Role of Alternative Electron Acceptors (AEA) to control methane flux from waterlogged paddy fields: Case studies in the southern part of West Bengal, India

The rice fields, depleted of O₂, contain large amount of moisture and organic substrates to provide an ideal anaerobic environment for methanogenesis and are one of the principal anthropogenic sources of methane. In order to mitigate this emission Alternative Electron Acceptors (AEA) were altered in the soil. The experiments were carried out in four seasons at the site of Balarampur, near Baruipur, South 24 Parganas, West Bengal, namely September–December, 2005 (Cultivar: Sundari), February–May, 2006 (Cultivar: Sundari), September–December, 2006 and February–May, 2007 (Cultivar: Swarna-Pankaj). The seasonal average methane flux (Fe treated), for the cultivar type “Sundari” (season: September–December, 2005), is 4.41 t ha⁻¹, as compared to the value of 6.40 t ha⁻¹ for the untreated soil. Similarly for February–May, 2006, the seasonal average methane flux (Fe treated) is 5.52 t ha⁻¹, whereas the untreated flux is 5.69 t ha⁻¹. In the third and fourth seasons we had two treatments with Ammonium Thiosulphate and Ferric Hydroxide. The seasonal average methane flux (treatment: Ammonium Thiosulphate) is 4.35 t ha⁻¹ and 5.41 t ha⁻¹ respectively, whereas for the ferric hydroxide treated soil it is 4.35 t ha⁻¹ and 6.14 t ha⁻¹ respectively. The properties related to the nutrient quality of the harvested paddy seeds supplement these results.     

Water monitoring and treatment for drinking purposes in 2004 tsunami affected area—Ban Nam Khem, Phang Nga, Thailand

University of Brescia and Mahidol University of Bangkok developed a project in Phang Nga province (Thailand), the most damaged by 2004 tsunami. In particular, the study, performed between April and May 2006, dealt with the surface and ground water monitoring in Ban Nam Khem village and the experimental evaluation of possible drinking treatment alternatives. The monitoring highlighted that saline content in the tsunami affected area is decreasing but still very high (conductivity presented values up to 2,600 and 6,230 microS/cm in ground and surface water, respectively); hence, advanced and complicated processes such as reverse osmosis should be adopted to treat such water for drinking purposes. Waiting for ground water salinity to assume acceptable values, activities for the reduction of its organic and microbiological contamination will be started. However, it has to be underlined that the diffusion of drinking water to a greater part of population can be obtained only through the realization of new centralised treatment plants and the improvement of existing ones (serving at the moment about 20% of inhabitants).     

Accumulation of Heavy Metals in Epiphytic Lichens Near a Municipal Solid Waste Incinerator (Central Italy)

The epiphytic lichen Parmelia caperata was usedas biomonitor in the area of a municipal solid wasteincinerator (Poggibonsi, central Italy) to investigatethe levels and the spatial distribution of the heavymetals Al, Cd, Cr, Cu, Fe, Hg, Pb and Zn. Levels ofAl, Cu and Hg were similar to those in unpollutedareas, whereas high values were found for Cr, Zn andespecially Cd. The distribution pattern of the lastthree metals and the exponential relationship of theirconcentrations with distance from the incinerator,showed that the disposal plant is a local source ofatmospheric pollution due to Cd, Cr and Zn. For thesemetals, long-term hazard should be seriously taken into account.     

Quantifying the introgressive hybridisation propensity between transgenic oilseed rape and its wild/weedy relatives

