Inhalation of Concentrated Ambient Particulate Matter near a Heavily Trafficked Road Stimulates Antigen-Induced Airway Responses in Mice

Abstract

The goal of this study was to test the following hypotheses:(1) exposure to mobile emissions from mobile sources close to a heavily trafficked roadway will exacerbate airway inflammation and allergic airway responses in a sensitized mouse model, and (2) the magnitude of allergic airway disease responses will decrease with increasing distance from the roadway. A particle concentrator and a mobile exposure facility were used to expose ovalbumin (OVA)-sensitized BALB/c mice to purified air and concentrated fine and concentrated ultrafine ambient particles at 50 m and 150 m downwind from a roadway that was heavily impacted by emissions from heavy duty diesel-powered vehicles. After exposure, we assessed interleukin (IL)-5, IL-13, OVA-specific immunoglobulin E, OVA-specific immunoglobulin G1, and eosinophil influx as biomarkers of allergic responses and numbers of polymorphonuclear leukocytes as a marker of inflammation. The study was performed over a two-year period, and there were differences in the concentrations and compositions of ambient particulate matter across those years that could have influenced our results. However, averaged over the two-year period, exposure to concentrated ambient particles (CAPs) increased the biomarkers associated with airway allergies (IL-5, immunoglobulin E, immunoglobulin G1 and eosinophils). In addition, mice exposed to CAPs 50 m downwind of the roadway had, on the average, greater allergic responses and showed greater indications of inflammation than did mice exposed to CAPs 150 m downwind. This study is consistent with the hypothesis that exposure to CAPs close to a heavily trafficked roadway influenced allergic airway responses.     

Use of fungi for the bioconversion of rice straw into cellulase enzyme

Cellulase production was carried out by solid state bioconversion (SSB) method using rice straw, a lignocellulosic material and agricultural waste, as the substrate of three Trichoderma spp. and Phanerochaete chrysosporium in lab-scale experiments. The results were compared to select the best fungi among them for the production of cellulase. Phanerochaete chrysosporium was found to be the best among these species of fungi, which produced the highest cellulase enzyme of 1.43 IU/mL of filter paper activity (FPase) and 2.40 IU/mL of carboxymethylcellulose activity (CMCase). The “glucosamine” and “reducing sugar” parameters were observed to evaluate the growth and substrate utilization in the experiments. In the case of Phanerochaete Chrysosporium, the highest glucosamine concentration was 1.60 g/L and a high concentration of the release of reducing sugar was measured as 2.58 g/L obtained on the 4th day of fermentation. The pH values were also recorded. The range of the pH was about 5.15 to 5.56 in the case of Phanerochaete Chrysosporium.     

Decolorization does not always mean detoxification: case study of a newly isolated Pseudomonas peli for decolorization of textile wastewater

The textile industry is a favor to the Tunisian economy by offering several job positions. However, it’s not environmentally friendly. In fact, textile industries discharge high volumes of wastewater which contain several toxic pollutants such as dyes, fixator, and whiteness. In our study, Pseudomonas peli, isolated and characterized from Oued Hamdoun (center of Tunisia), was found able to decolorize textile effluent about 81 % after 24 h shaking incubation. On the other hand, the in vitro antiproliferative effects of the untreated and treated effluent was evaluated by their potential cytotoxic activity using the MTT colorimetric method against three human cancer cell lines (A549, lung cell carcinoma; HT29, colon adenocarcinoma; and MCF7, breast adenocarcinoma). Results showed that intact textile effluent and its content azo dyes didn’t inhibit the proliferation of all tested cell lines. However, the cytotoxic effect was remarkable when we tested effluent obtained after treatment by P. peli in a dose-dependent manner. This activity was attributed to the presence, in our treated effluent, of some azo products of dyes which are responsible for inhibition of human cell lines proliferation. Thus, the use of this strain for testing on the industrial scale seems impossible and disadvantageous.     

Advanced oxidation treatment of physico-chemically pre-treated olive mill industry effluent

In this study, the applicability of physico-chemical methods was investigated for the pre-treatment of the olive mill effluents prior to the discharge into the common sewerage ending with a municipal wastewater treatment plant. The samples were taken from an olive oil industry operated as three-phase process located in Turkey. Various pre-treatment methods including acid craking, polyelectrolyte and lime additions were applied. Advanced oxidation study using Fenton's process was also investigated following pre-treatment by acid cracking and cationic polyelectrolyte. Acid cracking alone gave satisfactory treatment efficiencies and polyelectrolite additions to the acid-cracked samples enhanced treatment efficiency. Since a complete treatment plant is available at the end of the sewer system, results indicated that the effluents of the investigated industry could be discharged into the municipal sewerage in the case of total chemical oxygen demand (COD_tot), suspended solid (SS) and volatile suspended solid (VSS) concentrations according to the Turkish Water Pollution Control Regulation after pre-treatment with 5 ppm anionic polyelectrolyte following acid cracking. The minimum COD_tot, SS and VSS removals were observed when raw wastewater was pre-treated with lime and the discharge standards to the municipal sewer system could not be met. Advanced oxidation with Fenton's process was applied after acid cracking and cationic polyelectrolyte treatment in order to investigate further reduction in chemical oxygen demand (COD) concentration for minimizing the influence of this industrial discharge on the existing municipal wastewater treatment plant. Results indicated that COD_tot removal increased up to 89% from 74% after Fenton's oxidation for the acid cracked samples in which cationic polyelectrolite (10 ppm) was added.     

