Taboos and forest governance: informal protection of hot spot dry forest in southern Madagascar

In the dry forest of southern Madagascar, a region of global conservation priority, formally protected areas are nearly totally absent. We illustrate how the continued existence of unique forest habitats in the Androy region is directly dependent on informal institutions, taboos, regulating human behavior. Qualitative interviews to map and analyze the social mechanisms underlying forest protection have been combined with vegetation analyses of species diversity and composition. Of 188 forest patches, 93% were classified as protected, and in Southern Androy all remaining forest patches larger than 5 ha were protected. Eight different types of forests, with a gradient of social fencing from open access to almost complete entry prohibitions, were identified. Transgressions were well enforced with strong sanctions of significant economic as well as religious importance. Analyses of species diversity between protected and unprotected forests were complicated because of size differences and access restrictions. However, since, for example, in southern Androy >90% of the total remaining forest cover is protected through taboos, these informal institutions represent an important, and presently the only, mechanism for conservation of the highly endemic forest species. We conclude that social aspects, such as local beliefs and legitimate sanctioning systems, need to be analyzed and incorporated along with biodiversity studies for successful conservation.     

Structure of Mn-Zr mixed oxides catalysts and their catalytic performance in the gas-phase oxidation of chlorocarbons

The catalytic activity and selectivity of manganese zirconia mixed oxides were evaluated for the oxidation of two common chlorinated pollutants found in waste streams, namely 1,2-dichloroethane (DCE) and trichloroethylene (TCE). Mixed oxides with varying Mn-Zr content were prepared by coprecipitation via nitrates, and subsequent calcination at 600 degrees C for 4 h in air. These catalysts were characterised by means of several techniques such as atomic emission spectrometry, N2 adsorption-desorption, powder X-ray diffraction, temperature-programmed desorption of ammonia, pyridine adsorption followed by diffuse reflectance infrared spectroscopy and temperature-programmed reduction with hydrogen. The active catalytic behaviour of Mn-Zr mixed oxides was ascribed to a substantial surface acidity combined with readily accessible active oxygen species. Hence, the mixed oxide with 40 mol% manganese content was found to be an optimum catalyst for the combustion of both chlorocarbons with a T50 value around 305 and 315 degrees C for DCE and TCE oxidation, respectively. The major oxidation products were carbon dioxide, hydrogen chloride and chlorine. It was observed that the formation of both CO2 and Cl2 was promoted with Mn loading.     

Acid-base properties of humic substances from composted and thermally-dried sewage sludges and amended soils as determined by potentiometric titration and the NICA-Donnan model

The acid-base properties of humic acids (HAs) and fulvic acids (FAs) isolated from composted sewage sludge (CS), thermally-dried sewage sludge (TS), soils amended with either CS or TS at a rate of 80 t ha(-1)y(-1) for 3y and the corresponding unamended soil were investigated by use of potentiometric titrations. The non-ideal competitive adsorption (NICA)-Donnan model for a bimodal distribution of proton binding sites was fitted to titration data by use of a least-squares minimization method. The main fitting parameters of the NICA-Donnan model obtained for each HA and FA sample included site densities, median affinity constants and widths of affinity distributions for proton binding to low and high affinity sites, which were assumed to be, respectively, carboxylic- and phenolic-type groups. With respect to unamended soil HA and FA, the HAs and FAs from CS, and especially TS, were characterized by smaller acidic functional group contents, larger proton binding affinities of both carboxylic- and phenolic-type groups, and smaller heterogeneity of carboxylic and phenolic-type groups. Amendment with CS or TS led to a decrease of acidic functional group contents and a slight increase of proton binding affinities of carboxylic- and phenolic-type groups of soil HAs and FAs. These effects were more evident in the HA and FA fractions from CS-amended soil than in those from TS-amended soil.     

