A risk assessment of chlorinated aliphatics in bioremediated soils

Natural microbes living in contaminated subsurface media can be enhanced to degrade large concentrations of contaminating compounds at a faster rate than the microbes could degrade under natural conditions. A feasibility study demonstrating this principle was performed on-site in southern Louisiana to evaluate the effectiveness of two microbial degradation remediation methods used to decrease the human carcinogenic risks associated with exposure to ethylene dichloride and vinyl chloride concentrations in contaminated clay and sludge soils at the site. The results of the study are compared to an acceptable Louisiana Department of Environmental Quality closure level to evaluate in-situ microbial enhancement in chlorinated aliphatic-contaminated sludge and clay soils as a remediation/cleanup alternative in similar industrial situations.     

The town scheme approach to urban conservation in England and Scotland

The Town Scheme approach to urban conservation is being used increasingly as a major method of repairing historic buildings in conservation areas. A Town Scheme involves a long‐term financial and administrative partnership between the various levels of government. An annual budget made up of equal contributions from central government and the participating local authority is used to finance a multi‐year programme of repairs. Owners can apply for grants which are usually for 40 per cent of approved costs, and repair work must relate to the original structure and architectural details of an approved list of historic buildings. Town Schemes by themselves cannot totally transform the environmental quality of conservation areas, and the most successful schemes are part of wide‐ranging renewal and enhancement projects.     

CAGED FISH AS MONITORS OF POLLUTION: EFFECTS OF CHLORINATED EFFLUENT FROM A WASTEWATER TREATMENT PLANT1

ABSTRACT: Fish confined to cages were used to determine the effects of effluent from a wastewater treatment plant (WWTP). Control fish were kept in cages in an aquaculture pond. Acute effects of the effluent entering the final oxidation pond of the WWTP were determined by confining channel catfish (Ictalurus punctatus) at the pond inlet; the mean total residual chlorine (TRC) concentration was 0.9 mg/l during this exposure. After 8 h, 42 percent of the fish had died and survivors had severe lesions of the skin and gills. During the first two weeks of exposure, channel catfish at the outlet of the final oxidation pond (mean TRC=0.1 mg/l) were predisposed to bacterial infection but lost the parasitic trematodes that were on the gills when the fish were placed in cages. After several weeks, exposed fish had histologic lesions, enlarged livers, and reduced growth. The presence of unidentified carcinogen(s) in the effluent of this WWTP was indicated by papillomas developing on caged black bullheads (Ictalurus melas) and hepatic-enzyme induction in channel catfish. In situ exposure of caged fish was advantageous because storage and pretreatment of water samples were not required, and exposure levels corresponded to those present in the environment. The use of cages for containment of fish during field exposure allowed confinement to the location of interest and convenient sampling of the fish. Unlike wild fish, the caged fish could be compared to control fish with the same pre-exposure history.     

Assessing and evaluating environmental impacts at proposed nuclear power plant sites

The applicability of decision analysis for assessing, evaluating, and reporting possible environmental impacts of proposed large-scale projects is illustrated. A study concerning the ecological impacts of constructing and operating nuclear power facilities in the Pacific Northwest is used as an example. Possible impacts are quantified for two objectives: minimizing adverse impacts on salmonids and minimizing biological disturbance. The results provide information about both the direct and indirect consequences of the impact. This approach explicitly addresses the multiple objective and uncertainty issues inherent in environmental problems. It also provides a mechanism for illuminating the value structure which is utilized in the evaluation process.     

Evaluation of soil-erosion and pesticide-exposure control strategies

A linear-programming model of agriculture in the Chowan-Pasquotank river basin of North Carolina is used to analyze soil-erosion reduction strategies while holding pesticide loadings constant. Two forms of pesticide-exposure indexes, reflecting terrestrial and aquatic exposure, are used to aggregate the effects of pesticide applications for no-till and conventional till systems. Reductions in pesticide exposure are compatible with high levels of erosion control. Greater reductions of pesticide exposure with comparable levels of erosion control are achievable at relatively low cost. Such reductions imply shifts in cropping patterns and resource use, however.     