Comparison of phenanthrene biodegradation by free and immobilized cell systems: formation of hydroxylated compounds

One of the foremost environmental issues having a key role in the feasibility study of polycyclic aromatic hydrocarbons (PAHs) biodegradation is the concern of the toxicity of the formed intermediate metabolites. In this study, biodegradability of phenanthrene (PHE) at initial concentrations of 100–500 ppm and its hydroxylated intermediate metabolites (IMs) in aqueous phase were investigated using free cells (FC) and immobilized cells (IC) in polyvinyl alcohol (PVA) cryogel beads. Results showed that both FC and IC systems were capable of complete PHE biodegradation at initial concentrations lower than 250 ppm after 7 days, though IC system showed a higher PHE removal rate. The maximum IM concentrations observed at initial PHE concentrations of 100 and 250 ppm were 20 and 49 ppm for FC system, whereas 7.4 and 19 ppm were obtained for IC system, respectively, and IMs were finally removed after 7 days. Similarly, at 500 ppm, IC system resulted in higher removal of PHE compared to FC system. However, during the 7-day period for FC system, IMs concentration rose up to 59 ppm, while for IC system, IMs concentration reaches a maximum at day 5 and thereafter it follows a negative rate. It was also shown that resorcinol as an indicator of hydroxylated aromatic metabolites at concentrations of 0–100 ppm can well be biodegraded by free and immobilized cell systems. No prohibition on PHE biodegradation could hence occur due to IMs formation. Additionally, stability of IC system was examined in repeated-batch cultures, showing the effective removal of PHE up to nine reuse cycles.     

Bathymetric variation of epiphytic assemblages on Posidonia oceanica (L.) Delile leaves in relation to anthropogenic disturbance in the southeastern Mediterranean

A survey of the epiphytic leaves of Posidonia oceanica was conducted along a depth transect at both the control station Attaya in the Kerkennah Islands and the disturbed Mahres station on the Sfax coast (Tunisia). Samples were collected by scuba divers at depths of 5, 10, 15, and 20 m in July 2008. We evaluated whether the pattern of spatial variability of the macroepiphyte assemblages of leaves of Posidonia oceanica differed in relation to anthropogenic interference. The results indicate that the decrease in shoot density and leaf length according to depth was low at Mahres. The biomass of epiphytic leaves and the percentage cover of epiphytic assemblages decreased with depth for both stations and heavily at Mahres, this decline being related to anthropogenic disturbance. This study shows that the highest values of epifauna and epiflora were detected at the disturbed station Mahres. Macroalgae assemblages decreased with depth at both stations and were dominated by Rhodophyta, whereas the percentage cover of the epifauna leaf that decreases according to depth was dominated by Hydrozoa and Bryozoa. Changes in epiphyte assemblages, epiphytic biomass, percentage cover, and species richness in proportion to Heterokontophyta, Rhodophyta, Cyanobacteria, Hydrozoa, Porifera, and Tunicata between the two stations constitute promising tools for detecting environmental disturbance.     

Selective removal of some polyhydric phenols from aqueous solution by ferric antimonate

Ferric antimonate, a cation-exchanger, has been investigated as an adsorbent for the removal of phenol and polyhydric phenols from aqueous solution. It has been found that ferric antimonate in H+ form selectively adsorbs polyhydric phenols having hydroxyl groups on adjacent positions. While phenol, resorcinol, and quinol did not show any appreciable adsorption, catechol, pyrogallol, and gallic acid having hydroxyl groups on adjacent positions exhibited considerable adsorption on ferric antimonate. Batch equilibrium experiments were carried out to study the effect of contact time, initial concentration of phenolic compounds, and temperature on the adsorption of phenolic compounds on ferric antimonate. The equilibrium time was found to be 1.5 hours for gallic acid and pyrogallol and 2 hours for catechol and salicylic acid. The adsorption data of the phenols at temperatures of 30 degrees, 40 degrees, and 50 degrees C have been described by Langmuir and Freundlich isotherm models. The best fit was obtained with the Langmuir model in the whole range of concentrations studied at all temperatures, indicating a monolayer adsorption onto a homogeneous adsorption surface. On the basis of the Langmuir isotherm, the maximum adsorption capacity of ferric antimonate for gallic acid, pyrogallol, catechol, and salicylic acid was found to be 3.915, 3.734, 2.397, and 2.758 mg/g, respectively at 30 degrees C. The maximum sorption capacity of ferric antimonate for the phenolic compounds studied is in the following order: gallic acid > pyrogallol > salicylic acid > catechol. The adsorption of phenolic compounds was found to decrease with an increase in temperature. Thermodynamic parameters like free energy, enthalpy, and entropy changes were calculated and discussed. The adsorption of polyhydric phenols on ferric antimonate is exothermic and spontaneous in nature.     

