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61.
This paper seeks to quantify the impact of a 1-m sea-level rise on coastal wetlands in 86 developing countries and territories. It is found that approximately 68 % of coastal wetlands in these countries are at risk. A large percentage of this estimated loss is found in Europe and Central Asia, East Asia, and the Pacific, as well as in the Middle East and North Africa. A small number of countries will be severely affected. China and Vietnam (in East Asia and the Pacific), Libya and Egypt (in the Middle East and North Africa), and Romania and Ukraine (in Europe and Central Asia) will bear most losses. In economic terms, the loss of coastal wetlands is likely to exceed $703 million per year in 2000 US dollars.  相似文献   
62.
Effects of sub-lethal doses of carbaryl (1-Naphthyl-methylcarbamate), chlorpyrifos (O,O-diethyl O-3,5,6-trichloro-2-pyridinyl-phosphorothioate) and endosulfan (6,7,8,9,10,10-Hexachloro-1,5,5a,6,9,9a-hexahydro-6,9-methano-2,4,3-benzodioxathiepin-3-oxide), respectively a carbamate, an organophosphate and an organochlorine insecticide on growth, reproduction and respiration of the tropical earthworm, Perionyx excavatus (Perrier) were investigated under laboratory conditions. The results showed significant reduction in biomass, production and hatching of cocoon and production of juveniles of the worms exposed to 0.75 to 3.03 mg/kg soil of carbaryl, 0.91 to 3.65 mg/kg soil of chlorpyrifos and 3.75 to 15.0 μg/kg soil of endosulfan corresponding to 12.5 to 50 % of LC50 value of the respective insecticide for P. excavatus. Endosulfan was found most dangerous among the three insecticides followed by carbaryl and chlorpyrifos. There was no hatching of the worms at endosulfan treatment 5.0 μg/kg soil (25 % LC50) or above while the highest dose of carbaryl and chlorpyrifos (50 % of LC50) rendered respectively 87.13 and 24.84 % reductions in hatching as compared to control. Chlorpyrifos produced no change in respiration of the worms except at the highest dose, while the worms showed an increase in evolution of CO2 at all doses of carbaryl and endosulfan. Based on the recommended agricultural dose of each insecticide, it was concluded that application of endosulfan and carbaryl was potentially dangerous to earthworms.  相似文献   
63.

From an environmental perspective, the media have raised the level of environmental awareness and, rightly or wrongly, focused the attention of citizens on specific environmental issues. Public reaction to environmental news can filter back into the media and highlight specific policy issues. The importance of the media in this respect has gained strength, particularly in developing countries, where environmental problems have become legitimate concerns, and where access to 'official' information has been historically difficult. In general, newspapers have been found to be one of the most predominant sources of environmental information available to the public, particularly in developing countries. In this paper, we summarise, briefly analyse and compare the newspaper coverage of environmental issues in Argentina, Chile, Mexico and the Philippines. Among numerous other results, it appears that the coverage of environmental issues fell considerably over the period 1990-94 despite an increase in world-wide environmental awareness. Most news reports actions by the environmental agencies (warnings and rewards, etc.). In the Philippines, however, most environmental news reports investments in pollution abatement activities by the private sector. While citizens' complaints represent a small percentage of the coverage of environmental issues, closer examination reveals that such complaints, in the vast majority of cases, trigger governmental actions (warnings) and ultimately an improvement of firms' environmental performance (investment).  相似文献   
64.
65.