Heavy metal-rich wastes sequester in mineral phases through a glass-ceramic process

Certain sludges generated by industry are rich in contaminating elements and are a major environmental problem. In this study, we determine the ability of these contaminating elements to be incorporated into a glass-matrix and in various mineral phases after a crystallization process. The contaminating elements studied were obtained from sewage sludges (SS) and galvanic sludges (GS), our raw materials. The sludge samples were taken from urban wastewater treatment plant in Catalonia (NE Spain) with high levels of phosphorus oxide (P(2)O(5)). In silica glasses, P(2)O(5) acts as a network former. We determined the chemical composition of both the SS and GS, as well as their thermal behaviour by differential thermal analysis and thermal gravimetric analysis (DTA-TG) to obtain their melting curves. The vitreous transition temperature of the obtained glass was established by dilatometer technique at 725 degrees C. The DTA-TG curve of the glass obtained has an exothermal wide peak at 860 degrees C corresponding to crystallization of the two phases: a spinel phase and a phosphate phase. A second exothermal wide peak at 960 degrees C was attributed to the crystallization of aluminium pyroxene, anorthite and fluor-apatite, with two exothermal phenomena attributed to the evolution of these phases. An exothermal peak at 1100 degrees C was attributed to gehlenite crystallization. Scanning electron microscope observations and energy-dispersed X-ray spectroscopy microanalyses of glass-ceramic showed that the contaminating elements were concentrated in the spinel phases, which are the first phases to crystallize during the cooling of glass. Finally, the spinel structure permits the incorporation of all the contaminating elements into it.     

Polychlorinated biphenyls and DDT in swordfish (Xiphias gladius) and blue shark (Prionace glauca) from Brazilian coast

The polychlorinated biphenyls (PCBs) and DDT may bioaccumulate in the aquatic food web and have been of great concern due to their toxic effects on wildlife and human health. There is evidence showing that fish in the human diet contributes at a significant proportion to the total intake of PCBs and other organochlorine compounds, particularly fish with higher fat levels. This study investigated the concentration of PCBs and DDTs in muscle tissues of samples of the blue shark (Prionace glauca) and a swordfish (Xiphias gladius) from east Brazilian coast and estimate the human exposure to total DDTs through the consumption of both the species. Samples of the each species were caught between August and September 2001. The mean concentration for summation operator PCBs in P. glauca was 3.15 ng/g w.w. and the summation operator DDTs was 0.93 ng/g w.w. The mean concentration of summation operator PCBs in X. gladius was 6.50 ng/g and the mean of summation operator DDTs was 2.47 ng/g. The estimated daily intake of summation operator DDT through X. gladius or P. glauca consumption can be considered safe since it contributes to less than 0.1% of the limit of acceptable daily intake (ADI) of summation operator DDT proposed by WHO.     

Age and seasonal variability of polybrominated diphenyl ethers in free-ranging East Greenland polar bears (Ursus maritimus)

Polybrominated diphenyl ethers (PBDEs) were analysed in adipose tissue from 92 East Greenland polar bears (Ursus maritimus) sampled during 1999-2001. Mean SigmaPBDE concentrations were 70 ng/g lipid weight (lw) (range: 22-192 ng/g lw) and showed no relationship with age or sex. Of the 32 analysed PBDE congeners; BDE47, BDE153, BDE99 and BDE100 dominated, and comprised 99.6% of the SigmaPBDE concentration. The SigmaPBDE concentration had a highly significant correlation with SigmaPCB, SigmaCHL, dieldrin, HCB and SigmaHCH concentrations. We found a seasonal pattern of median SigmaPBDE concentration with 1.2 to 1.8 times higher concentrations in March to July than the rest of the year. The seasonal variation also provides a clue to the seasonal exposure, bio-availability, toxic exposure and degradation. We suggest that future geographical PBDE data comparisons may not need corrections for sex or age, but such data sets should be corrected for seasonal variability, using the presented correctional trigonometric regression.     

