Rhetorical Recommendations Built on Ecological Experience: A Reassessment of the Challenge of Environmental Communication

This article reconsiders the challenge of environmental communication by inquiring into the fundamental rhetorical difficulty of thinking in terms of ecology. We discuss two essential yet bewildering aspects of ecology: its focus on interconnection and its use of multiple scales. On this basis, we distil six rhetorical recommendations: a shift from appealing to pre-existing values to avenues for transforming values; a shift from arguments from authority to addressing legitimate resistances; a shift from a focus on mutual agreement to a mutual bewilderment; a shift from intellectual comprehension to personal experience; a shift from negative effects to positive connections; and, finally, a shift from a focus on political results to local transformations. We experiment with this rhetorical approach through two applications: for critical reassessments of past articulations we consider the Gaia Hypothesis and Deep Ecology, and for current refinements to environmental problems we consider controversies around Marcellus Shale gas development     

Serum concentrations of selected organochlorine pesticides in a Lebanese population and their associations to sociodemographic,anthropometric and dietary factors: ENASB study

Organochlorine pesticides (OCPs) were banned by the Stockholm Convention many years ago; however, they are still detected in the environment due to their high persistence, their current illegal use, and their import from countries where they have not been banned. We evaluated the serum concentrations of selected OCPs (hexachlorobenzene (HCB), β-hexachlorocyclohexanes (β-HCH), p,p′-dichlorodiphenyltrichloroethane (DDT) and its metabolite p,p′-dichlorodiphenyldichloroethylene (DDE) in a sample of Lebanese adults using gas chromatography coupled to an ion trap mass spectrometer detector. The mean concentrations of HCB, β-HCH, DDT, and DDE were 7.1, 8.6, 2.1, and 18.9 ng/g of lipids, respectively, and the major contributor among the four OCPs was DDE. The OCP levels in the present study were in general lower than the values observed in several countries worldwide and their concentrations at the 95th percentile were lower than the biomonitoring equivalents (BEs) excluding any appreciable health risk. We observed an inverse association between HCB concentrations and body mass index (BMI) as well as HCB, β-HCH, and DDE levels, and smoking habits. Milk consumption however was positively associated with an increased serum level of β-HCH. This study, which was the first to investigate OCP serum levels in a Lebanese population, provides a baseline to which future measurements can be compared.     

Stratigraphic flux—A method for determining preferential pathways for complex sites

Experience with groundwater remediation over several decades has demonstrated that successful outcomes depend on quantitative conceptual site models (CSMs). Over the last 30 years, we have progressed from groundwater pump‐and‐treat remedies, which were largely designed based on a water supply perspective, to in situ and combined remedy strategies, which are only beginning to benefit from understanding the aquifer architecture and distribution of contaminant mass to assess plume maturity, mass flux, and more reliable means of fate and transport assessment. The U.S. Air Force funded the development of the Stratigraphic Flux approach to provide a framework for understanding contaminant transport pathways at its complex sites and enable more reliable and cost‐effective remediation. Stratigraphic Flux enables the development of quantitative, flux‐based CSMs that are founded in sequence stratigraphy, and high‐resolution hydraulic conductivity and contaminant distribution measurements. The result is a three‐dimensional graphical mapping of relative contaminant flux and classification of transport potential that is easy for all stakeholders to understand. The Stratigraphic Flux graphical model is based on a hydrofacies classification system that describes transport potential in three segments of the aquifer: transport zones—where the majority of groundwater flow occurs and transport rates are measured in feet per day; slow advection zones—where transport rates are measured in feet per year; and storage zones—where typically less than 1% of flow occurs, and diffusion dominates contaminant transport. The hydrofacies architectures are based on stratigraphy and transport potential is defined by grouping facies by orders of magnitude classes in hydraulic conductivity. By combining the hydrofacies architecture with contaminant concentration distributions, one can map relative contaminant flux to define and target the complex pathways that control contaminant transport and cleanup behavior. In this article, we describe the Stratigraphic Flux framework, focusing on the key information needed and the methods of analysis. We illustrate the results of its application to evaluate migration pathways for trichlorethylene and chromium at a former chrome pit at Air Force Plant 4 in Fort Worth, Texas. A comprehensive guidance document that describes the approach with a broad spectrum of tools and several site examples can be requested from the authors.     

Anaerobic ammonia-oxidizing bacteria in tropical bioaugmented zero water exchange aquaculture ponds

Environmental Science and Pollution Research - Bioaugmented zero water exchange aquaculture production systems (ZWEAPS) maintained with minimal or no water exchange prevent the ammonia accumulation...     

Evaluation of bisphenol A levels in Nigerian thermal receipts and estimation of daily dermal exposure

Environmental Science and Pollution Research - Bisphenol A (BPA) is a high production volume chemical that has wide industrial applications, especially as a color developer in thermal papers. The...     

