Atrazine biodegradation modulated by clays and clay/humic acid complexes

The fate of pesticides in the environment is strongly related to the soil sorption processes that control not only their transfer but also their bioavailability. Cationic (Ca-bentonite) and anionic (Layered Double Hydroxide) clays behave towards the ionisable pesticide atrazine (AT) sorption with opposite tendencies: a noticeable sorption capacity for the first whereas the highly hydrophilic LDH showed no interactions with AT. These clays were modified with different humic acid (HA) contents. HA sorbed on the clay surface and increased AT interactions. The sorption effect on AT biodegradation and on its metabolite formation was studied with Pseudomonas sp. ADP. The biodegradation rate was greatly modulated by the material's sorption capacity and was clearly limited by the desorption rate. More surprisingly, it increased dramatically with LDH. Adsorption of bacterial cells on clay particles facilitates the degradation of non-sorbed chemical, and should be considered for predicting pesticide fate in the environment.     

Assessing the value of species: a case study on the willingness to pay for species protection in Chile

We conduct a valuation of species protection in central Chile's Campana National Park (CNP) using the choice experiment (CE) method. The CNP has been recognized as having global relevance for the conservation of biological diversity. Specifically, the aim is to estimate the willingness to pay (WTP) of park visitors for protection of different protected species in the area: popular species of flora and fauna that are known by visitors of the park, inconspicuous species (phytofagous, fungus) that are unknown to visitors, and species with conservation problems of which visitors are unaware. We also investigate the WTP for different levels of species biodiversity protection within the sample as the WTP for biodiversity protection is sensitive to the way in which biodiversity is presented to respondents. The levels of species biodiversity protection are represented using “icon” inconspicuous species and numbers of inconspicuous species protected in La Campana National Park. This methodology allowed us to obtain information on the sensitivity of the participants to the scope of the information provided. Overall, visitors attach positive and significant values to the local conservation of species. These values are derived not only from the desire to preserve popular species in the area but also from the preservation or assured existence of inconspicuous species that are protected in the park. Visitors behave as consumers who are sensitive to changes in the price of park admission as a result of the implementation of specific strategies for wildlife conservation management in the park. Furthermore, the study also elucidates the observations that the public is able to perceive biodiversity conservation in broader terms than a single species and that greater benefits are attached to the conservation of multiple species than single ones. Results also provide insights into methodological considerations regarding the conceptual framework used to assess the valuation of biodiversity changes in developing countries, including the level of biological diversity and the scale of the change.     

A Benefit‐Cost Analysis of Total Maximum Daily Load Implementation1

Abstract: Total Maximum Daily Load (TMDL) implementation generates benefits and costs from water quality improvements, which are rarely quantified. This analysis examines a TMDL written to address bacteria and aquatic‐life‐use impairments on Abrams and Opequon Creeks in Virginia. Benefits were estimated using a contingent valuation survey of local residents. Costs were based on the number and type of best management practices (BMPs) necessary to achieve TMDL pollution reduction goals. BMPs were quantified using watershed‐scale water quality simulation models (Generalized Watershed Loading Function and Hydrological Simulation Program‐FORTRAN). Based on our projections, the costs to achieve TMDL induced pollution reduction goals outweigh the estimated benefits. Benefit‐cost ratios ranged between 0.1 and 0.3.     

Knowledge Production and Learning for Sustainable Landscapes: Forewords by the Researchers and Stakeholders

This special issue of AMBIO presents a new approach to sustainability science that goes beyond interdisciplinary research. Using coupled natural and human systems, or landscapes, as multiple case studies in Europe’s East and West knowledge production and learning toward transdisciplinary research was applied in Sweden, countries in Central and Eastern Europe, and Russia. First, the research group Forest-Landscape-Society summarizes the research program (2005–2012) behind this special issue of AMBIO and its development to participate in transdisciplinary research. Second, stakeholders at multiple levels provide their views on the new approach presented and reported.     

The dissemination of antibiotic resistance in various environmental objects (Russia)

Environmental objects (surface and groundwater, soil, bottom sediments, wastewater) are reservoirs in which large-scale multidirectional exchange of determinants of antibiotic resistance between clinical strains and natural bacteria takes place. The review discusses the results of studies on antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARG) isolated from environmental objects (water, soil, sewage, permafrost) of the Russian Federation. Despite the relevance of the topic, the number of available publications examining the resistomes of Russian water bodies and soils is small. The most studied environmental objects are surface waters (rivers, lakes), permafrost deposits. Soil resistomes are less studied. Data on ARG and ARB in wastewater are the least covered in publications. In most of the studies, antibiotic resistance of isolated pure bacterial cultures was determined phenotypically. A significant number of publications are devoted to the resistance of natural isolates of Vibrio cholerae, since the lower reaches of the Volga and Don rivers are endemic to cholera. Molecular genetic methods were used in a small number of studies. Geographically, the south of the European part of Russia is the most studied. There are also publications on the distribution of ARG in water bodies of Siberia and the Russian Far East. There are practically no publications on such developed regions of Russia as the center and northwest of the European part of Russia. The territory of the country is very large, anthropogenic and natural factors in its various regions vary significantly; therefore, it seems interesting to combine all available data in one work.

