Micromorphology and chemistry of airborne particles in Brussels during agriculture working periods in surrounding region

The main objective of our research was to compare the airborne particle micromorphology and chemistry in the Brussels environment during agriculture working periods in the surrounding farming region. We used specific methods and instrumentation that are adapted to the climate peculiarities of the Brussels region, the period of investigations (12 months) and the proposed objectives. For the agricultural works we defined the following six periods: before sowing, sowing, after sowing, before harvest, harvest and after harvest. The results indicate a possible temporal correlation between agricultural work periods and airborne particle concentration, micromorphology and chemistry in the Brabant-Brussels region. For wheat and corn plant-growth periods, the average particle size, defined as the area obtained by a planar projection of the particulate, showed important variations in time. For sugar beet and endive, the average area size variations are less important. The roughness and sphericity parameters for the growth periods of the four different plants also showed significant differences. Many of the larger particulates (> 10 microm) are aggregates of even finer particles coated with many still finer ones. The airborne particle chemistry averages (atomic percentage At%), showed that three constituents (Si, S and Fe) dominate all the samples (except for particles 3-10 microm in size, which contain a relatively large percentage of Al). Applying similar investigation methods to study the correlations between airborne particle dynamics in urban zones and the agriculture working periods in their surrounding regions could be of interest to better understand the complexity of the PM problematic.     

Finding threatened forest areas in the central volcanic mountain range conservation area in Costa Rica

The degree at which tropical forests are exposed to human pressure is spatially dependent. Population density, proximity to roads, terrain slope, logging activities and land distribution projects are well known factors inducing deforestation and forest degradation in Latin America. Using expert knowledge to weight these threat factors and a Geographical Information System for spatial modeling, a multi-criteria analysis procedure is presented, that allows stratifying a study region in categories of deforestation threat. The procedure was implemented in the Central Volcanic Mountain Range Conservation Area (CVMRCA) in Costa Rica with the purpose of finding areas with a combination of physical and socioeconomic characteristics that is particularly predisposing to a high probability of deforestation. To validate the map, the CVMRCA was stratified in categories of deforestation risk, and the result was superposed to historical deforestation data of the period 1986–1996. The good correlation between risk category and historical deforestation (r = 0.91, p < 0.001) indicates that the map can be used as a decision support tool for defining priority areas for conservation action.     

Investigative monitoring within the European Water Framework Directive: a coastal blast furnace slag disposal, as an example

The European Water Framework Directive (WFD) establishes a framework for the protection of estuarine and coastal waters, with the most important objective being to achieve 'good ecological status' for all waters, by 2015. Hence, Member States are establishing programmes for the monitoring of water quality status, through the assessment of ecological and chemical elements. These monitoring programmes can be of three types: surveillance monitoring; operational monitoring (both undertaken on a routine basis); and investigative monitoring (carried out where the reason of any exceedance for ecological and chemical status is unknown). Until now, nothing has been developed in relation to investigative monitoring and no clear guidance exists for this type of monitoring, as it must be tackled on a 'case-by-case' basis. Consequently, the present study uses slag disposal from a blast furnace, into a coastal area, as a case-study in the implementation of investigative monitoring, according to the WFD.In order to investigate the potential threat of such slags, this contribution includes: a geophysical study, to determine the extent of the disposal area; sediment analysis; a chemical metal analysis; and an ecotoxicological study (including a Microtox test and an amphipod bioassay). The results show that metal concentrations are several times above the background concentration. However, only one of the stations showed toxicity after acute toxicological tests, with the benthic communities being in a good status. The approaches used here show that contaminants are not bioavailable and that no management actions are required with the slags.     

Multi-stand Forest Management under a Climatic Risk: Do Time and Risk Preferences Matter?

We propose a stochastic dynamic programming framework to model the management of a multi-stand forest under climate risk (strong wind occurrence). The preferences of the forest-owner are specified by a non-expected utility in order to separately analyze intertemporal substitution and risk aversion effects. A numerical method is developed to characterize the optimal forest management policies and the optimal consumption-saving strategy. The stochastic dynamic programming framework is applied to a non-industrial private forest-owner located in North-East of France. We show that the optimal decisions both depend upon risk and time preferences. The authors would like to thank participants at the international conference on Economics of Sustainable Forest Management in Toronto, at the PARIS 1 seminar on Environmental and Natural Resource Economics, at the 2004 Applied Microeconomics Conference in Lille and at the 13th annual conference of the European Association of Environmental and Resource Economists at Budapest.     

Speciation of Cr and its leachability in coal by-products from spanish coal combustion plants

This study evaluates the behaviour of total Cr and Cr (VI) during coal combustion in two Spanish power stations. The content and distribution of Cr in the feed coal and combustion wastes was determined and the Cr contents were normalized using enrichment factor indexes. The speciation of Cr in the fly ash fractions from the different hoppers of the electrostatic precipitators was established and the possibility that the Cr (VI) might lixiviate when ashes are disposed of at landfill sites was assessed. Differences in the distribution and behavior of Cr in the two power stations were observed. According to European directive 1999/31/CEE, soluble Cr(VI) in the fly ashes studied would be unlikely to pose an environmental or health risk when the ash is disposed of.     