In order to estimate the introgressive hybridisation propensity (IHP) between genetically modified (GM) oilseed rape (Brassica napus) and certain of its cross-compatible wild/weedy relatives at the landscape level, a conceptual approach was developed. A gene flow index was established enclosing the successive steps to successfully achieve introgressive hybridisation: wild/weedy relatives and oilseed rape should co-occur, have overlapping flowering periods, be compatible, produce viable and fertile progeny, and the transgenes should persist in natural/weedy populations. Each step was described and scored, resulting in an IHP value for each cross-compatible oilseed rape wild/weedy relative. The gene flow index revealed that Brassica rapa has the highest introgressive hybridisation propensity (IHP value = 11.5), followed by Hirschfeldia incana and Raphanus raphanistrum (IHP = 6.7), Brassica juncea (IHP = 5.1), Diplotaxis tenuifolia and Sinapis arvensis (IHP = 4.5) in Flanders. Based on the IHP values, monitoring priorities can be defined within the pool of cross-compatible wild/weedy oilseed rape relatives. Moreover, the developed approach enables to select areas where case-specific monitoring of GM oilseed rape could be done in order to detect potential adverse effects on cross-compatible wild/weedy relatives resulting from vertical gene flow. The implementation of the proposed oilseed rape-wild relative gene flow index revealed that the survey design of existing botanical survey networks does not suit general surveillance needs of GM crops in Belgium. The encountered hurdles to implement the gene flow index and proposals to acquire the missing data are discussed.     

Assessment and comparison of the environmental performances of a regional incinerator network

In Emilia-Romagna region (Northern Italy) the integrated waste treatment system consists of material collection and recycling, incineration with energy recovery and landfill as final disposal. In particular, at least one incineration plant is working in almost every province of the region. In this work, a screening life cycle assessment approach is applied to seven different incinerators, to compare the different plant technologies and identify the most relevant environmental impacts and processes. The characterization method used in the life cycle impact assessment step is Eco-indicator 99. The functional unit is 1 ton of waste input. As a first result, it can be noted that while the combustion systems are rather similar, the main variables are ascribable to gas cleaning options and efficiency in energy recovery, which result in quite different environmental performances. Among heavy metals, particular attention must be paid to Cd and As, due to their high toxicity, despite their low quantities. The impact due to dioxin emission is orders of magnitude lower than other contaminants (e.g., heavy metals). Furthermore, a catalytic system could be useful for a complete removal of organic contaminants and for a more effective abatement of nitrogen oxides. Finally, the environmental impact assessment sorts the various plants according to their age, i.e., the most recent plants provide the best environmental performances for the same quantity of combusted waste.     

Adsorption of a dye on clay and sand. Use of cyclodextrins as solubility-enhancement agents

Laboratory-scale studies were aimed at elucidating the physico-chemical aspects on the removal process of crystal violet (CV) from waters and solid substrates. The laponite clay (RD) and sand were chosen for the double aim at investigating them as CV adsorbents for water treatment and as substrates which mime the soil components. Sand is very effective in removing CV from waters. The cyclodextrins (CDs) were exploited as solubility-enhancement agents to remove CV from the solid substrates. They are powerful solvent media because they extract the CV from sand forming water-soluble CV/CD inclusion complexes and do not show affinity for sand. Optimum performance was shown by the modified CDs (i.e. hydroxypropyl-β-cyclodextrin and methyl-β-cyclodextrin). A linear correlation between the logarithm of the equilibrium constant for the CV/CD inclusion complexes formation (K_cpx) and the maximum amount of CV extracted from sand in the columns experiments at a flow rate of 1.5 ml min⁻¹ was drawn. This relationship predicts that CDs with K_cpx < 180 M⁻¹ are not suitable for CV removal from sand. CDs failed to displace CV from RD because they generate the formation of RD clusters where CV remains entrapped.     

Absorption, disposition and excretion of polybrominated diphenyl ethers (PBDEs) in chicken

Except for fish, no toxicokinetic data on polybrominated diphenyl ethers (PBDEs) is available on relevant animals for the human food chain. In the present work, absorption, elimination through eggs and disposition of PBDEs in laying chickens were studied and compared to dioxin behaviour. Hens were fed with diet containing 3.4 mg/kg feed of PBDEs and 0.95 ng TEQ/kg feed of polychlorodibenzo-p-dioxins (PCDDs) and polychlorodibenzofurans (PCDFs). PBDEs have been demonstrated to show drastically different behaviours from PCDD/Fs and dioxin-like compounds. Excretion of PBDEs increased for two weeks and then decreased to nearly 0%. Sixty-two percent of ingested 2,2',4,4'-tetraBDE (BDE-47) were found in excreta after two weeks, suggesting a reductive debromination of PBDEs in the digestive tract. PBDE level in eggs increased during five weeks and reached 24 microg/g fat. After then, levels decreased to 3 microg/g fat at the end of the trial. PBDE bioconcentration factors estimated for abdominal fat varied from 0.7 for BDE-47 to 2 for BDE-183.     

