LIMPACT: Ein Expertensystem zur Absch?tzung der Pflanzenschutzmittel-Belastung kleiner Flie?gew?sser mittels der Makroinvertebraten-Fauna

Zusammenfassung  Die Entwicklung, der Aufbau und die Evaluierung eines biologischen Indikatorsystems für die Pflanzenschutzmittel-Belastung in kleinen Flie?gew?ssern wird vorgestellt. In Flie?gew?ssern mit landwirtschaftlichem Einzugsgebiet stuft das Expertensystem LIMPACT die Belastung in vier Klassen ‘unbelastet/nicht nachgewiesen’, ‘gering’, ‘mittel’ und ‘hoch’ belastet ein. Eingangsdaten sind dabei die Abundanzdaten der benthischen Makroinvertebraten-Fauna zu vier Terminen im Jahresverlauf (M?rz/April; Mai/Juni; Juli/August; September/Oktober) und neun physikalisch-chemische bzw. morphologische Flie?gew?sserparameter. Die Wissenbasis wurde mit dem Shellbaukasten D3 aufgebaut und enth?lt 921 Regeln zum etablieren oder de-etablieren einer Bewertungsklasse. Es wurden 39 Arten und Taxa analysiert und dabei 13 positive und 24 negative Indikatorspezies definiert. Positive Indikatorarten zeigen eine hohe Belastung durch hohe Abundanzen an, w?hrend negative Indikatorarten durch eine hohe Abundanz eine Belastung ausschlie?en und unbelastete B?che anzeigen. Die Datenbasis enthielt 157 j?hrliche Untersuchungen und wurde auch zur Evaluierung eingesetzt. Die korrekte Klassifikationsrate liegt bei 66,7–85,5% der F?lle. Die meisten verbleibenden F?llen werden nicht falsch eingestuft, sondern infolge der konservativen Bewertung bei geringer Datengrundlage nicht klassifiziert. Online First: 31.05.2002     

Partielle Ordnung

Zusammenfassung  Sollen Chemikalien oder Umweltbelastungen ?kotoxikologisch beurteilt werden, so erfordert die Komplexit?t ?kosystemarer Zusammenh?nge, da? Bewertungsverfahren Informationen m?glichst nicht aggregieren soilten. Es gibt keine ?kologisch begründete, allgemein verwendbare Zielfunktion. Die Technik, dennoch beispielsweise Chemikalien miteinander vergleichen zu k?nnen, beruht auf der Verallgemeinerung des Ordnungsbegriffs und der Visualisierungsmethode durch Hasse-Diagramme. Am Beispiel von sechs Chemikalien wird das Verfahren erl?utert und gezeigt, da? ungünstige Einstufungen von Chemikalien verschiedene Ursachen haben k?nnen, die dann auch unterschiedliche ?kotoxikologische Konsequenzen bewirken.      

The ratio of clay content to total organic carbon content is a useful parameter to predict adsorption of the herbicide butachlor in soils

Thirteen soils collected from 11 provinces in eastern China were used to investigate the butachlor adsorption. The results indicated that the total organic carbon (TOC) content, clay content, amorphous Fe2O3 content, silt content, CEC, and pH had a combined effect on the butachlor sorption on soil. Combination of the data obtained from the 13 soils in the present study with other 23 soil samples reported by other researchers in the literature showed that Koc would be a poor predictive parameter for butachlor adsorption on soils with TOC content higher than 4.0% and lower than 0.2%. The soils with the ratio of clay content to TOC content (RCO) values less than 60 adsorbed butachlor mainly by the partition into soil organic matter matrix. The soils with RCO values higher than 60 apparently adsorbed butachlor by the combination of the partition into soil organic matter matrix and adsorption on clay surface.     

Verteilungskoeffizienten chlorierter Kohlenwasserstoffe zwischen Muskulatur und Leber bei Fischen

Zusammenfassung  Lipidbezogene Verteilungskoeffizienten (KL_M/L) zwischen Muskelkonzentrationen-(C_ML) und Leberkonzentrationen (C_LL) zweier Friedfischarten Brassen (Abramis brama) und Aalmutter (Zoarces viviparus) ergeben theoriekonform (KL_M/L=C_ML/C_LL=1) nominale Werte um 1 für persistente (hochchlorierte PCB) und Werte über 1 für metabolisierbare lipophile Umweltchemikalien wie chlorierte Cyclohexane oder DDT.      

