effects of spatial disturbance patterns on the persistence of an open woodland community of Juniperus spp. and Pinus spp. First, we estimated patch-occupancy dynamics by using the coefficients that best predicted the occupancy observed in 1998 based on occupancy data from 1957. Next, we evaluated the effects of the rate and pattern of the disturbance on the extinction probability. In modeling the disturbance, we considered (1) the degree of disturbance produced by scenarios of complete destruction or degradation (with the potential for recolonization), (2) the overall rate of disturbance, and (3) the spatial autocorrelation of habitat destruction. Twenty 40-year simulations predicted a 25% increase in the number of patches, and when 50% of the habitat was removed, the impact was more pronounced after complete destruction than it was after degradation of the area. Predictions based on scenarios of complete destruction, including random, contiguous, Brownian, and autoregressive noise, demonstrated that the impact of disturbance depends upon the spatial structure of the disturbance regimen. The autocorrelated structure of the disturbance regimen had the greatest impact on patch persistence. Patch-occupancy was higher after 20 40-year simulations when habitat loss was randomly distributed than when it followed an autocorrelated patch destruction, which was simulated using autoregressive noise to produce 50% habitat destruction. In addition, while habitat loss was negatively linearly correlated with patch persistence when habitat destruction was randomly distributed, a dramatic transition shift occurred when habitat destruction was simulated following an autoregressive spatial distribution after a certain threshold of habitat destruction (40% of the actual open woodland habitat). Our study suggests that the spatial patterns of the disturbance should be considered when predicting the consequences of fragmentation and improving management strategies. 相似文献
928.
Patrick Gautier Marco Barroca Sophie Bertrand Cyril Eraud Maria Gaillard Michael Hamman Sébastien Motreuil Gabriele Sorci Bruno Faivre 《Behavioral ecology and sociobiology》2008,62(7):1159-1166
Several environmental factors have been shown to shape the pattern of investment of carotenoids into the expression of sexual
signals. Surprisingly, the impact of the social environment has been neglected. If a carotenoid-based sexual trait is used
by females to choose a mate or by males to assess the quality of potential competitors for mates, males, in the presence of
females, should upregulate expression of the trait. We tested this hypothesis in male zebra finches that were housed either
with females or in a male-only social environment. Additionally, to investigate whether the social modulation of the expression
of a sexual trait depends on the physiological need of carotenoids, we challenged half of the males with Escherichia coli lipopolysaccharide (LPS). We found that the social environment modulated the expression of bill color, with males kept in
the presence of females harboring a redder bill at the end of the 3 weeks that the experiment lasted. Males injected with
LPS showed duller bill color regardless of the presence of females, and social interactions with females result in upregulated
bill color similarly for phosphate-buffered saline (PBS) and LPS males. Thus, social environment and immune activation had
an additive effect on the expression of bill color. The effect of social environment on plasma carotenoids was less clear.
Indeed, a first replicate of the entire experiment showed that both immune challenge and social context affected bill color,
with a negative effect of immune challenge and a positive effect of the presence of females on circulating carotenoids. However,
a second replicate of the experiment showed only a negative effect of the immune challenge. These results, therefore, suggest
that the social environment can affect the expression of carotenoid-based sexual traits under both benign and carotenoid-demanding
conditions. Whatever the signaling function of bill color (female mate choice or male–male competition for mates), the observed
flexibility may be adaptive because the expression of the signal can be modulated depending on the expected rewards or costs
associated with the presence or absence of females. Nevertheless, the mechanisms underlying such an effect are still unknown. 相似文献
929.
Gustavo Curaqueo Mauricio Schoebitz Fernando Borie Fuensanta Caravaca Antonio Roldán 《Environmental science and pollution research international》2014,21(12):7403-7412
A greenhouse experiment was carried out in order to investigate the effects of arbuscular mycorrhizal (AM) fungi inoculation and the use of composted olive waste (COW) in the establishment of Tetraclinis articulata and soil properties in a heavy metal-polluted soil. The treatments assayed were as follows: AM?+?0 % COW, AM?+?1 % COW, and AM?+?3 % COW. The higher doses of COW in combination with AM fungi increased shoot and root biomass production of T. articulata by 96 and 60 %, respectively. These treatments trended to improve the soil properties evaluated, highlighting the C compounds and N as well as the microbiological activities. In relation to the metal translocation in T. articulata, doses of COW applied decreased the Cr, Ni, and Pb contents in shoot, as well as Cr and As in root, although the most of them reached low levels and far from phytotoxic. The COW amendment aided Glomus mosseae-inoculated T. articulata plants to thrive in contaminated soil, mainly through an improvement in both nutrients uptake, mainly P and soil microbial function. In addition, the combined use of AM fungi plus COW could be a feasible strategy to be incorporated in phytoremediation programs because it promotes soil properties, a better performance of plants for supporting the stress in heavy metal-contaminated soils derived from the mining process, and also can be a good way for olive-mill waste disposal. 相似文献
930.
F. De Laender Paul J. van den Brink Colin R. Janssen Antonio Di Guardo 《Environmental science and pollution research international》2014,21(9):6263-6267
Current techniques for the ecological risk assessment of chemical substances are often criticised for their lack of environmental realism, ecological relevance and methodological accuracy. ChimERA is a 3-year project (2013–2016), funded by Cefic’s Long Range Initiative (LRI) that aims to address some of these concerns by developing and testing mechanistic fate and effect models, and coupling of these models into one integrated platform for risk assessment. This paper discusses the backdrop against which this project was initiated and lists its objectives and planned methodology. 相似文献