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Gas phase reactions of unsaturated esters with Cl atoms Full text
2010
Martín Porrero, María Pilar | Gallego-Iniesta García, Maria Paz | Espinosa Ruiz, Jose Luis | Tapia Valle, Araceli | Cabañas Galán, Beatriz | Salgado Muñoz, Maria Sagrario
Background, aim, and scope Acrylate and methacrylate esters are α,β-unsaturated esters that contain vinyl groups directly attached to the carbonyl carbon (CH₂=CHCOO- and CH₂=CCH₃COO-, respectively) and are widely used in the polymer plastic and resin production. Rate coefficients for Cl reactions for most of the unsaturated esters have not been previously determined, and a good understanding is needed of all the atmospheric oxidation processes of these compounds in order to determine lifetimes in the atmosphere and to evaluate the impact of these reactions on the formation of photo-oxidants and therefore on health and environment. Materials and methods The relative rate technique has been used to obtain rate coefficients for the reactions between the Cl atom and a series of unsaturated esters. The experiments have been carried out in a static Teflon reactor at room temperature and atmospheric pressure (N₂ as bath gas) using gas chromatography with flame ionization detection as detection system. Results The following rate coefficients are obtained (in cubic meter per molecule per second): methyl acrylate + Cl = 1.71 ± 0.13 × 10⁻¹⁰; methyl methacrylate + Cl = 2.30 ± 0.18 × 10⁻¹⁰; ethyl acrylate + Cl = 1.82 ± 0.13 × 10⁻¹⁰; ethyl methacrylate + Cl = 2.71 ± 0.21 × 10⁻¹⁰; butyl acrylate + Cl = 2.94 ± 0.23 × 10⁻¹⁰; butyl methacrylate + Cl = 3.83 ± 0.30 × 10⁻¹⁰; methyl 3-methyl acrylate + Cl = 2.21 ± 0.17 × 10⁻¹⁰; and methyl 3,3-dimethyl acrylate + Cl = 3.58 ± 0.28 × 10⁻¹⁰. Discussion Rate coefficients calculated for Cl reactions are around one order of magnitude higher than OH ones. The effect in the reactivity of increased substitution at the carbon-carbon double bond is analyzed and also the effect of the identity of the alkyl group R in the -C(O)OR. Atmospheric lifetimes of the compounds against the attack by the major oxidants are estimated and the atmospheric implications are discussed. Conclusions The dominant atmospheric loss process for acrylate esters is clearly their daytime reaction with the hydroxyl radical. However, in coastal areas and in the marine boundary layer and in some industrial zones, Cl-atom-initiated degradation of the unsaturated esters considered here can be a significant if not dominant homogeneous loss process. Recommendations and perspectives Product analysis should be necessary in order to evaluate the real environmental impact of these reactions. OH and ozone reactions of most of the considered compounds have already been studied and products determined, but kinetic and products information for NO₃ radical reactions is especially scarce.
Show more [+] Less [-]Study on adsorption and remediation of heavy metals by poplar and larch in contaminated soil Full text
2010
Wang, Xin | Jia, Youngfeng
Introduction Field experiments at the Shenyang Experimental Station of Ecology were conducted to study the adsorption, accumulation, and remediation of heavy metals by poplar and larch grown in artificially contaminated soil. Materials and methods The soil was spiked with a combination of Cd, Cu, and Zn at concentrations of 1.5, 100, and 200 mg·kg⁻¹, respectively. Results The results showed that the biomass of poplar (Populus canadensis Moench) was lower by 26.0% in the soil spiked with a mixture of Cd, Cu, and Zn, compared with the control. Concentrations of Cd in poplar leaf and Cu in poplar roots in the treated soil were 4.11 and 14.55 mg kg⁻¹, respectively, which are much greater than in corresponding controls. The migration of heavy metals in woody plant body was in the order Cd > Zn > Cu. Poplar had higher metal concentrations in aboveground tissues and a higher biomass compared with larch of the same age and therefore is potentially more suitable for remediation. In the heavy metal-polluted soil of this study, phytoremediation by poplar may take 56 and 245 years for Cd and Cu, respectively, for meeting the soil standards of heavy metals, and the corresponding phytoremediation times by larch would take 211 and 438 years. Conclusion The research findings could be used as a basis to develop ecological engineering technologies for environmental control and remediation of pollution caused by heavy metals in soils.
