Feasibility of soil dust source apportionment by the pyrolysis-gas chromatography/mass spectrometry method

This study tested the feasibility of using pyrolysis (Py)-gas chromatography (GC)/mass spectrometry (MS) to obtain organic chemical species data suitable for source apportionment modeling of soil-derived coarse particulate matter (PM10) dust on ambient filters. A laboratory resuspension apparatus was used with known soils to generate simulated receptor filter samples loaded with approximately 0.4 mg of PM10 dust, which is within the range of mass loading on ambient filters. Py-GC/MS at 740 degrees C generated five times more resolvable compounds than were obtained with thermal desorption GC/MS at 315 degrees C. The identified compounds were consistent with literature from Py experiments using larger samples of bulk soils. A subset of 91 organic species out of the 178 identified Py products was used as input to CMB8 software in a demonstration of source apportionment using laboratory-generated mixtures simulating ambient filter samples. The 178 quantified organic species obtained by Py of soil samples is an improvement compared with the 38 organic species obtained by thermal desorption of soils and the four functionally defined organic fractions reported by thermal/ optical reflectance. Significant differences in the concentration of specific species were seen between samples from different sites, both geographically distant and close, using analysis of variance and cluster analysis. This feasibility study showed that Py-GC/MS can generate useful source profile data for receptor modeling and justifies continued method development.     

Transfrontier conservation areas: Integrating biodiversity and poverty alleviation in Southern Africa

Sub‐Saharan Africa continues to face the daunting challenge of alleviating poverty due to slow economic growth. In southern Africa, most countries are adopting policies that promote the integration of biodiversity conservation and rural development to contribute to rural poverty alleviation. Numerous approaches have been undertaken in this endeavour, including Transfrontier Parks (TFPs) and Transfrontier Conservation Areas (TFCAs). This paper discusses some of the limitations of the TFPs. In conclusion I posit that unlike TFPs, which are state controlled and managed, TFCAs, which promote multi‐land use and multi‐stakeholder participation are attainable and have a higher probability of sustaining biodiversity conservation and contributing to the alleviation of rural poverty, if: (i) areas of high biodiversity conservation within communal areas can be identified, zoned and leveraged to biodiversity conservation and managed in partnership between the communities and the private sector; (ii) local communities can secure legal rights to their customary land being devoted to biodiversity conservation and use such pieces of land as collateral in negotiating partnerships with the private sector in developing conservation‐based enterprises; (iii) functional community natural resource governance institutions can be established and empowered to represent their constituencies in securing fair equity from profits made from sustainable use of the conserved biodiversity assets and tourism businesses; (iv) concerted effort can be invested in developing and implementing family planning and fertility reduction strategies that would slow down human population growth to levels that can be sustained by the available natural resources; and (v) if sustainable financing mechanisms can be developed, and the governance of protected areas occurring in the TFCAs can be broadened to include other stakeholders.     

Scales of justice: Is there a geographic bias in environmental equity analysis?

Many empirical environmental justice (EJ) studies lack a systematic framework in which to undertake research and interpret results. This paper characterizes the conventional EJ study and examines how results can be influenced by the choice of the spatial scale and scope of analysis. After thoroughly reviewing a sample of prominent EJ studies, a conventional EJ study was performed for (Superfund) National Priorities List sites at multiple scales and scopes. It was found that evidence of environmental injustice could be sensitive to scale and scope chosen, which partly explains the observed inconsistency in the empirical literature. Implications for interpreting existing EJ research and conducting future EJ research are discussed.     

Demonstrating Floodplain Uncertainty Using Flood Probability Maps1

Abstract: The U.S. Federal Emergency Management Agency (FEMA) flood maps depict the 100‐year recurrence interval floodplain boundary as a single line. However, because of natural variability and model uncertainty, no floodplain extents can be accurately defined by a single line. This article presents a new approach to floodplain mapping that takes advantage of accepted methodologies in hydrologic and hydraulic analysis while including the effects of uncertainty. In this approach, the extents of computed floodplain boundaries are defined as a continuous map of flood probabilities, rather than as a single line. Engineers and planners can use these flood probability maps for viewing the uncertainty of a floodplain boundary at any recurrence interval. Such a flood probability map is a useful tool for visualizing the uncertainty of a floodplain boundary and represents greater honesty in engineering technologies that are used for flood mapping. While institutional barriers may prevent adoption of such definitions for use in graduated flood insurance rates (as most other insurance industries use to account for relative risks), the methods open the door technically to such a reality.     