Review of the effects of in-stream pipeline crossing construction on aquatic ecosystems and examination of Canadian methodologies for impact assessment

Pipeline crossing construction alters river and stream channels, hence may have detrimental effects on aquatic ecosystems. This review examines the effects of crossing construction on fish and fish habitat in rivers and streams, and recommends an approach to monitoring and assessment of impacts associated with these activities. Pipeline crossing construction is shown to not only compromise the integrity of the physical and chemical nature of fish habitat, but also to affect biological habitat (e.g., benthic invertebrates and invertebrate drift), and fish behavior and physiology. Indicators of effect include: water quality (total suspended solids TSS), physical habitat (substrate particle size, channel morphology), benthic invertebrate community structure and drift (abundance, species composition, diversity, standing crop), and fish behavior and physiology (hierarchy, feeding, respiration rate, loss of equilibrium, blood hematocrit and leukocrit levels, heart rate and stroke volume). The Before-After-Control-Impact (BACI) approach, which is often applied in Environmental Effects Monitoring (EEM), is recommended as a basis for impact assessment, as is consideration of site-specific sensitivities, assessment of significance, and cumulative effects.     

Classification of alluvial soils according to their potential environmental risk: a case study for Belgian catchments

Alluvial soils may represent important sinks of contaminants as a result of the deposition of contaminated sediments along the river by overbank flooding or after dredging. Because of the erosion of alluvial deposits or the release of contaminants from sediments, alluvial soils can also be a source of contamination. In this paper, a risk assessment for contaminated (alluvial) soils is presented. The approach, mainly based on physico-chemical soil characteristics, single extractions and leaching tests, is illustrated by means of a case study from four Belgian catchments. The extractions and leaching tests that were used have been validated by European testing programs and can provide valuable information for classifying the potential environmental risks of soils. Irrespective of the location, pH, organic carbon content and 'mobilisable' metal concentrations were the most important factors explaining 'mobile' metal concentrations in the alluvial soils. Additionally, the data of the physico-chemical soil characterization, extractions and leaching tests were combined with local and regional factors to classify the alluvial soils in different categories according to their actual and potential risk for the environment.     

Comparison of different collection systems for sorted household waste in Sweden

Composition and quantity per person of municipal solid waste (MSW) have been analyzed in six municipalities in southern Sweden with similar socio-economic conditions but with different collection systems. Samples of residual waste have been sorted, classified and weighed in 21 categories during 26 analyses that took place from 1998-2004. Collection data of the total waste flow, including source sorted recycling materials, in the same area have been compiled and compared. Multivariate data analyses have been applied. Weight-based billing reduced delivered amounts of residual household waste by 50%, but it is unknown to what extent improper material paths had developed. With curbside collection more metal, plastic and paper packaging was separated and left to recycling. When separate collection of biodegradables was included in the curbside system, the overall sorting of dry recyclables increased. The large uncertainty associated with waste composition analyses makes it difficult to draw strong conclusions regarding the effects on specific recyclables or the changes in the composition of the residual waste.     

Management of MSW in Spain and recovery of packaging steel scrap

Packaging steel is more advantageously recovered and recycled than other packaging material due to its magnetic properties. The steel used for packaging is of high quality, and post-consumer waste therefore produces high-grade ferrous scrap. Recycling is thus an important issue for reducing raw material consumption, including iron ore, coal and energy. Household refuse management consists of collection/disposal, transport, and processing and treatment - incineration and composting being the most widely used methods in Spain. Total Spanish MSW production exceeds 21 million tons per year, of which 28.1% and 6.2% are treated in compost and incineration plants, respectively. This paper presents a comprehensive study of incineration and compost plants in Spain, including a review of the different processes and technologies employed and the characteristics and quality of the recovered ferrous scrap. Of the total amount of packaging steel scrap recovered from MSW, 38% comes from compost plants and 14% from incineration plants. Ferrous scrap from incineration plants presents a high degree of chemical alteration as a consequence of the thermal process to which the MSW is subjected, particularly the conditions in which the slag is cooled, and accordingly its quality diminishes. Fragmentation and magnetic separation processes produce an enhancement of the scrap quality. Ferrous scrap from compost plants has a high tin content, which negatively affects its recycling. Cleaning and detinning processes are required prior to recycling.