Estimated nationwide effects of pesticide spray drift on terrestrial habitats in the Netherlands

This study estimated the potential effects of pesticide drift on terrestrial ecosystems outside target areas, for the Dutch situation. A series of field trials was conducted to estimate the effects of drift on different species groups at different distances from a treated plot for different categories of pesticide: herbicides, fungicides and insecticides. Measurements of the pesticide drift deposition resulting from standard agricultural practice were used to model deposition outside the treated area. These data were then combined with national statistics on cropland and pesticide use to assess the ecological effects of pesticide drift for the Netherlands as a whole. Three scenarios were considered: the recent past (1998), the present (2005) and an optimised scenario based on 'best available practice' (2010). In the recent past the impact of herbicide drift on sensitive life stages non-target vascular plants is estimated to have exceeded the 50% effect level on 59% of adjacent linear landscape elements such as ditch banks and hedgerows. For the impact of insecticides and fungicides on non-target insects and fungi this 50% effect figure was 29% and 28% of linear elements, respectively. In the present situation, with (narrow) unsprayed buffer zones and other measures in place, these percentages are down to 41% for herbicides, 21% for insecticides and 14% for fungicides. In the optimised scenario, with a greater buffer width of 2.25m for potatoes (compared to 1.50m in 2005) and 1m for other crops (compared to 0.25 and 0.5m in 2005) and 'best available practice', these percentages can be cut to zero. In natural areas located within farming regions the 10% effect level can be reduced from 31% of such areas (1998) to 0% under conditions of 'best available practice'.     

污染土壤生物修复中存在问题的探讨

污染物生物修复过程中存在着若干问题,其中包括引入外源微生物的条件与原则,生物修复过程中微生物的适应性机制与影响因素研究;污染物的浓度与生物修复之间的关系;有机污染物降解过程中的次生污染物问题;生物修复的现场放大技术;污染物的淋溶过程;对生物修复技术的生态毒理诊断与评价等.本文旨在提高对生物修复过程中存在的重要科学问题的认识,使生物修复技术的有效利用成为可能.     

微塑料在土壤-地下水中的环境行为及其生态毒性研究进展

微塑料已成为一类新型污染物遍布全球各个角落,由此产生的环境问题日趋严峻。第二届联合国环境大会上将微塑料污染列为环境与生态科学研究领域的第二大科学问题。目前大多数研究集中在海洋环境方面,有关土壤-地下水系统中微塑料的环境行为及生态毒性相关研究还较为薄弱。本文基于大量文献调研,较系统地回顾梳理了有关土壤-地下水中微塑料的来源、迁移归趋及其生态毒理效应的研究成果,并对未来研究做出评述和展望,旨在促进土壤-地下水系统中微塑料污染的相关研究。     

腐殖酸(HA)作用下纳米氧化锌对鲫鱼的毒性效应

通过静态模拟实验,研究不同浓度(0、1、1.5、2.5 mg L-1)腐殖酸(Humic acid,HA)对纳米ZnO(5 mg L–1)毒性效应的影响.将鲫鱼暴露于HA与纳米ZnO混合体系中7 d后,分析Zn在鲫鱼体内的富集分布,及对鲫鱼脑部和肝脏自由基含量、抗氧化系统等的影响.结果显示:随HA浓度的增加,鲫鱼鳃部和肌肉中Zn的含量增高,眼、脑和肝部Zn含量则随之下降.纳米ZnO诱导鲫鱼肝脏和脑产生羟基自由基,HA浓度增大诱导鲫鱼肝脏和脑中SOD活性升高,MDA、GSH含量增加.纳米ZnO胁迫导致鲫鱼肝脏和脑氧化损伤,HA的浓度增加会促进纳米ZnO对鲫鱼肝脏和脑部的氧化损伤.研究表明HA改变了纳米ZnO在环境中的生物效应,因此在关注纳米材料的水生态安全时,不能忽视环境因子的影响.     

In-Situ Phytoremediation of Pahs Contaminated Soils Following a Bioremediation Treatment

Phytoremediation of pollutants in soils is an emerging technology, using different soil-plant interaction properties. For organic pollutants, such as polycyclic aromatic hydrocarbons (PAHs), phytodegradation seems to be the most promising approach. It occurs mostly through an increase of the microbial activity in the plant rhizosphere, allowing the degradation of organic substances, a source of carbon for soil microbes. Despite a large amount of available data in the literature concerning laboratory and short term PAH phytodegradation experiments, no actual field application of such technique was previously carried out. In the present study, a soil from a former coking plant was used to evaluate the feasibility and the efficiency of PAH phytodegradation in the field during a three years trial and following a bioremediation treatment. Before the phytoremediation treatment, the soil was homogenized and split into six independent plots with no hydrological connections. On four of these plots, different types of common plant species were sowed: mixture of herbaceous species, short cut (P1), long cut (P2), ornamental plants (P3) and trees (P4). Natural vegetation was allowed to grow on the fifth plot (P5), and the last plot was weeded (P6). Each year, representative sampling of two soil horizons (0–50 and 50–100 cm) was carried out in each plot to characterize the evolution of PAHs concentration in soils and in soils solution obtained by lixiviation. Possible impact of the phytoremediation technique on ecosystems was evaluated using different eco- and genotoxicity tests both on the soil solid matrix and on the soil solution. For each soil horizon, comparable decrease of soil total PAHs concentrations were obtained for three plots, reaching a maximum value of 26% of the initial PAHs concentration. The decrease mostly concerned the 3 rings PAHs. The overall low decrease in PAHs content was linked to a drastic decrease in PAHs availability likely due to the bioremediation treatment. However, soil solutions concentration showed low values and no signficant toxicity was characterized. The mixture of the herbaceous species seemed to be the most promising plants to be used in such procedure.     