Show more [+] Less [-]Comprehensive evaluation of municipal garbage disposal in Changchun City by the strategic environmental assessment Full text
2010
Xu, Jianling L. | Tang, Zhanhui H. | Shang, Jincheng C. | Zhao, Yuanhui H.
Purpose The environmental issues caused by the municipal solid waste disposal are becoming a worldwide concern. Methods We studied the situations both domestically and abroad by the strategic environmental assessment (SEA) approach and also conducted comprehensive evaluations of garbage disposal in Changchun City. Results On the basis of this study, we found that SEA is of great importance in the municipal solid waste disposal. Moreover, with the rapid socioeconomic development of Changchun City, municipal solid waste production increases on an annual basis, and thus, good waste management planning is of great significance. Conclusions Considering the situation of the economic development of Changchun City, garbage disposal was handled mainly in the major sanitary landfills with appropriate use of incineration technology. This plan is environmentally friendly at a relatively high degree and has met the requirements of minimum investment. It also takes into account the requirements of the development of incineration technology. Regarding environmental pollution in terms of groundwater pollution and atmospheric pollution, this plan is a feasible one by meeting various requirements with low environmental impact among the three plans discussed in this study.
Show more [+] Less [-]Non-target screening analysis of river water as compound-related base for monitoring measures Full text
2010
Schwarzbauer, Jan | Ricking, Mathias
Background, aim, and scope Building up a comprehensive accurate monitoring program requires the knowledge on the contamination in principal, complemented by detailed information on individual contaminants. The selection of pollutants to be considered in monitoring actions is based dominantly on the information available about their environmental relevance (e.g., persistence, bioaccumulation potential, toxicological and ecotoxicological properties) and their occurrence within the affected environmental system. Therefore, this study focused on the identification of organic contaminants in selected German and European rivers to demonstrate the usefulness of a screening approach as complementary base for the compound selection process within monitoring activities. Materials and methods Gas chromatography-mass spectrometry-based screening analyses were performed on five and six samples from German and European rivers, respectively. Identification of individual contaminants was based on the investigation of mass spectral and gas chromatographic properties compared with databases and reference materials. Results This study summarized the results of non-target screening analyses applied to river water samples and focused dominantly on, so far, unnoticed organic contaminants. Numerous compounds have been identified belonging to the groups of pharmaceuticals, technical additives, pesticides, personal care products, and oxygen-, nitrogen-, and sulfur-containing compounds of obviously anthropogenic origin. They are discussed in terms of their structural properties, their possible application or usage, and the environmental information available so far. Discussion Generally, two different groups of compounds have been differentiated that might contribute to potential monitoring programs. Firstly, more specific contaminants characterizing the individual riverine systems have been depicted (e.g., 4-chloro-2-(trifluoromethyl)aniline, di-iso-propylurea). The consideration of these substances in monitoring analyses to be applied to the corresponding catchment areas is recommended in order to monitor the real state of pollution. Secondly, contaminants have been introduced that appeared with higher multiplicity throughout the different river systems (e.g., TMDD, TXIB). Since these compounds tend to obviously have an elevated environmental stability accompanied by a widespread distribution, it is recommended to consider them in international high-scale monitoring programs. Conclusions For monitoring purposes, a fundamental knowledge on the diversity of pollutants is an important precondition, which can be supported by screening analyses. Obviously, numerous organic contaminants have been neglected so far in environmental studies on river water, comprising also investigation on potential harmful effects and, therefore, their implementation in monitoring activities has been hindered. Recommendations and perspectives Therefore, based on the results of this study, screening analyses should be established as principle tools to improve and complement the substance spectra for monitoring purposes. Secondly, scientific efforts should be strengthened to expand our knowledge on actually appearing organic contaminants in riverine systems.
