Enhancing Justice and Sustainability at the Local Level: Affordable Policies for Urban Governments*

Abstract

There are creative, affordable ways to address community development and also achieve goals of environmental sustainability. Approximately thirty case studies, based on interviews and usually also site visits, were completed during 2005. The case studies examined community gardening and urban agriculture, the greening of publicly controlled urban electricity and bus agencies, reuse centers and local business associations in the United States. Policy recommendations for city governments that emerged from the case studies are summarized here. There are many opportunities for financially pressed cities to assist the development of ‘just sustainability’ projects with minimal financial commitments. They can do so by rechannelling the purchasing decisions of public agencies, building partnerships with community organizations and developing the small business sector.     

Impact of climate change and seasonal trends on the fate of Arctic oil spills

We investigated the effects of a warmer climate, and seasonal trends, on the fate of oil spilled in the Arctic. Three well blowout scenarios, two shipping accidents and a pipeline rupture were considered. We used ensembles of numerical simulations, using the OSCAR oil spill model, with environmental data for the periods 2009–2012 and 2050–2053 (representing a warmer future) as inputs to the model. Future atmospheric forcing was based on the IPCC’s A1B scenario, with the ocean data generated by the hydrodynamic model SINMOD. We found differences in “typical” outcome of a spill in a warmer future compared to the present, mainly due to a longer season of open water. We have demonstrated that ice cover is extremely important for predicting the fate of an Arctic oil spill, and find that oil spills in a warming climate will in some cases result in greater areal coverage and shoreline exposure.     

Field dissipation of 4-nonylphenol, 4-t-octylphenol, triclosan and bisphenol A following land application of biosolids

The persistence of contaminants entering the environment through land application of biosolids needs to be understood to assess the potential risks associated. This study used two biosolids treatments to examine the dissipation of four organic compounds: 4-nonylphenol, 4-t-octylphenol, bisphenol A and triclosan, under field conditions in South Australia. The pattern of dissipation was assessed to determine if a first-order or a biphasic model better described the data. The field dissipation data was compared to previously obtained laboratory degradation data. The concentrations of 4-nonylphenol, 4-t-octylphenol and bisphenol A decreased during the field study, whereas the concentration of triclosan showed no marked decrease. The time taken for 50% of the initial concentration of the compounds in the two biosolids to dissipate (DT50), based on a first-order model, was 257 and 248 d for 4-nonylphenol, 231 and 75 d for 4-t-octylphenol and 289 and 43 d for bisphenol A. These field DT50 values were 10- to 20-times longer for 4-nonylphenol and 4-t-octylphenol and 2.5-times longer for bisphenol A than DT50 values determined in the laboratory. A DT50 value could not be determined for triclosan as this compound showed no marked decrease in concentration. The biphasic model provided a significantly improved fit to the 4-t-octylphenol data in both biosolids treatments, however, for 4-nonylphenol and bisphenol A it only improved the fit for one treatment. This study shows that the use of laboratory experiments to predict field persistence of compounds in biosolids amended soils may greatly overestimate degradation rates and inaccurately predict patterns of dissipation.     

Biodegradation of Bloodmeal-Based Thermoplastics in Green-Waste Composting

Polymers that are compostable and manufactured from renewable resources have gained significant importance in recent years. The objective of this work was to assess the biodegradability of bloodmeal-based thermoplastics in a commercial green-waste composting situation. Materials plasticised with tri-ethylene–glycol lost about 45% of their original mass after 12 weeks composting while unplasticised samples lost 35%. Degradation appeared to have been in two phases; an initial loss of soluble, low molecular compounds in the mesophilic phase followed by degradation of high molecular compounds as the temperature exceeded about 40 °C in the thermophilic phase. It was found that as degradation proceeded materials became more soluble. In addition, plasticised and unplasticized samples contained about 60 wt% moisture after 4 weeks of composting conditioning at 50% relative humidity resulted in approximately 8–10 wt% moisture, unaffected by the extent of degradation. FTIR revealed that proteins underwent hydrolytic cleavage resulting in the formation of primary amines. A significant reduction in combustion temperature was observed, indicative of a reduction in covalent bonding, likely due to shorter chains lengths or less cross-linking.     

