Global warming contributions from wheat,sheep meat and wool production in Victoria,Australia – a life cycle assessment

This paper compares the life cycle global warming potential of three of Australia’s important agricultural production activities – the production of wheat, meat and wool in grazed subterranean clover (sub-clover) dominant pasture and mixed pasture (perennial ryegrass/phalaris/sub-clover/grass and cape weed) systems. Two major stages are presented in this life cycle assessment (LCA) analysis: pre-farm, and on-farm. The pre-farm stage includes greenhouse gas (GHG) emissions from agricultural machinery, fertilizer, and pesticide production and the emissions from the transportation of these inputs to paddock. The on-farm stage includes GHG emissions due to diesel use in on-farm transport and processing (e.g. seeding, spraying, harvesting, topdressing, sheep shearing), and non-CO₂ (nitrous oxide (N₂O), and methane (CH₄)) emissions from pastures and crop grazing of lambs.The functional unit of this life cycle analysis is the GHG emissions (carbon dioxide equivalents – CO₂ -e) from 1 kg of wheat, sheep meat and wool produced from sub-clover, wheat and mixed pasture plots. The GHG emissions (e.g. CO₂, N₂O and CH₄ emission) from the production, transportation and use of inputs (e.g. fertilizer, pesticide, farm machinery operation) during pre-farm and on-farm stages are also included. The life cycle GHG emissions of 1 kg of wool is significantly higher than that of wheat and sheep meat. The LCA analysis identified that the on-farm stage contributed the most significant portion of total GHG emissions from the production of wheat, sheep meat and wool. This LCA analysis also identified that CH₄ emissions from enteric methane production and from the decomposition of manure accounted for a significant portion of the total emissions from sub-clover and mixed pasture production, whilst N₂O emissions from the soil have been found to be the major source of GHG emissions from wheat production.     

The risk assessment–policy gap: An example from the UK contaminated land regime

Risk-based regulation assumes that risk assessment can evaluate risks against policy objectives. However, policy goals are often ambiguous and require risk assessors to interpret them for use in risk assessment. This risk assessment-policy gap stems partly from normative and imprecise policy language but is rooted more fundamentally in society's uncertain expectations for the environment. Until this uncertainty is resolved, the democratic and regulatory effectiveness of risk regulation will be undermined by ad hoc policy decisions abdicated to risk assessors.     

Influence of flue-gas desulfurization systems on coal combustion by-product quality at kentucky power stations burning high-sulfur coal

Two Kentucky power plants burning similar blends of high-sulfur western Kentucky and southern Indiana coal provide a unique opportunity to examine the variations in coal combustion by-products due to differences in the method of wet flue-gas desulfurization (FGD). One plant employed carbide lime-based scrubbing for two units and a dual-alkali process for the third unit. The second plant employed a Mississippian limestone from Kentucky for all four units. This study provides an example of optical and SEM petrographic techniques, supplemented by chemical analyses, applied to the study of, at least from the geologic perspective, non-traditional materials. The coal sources comprise a blend of high volatile C and B bituminous, high vitrinite (85–90%, mmf), high-sulfur (> 3%, dry) coals. The fly ash is dominated by glassy phases (70–80%) with about 5–10% spinel (predominately magnetite), 3–10% quartz, and 4–10% isotropic coke comprising the remaining portion of the ash. SEM observations indicate that the glassy particles exhibit a bimodal size distribution with sub-micron glass spheres and a population of larger (several 10s of microns) spheres. The bottom ash has higher proportions of spinels and mullite, with negligible carbon forms, compared to the fly ash from the same units. Fly ashes were observed to be lower in Fe and higher in Al, Si, and S compared to the bottom ashes. Carbide lime, a by-product of acetylene manufacture, soda ash, and limestone were the reagents used in the flue-gas desulfurization processes. The primary FGD by-product is a calcium sulfite slurry which is vacuum filtered and mixed with fly ash and, usually, lime, to form a stable product for disposal. The FGD by-products have some potential, as yet unrealized, for utilization.     

