Use,exposure, and environmental impacts of pesticides in Pakistan: a critical review

Environmental Science and Pollution Research - The excessive use of pesticides is posing major threats to humans and the environment. However, the environmental exposure and impact of pesticides in...     

Water reuse in industries: analysis of opportunities in the Paraíba do Sul river basin,a case study in Presidente Vargas Plant,Brazil

Environmental Science and Pollution Research - In recent years, the demand for clean water has been growing all over the world despite the different threats posed, including increasing pollution,...     

Tobacco Plants Detect a Decrease of Environmental Genotoxicity in Toulouse (France)

Tobacco plants, heterozygous for two independent loci involved in the chlorophyll parenchyma differentiation, allow the genotoxic effects of the atmosphere of the industrial estate South of Toulouse to be estimated. Somatic spots of green cellular colonies on yellow-green background, were counted to calculate the cellular rates of reversion. Two experiments were carried out in 1981, and in 1997. A general decrease of genotoxic effects was observed. These observations were interpreted as being due to a general decrease of the air pollution evaluated by the development of the concentrations of three toxic gases before and after the implementation of cleanup devices. The results obtained demonstrate the efficiency of this bio-indicator, which is easy to use and capable of integrating, in situ, genotoxic variations throughout the duration of plants' growth.     

Experimental and numerical study of methylparaben decomposition in aqueous solution using the UV/H2O2 process

The present paper aims at presenting a kinetic model that is supposed to result in the decomposition of methylparaben in completely mixed batch reactor (CMBR) using the UV/H₂O₂ process. The proposed model incorporates photochemical, chemical reactions and their constant rates to formulate the overall kinetic rate expressions which are integrated into MATLAB. Thus, the changes in pH values during the process of oxidation are taken into consideration. In addition, the effects of hydrogen peroxide (HP) dosage, as well as the concentration of hydroxyl radicals, are examined. Accordingly, the pseudo-first-order rate constant, its variation as functions of HP concentration, incident UV-light intensity and the limitations of the adopted approach are discussed. In line with that, the authors provided evidence of the validity of the kinetic model through the exposure of previous experimental studies as reported in the literature review then through the evidence of the present experimental data.     

Future intensification of summer hypoxia in the tidal Garonne River (SW France) simulated by a coupled hydro sedimentary-biogeochemical model

Projections for the next 50 years predict a widespread distribution of hypoxic zones in the open and coastal ocean due to environmental and global changes. The Tidal Garonne River (SW France) has already experienced few episodic hypoxic events. However, predicted future climate and demographic changes suggest that summer hypoxia could become more severe and even permanent near the city of Bordeaux in the next few decades. A 3D model, which couples hydrodynamic, sediment transport, and biogeochemical processes, is applied to assess the impact of factors submitted to global and regional climate changes on oxygenation in the turbidity maximum zone (TMZ) of the Tidal Garonne River during low-discharge periods. The model simulates an intensification of summer hypoxia with an increase in temperature, a decrease in river flow or an increase in the local population, but not with sea level rise, which has a negligible impact on dissolved oxygen. Different scenarios were tested by combining these different factors according to the regional projections for 2050 and 2100. All the simulations showed a trend toward a spatial and temporal extension of summer hypoxia that needs to be considered by local water authorities to impose management strategies to protect the ecosystem.     

Development of a real-time polymerase chain reaction assay for the detection of the invasive Mediterranean fanworm, <Emphasis Type="Italic">Sabella spallanzanii</Emphasis>, in environmental samples

The Mediterranean fanworm, Sabella spallanzanii Gmelin 1791, was first detected in the Southern Hemisphere in the 1990s and is now abundant in many parts of southern Australia and in several locations around northern New Zealand. Once established, it can proliferate rapidly, reaching high densities with potential ecological and economic impacts. Early detection of new S. spallanzanii incursions is important to prevent its spread, guide eradication or control efforts and to increase knowledge on the species’ dispersal pathways. In this study, we developed a TaqMan probe real-time polymerase chain reaction assay targeting a region of the mitochondrial cytochrome oxidase I gene. The assay was validated in silico and in vitro using DNA from New Zealand and Australian Sabellidae with no cross-reactivity detected. The assay has a linear range of detection over seven orders of magnitude with a limit of detection reached at 12.4 × 10^?4 ng/μL of DNA. We analysed 145 environmental (water, sediment and biofouling) samples and obtained positive detections only from spiked samples and those collected at a port where S. spallanzanii is known to be established. This assay has the potential to enhance current morphological and molecular-based methods, through its ability to rapidly and accurately identify S. spallanzanii in environmental samples.     