Gas–liquid chromatography for fenvalerate residue analysis: alterations in the ionic concentration and associated adinosine triphosphatases in fish,Cirrhinus mrigala (hamilton)

In the present study, an attempt has been made to quantify the fenvalerate accumulated in different tissues (gill, muscle and liver) and observe changes involved in the levels of sodium, potassium and calcium ions and Na⁺–K⁺, Mg²⁺ and Ca²⁺ adenosine triphosphatase (ATPase) activities in the freshwater fish, Cirrhinus mrigala on short-term and long-term exposure to the median lethal and sublethal concentration of fenvalerate. Residue analysis using gas–liquid chromatography (GLC) technique revealed that fenvalerate accumulated in highest quantity in gill followed by liver and muscle under median lethal concentration (6?µg?L^?1). Whereas in sublethal concentration (0.6?µg?L^?1), muscle accumulated highest quantity followed by gill and liver, which might be due to the fact that fenvalerate is highly lyphophilic. The ion concentration and ATPase activity were found effected in fish exposed to lethal and sublethal concentrations of fenvalerate. Concentration of Na⁺, K⁺ and Ca²⁺ ions decreased in gill, muscle and liver on being exposed to median lethal concentration to a significant level. Whereas the changes were not highly pronounced at sub lethal level indicating low concentration of fenvalerate and its non-toxic effect at chronic exposure. Na⁺–K⁺, Mg²⁺ and Ca²⁺ ATPases activity were also found decreased in correspondence to the ionic change under median lethal and sub lethal concentrations in target tissues. This might have lead to behavioural changes and create wide-spread disturbance in the normal physiology, ultimately causing the death of the fish. The results suggest that in biomonitoring programmes, ions and associated ATPases can be a good diagnostic tool for fenvalerate toxicity.     

Effects of UV-B radiation on the gills of Catla catla during early development

Scanning electron microscopic (SEM) study of gills of Catla catla catla (17-day-old) exposed to UV-B radiation (145?µW?cm^?2 at the water surface) for three different exposure times: 5, 10 and 15?min was conducted. Fish without UV-B exposure served as control. UV-B radiation damaged both gill filaments and lamellae. The intensity of damage was minimal in 5?min exposed fish, followed by 10?min exposed fish and maximal in 15?min. The gill epithelium was severely damaged in 15?min irradiated fish compared to control. Pavement cells (PVCs) were damaged and the numbers of microridges within PVCs decreased. The deep boundary of PVC was not clear. In some area of gill epithelium, PVCs were destroyed and mitochondrion-rich cells (MRCs) were exposed. The 5?min exposure reduced the number of microridges in the PVCs, but the boundary of PVCs was still visible. MRCs in the gill epithelium were not exposed in 5?min exposed fish. The damage to PVCs and subsequent exposure of MRCs in UV-B irradiated fish may hamper respiratory functions and disturb osmoregulation in catla.     

Neuroprotective potential of N -acetylcysteine in carbofuran neurotoxicity: A biochemical and histopathological study

The present study was undertaken to evaluate biochemical markers of chronic carbofuran exposure to rats in terms of lipid peroxide and intrasynaptosomal calcium levels and to correlate them with the histopathological changes in brain regions. A significant increase in lipid peroxidation (LPO) in terms of thiobarbituric acid reactive substances (TBARS) was observed in the cerebral cortex (65%) and brain stem (33%) after carbofuran exposure. This was accompanied by a significant increase (87%) in the intracellular free-Ca²⁺ [Ca²⁺]_i levels. N-acetylcysteine (NAC) administration, on the other hand, reversed the carbofuran-induced increase in LPO and [Ca²⁺]_i. Histopathological studies of carbofuran-exposed brain revealed high frequency of pyknotic neurons in the cerebral cortex and microhaemorrhages in the brain stem. NAC supplementation to carbofuran-treated animals resulted in normalisation of the brain architecture as seen by a reduction in the number of pyknotic nuclei in the cerebral cortex. These findings indicate that increased LPO and elevated [Ca²⁺]_i levels are involved in the development of carbofuran neurotoxicity and are eventually responsible for the pathological alterations. The study also demonstrates potential neuroprotective effect of NAC treatment in carbofuran neurotoxicity.     