     

Time-dependency of the Cs contamination of wild boar from a region in Southern Germany in the years 1998 to 2008

Following the Chernobyl accident, ¹³⁷Cs contamination levels of wild boar in some districts of Southern Germany are still exceeding thousands of Bq kg⁻¹. While the long term ¹³⁷Cs concentration in forest plants, mushrooms, and roe deer meat has decreased significantly, for wild boar it has remained constant during the last decade. Between 1998 and 2008, we analysed the muscle meat of 656 wild boars shot in the district (“Landkreis”) Ravensburg. The ¹³⁷Cs activity concentration showed considerable variability from less than 5 up to 8266 Bq kg⁻¹ and it followed a seasonal pattern, which is attributed to changes in dietary habits, fodder availability, meteorological conditions and specific behaviour of ¹³⁷Cs in wild boar organism. T_ag values for wild boars from the district Ravensburg varied from 0.008 to 0.062 m² kg⁻¹ during 2000–2008.     

Genetic biomonitoring of an urban population exposed to mutagenic airborne pollutants

Biomonitoring studies have increased as a consequence of risks and effects to human health on exposure to environmental contaminants, mainly air pollutants. Genetic biomarkers are useful tools for the early assessment of exposure to occupational and environmental pollution. The objective of the present study was to investigate genotoxic effects on people residing and/or working downwind from an oil refinery in southern Brazil and the mutagenic activity of airborne particulate matter (PM10). Samples of peripheral blood and buccal mucosa cells were evaluated using the single-cell gel electrophoresis assay (comet assay) and the micronucleus (MN) assay, respectively. PM10 samples were collected in the target site and the organic matter extraced with dichloromethane was assessed for mutagenic activity in the Salmonella/microsome assay. The exposed group (n = 37) was compared to a reference group (n = 37) of subjects living in an urban area with limited traffic and industrial influence, located far from the main industrial areas. All PM10 organic extracts showed mutagenic positive responses and the effect decreased in the presence of S9 mix indicating that the predominant compounds present were direct-acting mutagens. The responses of YGs strains are consistent with aromatic amines and nitroarenes being present in the PM10 extracts. The group in the area under the influence of the oil refinery (exposed group) showed significantly higher DNA damage in lymphocytes than the reference group. The MN frequencies in buccal mucosa were very low for both groups and no difference between groups was observed. No association was found between age and tobacco smoking habit and level of DNA damages measured by the comet assay. The results indicate that the comet assay was a sensitive tool to detect DNA damage in subjects under the influence of an oil refinery, with marked genotoxic activity in the atmospheric environment.     

Interrogating Social Sustainability in the Biofuels Sector in Latin America: Tensions Between Global Standards and Local Experiences in Mexico,Brazil, and Colombia

Across the Americas, biofuels production systems are diverse due to geographic conditions, historical patterns of land tenure, different land use patterns, government policy frameworks, and relations between the national state and civil society, all of which shape the role that biofuels play in individual nations. Although many national governments throughout the Americas continue to incentivize growth of the biofuels industry, one key challenge for biofuels sustainability has been concern about its social impacts. In this article, we discuss some of the key social issues and tensions related to the recent expansion of biofuels production in Mexico, Colombia, and Brazil. We argue that a process of “simplification” of ecological and cultural diversity has aided the expansion of the biofuels frontier in these countries, but is also undermining their viability. We consider the ability of governments and non-state actors in multi-stakeholder initiatives (MSI) to address social and environmental concerns that affect rural livelihoods as a result of biofuels expansion. We analyze the tensions between global sustainability standards, national level policies for biofuels development, and local level impacts and visions of sustainability. We find that both government and MSI efforts to address sustainability concerns have limited impact, and recommend greater incorporation of local needs and expertise to improve governance.     

Regulating Functional Foods in the European Union: Informed Choice versus Consumer Protection?

Due to the rise of functional foods,the distinction between foods and medicines hasbecome increasingly blurred. A new EUregulation covering health claims and otherclaims on food and drink products is on thedocks. A basic motive of legal regulation oflabeling and advertising is to inform andprotect the consumer. Promotion of informedchoice and consumer protection may, however, beconflicting objectives. A further problemsprings from the fact that choice, likeconsent, is a propositional attitude andtherefore opaque. Thus it is extremelydifficult for regulators to fasten onparticular formulations of claims. Despite theprofessed respect for the autonomy of theconsumer, paternalism is never far away andeasily enters in various guises.