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971.
Long-range atmospheric transport of three toxaphene congeners across Europe. Modeling by chained single-box FATEMOD program 总被引:1,自引:1,他引:0
Jaakko Paasivirta Seija Sinkkonen Vladimir Nikiforov Fedor Kryuchkov Erkki Kolehmainen Katri Laihia Arto Valkonen Manu Lahtinen 《Environmental science and pollution research international》2009,16(2):191-205
Background, aims, and scope Since toxaphene (polychlorocamphene, polychloropinene, or strobane) mixtures were applied for massive insecticide use in the
1960s to replace the use of DDT, some of their congeners have been found at high latitudes far away from the usage areas.
Especially polychlorinated bornanes have demonstrated dominating congeners transported by air up to the Arctic areas. Environmental
fate modeling has been applied to monitor this phenomenon using parallel zones of atmosphere around the globe as interconnected
environments. These zones, shown in many meteorological maps, however, may not be the best way to configure atmospheric transport
in air trajectories. The latter could also be covered by connecting a chain of simple model boxes. We aim to study this alternative
approach by modeling the trajectory chain using catchment boxes of our FATEMOD model. Polychlorobornanes analyzed in biota
of the Barents Sea offered one case to study this modeling alternative, while toxaphene has been and partly still is used
massively at southern East Europe and around rivers flowing to the Aral Sea.
Materials and methods Pure model substances of three polychlorobornanes (toxaphene congeners P26, P50, and P62) were synthesized, their environmentally
important thermal properties measured by differential scanning calorimetry, as evaluated from literature data, and their temperature
dependences estimated by the QSPR programs VPLEST, WATSOLU, and TDLKOW. The evaluated property parameters were used to model
their atmospheric long-range transport from toxaphene heavy usage areas in Ukraine and Aral/SyrDarja/AmuDarja region areas,
through East Europe and Northern Norway (Finnmarken) to the Barents Sea. The time period used for the emission model was June
1997. Usual weather conditions in June were applied in the model, which was constructed by chaining FATEMOD model boxes of
the catchment’s areas along assumed maximal air flow trajectories. Analysis of the three chlorobornanes in toxaphene mixtures
function as a basis for the estimates of emission levels caused by its usage. High estimate (A) was taken from contents in
a Western product chlorocamphene and low estimate (B) from mean contents in Russian polychloroterpene products to achieve
modeled water concentrations. Bioaccumulation to analyzed lipid of aquatic biota at the target region was estimated by using
statistical calculation for persistent organic pollutants in literature.
Results The results from model runs A and B (high and low emission estimate) for levels in sea biota were compared to analysis results
of samples taken in August 1997 at Barents Sea. The model results (ng g−1 lw): 4–95 in lipid of planktovores and 7–150 in lipid of piscivores, were in fair agreement with the analysis results from
August 1997: 21–31 in Themisto libellula (chatka), 26–42 in Boreocadus saida (Polar cod), and 5–27 in Gadus morhua (cod) liver.
Discussion The modeling results indicate that the application of chained simple multimedia catchment boxes on predicted trajectory is
a useful method for estimation of volatile airborne persistent chemical exposures to biota in remote areas. For hazard assessment
of these pollutants, their properties, especially temperature dependences, must be estimated by a reasonable accuracy. That
can be achieved by using measurements in laboratory with pure model compounds and estimation of properties by thermodynamic
QSPR methods. The property parameters can be validated by comparing their values at an environmental temperature range with
measured or QSPR-estimated values derived by independent methods. The chained box method used for long-range air transport
modeling can be more suitable than global parallel zones modeling used earlier, provided that the main airflow trajectories
and properties of transported pollutants are predictable enough.
Conclusions Long-range air transport modeling of persistent, especially photo-resistant organic compounds using a chain of joint simple
boxes of catchment’s environments is a feasible method to predict concentrations of pollutants at the target area. This is
justified from model results compared with analytical measurements in Barents Sea biota in August 1997: three of six modeled
values were high and the other three low compared to the analysis results. The order of magnitude level was similar in both
modeled (planktovore and piscivore) and observed (chatka and polar cod) values of lipid samples. The obtained results were
too limited to firm validation but are sufficient to justify feasibility of the method, which prompts one to perform more
studies on this modeling system.