Climatic drivers of potential hazards in Mediterranean coasts

This paper studies climatic drivers (air and water temperature, precipitation rates, river discharge, sea level and storm patterns) in four Mediterranean regions: the Catalan-Valencia Coast (Spain), the Oran (Algeria) and Gabès (Tunisia) Gulfs and the western Nile Delta (Egypt). The paper also considers the potential hazards that these drivers can induce. It first analyses climatic trends in the drivers, taking into account the available time series of recorded and simulated meteo-oceanographic data from different sources. Next, it presents the general framework to assess biogeophysical hazards (flooding, erosion, droughts and water quality), followed by a simple and yet robust evaluation of those hazards for the four studied coastal sites. Assuming climate change projections under different scenarios and considering the observed trends in drivers, the resulting erosion rates due to sea-level rise and wave storm effects have been estimated. The Nile and Ebro Deltas, together with the Oran Gulf, are more vulnerable than the Gulfs of Valencia and Gabès. Regarding water quality in terms of (a) precipitation and dissolved oxygen in the water column and (b) sea surface temperature, the results show that the most vulnerable zones for the projected conditions (a) are the Gulfs of Oran, Valencia and Gabès, while the Nile Delta is the region where the decrease in water quality will be less pronounced. For the projected conditions (b), the most vulnerable zone is the Ebro Delta, while the impact in the other three cases will be smaller and of comparable magnitude. Finally, the overall future impact of these hazards (associated to climatic change) in the four sites is discussed in comparative terms, deriving some conclusions.     

Impact changes of climatic extremes on arable farming in the north of the Netherlands

Agriculture is vulnerable to climate change in multiple ways. Here, we use the northern region of the Netherlands as a case study to explore how risk assessments for climate change impacts on crop production can address multiple vulnerabilities. We present a methodology, which we call agro climate calendar (ACC) that (i) includes potential yield losses, as well as loss of product quality, and (ii) assesses the risks of a variety of climate factors including weather extremes and the emergence and abundance of pests and diseases. Climate factors are defined for two time slices: 1990 (1976–2005) and 2040 (2026–2055); the frequency of occurrence of the factors is compared for the two periods, and the resulting frequency shifts are presented in a crop calendar on a monthly basis. This yields an indication of the magnitude and direction of changes in climatic conditions that can lead to damage by extreme events and pests and diseases. We present results for the two most important crops in the region, seed potato, and winter wheat. The results provide a good overview of risks from climate factors, and the most important threats and opportunities are identified. This semi-quantitative approach is firmly rooted in farm management, which is the level where operational and strategic decisions are made. Thus, the approach is well suited to assist local stakeholders such as farmers and policy makers to explore farm-level adaptation. This work is complementary to previous modeling work that focused mainly on the relation between mean climate change factors (i.e., temperature) and crop yield.     

Understanding livelihood strategy-poverty links: empirical evidence from central highlands of Ethiopia

The aim of this paper is to disclose livelihood strategy-poverty links and gain a better understanding by developing typologies of rural households. Based on qualitative and quantitative data, we group households into different typologies and explore interactions. We identified six main agronomic strategies, four dominant livelihood diversification strategies, and income quartiles (proxies for poverty) using cluster and principal component factor analysis. We found that nearly 82% of the surveyed farmers in the study area belong to the bottom income quartiles while about 18% are on the upper quartiles. Households in the bottom income quartiles engaged in casual off-farm work and cereal-dominated livelihood strategies that tend to pursue subsistence farming by growing cereals and oil crops. Contrarily, farmers in the upper income quartiles adapted intensive agronomic strategies by integrating root crops, legumes, and vegetables with livestock. This was largely attributed to access to key livelihood assets such as land, livestock, education, and institutional support in which the upper quartiles were more endowed. Improving availability of the key assets for the bottom income quartiles might be a way out of poverty and ensuring sustainable development. It is crucial to recognize local-level heterogeneities of rural households when targeting development interventions.