Show more [+] Less [-]Occurrence and sources of selected phenolic endocrine disruptors in Ria de Aveiro, Portugal Full text
2010
Jonkers, Niels | Sousa, Ana | Galante-Oliveira, Susana | Barroso, Carlos M. | Kohler, Hans-Peter E. | Giger, W (Walter)
Background, aim and scope Ria de Aveiro (Portugal) is a shallow coastal lagoon of high economic and ecological importance. Hardly any data on its chemical pollution by polar organic pollutants are available in literature. This study focused on the presence and sources of a series of phenolic endocrine-disrupting compounds (EDCs) in this area, including parabens, alkylphenolic compounds and bisphenol-A (BPA). A number of possible sources of pollution are present in the area, including the large harbours present in the lagoon, the city of Aveiro and the rivers discharging into the area. A recently constructed submarine wastewater outfall, located a few kilometres from the lagoon inlet has also been suggested as a possible source of pollution to Ria de Aveiro in several publications. The aim of the current field study was to investigate the occurrence and main sources of phenolic endocrine disruptors in Ria de Aveiro. Materials and methods An extensive sampling campaign was performed, with surface water and wastewater grab samples taken at over 50 locations, in duplicate on different days. Samples were treated using solid phase extraction and analysed by liquid chromatography tandem mass spectrometry. Results and discussion Concentrations in lagoon water were generally low: not exceeding 20 ng/L for most analytes. Levels in river water exceeded those in the lagoon by a factor 3 to 500 (o-phenylphenol (PhP) and nonylphenoxy ethoxy acetic acids (A₉PEC), respectively), with concentrations up to 700 ng/L for BPA and 7,300 ng/L for A₉PEC. Samples from the harbours showed EDC levels similar to those in the rest of the lagoon, but in the city of Aveiro, elevated concentrations were observed for alkylphenol ethoxylates (A₉PEO), A₉PEC, PhP and BPA. Wastewater effluents showed low levels for parabens, whilst alkylphenolic compounds reached several micrograms per litre. The effluents are discharged into the ocean via a submarine outfall, but as marine water near the outfall showed slightly elevated concentrations only for A₉PEO, it does not seem to be a significant source of these EDCs for the area. Conclusions All the studied phenolic EDCs were detected in the study area, with high levels found in some of the rivers discharging into the lagoon, and generally low concentrations in the lagoon itself. The main sources for all investigated EDCs were the rivers Caster and Antuã which discharge into the lagoon. The city of Aveiro was identified as a secondary source. As the tidal water exchange volume is much larger than the freshwater input from the rivers, concentrations of phenolic EDCs remained low in the lagoon.
Show more [+] Less [-]Potential physiological effects of pharmaceutical compounds in Atlantic salmon (Salmo salar) implied by transcriptomic analysis Full text
2010
Hampel, Miriam | Alonso, Esteban | Aparicio, Irene | Bron, James E. | Santos, Juan Luis | Taggart, John B. | Leaver, Michael J.
Background, aim, and scope Pharmaceuticals are emerging pollutants widely used in everyday urban activities which can be detected in surface, ground, and drinking waters. Their presence is derived from consumption of medicines, disposal of expired medications, release of treated and untreated urban effluents, and from the pharmaceutical industry. Their growing use has become an alarming environmental problem which potentially will become dangerous in the future. However, there is still a lack of knowledge about long-term effects in non-target organisms as well as for human health. Toxicity testing has indicated a relatively low acute toxicity to fish species, but no information is available on possible sublethal effects. This study provides data on the physiological pathways involved in the exposure of Atlantic salmon as representative test species to three pharmaceutical compounds found in ground, surface, and drinking waters based on the evaluation of the xenobiotic-induced impairment resulting in the activation and silencing of specific genes. Materials and methods Individuals of Atlantic salmon (Salmo salar) parr were exposed during 5 days to environmentally relevant concentrations of three representative pharmaceutical compounds with high consumption rates: the analgesic acetaminophen (54.77 ± 34.67 µg L⁻¹), the anticonvulsant carbamazepine (7.85 ± 0.13 µg L⁻¹), and the beta-blocker atenolol (11.08 ± 7.98 µg L⁻¹). Five immature males were selected for transcriptome analysis in brain tissues by means of a 17k salmon cDNA microarray. For this purpose, mRNA was isolated and reverse-transcribed into cDNA which was labeled with fluorescent dyes and hybridized against a common pool to the arrays. Lists of significantly up- and down-regulated candidate genes were submitted to KEGG (Kyoto Encyclopedia of Genes and Genomes) in order to analyze for induced pathways and to evaluate the usefulness of this method in cases of not completely annotated test organisms. Results Exposure during 5 days to environmentally relevant concentrations of the selected pharmaceutical compounds acetaminophen, carbamazepine, and atenolol produced differences in the expression of 659, 700, and 480 candidate genes, respectively. KEGG annotation numbers (KO annotations) were obtained for between 26.57% and 33.33% of these differently expressed genes per treatment in comparison to non-exposure conditions. Pathways that showed to be induced did not always follow previously reported targets or metabolic routes for the employed treatments; however, several other pathways have been found (four or more features) to be significantly induced. Discussion Energy-related pathways have been altered under exposure in all the selected treatments, indicating a possible energy budget leakage due to additional processes resulting from the exposure to environmental contaminants. Observed induction of pathways may indicate additional processes involved in the mode of action of the selected pharmaceuticals which may not have been detected with conventional methods like quantitative PCR in which only suspected features are analyzed punctually for effects. The employment of novel high-throughput screening techniques in combination with global pathway analysis methods, even if the organism is not completely annotated, allows the examination of a much broader range of candidates for potential effects of exposure at the gene level. Conclusions The continuously growing number of annotations of representative species relevant for environmental quality testing is facilitating pathway analysis processes for not completely annotated organisms. KEGG has shown to be a useful tool for the analysis of induced pathways from data generated by microarray techniques with the selected pharmaceutical contaminants acetaminophen, carbamazepine, and atenolol, but further studies have to be carried out in order to determine if a similar expression pattern in terms of fold change quantity and pathways is observed after long-term exposure. Together with the information obtained in this study, it will then be possible to evaluate the potential risk that the continuous release of these compounds may have on the environment and ecosystem functioning.
