A statistical methodology for the evaluation of long-range dispersion models: an application to the ETEX exercise

This paper describes the statistical methodology applied to evaluate the performance of the long-range dispersion models that were used in the modelling activities of ETEX (European Tracer EXperiment). The availability of a large number of models makes this exercise rather unique. These models are used for the practical purpose to quantify the contamination effects over a vast area, following a hypothetical accidental release of harmful material. This makes the quality judgement that could be attributed to the results of each model particularly important.The statistical indicators considered to be the most effective for the evaluation of long-range dispersion models are introduced and commented, with specific examples in the frame of ETEX simulations. The importance of using several indices and critically interpreting the results is discussed.     

The downside of religious attire: The Muslim headscarf and expectations of obtaining employment

As laws are being passed or considered to ban certain forms of religious attire in the current international arena (France, Netherlands, Italy), it is important to address some of the concerns that Americans who wear religious attire might have. Based on stereotype threat theory, data from 219 American Muslim females were examined regarding their expectations of receiving job offers for a variety of occupations. Results indicated that Muslim women who wear the headscarf (Hijabis) had lower expectations of receiving a job offer than Muslim women who do not wear the hijab. This difference increased as the amount of public contact associated with the occupation decreased and job status of the occupation increased. Furthermore, work centrality moderated this relationship, but only for Muslim women who did not wear the headscarf. Implications of these findings with regard to Hijabis and occupational attainment are discussed. Copyright © 2009 John Wiley & Sons, Ltd.     

Response of bioaerosol cells to photocatalytic inactivation with ZnO and TiO2 impregnated onto Perlite and Poraver carriers

•ZnO/Perlite inactivated 72% of bioaerosols in continuous gas phase. •TiO₂ triggered the highest level of cytotoxicity with 95% dead cells onto Poraver. •Inactivation mechanism occurred by membrane damage, morphological changes and lysis. •ZnO/Poraver showed null inactivation of bioaerosols. •Catalysts losses at the outlet of the photoreactor for all systems were negligible. Bioaerosols are airborne microorganisms that cause infectious sickness, respiratory and chronic health issues. They have become a latent threat, particularly in indoor environment. Photocatalysis is a promising process to inactivate completely bioaerosols from air. However, in systems treating a continuous air flow, catalysts can be partially lost in the gaseous effluent. To avoid such phenomenon, supporting materials can be used to fix catalysts. In the present work, four photocatalytic systems using Perlite or Poraver glass beads impregnated with ZnO or TiO₂ were tested. The inactivation mechanism of bioaerosols and the cytotoxic effect of the catalysts to bioaerosols were studied. The plug flow photocatalytic reactor treated a bioaerosol flow of 460×1 0⁶ cells/m³_air with a residence time of 5.7 s. Flow Cytometry (FC) was used to quantify and characterize bioaerosols in terms of dead, injured and live cells. The most efficient system was ZnO/Perlite with 72% inactivation of bioaerosols, maintaining such inactivation during 7.5 h due to the higher water retention capacity of Perlite (2.8 mL/g_Perlite) in comparison with Poraver (1.5 mL/g_Perlite). However, a global balance showed that TiO₂/Poraver system triggered the highest level of cytotoxicity to bioaerosols retained on the support after 96 h with 95% of dead cells. SEM and FC analyses showed that the mechanism of inactivation with ZnO was based on membrane damage, morphological cell changes and cell lysis; whereas only membrane damage and cell lysis were involved with TiO₂. Overall, results highlighted that photocatalytic technologies can completely inactivate bioaerosols in indoor environments.     

Estimation of aerosol optical depth in relation to meteorological parameters over eastern and western routes of China Pakistan economic corridor