Importance of refractory plant material to the carbon budget of the oyster Crassostrea virginica

The ability of the oyster Crassostrea virginica (Gmelin) to filter, ingest and assimilate ¹⁴C-labeled Spartina alterniflora as a carbon source was investigated under laboratory conditions. The oyster assimilated crude-fiber carbon extracted from S. alterniflora with an efficiency of approximately 3%. Enteric bacteria did not enhance this process. The annual average (April 1984 to November 1985) of crude fiber in the Choptank River sub-estuary of the Chesapeake Bay, Maryland, USA, from which the oysters were collected, was 15.7 g l^-1 (range 4.3 to 34.3 g l^-1). The potential food value of crude fiber to oysters in this system was estimated to be less than 1% of their carbon demand. However, the potential contribution of crude fiber to the carbon requirements of other oyster populations, such as those in southeastern USA, may be as great as 20%, due to higher crudefiber concentrations in the seston.     

Effect of additions of dietary triacylglycerol microspheres on growth,survival, and settlement of mussel (<Emphasis Type="Italic">Mytilus</Emphasis> sp.) larvae

This study reports the effect of additions of dietary microspheres of triacylglycerol (TAG, extracted from the diatom Chaetoceros muelleri) on larval development and settlement of Mytilus sp. The first experiment showed that mussel larvae successfully ingested TAG microspheres as soon as they acquired the ability to feed from exogenous sources. In a second experiment, larvae were fed for 28 days on diets consisting of 0, 1, 20, or 50% TAG microspheres (based on the cell concentration of a full algal ration) added as partial replacements for a ration of Isochrysis sp. (T-ISO). Lipid content and growth of larvae fed on a diet composed of 20% TAG were higher than those of the control groups, whereas survival was negatively affected. No growth or survival effect was detected with larvae fed on a diet composed of 1% TAG, whereas high mortality after 14 days was observed for larvae fed on a diet composed of 50% TAG microspheres. In a third experiment, 22-day-old larvae were fed on rations of Isochrysis sp. supplemented with 0, 1, 10, 20, 50, and 100% TAG for 2 days and allowed to settle for a 7-day period. TAG content of the larvae increased with TAG added to the diet until a saturation threshold was reached between a 20 and 50% supplementation level. Similarly, free fatty acid (FFA) content increased with TAG level in the diet and was linearly correlated with TAG content of larvae. Increased levels of FFA in larvae were attributed to digestion of TAG supplements. Settlement success and survival of larvae were not affected by diet; however, regression analysis revealed that TAG level in pre-metamorphic larvae explained 28% of survival variability among cultures.Communicated by R.J. Thompson, St. Johns     

Survival, Pb-uptake and behaviour of three species of earthworm in Pb treated soils determined using an OECD-style toxicity test and a soil avoidance test

Mature (clitellate) Eisenia andrei Bouché (ultra epigeic), Lumbricus rubellus Hoffmeister (epigeic), and Aporrectodea caliginosa (Savigny) (endogeic) earthworms were placed in soils treated with Pb(NO(3))(2) to have concentrations in the range 1,000 to 10,000 mg Pb kg(-1). After 28 days LC50(-95%confidence limit)(+95%confidence limit) values were E. andrei 5824(-361)(+898) mg Pb kg(-1), L. rubellus 2867(-193)(+145) mg Pb kg(-1) and A. caliginosa2747(-304)(+239) mg Pb kg(-1) and EC50s for weight change were E. andrei2841(-68)(+150) mg Pb kg(-1), L. rubellus1303(-201)(+240) mg Pb kg(-1) and A. caliginosa1208(-206)(+212) mg Pb kg(-1). At any given soil Pb concentration, Pb tissue concentrations after 28 days were the same for all three earthworm species. In a soil avoidance test there was no difference between the behaviour of the different species. The lower sensitivity to Pb exhibited by E. andrei is most likely due to physiological adaptations associated with the modes of life of the earthworms, and could have serious implications for the use of this earthworm as the species of choice in standard toxicological testing.     