Recommendations and perspectives For assessment of the risk of environmental damages, chemical fate determination is an essential tool for chemical control,
e.g., for EU following the REACH rules. The present conclusion of applicability of the chained single-box multimedia modeling
can be validated by further studies using analyses of emissions and target biota in various other cases. To achieve useful
results, fate models built with databases having automatic steps for most calculations and outputs accessible to all chemical
control professionals are essential. Our FATEMOD program catchments at environments and compound properties listed in the
database represent a feasible tool for local, regional, and, according our present test results, for global exposure predictions.
As an extended use of model, emission estimates can be achieved by reversed modeling from analysis results of samples corresponding
to the target area.
This article is dedicated to the memory of Professor Alexander B Terentiev (who passed away in November 2006), our true friend.
With his Institute of Organo-Element Compounds, Russian Academy of Science, Moscow, he was an important main organizer of
the six joint Finnish–Russian seminars (every third year since 1989) on the field (‘Chemistry and Ecology of Organo-Element
Compounds’). He prompted us especially to search properties and environmental fates for various polyhalogen compounds. We
remember him for his friendly character and great sense of humor. 相似文献
972.
973.
A decision framework for possible remediation of contaminated sediments in the River Kymijoki, Finland 总被引:1,自引:1,他引:0
Verta M Kiviranta H Salo S Malve O Korhonen M Verkasalo PK Ruokojärvi P Rossi E Hanski A Päätalo K Vartiainen T 《Environmental science and pollution research international》2009,16(1):95-105
Background, aim, and scope The paper describes the spatial contamination of the River Kymijoki, South-Eastern Finland, and the coastal region of the
Gulf of Finland with PCDD/Fs and mercury. The findings of ecotoxicologial and human health studies are also reported, including
environmental and human risk assessments. Sediments from the River Kymijoki, draining into the Gulf of Finland, have been
heavily polluted by the pulp and paper industry and by chemical industries. A wood preservative, known as Ky-5, was manufactured
in the upper reaches of the river between 1940 and 1984 causing severe pollution of river sediments with polychlorinated dibenzo-p-dioxins (PCDD) and dibenzofurans (PCDF). Moreover, the sediments have been polluted with mercury (Hg) from chlor-alkali production
and the use of Hg as a slimicide in pulp and paper manufacturing.
Materials and methods An extensive sediment survey was conducted as well as sediment transport modeling, toxicity screening of sediment invertebrates,
and a survey of contaminant bioaccumulation in invertebrates and fish. Studies on human exposure to PCDD/Fs and the possible
effects on hypermineralization of teeth as well as an epidemiological study to reveal increased cancer risk were also conducted.
An assessment of the ecological and human health risks with a null hypothesis (no remediation) was undertaken.
Results The sediment survey revealed severe contamination of river and coastal sediments with PCDD/Fs and Hg. The total volume of
contaminated sediments was estimated to reach 5 × 106 m3 and hot spots with extremely high concentrations (max 292,000 ng g−1 or 1,060 ng I-TEQ g−1 d.w.) were located immediately downstream from the pollution source (approximately 90,000 m3). Sediment contamination was accompanied by changes in benthic assemblages, but direct effects were masked by many factors.
The fish showed only slightly elevated PCDD/F levels in muscle, but orders of magnitude higher in the liver compared with
reference freshwater sites and the Baltic Sea. The concentrations in human fat did not reveal high human exposure in the Kymijoki
area in general and was lower than in sea fishermen. The relative risk for total cancer among farmers was marginally higher
(RR = 1.13) among those living close to the river, compared with farmers living further away, and the possibility of increased
cancer risk cannot be ruled out. A conservative risk assessment revealed that the present probability of exceeding the WHO
upper exposure limit of 4 pg WHO-TEQ kg−1 d−1 for PCDD/Fs and DL-PCBs was 6%. The probability of exceeding the WHO limit value of 0.23 μg kg−1 d−1 for methyl mercury was estimated to be notably higher at 62%. Based on these studies and the estimated risks connected with
different remediation techniques a general remediation plan with cost benefit analysis was generated for several sub-regions
in the river. Dredging, on-site treatment, and a close disposal of the most contaminated sediments (90,000 m3) was suggested as the first phase of the remediation. The decision regarding the start of remediation will be made during
autumn 2008.
