Environmental Significance of the Diclofop-methyl and Cyclodextrin Inclusion Complexes

Cyclodextrins (CDs) possess a hydrophilic external surface and a hydrophobic cavity. They are thus highly soluble and, in the meantime, effectively form inclusion complexes with hydrophobic organic compounds to enhance their solubilities. In this study, the complexation between modified β-CDs and the herbicide diclofop-methyl (DM), (2-(4-(2,4-dichlorophenoxy)-phenoxy) propionate), was investigated. The complexation was confirmed by the shifts in the wavelengths of maximum ultra violet (UV) absorption and fluorescence excitation/emission. The deuterium isotope effects indicate that in the presence of β-CDs the solubility of DM was lower while that of diclofop was higher in D₂O than in H₂O, suggesting the primary role of hydrophobic interactions in complexation. The solubility of DM was enhanced in the presence of β-CDs, the extent of which depended on the modification of β-CDs. The complexation reduced the hydrolysis of DM and hence increased its stability. The small inconsistency in the power of β-CDs between hydrolysis retardation and solubilization suggests that hydrolysis was affected by the properties of β-CDs and the configuration of DM in the complexes. Use of β-CDs may thus result in the mobilization of soil DM. Properly modified β-CDs may be utilized as formulation additives for improved delivery of DM and for enhanced environmental remediation.     

Bayesian inference for source determination with applications to a complex urban environment

The problem of determining the source of an emission from the limited information provided by a finite and noisy set of concentration measurements obtained from real-time sensors is an ill-posed inverse problem. In general, this problem cannot be solved uniquely without additional information. A Bayesian probabilistic inferential framework, which provides a natural means for incorporating both errors (model and observational) and prior (additional) information about the source, is presented. Here, Bayesian inference is applied to find the posterior probability density function of the source parameters (location and strength) given a set of concentration measurements. It is shown how the source–receptor relationship required in the determination of the likelihood function can be efficiently calculated using the adjoint of the transport equation for the scalar concentration. The posterior distribution of the source parameters is sampled using a Markov chain Monte Carlo method. The inverse source determination method is validated against real data sets acquired in a highly disturbed flow field in an urban environment. The data sets used to validate the proposed methodology include a water-channel simulation of the near-field dispersion of contaminant plumes in a large array of building-like obstacles (Mock Urban Setting Trial) and a full-scale field experiment (Joint Urban 2003) in Oklahoma City. These two examples demonstrate the utility of the proposed approach for inverse source determination.     

Polychlorinated phenols,guaiacols and catechols in environment

Emissions, bioaccumulation and possible food chain enrichment of polychlorinated phenols, guaiacols and catechols have been studied by analyses of water, snow, ash, benthic animal, fish and bird samples in Finland. Seventeen individual compounds were analyzed using authentic reference model compounds and internal standard by GC/ECD. Although the enrichment potential of the studied compounds appeared to be lower than that of the chlorinated hydrocarbons, they proved to be very general pollutants and some of them showed specific bioaccumulation to certain species and high persistency thus forming environmental hazards.     

Chloroform in the environment: occurrence,sources, sinks and effects

The chloroform flux through the environment is apparently constant at some 660±220 Gg yr⁻¹ (±1σ) and about 90% of the emissions are natural in origin: the largest single source being in offshore sea water (contributing 360±90 Gg yr⁻¹), with soil processes the next most important (220±100 Gg yr⁻¹). Other natural sources, mainly volcanic and geological, account for less than 20 Gg yr⁻¹. The non-natural sources total 66±23 Gg yr⁻¹ and are much better characterised than the natural sources. They are predominantly the result of using strong oxidising agent on organic material in the presence of chloride ion, a direct parallel with the natural processes occurring in soils.

Chloroform partitions preferentially into the atmosphere; the equilibrium distribution is greater than 99% and the average global atmospheric concentration has been calculated to be 18.5 pmol mol⁻¹. Atmospheric oxidation, the principal removal process, is approximately in balance with the identified source fluxes. Chloroform is widely dispersed in the aquatic environment (even naturally present in some mineral waters). Consequently, it is also widely dispersed in the tissue of living creatures and in foodstuffs but there is little evidence of bioaccumulation and the quantities in foodstuffs and drinking water are not problematical for human ingestion at the highest concentrations found. Definitive studies have shown that current environmental concentrations of chloroform do not present an ecotoxicological risk, even to fish at the embryonic and larval stages when they are most susceptible.

By virtue of the very small amounts that actually become transported to the stratosphere, chloroform does not deplete ozone materially, nor is it a photochemically active volatile organic compound (VOC). It has a global warming potential that is less than that of the photochemically active VOCs and is not classed as a greenhouse gas.     

