Implications of high altitude desert dust transport from Western Sahara to Nile Delta during biomass burning season

The air over major cities and rural regions of the Nile Delta is highly polluted during autumn which is the biomass burning season, locally known as black cloud. Previous studies have attributed the increased pollution levels during the black cloud season to the biomass or open burning of agricultural waste, vehicular, industrial emissions, and secondary aerosols. However, new multi-sensor observations (column and vertical profiles) from satellites, dust transport models and associated meteorology present a different picture of the autumn pollution. Here we show, for the first time, the evidence of long range transport of dust at high altitude (2.5-6 km) from Western Sahara and its deposition over the Nile Delta region unlike current Models. The desert dust is found to be a major contributor to the local air quality which was previously considered to be due to pollution from biomass burning enhanced by the dominant northerly winds coming from Europe.     

Uncertainty in health risks due to anthropogenic primary fine particulate matter from different source types in Finland

The emission-exposure and exposure-response (toxicity) relationships are different for different emission source categories of anthropogenic primary fine particulate matter (PM_2.5). These variations have a potentially crucial importance in the integrated assessment, when determining cost-effective abatement strategies. We studied the importance of these variations by conducting a sensitivity analysis for an integrated assessment model. The model was developed to estimate the adverse health effects to the Finnish population attributable to primary PM_2.5 emissions from the whole of Europe. The primary PM_2.5 emissions in the whole of Europe and in more detail in Finland were evaluated using the inventory of the European Monitoring and Evaluation Programme (EMEP) and the Finnish Regional Emission Scenario model (FRES), respectively. The emission-exposure relationships for different primary PM_2.5 emission source categories in Finland have been previously evaluated and these values incorporated as intake fractions into the integrated assessment model. The primary PM_2.5 exposure-response functions and toxicity differences for the pollution originating from different source categories were estimated in an expert elicitation study performed by six European experts on air pollution health effects. The primary PM_2.5 emissions from Finnish and other European sources were estimated for the population of Finland in 2000 to be responsible for 209 (mean, 95% confidence interval 6–739) and 357 (mean, 95% CI 8–1482) premature deaths, respectively. The inclusion of emission-exposure and toxicity variation into the model increased the predicted relative importance of traffic related primary PM_2.5 emissions and correspondingly, decreased the predicted relative importance of other emission source categories. We conclude that the variations of emission-exposure relationship and toxicity between various source categories had significant impacts for the assessment on premature deaths caused by primary PM_2.5.     

Structural and functional responses of a freshwater plankton community to acute copper stress

An in-situ experiment was performed to quantify the impacts of copper sulfate on plankton structure and carbon dynamics. Plankton were exposed to 140 microg litre(-1) copper in quadruplicate mesocosms. Community structure was monitored for 14 days by microscopical counts and compared with untreated controls. Carbon dynamics were assessed by tracer studies using (14)C bicarbonate and (14)C glucose, to follow the fate of carbon in the algal- and bacterial-based pathways, respectively. Copper reduced the dry-weight biomass of zooplankton, ciliates, flagellates, and autotrophic phytoplankton. Bacterial biomass was increased by an order of magnitude relative to the controls. The bacterial response was most likely due to reduced grazing pressure and/or nutrient release from dying plankton. Copper reduced the effectiveness of the food web in transporting carbon to the surviving zooplankton. Bacterial-based pathways were more greatly affected than algal-based pathways, because zooplankton in the copper treatment were macro-grazers (cyclopoids), which cannot utilize bacteria.     

Characterizing spatial structure of sediment E. coli populations to inform sampling design

Escherichia coli can persist in streambed sediments and influence water quality monitoring programs through their resuspension into overlying waters. This study examined the spatial patterns in E. coli concentration and population structure within streambed morphological features during baseflow and following stormflow to inform sampling strategies for representative characterization of E. coli populations within a stream reach. E. coli concentrations in bed sediments were significantly different (p?=?0.002) among monitoring sites during baseflow, and significant interactive effects (p?=?0.002) occurred among monitoring sites and morphological features following stormflow. Least absolute shrinkage and selection operator (LASSO) regression revealed that water velocity and effective particle size (D ₁₀) explained E. coli concentration during baseflow, whereas sediment organic carbon, water velocity and median particle diameter (D ₅₀) were important explanatory variables following stormflow. Principle Coordinate Analysis illustrated the site-scale differences in sediment E. coli populations between disconnected stream segments. Also, E. coli populations were similar among depositional features within a reach, but differed in relation to high velocity features (e.g., riffles). Canonical correspondence analysis resolved that E. coli population structure was primarily explained by spatial (26.9–31.7 %) over environmental variables (9.2–13.1 %). Spatial autocorrelation existed among monitoring sites and morphological features for both sampling events, and gradients in mean particle diameter and water velocity influenced E. coli population structure for the baseflow and stormflow sampling events, respectively. Representative characterization of streambed E. coli requires sampling of depositional and high velocity environments to accommodate strain selectivity among these features owing to sediment and water velocity heterogeneity.     