Prior to Economic Treatment of Emissions and Their Uncertainties Under the Kyoto Protocol: Scientific Uncertainties That Must Be Kept in Mind

In a step-by-step exercise – beginning at full greenhouse gas accounting (FGA) and ending with the temporal detection of emission changes – we specify the relevant physical scientific constraints on carrying out temporal signal detection under the Kyoto Protocol and identify a number of scientific uncertainties that economic experts must consider before dealing with the economic aspects of emissions and their uncertainties under the Protocol. In addition, we answer one of the crucial questions that economic experts might pose: how credible in scientific terms are tradable emissions permits? Our exercise is meant to provide a preliminary basis for economic experts to carry out useful emissions trading assessments and specify the validity of their assessments from the scientific point of view, that is, in the general context of a FGA-uncertainty-verification framework. Such a basis is currently missing.     

Remediation with cyclodextrin: Recovery of the remedial agent by membrane filtration

Cyclodextrin‐enhanced flushing of contaminants from the subsurface is a promising innovative remediation technology. It will become more economically viable at more sites if methods can be developed to recover and reconcentrate the cyclodextrin solution after it has been flushed through an aquifer. The goal of this study was to determine if membrane technology is capable of meeting that need. Five membranes with different material properties were tested for this purpose in the laboratory. The results of these tests indicate that there are large differences both in the efficiency of these membranes to extract hydroxpropyl‐β‐cyclodextrin (HPCD) and their stability when exposed to trichloroethylene (TCE) at concentrations near aqueous solubility. Not only does the molecular weigh cutoff (MWCO) of a membrane determine if HPCD can be retained, but crucial selection criteria are the membrane's resistance and compatibility with TCE. Of the five membrane materials tested, only two (polymer composite membrane and polysulfone) met both these requirements. The polymer composite membrane (MPF‐44) showed reliable and stable HPCD recoveries (>95 percent) even when exposed to high TCE concentrations. The polysulfone membrane showed high HPCD recoveries, 88.5 ± 0.4 percent to 97 percent ±1 percent for ultrafiltration and nanofiltration membranes, respectively. However, membrane swelling and deterioration became a problem at high TCE concentrations (>1,000 mg/L). These problems diminished when the TCE concentration was less than 1 mg/L. Field tests demonstrated that batch mode treatment by ultrafiltration doubled the cyclodextrin concentration from 5 to 10 percent within three hours at a constant operating pressure of 13 psi. Under continuous single‐pass treatment conditions, cyclodextrin concentration also increased, although the rate of increase was much smaller than in batch mode. Overall, these tests showed that cyclodextrin recovery is possible under field conditions. © 2007 Wiley Periodicals, Inc.     

EEG bioeffects on cochlear deaf from cellular phones

Objectives This paper aims to provide evidence of an inductive electromagnetic bioeffect on the human brain, which is independent from sound waves and produced by mobile phones, in proximal field, through correlating the EEG data obtained from electrodes placed on both normal and cochlear deaf individuals. Methods Two groups of subjects are placed under controlled electromagnetic conditions inside a Faraday chamber, 12 healthy and another 12 suffering from cochlear deafness). Each is sitting on a chair, fitted with additional support, and holding a cellular phone 2 cm away form the right auricular, in order to avoid a thermal effect as much as possible. All of them, relaxed and with their eyes closed, are EEG recorded in a basal state with their mobile phones off. Then, each of them is again recorded under the same conditions but with the mobile on and listening to the same conversation. In order to assess the observed EEG changes, a statistical analysis by means of the FFT (Fast Fourier Transform) was carried out. Results For both, healthy and cochlear deaf, assimilation or integration of the mobile phone signal by some electrodes is to be found. This is due to the increase of amplitudes for alpha and theta waves, whereas the signal is not integrated in other electrodes. By correlating the spectra of frequencies of corresponding EEG records for the same brain areas, we have not observed significative differences for both groups. Conclusions A possible electromagnetic direct inductive, non-thermal, bioeffect on the human brain is observed. This effect is produced by the use of mobile phones and it bears no relation to the sound waves.     