Settlement analysis of fresh and partially stabilised municipal solid waste in simulated controlled dumps and bioreactor landfills

The patterns of settlement of fresh as well as partially stabilised municipal solid waste (MSW), undergoing degradation in five different landfill lysimeters, were studied elaborately. The first two lysimeters, R1 and R2, contained fresh MSW while the other three lysimeters, R3, R4 and R5, contained partially stabilised MSW. R1 and R3 simulated conventional controlled dumps with fortnightly disposal of drained leachate. R2 and R4 simulated bioreactor landfills with leachate recirculation. Fortnightly water flushing was done in R5. Settlement of MSW, monitored over a period of 58 weeks, was correlated with the organic carbon content of leachate and residual volatile matter in the MSW to establish the relationship between settlement and organic destruction. Compressibility parameters such as modulus of elasticity and compression indices were determined and empirical equations were applied for the settlement data. Overall settlements up to 49% were observed in the case of landfill lysimeters, filled with fresh MSW. Landfill lysimeters with liquid addition, in the form of leachate or water, experienced lower primary settlements and higher secondary settlements than conventional fills, where no liquid addition was practised. Modified secondary compression indices for MSW in lysimeters with leachate recirculation and flushing were 30%-44% higher than that for lysimeters where no liquid addition was done. Secondary settlements in bioreactor landfills were found to vary exponentially with time.     

Comparative study of transport processes of nitrogen, phosphorus, and herbicides to streams in five agricultural basins, USA

Agricultural chemical transport to surface water and the linkage to other hydrological compartments, principally ground water, was investigated at five watersheds in semiarid to humid climatic settings. Chemical transport was affected by storm water runoff, soil drainage, irrigation, and how streams were linked to shallow ground water systems. Irrigation practices and timing of chemical use greatly affected nutrient and pesticide transport in the semiarid basins. Irrigation with imported water tended to increase ground water and chemical transport, whereas the use of locally pumped irrigation water may eliminate connections between streams and ground water, resulting in lower annual loads. Drainage pathways in humid environments are important because the loads may be transported in tile drains, or through varying combinations of ground water discharge, and overland flow. In most cases, overland flow contributed the greatest loads, but a significant portion of the annual load of nitrate and some pesticide degradates can be transported under base-flow conditions. The highest basin yields for nitrate were measured in a semiarid irrigated system that used imported water and in a stream dominated by tile drainage in a humid environment. Pesticide loads, as a percent of actual use (LAPU), showed the effects of climate and geohydrologic conditions. The LAPU values in the semiarid study basin in Washington were generally low because most of the load was transported in ground water discharge to the stream. When herbicides are applied during the rainy season in a semiarid setting, such as simazine in the California basin, LAPU values are similar to those in the Midwest basins.     

Preparation of acidic and alkaline macrocapsules for pH control

A series of experiments was performed to prepare acidic macroencapsulated buffers composed of 20% Ca(H2PO4)(2) and 80% Eudragit S 100 polymer and alkaline macrocapsules composed of 65% K2HPO4 and 35% Eudragit E PO polymer (the powdered form of Eudragit E 100). Eudragit S 100 was shown to be soluble at a pH greater than 7.0, while Eudragit E 100 was soluble at a pH less than 7.0. Both polymers did not impart significant biochemical oxygen demand. The Eudragit E PO polymer solution showed low toxicity (EC50=91%) based on the Microtox Acute Toxicity Test compared to the 0.1mM background phosphate buffer solution (EC50=100%) while the Eudragit S 100 polymer solution showed higher toxicity (EC50=53%). Batch tests showed that the acidic macrocapsules reduced the pH of a 0.1mM phosphate solution from 11 to neutral, while the alkaline macrocapsules increased the pH of a 0.1mM phosphate solution from 3 to neutral. The macrocapsules could potentially be used as an in situ proportional pH controller for groundwater remediation.     

Effects of decadal exposure to interacting elevated CO2 and/or O3 on paper birch (Betula papyrifera) reproduction

We studied the effects of long-term exposure (nine years) of birch (Betula papyrifera) trees to elevated CO(2) and/or O(3) on reproduction and seedling development at the Aspen FACE (Free-Air Carbon Dioxide Enrichment) site in Rhinelander, WI. We found that elevated CO(2) increased both the number of trees that flowered and the quantity of flowers (260% increase in male flower production), increased seed weight, germination rate, and seedling vigor. Elevated O(3) also increased flowering but decreased seed weight and germination rate. In the combination treatment (elevated CO(2)+O(3)) seed weight is decreased (20% reduction) while germination rate was unaffected. The evidence from this study indicates that elevated CO(2) may have a largely positive impact on forest tree reproduction and regeneration while elevated O(3) will likely have a negative impact.     

Microcosm investigations of stormwater pond sediment toxicity to embryonic and larval amphibians: variation in sensitivity among species

Stormwater ponds have become common features of modern development and often represent significant amounts of open space in urbanized areas. Although stormwater ponds may provide habitat for wildlife, factors responsible for producing variation in wildlife use of ponds have received limited attention. To investigate the role of variation in species tolerances of pollutants in structuring pond-breeding amphibian assemblages, we exposed species tolerant (Bufo americanus) and not tolerant (Rana sylvatica) of urbanization to pond sediments in laboratory microcosms. Pond microcosms had elevated sediment metal levels and chloride water concentrations. Among R. sylvatica embryos, exposure to pond sediments resulted in 100% mortality. In contrast, B. americanus embryos and larvae experienced only sublethal effects (i.e., reduced size at metamorphosis) due to pond sediment exposure. Our results suggest variation in pollutant tolerance among early developmental stages of amphibians may act in concert with terrestrial habitat availability to structure amphibian assemblages associated with stormwater ponds.