排序方式: 共有53条查询结果,搜索用时 448 毫秒
41.
Vives I Müller A Umlauf G Christoph EH Mariani G Skejo H Cenci RM Sena F Beone GM 《Environment international》2008,34(7):994-1000
Trace elements and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) were analyzed in soils from rural and light-industrialized sites (n=168) of Province of Pavia (Northern Italy). Most of the trace element values fit in typical ranges of concentrations in soils and are similar to the ones reported for rural sites in Italy or sites with no direct anthropogenic impact. Total concentrations of 2,3,7,8 chlorine substituted PCDD/Fs in superficial soils ranged between 24.4 and 1287 pg g(-1) dw (0.5-28.9 pg WHO(98)-TEQ g(-1) dw). The North Eastern part of the Province presented significantly higher levels (p<0.001) than the rest of the Province for As, Cd, Hg, Pb, Zn and PCDD/Fs. While the existence of a defined heavy metal polluting source for this specific site has been suggested, in the case of PCDD/Fs, profiles were not linked to any specific emission source fingerprint. In the whole extension of Pavia Province, OCDD/F dominated the 2,3,7,8 chlorine substituted congener soil pattern, followed by the 1,2,3,4,6,7,8 hepta-CDD/F congener. Principal Component Analysis (PCA) showed that this profile could not be associated to any described PCDD/F emission source fingerprint and was relatively similar to the baseline deposition of sites with no direct impact of PCDD/F emission sources independently of land use. 相似文献
42.
Lars C. Larsen Kim C. Zambrano Helle Christiansen Almut Köhler Ulrich Karlson Stefan Trapp 《Environmental Sciences Europe》2001,13(4):227-236
In Axelved, Denmark, an abandoned gas filling station serves as a test field for phytoremediation. Laboratory studies accompany the project. The toxicity of fresh and weathered gasoline and diesel to willow and poplar trees was studied by use of a tree transpiration toxicity test. The correlation between diesel content in soil and decrease in willow tree transpiration (Salix viminalis x schwerinii) was highly significant (r 2=0.81, n=19). the EC50 (50% inhibition of transpiration) for the sum of hydrocarbons (HC) was determined to be 3910 mg/kg (95% confidence interval from 2900 to 5270 mg/kg). The EC10 was 810 mg/kg (95% confidence interval 396 to 1660 mg/kg). The results were verified with artificially mixed diesel and gasolinecontaminated soils and two willow and one poplar species (S. viminalis, S. alba andPopulus nigra). The degradation of radiolabeledm-xylene was studied with and without willows. The compound was readily degraded. Willow trees accelerated the elimination, but mainly due to the volatilization ofm-xylene. Model studies provided the result that biodegradation in soil is the fastest elimination process at the site, but it is limited by the availability of electron acceptors. The pollutants are almost persistent in the groundwater, but in aerated soil, 10000 mg/kg hydrocarbons at 1 m depth are degraded within 13 years. The main effect of willows on the pollutants’ persistence is that willows transpire water, lower the groundwater level and aerate the soil, hereby speeding up biodegradation. 相似文献
43.
Gunther Umlauf Eugen H. Christoph Laura Lanzini Risto Savolainen Helle Skejo Giovanni Bidoglio Joachim Clemens Heiner Goldbach Heinrich Scherer 《Environmental science and pollution research international》2011,18(3):461-470
Background, aim, and scope
Biowaste contains compounds of agricultural value such as organic carbon, nutrients, and trace elements and can partially replace mineral fertilizer (MIN) and improve the physical properties of the soil. However, the obvious benefits of land spreading need to be carefully evaluated against potential adverse effects on the environment and human health. Environmental contamination resulting from biowaste application is one of the key variables when assessing cost/benefits. This study provides data on the resulting concentration of polychlorinated dibenzodioxins and dibenzofurans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (DL-PCBs) in the soil column as a result of the different types of fertilizers. 相似文献44.