Show more [+] Less [-]Seawater carbonate chemistry and biological processes of zooplankton Amphiascoides atopus and Schizopera knabeni during experiments, 2010 Full text
2010
Pascal, Pierre-Yves | Fleeger, J W | Galvez, Fernando | Carman, Kevin R
Increased atmospheric CO2 concentrations are causing greater dissolution of CO2 into seawater, and are ultimately responsible for today's ongoing ocean acidification. We manipulated seawater acidity by addition of HCl and by increasing CO2 concentration and observed that two coastal harpacticoid copepods, Amphiascoides atopus and Schizopera knabeni were both more sensitive to increased acidity when generated by CO2. The present study indicates that copepods living in environments more prone to hypercapnia, such as mudflats where S. knabeni lives, may be less sensitive to future acidification. Ocean acidification is also expected to alter the toxicity of waterborne metals by influencing their speciation in seawater. CO2 enrichment did not affect the free-ion concentration of Cd but did increase the free-ion concentration of Cu. Antagonistic toxicities were observed between CO2 with Cd, Cu and Cu free-ion in A. atopus. This interaction could be due to a competition for H+ and metals for binding sites.
Show more [+] Less [-]Water pollution monitoring and management: a review of Bangkok
2010
Ali, G. | Nitivattananon, V. | Ahmad, Waqas | Nawaz, R.
An increasing amount of scientific information is available on water pollution and its effect. Water pollution management for pollution control seldom considers the scientific information. The main objective of this paper is to review the water pollution management in Bangkok and link the entire process to the cause and effects of water pollution. Existing approaches for water pollution control primarily focuses on enforcing various standards. Respective local authorities in Bangkok have also set their own surface water quality requirement. However, the entire management approach requires further analysis in line with the present situation. This paper attempts to review the entire management approach and suggests reduction strategies, control measures/treatment systems and some preferred solutions to the water pollution management. It also covers other important measures for control. The conclusion proposes some policy recommendations on reducing pollution through effect management approach.
Show more [+] Less [-]A cheap and rapidly built bottom water sampler for shallow-water environments Full text
2010
Krumme, Uwe | Zheng, Yun | Wang, Tian C
Earthworm cast production as a new behavioural biomarker for toxicity testing. Full text
2010
Capowiez, Yvan | Dittbrenner, Nils | Rault-Léonardon, Magali | Triebskorn, Rita | Hedde, Mickaël | Mazzia, Christophe
There is currently a lack of ecotoxicity tests adapted to earthworm species of higher ecological relevance and whose endpoints could be directly related to their ecological role in the soil. We propose a new and relatively simple ecotoxicity test based on the estimation of cast production (CP) by Lumbricus terrestris under laboratory conditions. CP was found to be linearly correlated to earthworm biomass and to be greatly influenced by soil water content. Azinphos-methyl had no effect on CP at all the concentrations tested. Significant decreases were observed at the normal application rate for other pesticides with (imidacloprid, carbaryl, methomyl) or without (ethyl-parathion and chlorpyrifos-ethyl) a clear concentration–effect response. For the highest concentration tested, reduction in CP varied between 35 and 67%. CP is straightforward and rapidly measured and ecologically meaningful. We thus believe it to be of great use as an endpoint in ecotoxicity testing.
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