Underage drinking: frequency, consequences, and interventions

OBJECTIVES: To examine the frequency of underage drinking, driving after drinking and alcohol-related crashes, trends in these behaviors, and promising interventions. METHODS: We examined drinking and drinking- and-driving behaviors reported in the United States in the 2001 U.S. National Household Survey of Drug Abuse, the Centers for Disease Control and Prevention 2001 Youth Risk Behavior Survey, the 1992 National Longitudinal Alcohol Epidemiologic Study, and the 1999 National Survey of Drinking and Driving conducted for the National Highway Traffic Administration. We also examined the 1999 European School Survey Project on Alcohol and Other Drugs. Alcohol-related fatal crashes were examined from the U.S. Fatality Analysis Reporting System. Evaluation of interventions to reduce teenage drinking and driving after drinking were reviewed. RESULTS: In the United States, 19% of youth ages 12-20 consumed five or more drinks on an occasion in the past 30 days. Although European nations have lower legal drinking ages (16-18) than in the United States (21), similar proportions engage in underage drinking. In two-thirds of European countries, a greater percentage of 15-16 year-olds drank five or more drinks on an occasion in the past month than in the United States. In both the United States and Europe, the earlier people begin to drink, the greater the likelihood of developing alcohol dependence and other alcohol-related problems, including alcohol-related crash involvement, during adolescence and adult years. During the past 20 years alcohol-related traffic deaths among people younger than 21 have been cut in half in the United States, but progress has halted since 1995 and the problem is still large. Interventions shown by research to reduce alcohol-related crashes among youth include raising the legal drinking age to 21, zero tolerance laws, and some interventions that are family, school, or community based. CONCLUSIONS: Despite research showing that a variety of interventions can reduce underage drinking and alcohol-related crash fatalities, the frequency of these behaviors remains high and the average age of drinking initiation is declining in the United States. Efforts are needed to enhance publicized enforcement of underage drinking laws. Comprehensive community interventions that include enforcement of these laws also are needed.     

Statistical models of health risk due to microbial contamination of foods

Between 6 million and 33 million cases of food-related illness are estimated to occur in the United States each year, with about 5000 episodes resulting in death. Growing concerns about the safety of food prompted the National Food Safety Initiative of 1997, the goal of which is to reduce the incidence of illness caused by food-borne pathogens. A key component of the food safety initiative is the improvement of farm-to-table risk assessment capabilities, including the development of improved dose-response models for estimating risk. When sufficient data are available, allowable contamination levels of specific micro-organisms in food are established using dose-response models to predict risk at very low doses based on experimental data at much higher doses. This necessitates having reliable models for setting allowable exposures to food-borne pathogens. While only limited data on relatively few micro-organisms that occur in food are available at present for dose-response modeling and risk estimation, still none of the two-parameter models proposed so far, including the popular Beta-Poisson (BP) model, appears to be completely satisfactory for describing and fitting all of the present data (Holcomb et al., 1999). The Weibull–Gamma (WG) model is the only three-parameter model that has been proposed to date. In this paper, new competitive three-parameter models are derived, using a formulation that can be parameterized to represent statistical variation with respect to the dose of micro-organism received by the host and the hosts susceptibility to infection. Parameters of the models are estimated using the maximum likelihood method. Experimental data on several common microbial contaminants in food are used to illustrate the methodology.     