Reusability of sewage sludge in clay bricks

Bricks produced from sewage sludge in different compositions were investigated. Results of the tests indicated that the sludge proportion is a key factor in determining the brick quality. Increasing the sludge content results in a decrease in brick shrinkage, bulk density, and compressive strength. Brick weight loss on ignition was mainly due to the contribution of the contained organic matter from the sludge being burnt off during the firing process, as well as inorganic substances found in both clay and sludge. The physical, mechanical, and chemical properties of the bricks that were supplemented with various proportions of dried sludge from 10 to 40wt% and generally complied with the General Specification for Brick as per the Malaysian Standard MS 7.6:1972, which dictates the requirements for clay bricks used in walling in general. A standard leaching test method also showed that the leaching of metals from the bricks is very low.     

Variation in root density along stream banks

While it is recognized that vegetation plays a significant role in stream bank stabilization, the effects are not fully quantified. The study goal was to determine the type and density of vegetation that provides the greatest protection against stream bank erosion by determining the density of roots in stream banks. To quantify the density of roots along alluvial stream banks, 25 field sites in the Appalachian Mountains were sampled. The riparian buffers varied from short turfgrass to mature riparian forests, representing a range of vegetation types. Root length density (RLD) with depth and aboveground vegetation density were measured. The sites were divided into forested and herbaceous groups and differences in root density were evaluated. At the herbaceous sites, very fine roots (diameter < 0.5 mm) were most common and more than 75% of all roots were concentrated in the upper 30 cm of the stream bank. Under forested vegetation, fine roots (0.5 mm < diameter < 2.0 mm) were more common throughout the bank profile, with 55% of all roots in the top 30 cm. In the top 30 cm of the bank, herbaceous sites had significantly greater overall RLD than forested sites (alpha = 0.01). While there were no significant differences in total RLD below 30 cm, forested sites had significantly greater concentrations of fine roots, as compared with herbaceous sites (alpha = 0.01). As research has shown that erosion resistance has a direct relationship with fine root density, forested vegetation may provide better protection against stream bank erosion.     

Impact of glyphosate on the Bradyrhizobium japonicum symbiosis with glyphosate-resistant transgenic soybean: a minireview

Glyphosate-resistant (GR) soybean [Glycine max (L.) Merr.] expressing an insensitive 5-enolpyruvylshikimic acid-3-phosphate synthase (EPSPS) gene has revolutionized weed control in soybean production. The soybean nitrogen fixing symbiont, Bradyrhizobium japonicum, possesses a glyphosate-sensitive enzyme and upon exposure to glyphosate accumulates shikimic acid and hydroxybenzoic acids such as protocatechuic acid (PCA), accompanied with B. japonicum growth inhibition and death at high concentrations. In a series of greenhouse and field experiments, glyphosate inhibited nodulation and nodule leghemoglobin content of GR soybean. Glyphosate accumulated in nodules of field-grown GR soybean, but its effect on nitrogenase activity of GR soybean was inconsistent in field studies. In greenhouse studies, nitrogenase activity of GR soybean following glyphosate application was transiently inhibited especially in early growth stages, with the greatest inhibition occurring under moisture stress. Studies using bacteroid preparations showed that the level of glyphosate inhibition of bacteroid nitrogenase activity was related to in vitro glyphosate sensitivity of the B. japonicum strains. These studies indicate the potential for reduced nitrogen fixation in the GR soybean system; however, yield reductions due to this reduced N2 fixation in early stages of growth have not been demonstrated.