Conclusions The sediments in the River Kymijoki are heavily polluted with PCDD/Fs and mercury from earlier chlorophenol, chlor-alkali,
and pulp and paper manufacturing. A continuous transport of contaminants is taking place to the Gulf of Finland in the Baltic
Sea. The highly increased PCDD/F and Hg levels in river sediments pose an ecotoxicological risk to benthic fauna, to fish-eating
predators and probably to human health. The risks posed by mercury exceed those from PCDD/Fs and need to be evaluated for
(former) chlor-alkali sites and other mercury releasing industries as one basis for remediation decision making.
Recommendations and perspectives The studies form the basis of a risk management strategy and a plan for possible remediation of contaminated sediments currently
under consideration in the Southeast Finland Regional Environment Centre. It is recommended that a detailed restoration plan
for the most seriously contaminated areas should be undertaken. Based on current knowledge, the restoration of the whole river
is not feasible, considering the current risk caused by the contaminated sediment in the river and the costs of an extensive
restoration project. The experiences gained in the present case should be utilized in the evaluation of PCDD/F- and mercury-contaminated
sites in other countries. The case demonstrates that the historic reservoirs are of contemporary relevance and should be addressed,
e.g., in the national implementation plans of the Stockholm Convention.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
974.
Zusammenfassung
Hintergrund, Ziel und Zweck Borkenbewohnende (epiphytische) Flechten reagieren sehr empfindlich auf verschiedene Umwelteinflüsse wie Stoffgehalte in
der Atmosph?re und Temperaturen. Sie haben als Bioindikatoren für Luftverunreinigungen einen hohen Stellenwert bei Umweltuntersuchungen.
Basierend auf einer 1989 durchgeführten Kartierung borkenbewohnender (epiphytischer) Flechten in einem landwirtschaftlich
intensiv genutzten Raum Nordwestdeutschlands erfolgte 2007 eine Wiederholungsuntersuchung. Dabei galt es, m?gliche Ver?nderungen
der Immissionssituation und des Klimas zu erkennen.
Material und Methoden Die Studie basiert auf einer vergleichenden Kartierung epiphytischer Flechten von 355 Tr?gerb?umen an 45 Monitoringpunkten.
Die angewandte Methode orientiert sich an der 1989 angewandten halb-quantitativen Erfassung.
Ergebnisse Es stellten sich gravierende Ver?nderungen in der Vegetation rindenbewohnender Flechten heraus. Insgesamt war eine Erh?hung
der Artenzahl an nahezu allen Monitoringpunkten festzustellen. Es wurde eine sehr starke Abnahme s?uretoleranter Arten und
eine deutliche Zunahme basen- und n?hrstofffordernder Flechtenarten festgestellt. Darüber hinaus zeigte sich eine deutliche
Zunahme w?rmeliebender Flechtenarten mit einem Verbreitungsschwerpunkt in Südeuropa bei gleichzeitigem Rückgang von Arten
mit einem boreal-montanem Verbreitungsschwerpunkt.
Diskussion Die festgestellte Entwicklung steht im Einklang mit überregionalen Beobachtungen. Sie wird im Wesentlichen auf eine gro?r?umig
ver?nderte Immissionssituation, d. h. einer Abnahme der atmosph?rischen SO2-Belastung und Zunahme der Ammoniakbelastung zurückgeführt. Ebenso treten deutliche Auswirkungen der Klimaerw?rmung hervor.
Schlussfolgerungen Mit relativ geringem Untersuchungsaufwand lie?en sich Ver?nderungen bei den epiphytischen Flechten in den letzten 18 Jahren
aufzeigen. Diese sind relevant für die Beurteilung regional und kleinr?umig ver?nderter Umweltbedingungen, die auch für andere
Organismen und ?kosysteme l?ngerfristig von gro?er Bedeutung sind.
