环境税收对墨西哥杀虫剂的影响

一种最理想的杀虫剂税将按照毒性程度对市场销售的物质加以区分.在墨西哥采取这一税收是准备将来扩展按照国际协议逐步淘汰并最终消除的杀虫剂名单的最有效的方法.本文分析了三种不同的环境征税方案的内涵;对所有的杀虫剂普遍征税15%(弥补目前免征增值税的状况);根据毒性分别征税15%、10%、5%或者0%;对现在经审定的毒性最大的物质征税10%.税收必须用于恢复人类和生态系统健康以及赔付其他类型的损害.     

环境、多文化和人权:采矿工业及政府面临的挑战

下一个１０年采矿与可持续发展面临的挑战将是大量的，同时也是种类各异的．如果说，在１９８０年代和１９９０年代中，环境规则影响了法人行为，那么新千年的来临见证了社会规则的出现．从这种观点来看，将出现如下挑战． 为矿物发展提供并帮助获得相关和充足的改进共享决策及交流理解的信息． 开发对所有利益攸关者都有意义的透明、有效、可靠的环境及社会评价和监测系统． 为了在采矿所在地及区域实现持续及公平发展，在公司、社区及政府间建立持久的合作关系． 设计并采用不同文化间的机制解决本土自然资源的纷争． 建立并实施矿场关闭…     

Incorporation of gypsum waste in ceramic block production: Proposal for a minimal battery of tests to evaluate technical and environmental viability of this recycling process

Civil engineering-related construction and demolition debris is an important source of waste disposed of in municipal solid waste landfills. After clay materials, gypsum waste is the second largest contributor to the residential construction waste stream. As demand for sustainable building practices grows, interest in recovering gypsum waste from construction and demolition debris is increasing, but there is a lack of standardized tests to evaluate the technical and environmental viability of this solid waste recycling process. By recycling gypsum waste, natural deposits of gypsum might be conserved and high amounts of the waste by-product could be reused in the civil construction industry. In this context, this paper investigates a physical property (i.e., resistance to axial compression), the chemical composition and the ecotoxicological potential of ceramic blocks constructed with different proportions of clay, cement and gypsum waste, and assesses the feasibility of using a minimal battery of tests to evaluate the viability of this recycling process. Consideration of the results for the resistance to axial compression tests together with production costs revealed that the best formulation was 35% of plastic clay, 35% of non-plastic clay, 10% of Portland cement and 20% of gypsum waste, which showed a mean resistance of 4.64 MPa. Energy dispersive X-ray spectrometry showed calcium and sulfur to be the main elements, while quartz, gypsum, ettringite and nacrite were the main crystalline compounds found in this formulation. Ecotoxicity tests showed that leachate from this formulation is weakly toxic toward daphnids and bacteria (EC_20% = 69.0 and 75.0, respectively), while for algae and fish the leachate samples were not toxic at the EC_50% level. Overall, these results show that the addition of 20% of gypsum waste to the ceramic blocks could provide a viable substitute for clay in the ceramics industry and the tests applied in this study proved to be a useful tool for the technical and environmental evaluation of this recycling process, bacterial and daphnid tests being more sensitive than algae and fish tests.     

Determination of PM2.5 sources using time-resolved integrated source and receptor models

Multivariate statistical techniques are applied to particulate matter (PM) and meteorological data to identify the sources responsible for evening PM spikes at Sunland Park, NM (USA). The statistical techniques applied are principal components analysis (PCA), redundancy analysis (RDA), and absolute principal components scores analysis (APCSA), and the data evaluated are 3-h average (6–9 p.m.) PM_2.5 mass and chemical composition and 1-h average PM_2.5 and PM₁₀ mass and environmental data collected in the winter of 2002. Although the interpretation of the data was complicated by the presence of sources which are likely changing in time (e.g. brick kilns), the multivariate analyses indicate that the evening high PM_2.5 is associated with burning-activities occurring to the south of Sunland Park, and these emissions are characterized by elevated Sb, Cl⁻, and elemental carbon; 68% of the PM_2.5 mass can be attributed to this source. The PM₁₀ evening peaks, on the other hand, are mainly caused by resuspended dust generated by vehicular movements south of the site and transported by the local terrain-induced drainage flow.     

Influence of substrate on bioaccumulation of 14C-paraquat in compost worms Eisenia foetida

Contamination of soil with pesticides can be evaluated using toxicity tests with worms because their ecological niche makes them good bioindicators. Bioaccumulation in compost worms of [methyl-14C] paraquat (1,1'-dimethyl-4,4'-bipyridinium dichloride) was measured after three-month exposure in two substrates with differing physicochemical characteristics, in particular their organic matter and clay contents. The treatments were 1.2, 12, and 120 microg paraquat g(-1) substrate. The action of the worms did not influence the loss of 14C from the substrates, as the 14C-recovered was essentially quantitative at the end of the study in both the presence and absence of the worms. The organic matter and clay contents of the substrates determined the extent of the paraquat uptake by the worms; worms from the substrate with smaller amounts of clay and organic matter had the higher values of the bioconcentration factor (BCF), these being about 5 (fresh-weight basis) and independent of the application rate. The BCF values in the substrate containing more organic matter and clay were smaller but increased from 1.1 to 3.8 with the increasing rates of application. However, in both substrates the amounts of paraquat bioaccumulated in the worms was always less than 1% of that applied, indicating the very strong binding of paraquat to the substrates and hence low availability to the worms.     