Comparative study between using natural and synthetic zeolites for the improvement of soil salinity and crop yield

The effects of natural zeolite (clinoptilolite, NZ) and synthetic zeolite (Y, SZ) on salinity and the presence of the harmful salts in the soil were compared on Raphanus sativus L. Nine soil treatments were studied: 1 (control), 2 (NaCl), 3 (Na₂SO₄), 4 (NZ), 5 (SZ), 6 (NZ?+?NaCl), 7 (SZ?+?NaCl), 8 (NZ?+?Na₂SO₄), and 9 (SZ?+?Na₂SO₄). Five radish seeds were planted in each pot. Each treatment was repeated 10 times. After 50 days under equal conditions some parameters consisting of the number of leaves (NL), total leaf area (TLA), total fresh weight (TFW), total dry weight (TDW), root fresh weight (RFW), air fresh weight (AFW), root dry weight (RDW) and air dry weight (ADW) were determined. Results showed that adding either NZ or SZ to salinic soil (treatments NZNaCl, NZNa₂SO₄, SZNaCl and SZNa₂SO₄) increased AFW, TFW and TDW. Using both NZ and SZ in normal soil increased the weight of plants by developing AFW. Further NZ was more effective on soil with NaCl than SZ.     

Environmental contamination using accumulation of metals in marine sponge,Sigmadocia fibulata inhabiting the coastal waters of Gulf of Mannar,India

Coastal marine ecosystems in many parts of the world are under unrelenting stress caused by urban development, pollutants and other ecological impacts such as building of infrastructure, land reclamation for port and industrial development, habitat modification, tourism and recreational activities. The present work is a first extensive field study using the marine sponge, Sigmadocia fibulata as a bioindicator to detect metal pollution between inshore and offshore environment of the ‘Gulf of Mannar’, India. Samples of S. fibulata were collected from different places of inshore (0.1–0.5?km) and offshore (3–5?kms) locations. Metal concentrations in water and bioaccumulation in sponges were determined by ICP-MS (Inductively coupled plasma-mass spectrometry). Enrichment of metal contamination was more in the inshore, when compared to offshore environment. Higher concentrations of metals Fe, Al, Ni, Mn, Cu, Cr, Co, Ba, Zn, V, Pb and Cd in inshore waters (3–6.4 times than offshore) may be due to the discharge of monsoonal rains, carrying a discharge of industrial and agricultural wastes and sewage directly into the coast. This is substantiated by a highly significant positive correlation between concentrations of metals in the water and accumulation in sponges. The bioaccumulation of metals in sponge tissue were in order of Fe?>?Al?>?Ni?>?Mn?>?Cu?> Cr?>?Co?>?Ba?>?Zn?>?V?>?Cd?>?Pb in both the inshore and offshore regions. Apparently, the macromolecule composition (sugars, proteins and lipids) was significantly reduced by the accumulation of metals in inshore sponges. The current findings indicated that the frequent monitoring is necessary to assess the eco-health of the marine environment by choosing bio-indicator species like S. fibulata, which provide accurate, reliable measurements of environmental quality.     

Manganese toxicity in Drosophila melanogaster: extension of the life span by resveratrol

The effect of resveratrol was studied on the life span and motor activity of Drosophila melanogaster treated with manganese (Mn). Two days after emerging from the pupa, male wild type D. melanogaster were fed for 13 days with corn media containing 15?mM Mn. Thereafter, Drosophila were divided into six groups of 300 flies each: (1) the flies remained treated with Mn; (2) began treatment with 0.43?mM resveratrol (Mn-resveratrol group); (3) received no additional treatment (Mn-no treatment group); (4) simultaneously fed with Mn and resveratrol (Mn?+?resveratrol group). In addition, a control (5) with no treatment and another group (6) fed only with resveratrol after emerging from the pupa were included. All Mn-treated flies (group 1) were dead on the 25th day. The life span in the resveratrol group was 91?±?0.33 days (mean?±?S.E.M.) and in Mn-resveratrol flies was 83?±?2 days. These two values were significantly higher than those detected in the control (5) and Mn-no treatment (group 3) flies whose life span were 68?±?0.33 and 67?±?2.31 days, respectively. The Mn?+?resveratrol-fed flies had a markedly higher life span (31?±?1.53 days) than Mn-fed flies (23?±?0.88 days). In the flies that received Mn (Mn and Mn?+?resveratrol groups), the motor activity decreased significantly with respect to control (groups 5) and the Mn–resveratrol and resveratrol groups. In conclusion, resveratrol increased significantly the life span of Mn-treated D. melanogaster.