Empfehlungen und Ausblick Unter Verwendung standardisierter Methoden vermitteln epiphytische Flechten ein differenziertes Bild der Luftbelastungssituation
in Ballungsr?umen und in landwirtschaftlich genutzten Regionen. Darüber hinaus sind sie offensichtlich gute Indikatoren für
Temperatur?nderungen ihrer Umgebung. Weiterer Forschungsbedarf besteht für die Verwendung epiphytischer Flechten zum Biomonitoring
von Klimaver?nderungen.
相似文献
975.
New best estimates for the solid–liquid distribution coefficient (Kd) for a set of radionuclides are proposed, based on a selective data search and subsequent calculation of geometric means. The Kd best estimates are calculated for soils grouped according to the texture and organic matter content. For a limited number of radionuclides this is extended to consider soil cofactors affecting soil–radionuclide interaction, such as pH, organic matter content, and radionuclide chemical speciation. Correlations between main soil properties and radionuclide Kd are examined to complete the information derived from the best estimates with a rough prediction of Kd based on soil parameters. Although there are still gaps for many radionuclides, new data from recent studies improve the calculation of Kd best estimates for a number of radionuclides, such as selenium, antimony, and iodine. 相似文献
976.
S.J. Sartandel S.K. Jha S.V. Bara R.M. Tripathi V.D. Puranik 《Journal of environmental radioactivity》2009,100(10):831-834
The understanding and evaluation of the possible interactions of various naturally occurring radionuclides in the world's third largest man-made dam, Nagarjuna Sagar located in Andhra Pradesh, India and built on river Krishna assumed significance with the finding of uranium deposits in locations near the dam. For the present work, surface soil samples from the mineralized area of Lambapur, Mallapuram, Peddagattu and sediment core samples from the Nagarjuna Sagar dam were analyzed for naturally occurring radionuclides namely uranium and thorium using gamma spectrometric technique. Also toxic elements lead and chromium were analysed by the Energy Dispersive X-ray Fluorescence Spectrometer (EDXRF) technique. Surface soil samples show a variation from 25 to 291 Bq/kg (2.02–23.5 mg/kg) for 238U and 32–311 Bq/kg (7.9–76.9 mg/kg) for 232Th. U/Th concentration ratio in surface soil samples ranged from 0.19 to 0.31 and was found comparable with the nation wise average of 0.26. The study of sediment core samples reflected higher U/Th concentration ratio of 0.30–0.33 in the bottom section of the core as compared to 0.22–0.25 in the upper section. The concentration ratio in the upper section of the core was similar to the ratio 0.23 found in the western Deccan Basalt region through which the river originates. A higher concentration of lead and chromium was observed in the upper section of the core compared to bottom section indicating the impact of river input on the geochemical character of dam sediment. 相似文献
977.
978.
Typologically identical (dwarf birch-herb-dwarf shrub-moss) open and closed larch forests growing on the same altitudinal transect have proved to differ in the structural-functional organization of lower vegetation layers. Coverage, general species composition, and species richness of the herb-dwarf shrub layer are higher in the open forest than in the closed forest. Correlations between individual species of vascular plants weaken upon transition from the open to the closed forest. Conversely, the coverage of the lichen-moss layer increases in the closed forest, which contributes to its role as a factor of selection of vascular plant species against the background of the prevailing influence of the tree layer. 相似文献
979.
E. L. Zheleznaya 《Russian Journal of Ecology》2009,40(1):39-43
The overgrowing of meadow-bog communities by shrubs and trees (age 5–40 years, crown closure 0.4–0.9) leads to a decrease in incident illumination. As a consequence, juvenile and generative plants disappear from D. incarnata population loci, their average ecological density decreases, and the loci enter the state of regression. The digging activity of wild boars disrupts phytocenotically closed groups of longirhizomatous herbs, thereby creating favorable conditions for seed reproduction of D. incarnata. The species begins to form population loci with a complete ontogenetic spectrum and high ecological density, eventually restoring the normal (definitive) population structure. 相似文献
980.