Spring sea ice photosynthesis,primary productivity and biomass distribution in eastern Antarctica, 2002–2004

While it is known that Antarctic sea ice biomass and productivity are highly variable over small spatial and temporal scales, there have been very few measurements from eastern Antarctic. Here we attempt to quantify the biomass and productivity and relate patterns of variability to sea ice latitude ice thickness and vertical distribution. Sea ice algal biomass in spring in 2002, 2003 and 2004 was low, in the range 0.01–8.41 mg Chl a m⁻², with a mean and standard deviation of 2.08 ± 1.74 mg Chl a m⁻² (n = 199). An increased concentration of algae at the bottom of the ice was most pronounced in thicker ice. There was little evidence to suggest that there was a gradient of biomass distribution with latitude. Maximum in situ production in 2002 was approximately 2.6 mg C m⁻² h⁻¹ with assimilation numbers of 0.73 mg C (mg Chl a)⁻¹ h⁻¹. Assimilation numbers determined by the ¹⁴C incubations in 2002 varied between 0.031 and 0.457 mg C (mg Chl a)⁻¹ h⁻¹. Maximum fluorescence quantum yields of the incubated ice samples in 2002 were 0.470 ± 0.041 with E _k indices between 19 and 44 μmol photons m⁻² s⁻¹. These findings are consistent with the shade-adapted character of ice algal communities. In 2004 maximum in situ production was 5.9 mg C m⁻² h⁻¹ with an assimilation number of 5.4 mg C (mg Chl a)⁻¹ h⁻¹. Sea ice biomass increased with ice thickness but showed no correlation with latitude or the time the ice was collected. Forty-four percent of the biomass was located in bottom communities and these were more commonly found in thicker ice. Surface communities were uncommon.     

Putting the “Ecology” into Environmental Flows: Ecological Dynamics and Demographic Modelling

There have been significant diversions of water from rivers and streams around the world; natural flow regimes have been perturbed by dams, barriers and excessive extractions. Many aspects of the ecological 'health' of riverine systems have declined due to changes in water flows, which has stimulated the development of thinking about the maintenance and restoration of these systems, which we refer to as environmental flow methodologies (EFMs). Most existing EFMs cannot deliver information on the population viability of species because they: (1) use habitat suitability as a proxy for population status; (2) use historical time series (usually of short duration) to forecast future conditions and flow sequences; (3) cannot, or do not, handle extreme flow events associated with climate variability; and (4) assume process stationarity for flow sequences, which means the past sequences are treated as good indicators of the future. These assumptions undermine the capacity of EFMs to properly represent risks associated with different flow management options; assumption (4) is untenable given most climate-change predictions. We discuss these concerns and advocate the use of demographic modelling as a more appropriate tool for linking population dynamics to flow regime change. A 'meta-species' approach to demographic modelling is discussed as a useful step from habitat based models towards modelling strategies grounded in ecological theory when limited data are available on flow-demographic relationships. Data requirements of demographic models will undoubtedly expose gaps in existing knowledge, but, in so doing, will strengthen future efforts to link changes in river flows with their ecological consequences.     

A clash of cultures (and lawyers): Anglo Platinum and mine-affected communities in Limpopo Province,South Africa

The human rights related controversies surrounding Anglo Platinum's Mogalakwena mine in South Africa's Limpopo Province hit the world stage in 2008, attracting public scrutiny and instigating much debate in the realm of international business and human rights discussions. We provide an in-depth analysis of the controversies at Mogalakwena, and Anglo Platinum's responses. This case study contributes to ongoing debates on mining company-community relations in the context of the emerging business and human rights agenda, specifically with respect to the notion of human rights ‘due diligence’. We argue that the Mogalakwena case study illustrates the risks of companies adhering to and emphasizing the technical and logistical facets of due diligence, without sufficient attention to the relational, communicative and emergent aspects, which are closely tied to corporate culture. We highlight the complexities of company-community relationships, with particular reference to the issues of legitimate community representation and participatory decision-making, and discuss the role that organizational culture plays in exacerbating or mitigating corporate-community conflict. The case study demonstrates how legal challenges often exacerbate rather than resolve the conflicts that arise due to a clash between corporate and community cultures. We suggest the need for corporate leaders to become more conscious of this cultural dimension of effective social management, particularly when interacting with communities whose cultures are markedly different from those of business corporations.