Enhanced biodegradation of creosote-contaminated soil

Bioremediation, a viable option for treatment of cresote-contaminated soil, can be enhanced by the use of surfactant. A study was conducted to investigate the effect of a non-ionic surfactant, Triton X-100, on biodegradation of creosote-contaminated soil. Abiotic soil desorption experiments were performed to determine the kinetics of release of selected polynuclear aromatic hydrocarbon (PAH) compounds. Respirometric experiments were also conducted to evaluate the effect of nonionic surfactant on biodegradation. The N-Con system respirometer was used to monitor the oxygen uptake by the microorganisms. The abiotic experiments results indicated that the addition of surfactant to soil/water systems increased the desorption of PAH compounds. It was also observed that the desorption rate of PAH compounds depended on their molecular weight. The 3- and 4-ring PAH compounds showed higher and faster desorption rates than the 5- and 6-ring PAHs. The respirometric experiments indicated that an increase in soil contamination level from 112.5 to 771.8 mg/kg showed an increase in oxygen uptake. But for a soil contamination level of 1102.5 mg/kg, the oxygen uptake was similar to the contamination level of 771.8 mg/kg. This might be due to toxicity by the surfactant or the solubilized PAHs at high concentration or interference with contaminant transport into the cell or to reversible physical-chemical interferences with the activity of enzymes involved in the PAH degradation. The increase in PAH availability to the microorganisms in the aqueous phase produced an increase in oxygen consumption that is proportional to the biodegradation of organic compounds.     

Social-environmental certification: Sustainable development and competitiveness in the mineral industry of the Brazilian Amazon

This article examines the relationship between increased metal mining and sustainable development in the eastern section of the Amazonian state of Pará in Brazil. Since the early 1980s, mining has grown rapidly in Pará and local mining operations have become global leaders in the production of iron, manganese, bauxite, aluminum, gold, copper and — in the near future — nickel. To stay in tune with global standards, these companies have committed themselves to the principles of sustainability and have obtained certification for both social and environmental aspects of their activities. The article looks into whether such certification is linked to sustainable development of the relatively poor regions where these companies operate. The main findings are that: (1) there is a visible association between certification and improved performance by the companies, but not with the development of nearby areas; and (2) social‐environmental certification processes place more emphasis on ecological variables than on social ones.     

Estimating the Relative Efficiency of Brazilian Publicly and Privately Owned Water Utilities: A Stochastic Cost Frontier Approach1

Abstract: This paper assesses cost efficiencies of Brazilian public and private companies of water supply. To measure the efficiency, we used a stochastic frontier model derived from the translog family – a specification similar to a Cobb‐Douglas including a quadratic term in log output. The model parameters are estimated by maximum likelihood using Brazilian data for the year 2002. Statistical inference leads to the conclusion that there is no evidence that private firms and public firms are significantly different in terms of efficiency measurements.     

The vulnerability context of a savanna area in Mozambique: household drought coping strategies and responses to economic change

In this paper, we investigate the ways in which climate stressors and economic changes related to liberalisation alter the local vulnerability context. Household and key informant data from two villages in Mozambique are analysed. First, we explore how changes such as increased market integration, altered systems of agricultural support, land tenure change and privatisation of agro-industries may affect factors important for response capacity, including access to local natural resources, employment opportunities, and household labour and capital. Next, we investigate how people related to the market while coping with the 2002–2003 drought. The study reveals that there had been an increase in informal trade and casual employment opportunities; however, market relations were very unfavourable and as the drought intensified, smallholders were locked into activities that barely secured economic survival and which sometimes endangered long-term response capacity. Only a few large-scale farmers had the capital and skills necessary to negotiate a good market position in urban markets, thus securing future incomes. Inequality, social sustainability, vulnerability and natural resource use are all closely linked in the savannas. Hence, both climate change adaptation policies and sustainability measures need to target vulnerability context and the social and environmental stressors shaping it.     

Why the Use of Adenoviruses as Water Quality Virologic Marker?

Adenovirus is the virus that contains the highest amount of features favorable to its use as a virologic marker for water quality. Those pathogens are resistant on the environment, abundant, easily detected by molecular methods and are of great importance in public health.     

