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Jessing Karina K. Andresen Marianne Cedergreen Nina 《Water, air, and soil pollution》2014,225(6):1-12
Oil spills impose serious damage to the environment. A spilled crude oil or its products affect aquatic flora and fauna and influence the atmosphere as well. Such pollutants are especially dangerous for the water ecosystems, where biological self-purification processes are slower (for example the Baltic Sea), than in warmer regions. In this paper, we evaluate a sorption capacity of ecologically friendly natural sorbents, when the crude oil and diesel are spilled on the surface of water. The experiments are carried out in the laboratory, and the water from the Lithuanian Baltic Sea coastline and Curonian Lagoon is used. Moss, straw, wool, sawdust, and peat are the natural sorbents evaluated during the experiments. Chromatographic analysis of crude oil and diesel during the process of sorption was conducted as well. An experiment with some synthetic sorbents was carried out to compare the results with natural ones. The experiments showed that the most suitable material for crude oil or diesel fuel spilled on the water surface is peat. As well, Lagergren’s model was adopted to the case of the sorption processes we have investigated. It can be exploited as a decision support tool while deciding the required time interval to achieve maximum sorption capacity of the sorbent in use. 相似文献
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Risk assessment of herbicides towards non-target plants in Europe is currently based solely on tests on algae and floating aquatic plants of Lemna sp. Effects on terrestrial non-target species is not systematically addressed. The purpose of the present study was to compare combination effects of herbicide mixtures across aquatic and terrestrial test systems, and to test whether results obtained in the traditional aquatic test systems can be extrapolated to the terrestrial environment. This was done by evaluating ten binary mixtures of nine herbicides representing the seven most commonly used molecular target sites for controlling broadleaved weeds. Data were evaluated statistically in relation to the concentration addition model, and for selected concentrations to the independent action model. The mixtures were tested on the terrestrial species Tripleurospermum inodorum (L.) Schultz-Bip. (Scentless Mayweed) and Stellaria media (L.) Vill. (Common Chickweed), and on the aquatic species Lemna minor L. (Lesser duckweed) and the alga Pseudokirchneriella subcapitata (Korschikov) Hindak. For the two mixtures of herbicides with the same molecular site of action, the joint effect was additive. For the eight mixtures of herbicides with different sites of action, two of the mixtures were consistently antagonistic across species, while for the remaining six mixtures the joint effect depended on the species tested. This dependence was, however, not systematic, in the sense that none of the species or test systems (terrestrial versus aquatic) had a significantly higher probability of showing synergistic or antagonistic joint effects than others. Synergistic interactions were not observed, but approximately 70% of the mixtures of herbicides with different sites of action showed significant antagonism. Hence, the concentration addition model can be used to estimate worst-case effects of mixtures of herbicides on both terrestrial and aquatic species. Comparing the sensitivity of the species to a 10% spray drift event showed that the terrestrial species were more vulnerable to all herbicides compared with the aquatic species, emphasising the importance of including terrestrial non-target plants in herbicide risk assessment. 相似文献
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BACKGROUND: Changes in chlorophyll fluorescence have often been advocated as a sensitive biomarker of plant stress, assuming that any kind of plant stress serious enough to affect plant growth will also affect photosynthesis. Glyphosate affects photosynthetic electron transport indirectly by inhibiting sink processes. The question is how fast this inhibition can be observed on CO2 assimilation and ultimately on chlorophyll fluorescence? RESULTS: Experiments measuring CO2 assimilation, conductance and chlorophyll fluorescence using four Kautsky curve parameters on barley (Hordeum vulgare L.) exposed to increasing doses of glyphosate showed a total cessation of CO2 fixation and conductance without significant changes in chlorophyll fluorescence. The decrease in CO2 fixation and conductance was significant 1 day after spraying and corresponded well to the decrease in biomass 5–7 days after spraying. CONCLUSION: A total cessation of CO2 assimilation can take place without affecting chlorophyll fluorescence. Hypotheses concerning what happens to the energy from the photosynthetic apparatus that is not used for CO2 assimilation are discussed. The results question the use of chlorophyll fluorescence as a universal indicator of stress on photosynthetic processes. Also, they demonstrate that changes in gas‐exchange parameters are more sensitive biomarkers for glyphosate toxicity compared with chlorophyll fluorescence. Copyright © 2010 Society of Chemical Industry 相似文献