Fluoride in drinking water: A survey of expert opinions

In recent years, public debate over the standard setting process related to fluoride in drinking water and the fiuoridation of water supplies has been steeped in much controversy. Discussion of such issues has been con strained by the limited consideration of options relevant to particular problems. To examine the responses to specific issues, we presented an analysis of the problem of excessive fluoride in drinking water to a group of 120 experts. Ninety-seven of the 120 responded to a detailed mail questionnaire distributed as part of a larger exploratory survey. Definite patterns in preferences were noted with certain aspects of the problem, although in some cases significant differences were found due to such factors as the institutional affiliation, residential status, and the length of professional experience of the participants. In general, our experts preferred immediate corrective action over extensive further research into the reduction of scientific uncertainties; were willing to take personal action to obtain fluoride-free water rather than wait for official action; preferred the supplier to fluoridate the supplies, if needed; and favoured a strong local control of such issues with consumers of public water systems and private well owners shouldering much of the financial responsibility. Preliminary results from such exploratory surveys can lead to insightful research hypotheses for further testing. Verification of such hypotheses by consumers, from areas with excessive fluoride in drinking water, is a valuable area for future research.     

Chemometric studies of the effect of toxic metals on plants: the use of response surface methodology to investigate the influence of Tl, Cd and Ag on the growth of cabbage seedlings

The growth of cabbage seedlings at five concentrations of Cd, Tl and Ag was monitored by measuring their wet weights, root and shoot lengths after four week's growth in a controlled environment. Toxicity curves were constructed using a three factor central composite experimental design. The interaction and competition between any two metals were studied by displaying response surfaces. Ag was observed to be the most toxic, while Tl and Cd, although toxic, exhibited fairly similar effects. Analysis of variance was used to test for the significance of each of the computed parameters.     

Degradation of octylphenol and nonylphenol by ozone - part I: direct reaction

This aqueous reaction between ozone and two alkylphenols (APs), namely octylphenol (OP) and nonylphenol (NP), has been investigated. Both compounds are important endocrine disrupting chemicals, which arise from the biodegradation of alkylphenol ethoxylates and are often found at relatively high concentrations in wastewater effluents. In this paper the results of an experimental study are presented which provide values for the reaction rate constants between molecular ozone and undissociated OP and NP, and overall reaction rate constants for the degradation of the two APs at pH values in the range of 7-9. The kinetic rate constants for OP and NP degradation by molecular ozone were 4.33(+/-0.18) x 10(4) and 3.90(+/-0.10) x 10(4) M(-1) s(-1), and the reaction stoichiometry was similar in both cases and equal to approximately 1.3:1 ([O3]:[AP]). The overall second order reaction rate constants for the two APs increased significantly with increasing pH, which is believed to be mainly due to the increasing influence of indirect radical reaction with increasing pH; this aspect is considered in more detail in a companion paper. A preliminary investigation of the reaction mechanism suggests that an initial product of ozonation is hydroxyl-alkyl phenol.     

Lessons from Integrating Fishers of Arapaima in Small-Scale Fisheries Management at the Mamirauá Reserve,Amazon

Fishers and small-scale fisheries worldwide have been marginalized historically. Now it is clear that integrating fishers in management processes is key to resource conservation, but it is less clear how to do it. Here, based on a literature review and new information, we present and analyze a case in which the participation of fishers in the management process was crucial in recovering an overexploited small-scale fishery for the pirarucu (Arapaima spp.) in the Amazon Basin, Brazil. In 8 years of experimental management, from 1999 to 2006, the population of pirarucu increased 9-fold (from about 2200 to 20,650 individuals), harvest quotas increased 10-fold (from 120 to 1249 individuals), and fishers’ participation in the management process increased and they benefited from increased monetary returns. Additionally, the number of communities conducting the management scheme increased from 4 in 1999 to 108 in 2006, following the demands of fishers and regional government agencies. Based on our analysis, we suggest that the participation of fishers in the management of other small-scale fisheries in the world can be improved by focusing on (1) applying the knowledge and skills of fishers in resource monitoring and management, (2) bridging knowledge systems among all involved stakeholders, (3) collaborating with fishers that are interested in, and capable of conducting, resource conservation schemes, and (4) conducting management under conditions of uncertainty.     

Biodegradation of microcystins and nodularin in freshwaters

Microcystin-LR (MC-LR) was readily biodegraded on addition to six different water samples irrespective of their previous exposure to microcystins. Subsequent studies with water from three of these water bodies confirmed the degradation of MC-LR and also demonstrated the biodegradation of MC-LF, nodularin and mixture of microcystins and nodularin. Rates of degradation of MC-LR, MC-LF and NOD in individual water samples ranged from a half-life of 4 to 18d. Analysis by HPLC-PDA-ESI+ and MALDI MS/MS revealed novel intermediate degradation products of MC-LF and nodularin which included demethylation, hydrolysis, decarboxylation and condensation of the parent compound(s). Our study suggests a possible diversity of micro-organisms and/or pathways which has not been previously observed.