Marcussen H Joergensen K Holm PE Brocca D Simmons RW Dalsgaard A 《Environmental monitoring and assessment》2008,139(1-3):77-91
Extensive aquatic or semi-aquatic production of water spinach (Ipomoea aquatica Forssk.) for human consumption takes place in Southeast Asia. The aim of this study was to assess the concentrations of 38
elements in soil and water spinach cultivated under different degrees of wastewater exposure in Hanoi, Vietnam. The results
showed no effect of wastewater use on the overall element concentrations in soil and water spinach. Mean soil concentrations
for selected potentially toxic elements at the studied field sites had the following ranges 9.11–18.7 As, 0.333–0.667 Cd,
10.8–14.5 Co, 68–122 Cr, 34.0–62.1 Cu, 29.9–52.8 Ni, 32.5–67.4 Pb, 0.578–0.765 Tl and 99–189 Zn mg kg−1 dry weight (d.w.). In all samples Cd, Pb and Zn soil concentrations were below the Vietnamese Guideline Values (TCVN 7209-2002)
for agricultural soils whereas As and Cu exceeded the guideline values. Maximum site element concentrations in water spinach
were 0.139 As, 0.032 Cd, 0.135 Cr, 2.01 Cu, 39.1 Fe, 57.3 Mn, 0.16 Ni, 0.189 Pb and 6.01 Zn mg kg−1 fresh weight (f.w.). The site and soil content of organic carbon were found to have high influence on the water spinach element
concentrations whereas soil pH and the total soil element concentrations were of less importance. The estimated average daily
intake of As, Cd, Cu, Fe, Pb and Zn for adult Vietnamese consumers amounts to <11% of the maximum tolerable intake proposed
by FAO/WHO for each element. It is assessed that the occurrence of the investigated elements in water spinach will pose low
health risk for the consumers. 相似文献
45.
46.
Fant ML Nyman M Helle E Rudbäck E 《Environmental pollution (Barking, Essex : 1987)》2001,111(3):493-501
The concentrations of mercury (Hg), cadmium (Cd), lead (Pb) and selenium (Se) were determined in liver, kidney and muscle samples from 20 Baltic ringed seals (Phoca hispida botnica) (3-32 years), and from 17 ringed seals (Phoca hispida) (0-20 years) from Svalbard, in the Arctic. The concentrations of Hg and Se were considerably higher in the Baltic ringed seals, but the Cd concentrations lower than in the Svalbard ringed seals. There was no big geographical difference with respect to Pb concentrations. Se and Hg concentrations showed a significant positive correlation in both regions. By comparison with earlier studies on Baltic seals, the metal concentrations have remained at the same level since the 1980s. Of the metals we studied, only the level of Hg in Baltic ringed seals can be considered high (mean 53 mg/kg, range 6.5-124 mg/kg wet wt. for liver), but probably not high enough to cause metal intoxication. No pathological changes associated with metal intoxication were observed in the seals. 相似文献
47.
The sorption of the pyrethroid, esfenvalerate, to the dissolved and/or dispersed fraction of eight different natural humic compounds has been investigated. The dissolved organic matters (DOMs) included in this study originate from ground water, soil pore water, and surface waters. Sorption was modelled at DOM concentration levels where equilibrium partitioning of esfenvalerate between DOM and the aqueous bulk phase prevails. The inherent characteristics of the eight different humic materials, quantified in the preceding paper by Thomsen et al. (2002, this issue (PII: S0045-6535(02)00335-1)), have been used as explanatory variables for modelling this equilibrium partitioning. Using a reverse QSAR approach based on by projection-into-latent-structure regression (PLS-R) inherent sorbent properties determining for the sorption affinity of esfenvalerate to DOM were analysed. For all humic substances a decrease in the DOM-normalised equilibrium-partitioning coefficient, KDOM, with increasing concentration of DOM was observed. Significant variations in KDOM values, as function of the inherent characteristics of the individual humic substances, were found at DOM concentrations of 75 and 100 ppm, respectively. The latter is a strong indication of variations in sorption mechanisms of esfenvalerate to DOM of varying inherent properties. Groupings in the principal property space quantifying DOMs may indicate that separate models are needed for quantifying the equilibrium partitioning to different classes of DOM. 相似文献
48.