抗癌药卡培他滨对四膜虫的生态毒性研究

水环境抗癌药残留的生态毒性效应是当前环境领域研究热点。本文以四膜虫为模式生物,研究了抗癌药卡培他滨(CAP)对四膜虫的毒性作用。结果表明,0.25-16μMCAP对四膜虫的生长抑制无显著影响。CAP对罗丹明B在四膜虫体内积累的试验结果显示CAP对四膜虫的多药耐药性(MDR)的影响亦不显著。研究结果提示,要进一步探索敏感物种和敏感分子指标,同时考虑CAP代谢产物的生态毒性,为科学认识和评价抗癌药生态风险积累基础数据。     

Identification of chemical hazards for terrestrial plants in the regulatory context: Comparison of OECD and ISO guidelines

Standardized test protocols are used in the regulatory context for identifying the hazardous properties of chemicals, wastes, and contaminated materials. This paper compares the relevance of two guidelines measuring effects on terrestrial plants, the OECD TG 208 and the ISO TG 22030 and presents the scientific basis for a recent decision of the European Chemicals Agency (ECHA) under the European chemicals regulation REACH. If there are no specific phytotoxicity alerts, both guidelines are considered suitable for assessing long-term hazards, providing that a sufficient number of species is included in the OECD protocol, the recommended minimum number is six, which offer a reasonably broad selection of species to account for interspecies sensitivity. The proposed methodology, based on a combination of probabilistic assessments using Monte Carlo analysis, can be adapted for supporting similar decisions under specific regulatory processes; for example, for assessing contaminated soils or pesticides’ applications.     

Levels and transfer of Po and Pb in Nordic terrestrial ecosystems

Recent developments regarding environmental impact assessment methodologies for radioactivity have precipitated the need for information on levels of naturally occurring radionuclides within and transfer to wild flora and fauna. The objectives of this study were therefore to determine activity concentrations of the main dose forming radionuclides ²¹⁰Po and ²¹⁰Pb in biota from terrestrial ecosystems thus providing insight into the behaviour of these radioisotopes. Samples of soil, plants and animals were collected at Dovrefjell, Central Norway and Olkiluoto, Finland. Soil profiles from Dovrefjell exhibited an approximately exponential fall in ²¹⁰Pb activity concentrations from elevated levels in humus/surface soils to “supported” levels at depth. Activity concentrations of ²¹⁰Po in fauna (invertebrates, mammals, birds) ranged between 2 and 123 Bq kg⁻¹ d.w. and in plants and lichens between 20 and 138 Bq kg⁻¹ d.w. The results showed that soil humus is an important reservoir for ²¹⁰Po and ²¹⁰Pb and that fauna in close contact with this media may also exhibit elevated levels of ²¹⁰Po. Concentration ratios appear to have limited applicability with regards to prediction of activity concentrations of ²¹⁰Po in invertebrates and vertebrates. Biokinetic models may provide a tool to explore in a more mechanistic way the behaviour of ²¹⁰Po in this system.     

Life-cycle model of terrestrial carbon exchange

We present here a terrestrial carbon cycle model based on a scheme of the phytomass change, which is continuous in time. The experimental information about net primary production, living and dead phytomass, and soil organic matter for various ecosystems is used for calibration of the model. The suggested model enables to characterize terrestrial ecosystems as carbon sources or carbon sinks and to evaluate intensity of these sources and sinks. The model is applied for the European territory of Russia as a case study. Intensity of the total exchange carbon flux for this territory is evaluated. The obtained results allow to conclude that the given territory is the sink of carbon.     

Locating food in a spatially heterogeneous environment: Implications for fitness of the macrodecomposer Armadillidium vulgare (Isopoda: Oniscidea)

To assess the fitness consequences of foraging on patchy resources, consumption rates, growth rates and survivorship of Armadillidium vulgare were monitored while feeding in arenas in which the spatial distribution of patches of high quality food (powdered dicotyledonous leaf litter) was varied within a matrix of low quality food (powdered grass leaf litter). Predictions from behavioural experiments that these fitness correlates would be lower when high quality food is more heterogeneously distributed in space were tested but not supported either by laboratory or field experiments. To investigate whether A. vulgare can develop the ability to relocate high quality food patches, changes in foraging behaviour, over a comparable time period to that used in the fitness experiments, were monitored in arenas in which there was a high quality food patch in a low quality matrix. A. vulgare increased its ability to relocate the position of high quality food over time. It reduced time spent in low quality food matrices and increased time spent in high quality food patches with time after the start of the experiment. When the position of a high quality food patch was moved, the time spent in the low quality food matrix increased and less time was spent in high quality food patches, compared to arenas in which the food was not moved. The fitness benefits for saprophages of developing the ability to relocate high quality patches while foraging in spatially heterogeneous environments are discussed.