Occurrence, behavior and effects of nanoparticles in the environment

The increasing use of engineered nanoparticles (NP) in industrial and household applications will very likely lead to the release of such materials into the environment. Assessing the risks of these NP in the environment requires an understanding of their mobility, reactivity, ecotoxicity and persistency. This review presents an overview of the classes of NP relevant to the environment and summarizes their formation, emission, occurrence and fate in the environment. The engineered NP are thereby compared to natural products such as soot and organic colloids. To date only few quantitative analytical techniques for measuring NP in natural systems are available, which results in a serious lack of information about their occurrence in the environment. Results from ecotoxicological studies show that certain NP have effects on organisms under environmental conditions, though mostly at elevated concentrations. The next step towards an assessment of the risks of NP in the environment should therefore be to estimate the exposure to the different NP. It is also important to notice that most NP in technical applications are functionalized and therefore studies using pristine NP may not be relevant for assessing the behavior of the NP actually used.     

Hydroxylated polychlorinated biphenyls in the environment: sources,fate, and toxicities

Hydroxylated polychlorinated biphenyls (OH-PCBs) are produced in the environment by the oxidation of PCBs through a variety of mechanisms, including metabolic transformation in living organisms and abiotic reactions with hydroxyl radicals. As a consequence, OH-PCBs have been detected in a wide range of environmental samples, including animal tissues, water, and sediments. OH-PCBs have recently raised serious environmental concerns because they exert a variety of toxic effects at lower doses than the parent PCBs and they are disruptors of the endocrine system. Although evidence about the widespread dispersion of OH-PCBs in various compartments of the ecosystem has accumulated, little is currently known about their biodegradation and behavior in the environment. OH-PCBs are, today, increasingly considered as a new class of environmental contaminants that possess specific chemical, physical, and biological properties not shared with the parent PCBs. This article reviews recent findings regarding the sources, fate, and toxicities of OH-PCBs in the environment.     

Economic instruments, transport and the global environment

The use of economic instruments, such as charges, in abating climate change is assessed, with special reference to their application in the transport sector. The general strategies and instruments for global environmental policies are presented. The role of economic instruments in this context is highlighted, both in terms of theory and of application. Economic instruments are then analysed from the perspective of transport policies. Climate and transport appear to have different perspectives on economic instruments. The analysis leads to a framework for developing climate-related economic instruments in transport. These may result in substantial economic savings, especially if approached internationally and if distributional and institutional problems can be overcome. The integration of climate concerns into transport policies can be improved, and several suggestions are made in this respect.     

Hormesis and plant biology

A database has been developed that demonstrates experimental evidence of hormesis. It includes information from a broad range of biological models, including plants, and information on study design, dose-response features, and physical/chemical properties of the agents. An assessment of plant hormetic dose responses is presented based on greater than 3000 plant endpoints. Plant hormetic dose responses were observed for numerous endpoints including disease incidence, reproductive indices, mutagenic endpoints, various metabolic parameters, developmental processes, and a range of growth indicators. Quantitative features of these dose responses typically display a maximum stimulatory response less than two-fold greater than controls and a width of the stimulatory response usually less than 10-fold in dose range. The database establishes that hormetic dose responses commonly occur in plants, are broadly generalizable, and have quantitative features similar to hormetic dose responses found for animals.     

大学环境教育与环境建设

从中国生态环境的现状和大学传授学生知识、确立学生观念的特殊地位说明了在高校进行环境教育的必要性。环境教育是让学生了解人类生活和文明发展历程中的环境状况和问题，思考环境保护的意义和价值，进而确立环境观念。提出了建设环境友好型大学。建议在高校中建立讲座、选修、必修三位一体的环境教育教学体系。     

Biodegradability and ecotoxicitiy of tramadol, ranitidine, and their photoderivatives in the aquatic environment

Purpose  

This study was designed to assess the fate and the overall potential impacts of the widely prescribed drugs ranitidine and tramadol after their introduction into the aquatic environment.     

Nexus between environment regulation,FDI, and green technology innovation in OECD countries

Environmental Science and Pollution Research - To achieve the goal of “sustainable development,” a crucial way is promoting green technology innovation. This paper examines the nexus...     

A bibliometric study about energy,environment, and climate change

Environmental Science and Pollution Research - Using the extended science citation index database (SCI) and social science citation index (SSCI) databases, this paper analyzed the characteristics...     

Emerging pollutants: impact on environment,management, and challenges

Environmental Science and Pollution Research -     

Occurrence,sorption, and transformation of free and conjugated natural steroid estrogens in the environment

Environmental Science and Pollution Research - Natural steroid estrogens (NSEs), including free estrogens (FEs) and conjugated estrogens (CEs), are of emerging concern globally among public and...