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331.
In recent years, policy mechanisms to support a formalized artisanal and small‐scale mining (ASM) sector in sub‐Saharan Africa have gained increasing currency. Proponents of formalization argue that most social and environmental problems associated with the sector stem from the fact that ASM is predominantly unregulated and operates outside the legal sphere. This paper critically examines recent efforts to formalize artisanal and small‐scale mining in West Africa, drawing upon recent fieldwork carried out in Sierra Leone, Ghana and Mali. In exploring the sector's livelihood dimensions, the analysis suggests that bringing unregulated, informal mining activities into the legal domain remains a considerable challenge. The paper concludes by confirming the urgent need to refocus formalization strategies on the main livelihood challenges and constraints of small‐scale miners themselves, if poverty is to be alleviated and more benefits are to accrue to depressed communities in mineral‐rich regions. 相似文献
332.
Ashis Bhattacharjee Haradhan Mandal Madhusudan Roy Tapas Kumar Chini 《Environmental monitoring and assessment》2011,176(1-4):473-481
Powder X-ray diffraction (XRD), scanning electron microscopy (SEM), and tunneling electron microscopy (TEM) studies of two solid vehicle wastes (pollutants) from petrol- and diesel-fueled engines of Kolkata (India) have detected a significant amount of ultrafine particles in the nanometer scale in these wastes. Both powder XRD and selected area electron diffraction from TEM have confirmed the existence of inhomogeneous distribution of nanocrystallites in these pollutants. Energy dispersive X-ray spectrometry shows that these wastes contain mainly carbon and oxygen as the constituent components. These pollutants are magnetic in nature as seen with SQUID magnetometry, and the presence of a high amount of carbon presumably is likely the origin of the magnetic property. 相似文献
333.
A new approach to investigate the interactions between sediment transport and ecotoxicological processes during flood events 总被引:1,自引:0,他引:1
Holger Schüttrumpf Markus Brinkmann Catrina Cofalla Roy M Frings Sabine U Gerbersdorf Markus Hecker Sebastian Hudjetz Ulrike Kammann Gottfried Lennartz Sebastian Roger Andreas Schäffer Henner Hollert 《Environmental Sciences Europe》2011,23(1):1-5
Purpose
The 'step-by step' principle was introduced into the European Union legislation on genetically modified organisms as a means to cope with uncertainty about environmental risks from the release of genetically modified organisms into the environment. The approval process is orientated along the stepwise reduction of containment which reflects a precautionary approach towards the risks of genetically modified organism release. Thus, the gradual reduction of containment should keep pace with the gradual generation of risk-related knowledge. This paper strives to clarify the meaning, legal status and practical importance of the principle. It also looks at whether non-European Union countries have adopted the principle as well, and how they practice it.Methods
The article is based on research of the relevant legal texts, court cases and legal literature. In addition, a number of dossiers of applications for the European Union authorisation of release and placing on the market of genetically modified seed were analysed.Results and conclusions
Although 'step-by-step' is not a precise legal rule it does have legal meaning as a principle guiding the risk assessment and management of genetically modified organism introduction into the environment. Assuming a process of gradual reduction of containment and scaling up of release ranging from closed systems via experimental release to cultivation the 'step-by-step principle' requires that the knowledge on environmental risks of genetically modified organisms should be generated on stages previous to the ones where the risk can result in damage. The analysis of the legislation of China, the United States of America and Brazil showed a differentiated approach towards the step-by-step principle. 相似文献334.
Benjamin Honigman Roy Cromer Thomas L. Kurt 《Journal of the Air & Waste Management Association (1995)》2013,63(1):77-79
ABSTRACT Gas phase concentrations of individual polycyclic aromatic hydrocarbons (PAHs) were measured in real time in combustion products from a co-flow diffusion flame using laser photoionization (LP) time-of-flight mass spectrometry (TOF/MS). In particular, a naphthalene detection sensitivity of 4 parts per billion (ppb) was demonstrated. The use of calibration mixtures with argon indicated the feasibility of naphthalene detection at about 45 parts per trillion (ppt) at a signal-to-noise (S/N) ratio of 20. This suggests the possibility of low-ppt level detection at a S/N of 1. The novelty of the system is the use of a heated sampling probe and a continuously purged, heated-pulse valve that was positioned close to the ionization zone, thereby allowing the generation of photoions in the high-density region of the sample jet, where concentrations of PAH are high. Because the system developed allows for the real time detection of select species, it represents a useful tool in continuous emissions monitoring (CEM) for environmental compliance as well as direct process control. 相似文献
335.
Trygve Hesthagen Bjørn Walseng Leif Roger Karlsen Roy M. Langåker 《Water, Air, & Soil Pollution: Focus》2007,7(1-3):339-345
We studied the effects of liming on fish and crustaceans in a watershed which is in a region known to have one of the highest
diversity of aquatic biota in Norway. This watershed, Enningdal, is shared between Norway (1/3) and Sweden (2/3) and includes
61 lakes > 1.0 ha in Norway. Liming started on a large scale in the 1980s. Currently, a total of 26 of lakes (43%) are limed,
covering 93% of the total lake area. The mean value ± S.D. of pH and the concentration of inorganic labile Al in these lakes
is 6.62 ± 0.35 and 3 ± 4 μg l−1, respectively. Historical data of fish communities have been obtained from surveys, while test-fishing and sampling of crustaceans
were conducted in 24 lakes in recent years (2002–2004). The present study shows that crustaceans to a greater extent than
fish has responded to improved water quality after more than 20 years of liming. Of a total of 120 fish populations, 42 (35%)
have gone extinct. Only five of the lost fish populations (12%) have been re-established, all due to human re-introductions.