As-resistance in laboratory-reared F1, F2 and F3 generation offspring of the earthworm Lumbricus rubellus inhabiting an As-contaminated mine soil

Previous studies provided no unequivocal evidence demonstrating that field populations of Lumbricus rubellus Hoffmeister (1843), exhibit genetically inherited resistance to As-toxicity. In this study F1, F2 and F3 generation offspring derived from adults inhabiting As-contaminated field soil were resistant when exposed to 2000 mg kg⁻¹ sodium arsenate. The offspring of uncontaminated adults were not As-resistant. Cocoon viability was 80% for F1 and 82% for F2 offspring from As-contaminated adults and 59% in the F1 control population. High energy synchrotron analysis was used to determine whether ligand complexation of As differed in samples of: resistant mine-site adults, the resistant F1 and F2 offspring of the mine-site earthworms exposed to the LC₂₅ sodium arsenate (700 mg kg⁻¹) of the F1 parental generation; and adult L. rubellus from an uncontaminated site exposed to LC₂₅ concentrations of sodium arsenate (50 mg kg⁻¹). XANES and EXAFS indicated that As was present as a sulfur-coordinated species.     

Oil spill response capabilities and technologies for ice-covered Arctic marine waters: A review of recent developments and established practices

Renewed political and commercial interest in the resources of the Arctic, the reduction in the extent and thickness of sea ice, and the recent failings that led to the Deepwater Horizon oil spill, have prompted industry and its regulatory agencies, governments, local communities and NGOs to look at all aspects of Arctic oil spill countermeasures with fresh eyes. This paper provides an overview of present oil spill response capabilities and technologies for ice-covered waters, as well as under potential future conditions driven by a changing climate. Though not an exhaustive review, we provide the key research results for oil spill response from knowledge accumulated over many decades, including significant review papers that have been prepared as well as results from recent laboratory tests, field programmes and modelling work. The three main areas covered by the review are as follows: oil weathering and modelling; oil detection and monitoring; and oil spill response techniques.     

Delivery of dietary components to larval shrimp (Penaeus vannamei) by means of complex microcapsules

Efficient delivery of nutrients is necessary for the successful study of aquatic larval nutrition. Conventional artificial food particles for larval shrimp (Penaeus vannamei) have poor water stability and poor nutrient retention or both. We developed a novel food particle type that retained low-molecular weight, water-soluble nutrients (vitamins and glucose) within lipid-wall microcapsules embedded with dietary ingredients in particles of gelled alginate-gelatin. The combination of lipid-wall microcapsules (LWMs) embedded in gelled food particles was termed complex microcapsules (CXMs). Eighty-five percent of ¹⁴C-activity associated with encapsulated ¹⁴C-glucose was retained by CXMs (after 18 h of suspension in seawater). Bioavailability of CXM-encapsulated molecules was demonstrated by release of encapsulated dye marker into the gut lumen of larval shrimp, and by uptake of ¹⁴C from encapsulated ¹⁴C-glucose. Minimum ingestion rates, calculated from ¹⁴C-uptake for larval shrimp (Mysis-1 through Postlarva-2) fed CXMs, ranged from 48 to 99 g dry wt larva^-1 d^-1, and were similar to literature values reported for ingestion of live rotifers by penaeid larvae. Complex microcapsules described in this study will be a valuable new tool for studying nutrition of suspension-feeders in that both micro-and macronutrients can be delivered to these animals by one particle type.