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The toxicity of herbicides to non-target aquatic plants and algae: assessment of predictive factors and hazard 总被引：4，自引：0，他引：4
Widely used herbicides sometimes inadvertently contaminate surface waters. In this study we evaluate the toxicity of herbicides to aquatic plants and algae and relate it to environmental herbicide concentrations and exposure scenarios, herbicide formulation and mode of action. This was done experimentally for ten herbicides, using the aquatic macrophyte Lemna minor L. and the green alga Pseudokirchneriella subcapitata (Korshikov) Hindak, supplemented with a database study comprising algae toxicity data for 146 herbicides. The laboratory study showed that herbicide formulations in general did not enhance herbicide efficacy in the aquatic environment. The Roundup formulation of glyphosate proved to be the only exception, decreasing the EC(50) of the technical product for both L. minor and P. subcapitata approximately fourfold. Comparison of the sensitivity of L. minor and P. subcapitata revealed up to 1000-fold higher sensitivity of L. minor for the herbicides categorized as weak acids (pK(a) < 5), emphasizing the importance of higher plants in hazard assessment. Database analyses showed that no herbicide group, categorized by site of action, was significantly more toxic than another. Synthetic auxins were the exception as they are virtually non-toxic to unicellular algae. There was no strong correlation between toxicity to algae and K(ow) of the herbicides, not even within groups having the same site of action. Evaluating all data, few herbicides were toxic at concentrations below 1 microg l(-1), which is the 99.9th percentile of the herbicide concentrations measured in the Danish surveillance programme. Joint action of several herbicides cannot however be excluded. 相似文献
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The joint action of soil-applied herbicide mixtures with similar or different modes of action has been assessed by using the additive dose model (ADM). The herbicides chlorsulfuron, metsulfuron-methyl, pendimethalin and pretilachlor, applied either singly or in binary mixtures, were used on rice (Oryza sativa L.). The growth (shoot) response curves were described by a logistic dose-response model. The ED50 values and their corresponding standard errors obtained from the response curves were used to test statistically if the shape of the isoboles differed from the reference model (ADM). Results showed that mixtures of herbicides with similar molecular targets, i.e. chlorsulfuron and metsulfuron (acetolactate synthase (ALS) inhibitors), and with different molecular targets, i.e. pendimethalin (microtubule assembly inhibitor) and pretilachlor (very long chain fatty acids (VLCFAs) inhibitor), followed the ADM. Mixing herbicides with different molecular targets gave different results depending on whether pretilachlor or pendimethalin was involved. In general, mixtures of pretilachlor and sulfonylureas showed synergistic interactions, whereas mixtures of pendimethalin and sulfonylureas exhibited either antagonistic or additive activities. Hence, there is a large potential for both increasing the specificity of herbicides by using mixtures and lowering the total dose for weed control, while at the same time delaying the development of herbicide resistance by using mixtures with different molecular targets. 相似文献
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Low dose chemical stress has been shown to increase plant vegetative growth, though not all chemicals induce the response. Glyphosate is the most widely used herbicide by volume and treated area. At low doses, it can increase growth in a variety of species. Here we show that a glyphosate-induced growth increase can be transformed into an increase in crop yield, if applied at the right time. Glyphosate, in the dose range of 2.5–20 g a.e. ha−1, corresponding to less than 1% of the rate normally used for weed control in the field, increased grain yield of barley by 12–15% when applied at the time of grain filling. Straw yield and the quality of the grains in terms of nitrogen and starch content were not affected by the treatment. The physiological mechanism behind this counter intuitive increase in growth is still unknown, as are possible adverse effects. It is, however, evident that understanding the physiological processes behind chemically induced growth increases in plants holds the promise of improving food yield. 相似文献
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Helle Sørensen Nina Cedergreen Jens C. Streibig 《Journal of Agricultural, Biological & Environmental Statistics》2010,15(4):562-577
We suggest a simple isobole analysis for binary mixture toxicity experiments. The analysis is based on estimated logarithmic
effect concentrations and their corresponding standard errors. The suggested model allows for synergism/antagonism and incorporates
within-mixture variation as well as between-mixture variation in a random effects model. The likelihood ratio test for the
hypothesis of concentration addition (CA) is examined, in particular its small sample properties. We study two datasets on
the joint effect of acifluorfen versus diquat and glyphosate versus mechlorprop, respectively, on the growth of the aquatic
macrophyte Lemna minor. 相似文献
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