Vegetable and synthetic tannins induce hormesis/toxicity in sea urchin early development and in algal growth

Mimosa tannin and phenol-based synthetic tannin (syntan) were tested for toxicity to sea urchin (Paracentrotus lividus and Sphaerechinus granularis) early development and to marine algal growth (Dunaliella tertiolecta). Sea urchin embryogenesis was affected by vegetable tannin and syntan water extracts (VTWE and STWE) at levels >or=1mg/L. Developmental defects were significantly decreased at VTWE and STWE levels of 0.1 and 0.3mg/L when control cultures displayed suboptimal quality, i.e. <70% "viable" (normal or retarded) larvae. Fertilization success of sea urchin sperm was increased up to 0.3 mg/L STWE or VTWE, then was inhibited by increasing tannin levels (1-30 mg/L). Offspring abnormalities, following sperm exposure to VTWE or STWE, showed the same shift from hormesis to toxicity. Cell growth bioassays in D. tertiolecta exposed to VTWE or STWE (0.1-30 mg/L) showed non-linear concentration-related toxicity. Novel criteria are suggested in defining control quality that should reveal hormetic effects.     

Effect of coumaphos on cholinesterase activity, hematology, and biochemical blood parameters of bovines in tropical regions of Mexico

To assess the effect of coumaphos [O-(3-chloro-4-methyl-2-oxo-2H-1-benzopyran-7-yl) O,O-diethyl phosphorothioate] exposure on physiological responses during bovine production, acetylcolinesterase (AChE) and butyrylcholinesterase (BuChE) activities were measured in whole blood, erythrocytes, and plasma of healthy male steers (Bos Taurus x Bos indicus) sprayed with coumaphos at a non-lethal dose of 1 mg kg(- 1) body weight per day once every 14 (in vivo group) or 21 days (southern and central groups). Coumaphos topically administered at 1 mg/kg body weight per day to cattle under normal management practices in tropical areas produced a significant inhibition in erythrocyte (RBC) AChE and BuAChE activities when compared to baseline levels. RBC-AChE activity for the in vivo group decreased 71.3% (P < 0.05) and BuChE activity 59.1% (P < 0.05); RBC-AChE activity decreased 55.1% (P < 0.05) (southern group) and 43.4% (P < 0.05) (central group). Compared to the control specimens, steers from in vivo, southern, and central groups after 150 days of exposure had lower (P < 0.05) leukocyte count, absolute lymphocyte, erythrocyte, and platelet counts. Decreases in RBC-AChE activities correlated with decreased lymphocyte (r = 1.000, p = 0.01), erythrocyte (r = 1.000, p = 0.003), and platelet counts (r = 0.841, p = 0.036). Significantly increased BUN levels (P < 0.05) correlated with the decrease in RBC-AChE activities (r = - 0.997, p = 0.047) and with the decrease in absolute red blood cell (r = - 0.883, p = 0.020) and lymphocyte (r = - 0.825, p = 0.043) counts; increased (P < 0.05) total plasma protein levels correlated with the decrease in RBC-AChE activities (r = -0.998, p = 0.043), absolute red blood cell (r = - 0.998, p = 0.040), lymphocyte (r = - 0.893, p = 0.017), and platelet (r = -0.855, p = 0.030) counts. The physiological responses correlated with the erythrocyte acetylcholinesterase inhibition could be considered as early indicators or warning responses of bovine exposures to organophosphorus pesticides (OPs).