This study finds out seasonal and monthly variations in Aerosol Optical Depth (AOD) over eastern and western routes of China Pakistan Economic Corridor (CPEC) and the relationship between AOD and meteorological parameters (i.e., temperature, rainfall and wind speed). The Moderate Resolution Imaging Spectroradiometer (MODIS) and Multi-angle Imaging Spectroradiometer (MISR) data was used from the terra satellite for the period of 2000-2016. This study aims to overtake the conventional view of the purpose of using the satellite datasets. This study takes on to the concept that validated satellite data sets rather should be used for the analysis instead of just validation specifically for our study region. Hence, after comparing MODIS AOD with MISR AOD, only MISR AOD dataset is used for further analysis. The results show a decreasing trend of AOD in summer season, a positive relationship between temperature and AOD during winter and spring seasons whereas a positive relationship between wind speed and AOD in winter and spring seasons over eastern and western routes. Periodic analysis of MODIS AOD and MISR AOD depicts May-Aug as the peak period of aerosol concentration over central Pakistan. The inter-annual analysis shows the aerosol trend remained higher during summer season however rainfall shows the washout effect. Eastern route has higher standard deviation and larger values for aerosol prevalence as compared to western route. The trajectory analysis using the HYSPLIT model suggests the bias of air mass trajectory caused deviation in the aerosol trend in the year 2014.     

Pesticide and agro-ecological transition: assessing the environmental and human impacts of pesticides and limiting their use

Environmental Science and Pollution Research -     

Assessment of the effects of soil PAH accumulation by a battery of ecotoxicological tests

Surface soils were collected at remote, urban and industrial sites in the Southern of Italy in order to evaluate PAH concentrations and assess the toxic effects by a battery of ecotoxicological tests. The tests were performed on whole soils and on both organic and aqueous extracts. Further goal of this study was to integrate the results coming from each test and matrix in a synthetic toxicity index. The highest summation sigmaPAH concentrations were measured at the industrial soil, although this one did not show an high ecotoxicological risk. Among the performed tests, the phytotoxicity tests showed the highest sensitivity. For whole soil, the worst case always has been represented by test through bacteria. Our results could represent the first step toward the selection of a proper battery to characterize the soil ecotoxicological risk.     

Soil Respiration and Carbon Storage of an Acrisol Under Forest and different Cultivations in rio de Janeiro State, Brazil

Soil respiration rates of a clay-loam textured Acrisol under different uses (Atlantic forest, manioc, horticulture and pasture) from Rio de Janeiro State were measured. The relationship between carbon dioxide (CO₂) emissions and soil physico-chemical properties were investigated. Rates of CO₂ emission of two sites (Atlantic forest and horticulture) were also evaluated in different seasons in 1997 and 1998. In the forest site, monthly means of measured respiration rates showed good correlation with soil temperature in the range 19.6–24.1°C (r² = 0.89). In the horticulture site, no change was observed with soil moisture alone, in the range 3.0–13.2 wt%. In the horticulture soil, even when the surface soil was very dry, respiration rates increased in the hot, wetter summer but remained higher than the mean flux from forest soil. The CO₂ emission flux of the Acrisol under different use showed good correlation with soil temperature (r² = 0.72) and moisture (r² = 0.61).     

Persistence of carbofuran in marine sand and water

Marine sand and seawater samples were collected in March 2002 from Laysan Island in the Hawaiian Islands National Wildlife Refuge, where a small area was contaminated by the carbamate insecticide carbofuran. Carbofuran was still detected at microg g(-1) levels in the Laysan sand after its identification in 1998 and initial observation of the toxicity in 1988. The persistence of carbofuran in the marine sand was investigated in the dark in a 30 degrees C oven, and in distilled deionized water and seawater samples exposed to artificial 300 nm light and to direct sunlight. The laboratory study showed a half-life (t1/2) of approximately 40 days for carbofuran in the native sand and in Ottawa sand. The photolysis of carbofuran was faster in seawater than in distilled deionized water when it was exposed to 300 nm light (t1/2, 0.1 vs. 3.1 h) and to direct sunlight (t1/2, 7.5 vs. 41.6 h). The large difference between the laboratory results and the field observation of carbofuran dissipation suggests that carbofuran degradation at the remote, undisturbed marine site may be governed by its unique environmental factors.     

Allelopathic potential and systematic evaluation of organic extracts from Canavalia ensiformis leaves (Jack beans)

This article describes the assessment of possible allelopathic potential of organic extracts obtained from leaves of Canavalia ensiformis under laboratory conditions. Furthermore, a systematic evaluation of these extracts was carried out using specific protocols developed in capillary electrophoresis (CE) to determine some groups of secondary metabolites. After the identification and quantification of compounds, the effects of compounds on germination of some common weeds was investigated, which are becoming a real problem in pastures in the state of Pará, Brazil.