Estimation of mass transport parameters of gases for quantifying CH4 oxidation in landfill soil covers

Methane (CH(4)), which is one of the most abundant anthropogenic greenhouse gases, is produced from landfills. CH(4) is biologically oxidized to carbon dioxide, which has a lower global warming potential than methane, when it passes through a cover soil. In order to quantify the amount of CH(4) oxidized in a landfill cover soil, a soil column test, a diffusion cell test, and a mathematical model analysis were carried out. In the column test, maximum oxidation rates of CH(4) (V(max)) showed higher values in the upper part of the column than those in the lower part caused by the penetration of O(2) from the top. The organic matter content in the upper area was also higher due to the active microbial growth. The dispersion analysis results for O(2) and CH(4) in the column are counter-intuitive. As the upward flow rate of the landfill gas increased, the dispersion coefficient of CH(4) slightly increased, possibly due to the effect of mechanical dispersion. On the other hand, as the upward flow rate of the landfill gas increased, the dispersion coefficient of O(2) decreased. It is possible that the diffusion of gases in porous media is influenced by the counter-directional flow rate. Further analysis of other gases in the column, N(2) and CO(2), may be required to support this hypothesis, but in this paper we propose the possibility that the simulations using the diffusion coefficient of O(2) under the natural condition may overestimate the penetration of O(2) into the soil cover layer and consequently overestimate the oxidation of CH(4).     

Optimising energy recovery and use of chemicals,resources and materials in modern waste-to-energy plants

Due to ongoing developments in the EU waste policy, Waste-to-Energy (WtE) plants are to be optimized beyond current acceptance levels. In this paper, a non-exhaustive overview of advanced technical improvements is presented and illustrated with facts and figures from state-of-the-art combustion plants for municipal solid waste (MSW). Some of the data included originate from regular WtE plant operation – before and after optimisation – as well as from defined plant-scale research. Aspects of energy efficiency and (re-)use of chemicals, resources and materials are discussed and support, in light of best available techniques (BAT), the idea that WtE plant performance still can be improved significantly, without direct need for expensive techniques, tools or re-design. In first instance, diagnostic skills and a thorough understanding of processes and operations allow for reclaiming the silent optimisation potential.     

It’s All in the Numbers: Acreage Tallies and Environmental Program Evaluation

Increasingly, performance measurement is being used to hold federal agencies accountable, represent environmental progress, and evaluate the effectiveness of environmental programs. The need to track measurable outputs has created a tendency to present programmatic progress solely by quantifiable data, despite the inherent complexity of natural resource management. Wetlands and fire management programs are two specific environmental arenas that have come to overemphasize the tracking of acreage numbers to validate existing policy direction. In both of these arenas, we find the definition and categorization of "countable" acres to be inconsistent and unreliable. We explore this systemic flaw for both wetlands and fire programs and describe its implications for environmental policy and natural resource management more broadly. We conclude with recommendations for improved performance measurement in these arenas.     

Comparative analysis of small mammal communities in Chisinau and Yaroslavl, two European cities located in different biomes

Comparative analysis of the structure of small mammal communities has been performed in two European cities located in different biomes: Chisinau (2008?C2009) and Yaroslavl (1994?C2002). The parameters studied included abundance, species composition, similarity and difference of faunas, species diversity, and proportions of groups differing in predisposition to synanthropy. It has been found that the structure of small mammal communities in these cities depends on specific physiographic conditions of the surrounding areas and on the distinctive features of the cities themselves (their structure, age, etc.). The similarity between the faunas is accounted for by the common ecological patterns of fauna formation in the biota of urban cenoses.