Mohammed S. Rahman Ana B. Payá-Pérez Helle Skejø-Andresen Bo R. Larsen 《Environmental science and pollution research international》1994,1(3):131-139
Reductions in the apparent soil-water partition coefficients (Kd *) for 28 polychlorinated biphenyls (PCBs) caused by the surfactant sodium dodecylsulphate (SDS) in the aqueous phase were studied. Above the critical micelle concentration (CMC) of the surfactant, Kd * was reduced by 2–3 orders of magnitude, but even far below CMC at environmentally relevant surfactant concentrations significant reductions in Kd * were observed. The plot of the soil-water partition coefficient (Kd) divided by Kd * versus the concentration of SDS allowed for the calculation of monomer (Kmn oc) and micellar (Kmc oc) surfactant-water partition coefficients normalized to organic carbon for each PCB congener. Kmn oc values were comparable with published values for the partition of PCBs between natural dissolved organic matter and lake water. Kmc oc values were up to 30 times higher than Kmn oc values and comparable with published octanol-water distribution coefficients. The findings of the present study underline the potential of surfactants at concentrations below their CMC to mobilize otherwise strongly bound hydrophobic compounds in soil-water systems. 相似文献
49.
Søren Lophaven Jacob Carstensen Helle Rootzén 《Environmental and Ecological Statistics》2004,11(3):237-256
This study describes and applies statistical methods for space-time modeling of data from environmental monitoring programs, e.g., within areas such as climate change, air pollution and aquatic environment. Such data are often characterized by sparse sampling in both the temporal and spatial dimensions. In order to improve the amount of information on the physical system in question we suggest using statistical modeling methods for monitoring data. Model predictions combined with observations could be analyzed directly to assess the environmental state or as forcing functions for time series models and deterministic, hydrodynamic models. To illustrate the approach we applied the proposed modeling methods to data from the Danish and Swedish marine monitoring programs. Time series with a weekly resolution were predicted from observations of dissolved inorganic nitrogen (DIN) from the Kattegat basin (1993–1997). DIN observations were sparse, irregularly distributed and comprised approximately 10% of the generated time series. 相似文献
50.
Thomas Lilley Toni Laaksonen Otso Huitu Samuli Helle 《Behavioral ecology and sociobiology》2009,63(10):1539-1547
The ratio of second-to-fourth digit length (2D/4D) has been suggested to be a useful adult age marker of intrauterine exposure
to steroids because it should be sexually dimorphic and fixed already in utero. Numerous studies mainly on humans have supported
this conclusion, but it is yet unclear how well this applies to other vertebrates. This information would be especially valuable
to field biologists to whom measuring steroids in utero is often impossible. The non-human studies conducted so far have yielded
inconsistent results, perhaps due to the variety of different methods employed in measuring 2D/4D. We examined the age and
sex dependency and lateral asymmetry of 2D/4D in field voles (Microtus agrestis) and compared whether these effects differed between 2D/4D measurements taken from photographs and X-rays. Our results show
that 2D/4D measurements from photos had a higher measurement error and gave consistently higher 2D/4D than those from X-rays.
According to both measurement methods, the right paw showed higher 2D/4D values than the left paw (lateral asymmetry). Adult
voles had a lower 2D/4D than juveniles when measured from X-rays, but not when measured from photographs. We found no evidence
for a sex difference in 2D/4D using either of the measurement methods. Our findings thus suggest that X-rays, due to their
greater accuracy, should be preferred over photographs for measuring digit ratios in rodents. Our results also indicate that
in this species, 2D/4D is laterally asymmetric, but it may not be either fixed in utero or sexually dimorphic. In conclusion,
2D/4D appears to be a rather species- and method-specific measure and researchers should be careful when generalising its
applicability to study early hormonal effects in vertebrates. 相似文献