LCA of selective waste collection systems in dense urban areas

This paper presents research concerning the environmental analysis of the selective collection management of municipal solid waste. The main goal of this study is to quantify and to compare, by means of Life Cycle Assessment (LCA), the potential environmental impacts of three selective collection systems modelled on densely populated urban areas. These systems are: the mobile pneumatic, the multi-container and the door-to-door. Impact assessment method based on CML 2 baseline 2000 is applied to the different systems. The study separates and analyzes the collection systems in substages: two urban substages and one inter-city substage. At the urban level, the multi-container system has the least environmental impact of all systems. The mobile pneumatic system has greater environmental impacts in terms of global warming, fresh water aquatic ecotoxicity, terrestrial ecotoxicity, acidification and eutrophication. In this system, the pipes and the pneumatic transport have the greatest impacts. The door-to-door system has a greatest environmental impact in terms of abiotic depletion, ozone layer depletion and human toxicity. An overall evaluation of the three substages, with a sensitivity analysis, indicates that the mobile pneumatic system at an inter-city distance of 20 km shows the greatest environmental impacts and the greatest energy demand. Inter-city transport is key; the results show that from an inter-city distance of 11 km onwards, this becomes the substage which most contributes to global warming impact and energy demand, in all the systems.     

Study of the use of coal fly ash as an additive to minimise fluoride leaching from FGD gypsum for its disposal

The use of coal fly ash as a fluoride retention additive has been studied as a way of treating flue gas desulphurisation (FGD) gypsum for its disposal in landfills. With this end leaching studies following the standard EN-12457-4 [Characterization of waste- Leaching-Compliance test for leaching of granular waste materials and sludges - Part 4: One stage batch test at a liquid to solid ratio of 10l/kg for materials with particle size below 10mm (without or with size reduction)] have been performed on FGD gypsum samples treated with different proportions of fly ash (0.1-100%). It was found that the fluoride leachable content in FGD gypsum was reduced in the range 1-55%, depending on the fly ash proportion added to FGD gypsum. High levels of fluoride leaching reduction (close to 40%) were achieved even at relatively low fly ash additions (5%). So, low fly ash incorporations assure the characterization of this by-product as a waste acceptable at landfills for non-hazardous wastes according to the Council Decision 2003/33/EC [Council Decision 2003/33/EC of 19 December 2002 establishing criteria and procedures for the acceptance of waste at landfills pursuant to Article 16 of and Annex II to Directive 1999/31/EC] on waste disposal. Furthermore, the effectiveness of the proposed FGD gypsum stabilization method was also studied in column leaching systems, proving its good performance in simulated conditions of disposal. In such conditions a fluoride leaching reduction value slightly higher than 25% was displayed for a fly ash added amount of 5%.     

Ten years measuring PCDDs/PCDFs in ambient air in Catalonia (Spain)

This work summarizes the results of a ten year surveillance programme on PCDD/F in ambient air carried out in Catalonia (Spain). The study has been conducted by the Dioxin Laboratory of Spanish Council for Scientific Research (CSIC) in collaboration with the Environment Department of the Catalonian Government. 175 samples have been collected throughout Catalonia from 1994 to 2004. Different sampling locations classified as industrial, traffic, urban, suburban and rural sites have been monitored in order to find the most contaminated zones as well as the ones with expected background concentrations. The highest concentrations found in this study were determined at the industrial locations. Concentrations ranging from 5 to 1196 fg I-TEQ/m3, with a mean value of 140 fg I-TEQ/m3 and from 10 to 357 fg I-TEQ/m3, with a mean value of 72 fg I-TEQ/m3 were determined in industrial and traffic sampling points, respectively. In contrast, the lowest concentrations were found in rural stations, ranging from 5 to 45 fg I-TEQ/m3, with a mean value of 28 fg I-TEQ/m3. The PCDD/F concentration trend in Catalonian ambient air shown a clear drop of the median values occurred during the study sampling period. A decline of about 70% was observed from 1997-1998 to 2003-2004.     

Arsenic speciation of atmospheric particulate matter (PM10) in an industrialised urban site in southwestern Spain

An arsenic speciation study has been performed in PM10 samples collected on a fortnight basis in the city of Huelva (SW Spain) during 2001 and 2002. The arsenic species were extracted from the PM10 filters using a NH2OH x HCl solution and sonication, and determined by HPLC-HG-AFS. The mean bulk As concentration of the samples analyzed during 2001 and 2002 slightly exceed the mean annual 6 ng m(-3) target value proposed by the European Commission for 2013, arsenate [As(V)] being responsible for the high level of arsenic. The speciation analyses showed that As(V) was the main arsenic species found, followed by arsenite [As(III)] (mean 6.5 and 7.8 ng m(-3) for As(V), mean 1.2 and 2.1 ng m(-3) for As(III), in 2001 and 2002, respectively). The high levels of arsenic species found in PM10 in Huelva have a predominant industrial origin, such as the one from a nearby copper smelter, and do not present a seasonal pattern. The highest daily levels of arsenic species correspond to synoptic conditions in which the winds with S and SW components transport the contaminants from the main emission source. The frequent African dust outbreaks over Huelva may result in an increment of mass levels of PM10, but do not represent a significant input of arsenic in comparison to the anthropogenic source. The rural background levels of arsenic around Huelva are rather high, in comparison to other rural or urban areas in Spain, showing a relatively high atmosphere residence time of arsenic. This work shows the importance of arsenic speciation in studies of aerosol chemistry, due to the presence of arsenic species [As(III) and As(V)] with distinct toxicity.