Physical barriers are considered to be the main factor preventing fish from invading limed lakes. In contrast, crustaceans
have been re-established in most limed lakes. This may be mainly due to their good spreading capacity. However, they might
also have survived in refuges within the watershed, or as resting-eggs in the sediment. 相似文献
336.
Kosuke Toshiki Pham Quy Giang Kevin Roy B. Serron Takahiro Sekikaw Jeoung-soo Yu Baasandash Choijil Shoichi Kunikane 《环境科学学报(英文版)》2015
Currently, most developing countries have not set up municipal solid waste management systemswith a viewof recovering energy fromwaste or reducing greenhouse gasemissions. In this article, we have studied the possible effects of introducing three energy recovery processes either as a single or combination approach, refuse derived fuel production, incineration and waste power generation, and methane gas recovery from landfill and power generation in Ulaanbaatar, Mongolia, as a case study. We concluded that incineration process is the most suitable as first introduction of energy recovery. To operate it efficiently, 3Rs strategies need to be promoted. And then, RDF production which is made of waste papers and plastics in high level of sortingmay be considered as the second step of energy recovery. However, safety control and marketability of RDF will be required at that moment. 相似文献
337.
Dr Anjan Kumer Dev Roy Jeff Gow 《Journal of Environmental Planning and Management》2015,58(2):213-228
This paper examines the challenges of achieving sustainable management of the world's largest mangrove forest, the Sundarbans (SMF) in Bangladesh. During the past two decades, conflicts between mangrove maintenance and the pressure to provide economic livelihoods to forest-dependent communities (FDCs) have emerged and persisted. The SMF is currently managed by the Bangladesh Forest Department (BFD) under a state property rights regime. This study explores an alternative property rights regime which includes participatory approaches and co-management with FDCs to achieve sustainability, both economically and environmentally. Focus group discussions and a survey were the methods used to assess the prospects. The study finds that the absence of a management partnership between the BFD and FDCs is mainly responsible for the policy failures to achieve sustainable management of the SMF. However, evidence is presented that a ‘co-management’ property rights regime cannot be established until FDC capacity is enhanced through the formation of community level institutions. 相似文献
338.
Atalanta Narayan Chowdhury S.K. Manna A.P. Sharma C. Bandopadhyay K. Pramanik 《毒物与环境化学》2015,97(5):538-551
The study aimed to examine the contamination status of arsenic (As) in excavated small water bodies, commonly known as ponds – the integral part of daily life in the arsenic-affected rural areas of West Bengal, India in comparison to the unaffected areas. The ponds of the contaminated area had higher levels of As: water 2–174 µg L?1 (mean 31 ± 2 µg L?1) and sediment 1.3–37.3 mg kg?1 (mean 10.3 ± 0.4 mg kg?1), than those from the unaffected area: water 1–8 µg L?1 (mean 4 ± 0 µg L?1) and sediment 1.4–5.3 mg kg?1 (mean 3.0 ± 0.1 mg kg?1). A moderate positive correlation was observed between the water and sediment arsenic content of the ponds of the arsenic-affected region (r = 0.688, n = 277, p < 0.0001). Contaminated ground water, either as direct input or through agricultural washings, was found to be the major contributor of arsenic pollution to these ecosystems. Seasonal variations were not prominent. This study emphasized the beneficial role of using the studied ecosystems over the highly contaminated ground water for various livelihood activities in the Gangetic delta region. 相似文献
339.
Khan Pathan Mohsin Lombardo Anna Benfenati Emilio Roy Kunal 《Environmental science and pollution research international》2021,28(2):1627-1642
Environmental Science and Pollution Research - Hydrolysis is one of the most important processes of transformation of organic chemicals in water. The rates of reactions, final chemical entities of... 相似文献
340.
W R Roy I G Krapac S F Chou F W Simmons 《Journal of environmental science and health. Part. B》2001,36(3):245-260
The chemical fate and movement of pesticides may be subject to transient storage in unsaturated soils during periods of light rainfall, and subsequent release into shallow groundwater by increased rainfall. The objective of this study was to conduct field-scale experiments to determine the relative importance of transient storage and subsequent release of agrichemicals from the vadose zone into potential aquifers. Two field-scale experiments were conducted under a rain exclusion shelter. In the 1x experiment, atrazine and chlorpyrifos were applied at application-rate equivalents (1.6 kg ha(-1) and 1.3 kg ha(-1), respectively). In the 4x experiment, atrazine was applied in an amount that was four times greater than that usually applied to fields (6.7 kg ha(-1)). Water was either applied to simulate rain or withheld to simulate dry periods. In the 1x experiment, atrazine was detected in the water samples whereas chlorpyrifos was not detected in the majority of the samples. The dry period imposed on the treatment plot did not appear to result in storage of the chemicals, whereas the wet period resulted in greater leaching of atrazine, although the concentrations remained less than the Maximum Contaminant Level of 3 microg L(-1). Both chemicals were detected in soil samples collected from a 20- to 30-cm depth, but it appeared that both chemicals dissipated before the field experiment was concluded. It appeared that the one-time application of atrazine and chlorpyrifos at the label rates did not result in a sufficient mass to be stored and flushed in significant concentrations to the saturated zone. When atrazine was applied at 4x and a longer drought period was imposed on the treatment plot, the resulting concentrations of dissolved atrazine were still less than 3 microg L(-1) . Atrazine was detected in only the near-surface (0 to 15 cm) soil samples and the herbicide dissipated before the onset of the dry period in the treatment plot. The results of this field study demonstrated that atrazine and chlorpyrifos were not sufficiently persistent to be stored and then released in significantly large concentrations to the saturated zone. The dissipation half-life of atrazine in the 4x application was about 44 days. This study, in addition to others, suggested that atrazine may be less persistent in surface soil than has been generally reported. 相似文献