Measurements in urban Atlanta of transient aerosol events in which PM2.5 mass concentrations rapidly rise and fall over a period of 3-6 hr are reported. The data are based on new measurement techniques demonstrated at the U.S. Environmental Protection Agency (EPA) Atlanta Supersite Experiment in August 1999. These independent instruments for aerosol chemical speciation of NO3-, SO4(2-), NH4+, and organic and elemental carbon (OC and EC), reconstructed the observed hourly dry PM2.5 mass to within 20% or better. Data from the experiment indicated that transient PM2.5 events were ubiquitous in Atlanta and were typically characterized by a sudden increase of EC (soot) and OC in the early morning or SO4(2-) in the late afternoon. The frequent temporal decoupling of these events provides insights into their origins, suggesting mobile sources in metro Atlanta as the main contributor to early morning PM2.5 and more regionally located point SO2 sources for afternoon PM2.5 events. The transient events may also have health implications. New data suggest that short-term PM2.5 exposures may lead to adverse health effects. Standard integrated filter-based techniques used in PM2.5 compliance monitoring networks and in most past PM2.5 epidemiologic studies collect samples over 24-hr periods and thus are unable to capture these transient events. Moreover, health-effects studies that focus on daily PM2.5 mass alone cannot evaluate the health implications of the unique and variable chemical properties of these episodes.  相似文献   
66.
From an environmental perspective, the media have raised the level of environmental awareness and, rightly or wrongly, focused the attention of citizens on specific environmental issues. Public reaction to environmental news can filter back into the media and highlight specific policy issues. The importance of the media in this respect has gained strength, particularly in developing countries, where environmental problems have become legitimate concerns, and where access to 'official' information has been historically difficult. In general, newspapers have been found to be one of the most predominant sources of environmental information available to the public, particularly in developing countries. In this paper, we summarise, briefly analyse and compare the newspaper coverage of environmental issues in Argentina, Chile, Mexico and the Philippines. Among numerous other results, it appears that the coverage of environmental issues fell considerably over the period 1990-94 despite an increase in world-wide environmental awareness. Most news reports actions by the environmental agencies (warnings and rewards, etc.). In the Philippines, however, most environmental news reports investments in pollution abatement activities by the private sector. While citizens' complaints represent a small percentage of the coverage of environmental issues, closer examination reveals that such complaints, in the vast majority of cases, trigger governmental actions (warnings) and ultimately an improvement of firms' environmental performance (investment).  相似文献   
67.
Research was conducted to evaluate the potential use of laccase and its susceptibility to inactivation in an alternative enzyme-based treatment technology to remove parent phenol from buffered distilled water. Enzymatic oxidative polymerization of phenol with laccase was carried out in continuously stirred batch reactors. The reaction products were insoluble polymers, which precipitated out of the solution once their solubility limits were exceeded. The findings demonstrated that the polymeric products had significant effects on enzyme activity consumption and subsequent phenol removal. Enzyme species present in the reaction vessel were classified into enzyme remaining in the solution (type 1) and enzyme adhering to the precipitate polymers (type 2). Type 1 enzyme was more efficient in removal of phenol from solution compared with type 2. Subsequent filtration enhanced the phenol removal by removing type 2 enzyme adhering to the polymer particles and decelerating enzyme inactivation. The study also investigated the effects of available dissolved oxygen, provided through aeration and hydrogen peroxide addition, on phenol removal. Aeration and hydrogen peroxide addition increased the dissolved oxygen concentration, but had no effect on the progress curve for phenol removal.  相似文献   
68.
69.
Chlorimuron-ethyl, a post-emergent herbicide selectively used in soybean and maize, degrades mainly through chemical hydrolysis. Photolysis has also an important role in the degradation of this compound. Phototransformation of chlorimuron-ethyl takes place through the cleavage of the sulfonylurea bridge, dechlorination, de-esterification and cyclization. Enzymatic de-esterification usually takes place in plant system to liberate the free acid, chlorimuron, which, in fact, inhibits the acetolactate synthase enzyme. In the non-enzymatic environment, de-esterification generally does not occur at normal pH and in moisture-free medium. But on the leaf surface of maize crop de-esterification of chlorimuron-ethyl takes place. The moisture deposited on leaf surfaces by virtue of evapo-transpirational loss of water may cause the de-esterification of chlorimuron-ethyl to the free acid, chlorimuron.  相似文献   
70.
Journal of Material Cycles and Waste Management - Despite electronic waste (e-waste) rules in force, there is still a huge gap in awareness among communities about the handling of discarded...  相似文献   
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