Reduction in ecological cost through biofuel production from cooking oils: An ecological solution for the city of Campinas, Brazil

The aim of the present study was to produce biodiesel from mixtures of cooking oil and provide a possible environmental solution for the region of Campinas (state of São Paulo, Brazil) based on the theory of environmental cost accounting (ECA). Cooking oil collected from homes in Campinas was mixed with ethanol at a ratio of 7:1 and transesterified at 60 °C for one hour for the obtainment of biodiesel using NaOH as a catalyst. The results of the physicochemical analyses demonstrated that the biodiesel possessed characteristics close to those required by Brazilian standards. A recent survey carried out in the city of Campinas revealed that residents are not concerned with the increased of environmental impact and ecological costs in the region caused by the disposal of used cooking oil, which is discarded in sewers and soil. Urgent action is recommended, beginning with raising awareness among the population and the implementation of a policy to determine the storage, periodic collection and use of cooking oil for the production of biodiesel. This fuel could be used for buses, trucks and machines or sold to fuel distributors, offering a savings of US$ 0.8 to 4.5 millions. Campinas could then gain environmental credits and become a sustainable city. Moreover, used cooking oil constitutes low-cost biodiesel with no consumption of raw materials and will reduce worldwide criticism directed at Brazil regarding the use of oleaginous plants for biodiesel production.     

Measuring mining safety with injury statistics: lost workdays as indicators of risk

PROBLEM: Mining in the United States remains one of the most hazardous industries, despite significant reductions in fatal injury rates over the last century. Coal mine fatality rates, for example, have dropped almost a thousand-fold since their peak in 1908. While incidence rates are very important indicators, lost worktime measures offer an alternative metric for evaluating job safety and health performance. The first objective of this study examined the distributions and summary statistics of all injuries reported to the Mine Safety and Health Administration from 1983 through 2004. Over the period studied (1983-2004), there were 31,515,368 lost workdays associated with mining injuries, for an equivalent of 5,700 person-years lost annually. The second objective addressed the problem of comparing safety program performance in mines for situations where denominator data were lacking. By examining the consequences of injuries, comparisons can be made between disparate operations without the need for denominators. Total risk in the form of lost workday sums can help to distinguish between lower- and higher-risk operations or time periods. METHOD: Our method was to use a beta distribution to model the losses and to compare underground coal mining to underground metal/nonmetal mining from 2000 to 2004. RESULTS: Our results showed the probability of an injury having 10 or more lost workdays was 0.52 for coal mine cases versus 0.35 for metal/nonmetal mine cases. In addition, a comparison of injuries involving continuous mining machines over 2001-2002 versus 2003-2004 showed that the ratio of average losses in the later period to those in the earlier period was approximately 1.08, suggesting increasing risks for such operations. DISCUSSION: This denominator-free safety measure will help the mining industry more effectively identify higher-risk operations and more realistically evaluate their safety improvement programs. IMPACT ON INDUSTRY: Attention to a variety of metrics concerning the performance of a job safety and health program will enhance industry's ability to manage these programs and reduce risk.     

Glutathione S-tranferases and cytochrome P450 activities in Mytilus galloprovincialis from the South coast of Portugal: effect of abiotic factors

To assess the health of aquatic organisms, biomarkers that measure changes at the biochemical level have been used as effective early warning tools in ecological risk assessment. In order to develop an integrated risk assessment strategy for the south coast of Portugal, mussels Mytilus galloprovincialis were collected from six sites along the coast with different organic contaminant characteristics. Additionally, an active biomonitoring approach was followed by transplanting indigenous mussels from site 4 to 6 and vice versa (from site 6 to 4) for 28 days. PAHs and PCBs contents were measured and the associated responses of phase I and phase II detoxification mechanisms evaluated by measuring cytochrome P450 and GST activities. GST activity was also determined on different tissues (gills, digestive gland, foot, mantle and gonads) of M. galloprovincialis and the impact of abiotic parameters (temperature, salinity, pH, conductivity and dissolved oxygen) on the GST activity assessed. Results indicate that CYP 450 follow the same pattern of PAHs and a direct relationship exist between CYP 450 and PAH levels from the different sites. Although there is a decrease between GST and PAHs concentrations it was not significant. The majority of the GST activity was in the gills and the digestive gland (around of 75% of the activity measured in all tissues) followed in decreasing order by the mantle, gonads. An inverse relationship between GST activity and salinity was detected along with temperature although not significant. These two biomarkers respond to changes of these two groups of compounds and to salinity especially for GST. In conclusion CYP 450 in mussels gives a reliable response as biomarker for organic contaminants in risk assessment in the South Coast of Portugal.