Radiocarbon dating of archaeological samples (sambaqui) using CO(2) absorption and liquid scintillation spectrometry of low background radiation

Sambaqui means, in the Tupi language, a hill of shells. The sambaquis are archaeological sites with remains of pre-historical Brazilian occupation. Since the sambaqui sites in the Rio de Janeiro state region are older than 10,000 years, the applicability of CO(2) absorption on Carbo-sorb and (14)C determination by counting on a low background liquid scintillation counter was tested. In the present work, sambaqui shells were treated with H(3)PO(4) in a closed vessel in order to generate CO(2). The produced CO(2) was absorbed on Carbo-sorb. On saturation about 0.6g of carbon, as CO(2), was mixed with commercial liquid scintillation cocktail (Permafluor), and the (14)C activity determined by counting on a low background counter, Packard Tricarb 3170 TR/SL, for a period of 1000 mins to enable detection of a radiocarbon age of 22,400 BP. But only samples with ages up to 3500 BP were submitted to the method because the samples had been collected in the municipality of Guapimirim, in archaeological sambaqui-type sites belonging to this age range. The same samples were sent to the (14)C Laboratory of the Centro de Energia Nuclear na Agricultura (CENA/USP) where similar results were obtained.     

The evolution of the pH in Europe (1986-1997) using panel data

The temporal evolution of pH values in precipitation over Europe during the period 1986-1997 is examined using panel data. The use of panel data techniques allows us to determine the temporal evolution of groups of stations rather than analyzing the temporal behavior of each of them. The analysis reveals three different temporal patterns: Peripheral, Central and French. We find a significant increasing trend (P < 0.00001) in both Peripheral and Central patterns. The annual increases are +0.057 pH-units yr(-1) and +0.022 pH-units yr(-1) respectively. However the French pattern is characterized by a significant decreasing trend (P < 0.004) and the annual decrease is -0.022 pH-units yr(-1). The standard errors of panel data estimates are around 47% smaller than those of classical pooling and 32% smaller than aggregate time-series regression. The use of panel data produces higher R2 values than classical pooling and aggregate data. This technique takes into account the individual heterogeneity, allows a larger number of data points and improves the efficiency of the estimates. In general, the policies of governments to reduce pollutant emissions seem to be effective.     

Satellite change detection analysis of deforestation rates and patterns along the Colombia-Ecuador border

This study uses Landsat satellite data to document the rates and patterns of land-cover change along a portion of the Colombia-Ecuador border during a 23-yr period (1973-1996). Human colonization has resulted in extensive deforestation in both countries. Satellite change detection analysis showed that the annual rates of deforestation were considerably higher for the Colombian side of the border. In addition, loss of forest cover on the Colombian side for the study period was almost 43%, while only 22% on the Ecuadorian side. The study found that there is no single factor driving deforestation on either side of the border, but concluded that the higher rates on the Colombian side may be due to higher colonization pressures and intensification of illegal coca cultivation. On the Ecuador side of the border the satellite images documented patterns of deforestation that reflected road networks associated with oil exploration and development.     

Assessing pollution levels in sediments of a harbour with two opposing entrances: environmental implications

The harbour of Ceuta, North Africa, differs substantially from conventional harbours with only one entrance since it has two opposing entrances and a channel which increases water renewal and local currents, with implications for sedimentary processes, levels of pollution and oxygen concentration. The distribution of heavy metals, nutrients and total hydrocarbons was investigated in sediment samples from this particular harbour. The grain size effect, a normalization technique using Fe concentrations and different sediment quality guidelines are discussed, and the data from the harbour of Ceuta are compared with other harbours worldwide. In spite of the water renewal, sediments inside the harbour of Ceuta were characterised by moderate levels of pollution, mainly hydrocarbons (496--6972 microg/g), P (282--1350 microg/g), N (100--2600 microg/g) and heavy metals Cu (5--865 microg/g), Pb (10--516 microg/g), Zn (296--695 microg/g), Cr (13--381 microg/g) and Ni (8--671 microg/g). Taking into account that there is no industrial activity around the harbour of Ceuta, the major sources of contamination are the sewage effluents of urban influence, anti-fouling paints and accidental oil spills during loading and dumping involved in shipping operations. The design of Ceuta harbour should be taken into consideration in the design, construction and management of future harbours.     

Effects of azadirachtin on Beet soilborne pomovirus and soil biological properties on sugar beet

Beet soilborne pomovirus (BSBV) is an important soilborne virus disease in growing areas of sugar beet. BSBV was transmitted by Polymyxa betae Keskin. Effects of azadirachtin on BSBV and soil biological properties were studied under a greenhouse. The presence of BSBV was tested in soil samples using bait plant test and triple antibody sandwich-enzyme-linked immunosorbent assay (TAS-ELISA). The concentration of BSBV in sugar beet roots was significantly reduced by the application of azadirachtin to the soils. TAS-ELISA absorption values in 1.52, 3.04, and 7.60 ppm were lower than that 0.38 and 0.76 ppm of azadirachtin. Furthermore, in this study, it was determined the 0.38, 0.76, and 1.52 ppm doses of azadirachtin in soils had high amounts of soil biological properties (Cmic, BSR, DHA), while the 3.04 and 7.60 ppm doses had no statistical significance compared to the control treatments.