Characteristics of dwellings contaminated by moulds

Dwellings showing a presence of moulds are considered to be unhealthy both by the inhabitants and by sanitary authorities. Although the thresholds of pathogenicity have not yet been established, the toxic, allergic and infectious risk of indoor moulds is better understood today. A study on indoor fungi contamination for 128 dwellings was done between October and May in France. It concerned 69 dwellings, the occupants of which either complained to the sanitary authorities about problems of moulds and humidity or consulted a doctor who related their symptoms to housing conditions. Fifty-nine other dwellings, the occupants of which were healthy, constituted the control group. We present the statistical analysis of questionnaires, which aimed to clarify characteristics of dwellings associated with high concentrations of airborne moulds. Air samples were taken with an impactor in 500 rooms. On visiting dwellings, investigators obtained answers to 25 questions concerning characteristics of inhabitants and living space, as well as the presence of mould indicators. Indoor and outdoor temperature and indoor relative humidity of air measurements were taken. The total concentration of fungi in the air was significantly higher in ground floor apartments versus those on other floors (p = 0.047), in small and highly occupied dwellings (p = 0.03 and 0.003), in dwellings with electric heating (p = 0.04), without a ventilation system (p = 0.003), with water damage (p = 0.003), and finally, in those where the investigator noted an odour of moisture or visible moulds (p < 0.001). The efficacy of the latter criteria in the evaluation of insalubrity is discussed.     

Essential (Cu) and nonessential (Cd and Pb) metals in ichthyofauna from the coasts of Sinaloa state (SE Gulf of California)

With the aim of giving an overview on concentration and distribution of Cd, Cu, and Pb in fish from the coasts of Sinaloa state (SE Gulf of California), specimens with different feeding habits were collected in five locations. Sampling occurred between June 2003 and March 2004. Metal analyses on fish tissues were made by graphite furnace (Cd, Pb) and flame (Cu) atomic absorption spectrophotometry. Metal concentrations in tissues of carnivorous fish were grouped together and compared with corresponding concentrations in non-carnivorous fish; Cu and Pb levels were significantly (p?<?0.05) higher in liver of non-carnivorous species. Though no samples exceeded the maximum level set in international legislation for fish, from the perspective of the public health and considering the legal limits of fishery products for human consumption, Cu concentrations were exceeded (in tissues different from muscle) in four carnivorous and five non-carnivorous species according to the Australian legislation. In the case of Cd, two carnivorous species (Pomadasys leuciscus and Caulolatilus princeps) and one non-carnivorous species (Mugil cephalus), showed concentrations over the maximum level of 2 μg g^???1 dry weight considered in the Mexican legislation. Considering average amounts of fish consumption in Mexico, daily mineral intake (DMI) values for Cu and percentage weekly intake (PWI) of Cd and Pb were estimated; none of the analyzed metals in edible portion of analyzed fish could be detrimental to humans.     

An assessment of heavy metal contamination in surface sediment using statistical analysis

The distribution and accumulation of heavy metals in the sediments, especially those nearest of wastewater discharges of south of Spain, were investigated. Sediment samples from 14 locations were collected and characterised for metal content (e.g. Ni, Cu, Zn, Cr, Pb, Mn, Cd and Hg), organic carbon, total nitrogen, total phosphorous, n-hexane-extractable material, carbonates and grain size. Concentration data were processed using correlation analysis and factor analysis. The correlation analysis of concentrations data showed important positive correlations among organic carbon, total phosphorus, Cu, Zn, Cd and Hg, otherwise weak correlations among Mn, Cr, Ni and CO₃ ^2???, indicating that these metals have complicated geochemical behaviours. The use of statistical factor analysis also confirmed these results. Sediments pollution assessment was carried out using geoaccumulation and metal pollution indexes (MPI₈). The results revealed that sediments of Cádiz bay and Sancti Petri channel were uncontaminated with the studied metals.     

Estimation of pollutant partition in sandy soils with different water contents

The objectives of this work were: (1) to identify an isotherm model to relate the contaminant contents in the gas phase with those in the solid and non-aqueous liquid phases; (2) to develop a methodology for the estimation of the contaminant distribution in the different phases of the soil; and (3) to evaluate the influence of soil water content on the contaminant distribution in soil. For sandy soils with negligible contents of clay and natural organic matter, contaminated with benzene, toluene, ethylbenzene, xylene, trichloroethylene (TCE), and perchloroethylene (PCE), it was concluded that: (1) Freundlich’s model showed to be adequate to relate the contaminant contents in the gas phase with those in the solid and non-aqueous liquid phases; (2) the distribution of the contaminants in the different phases present in the soil could be estimated with differences lower than 10% for 83% of the cases; and (3) an increase of the soil water content led to a decrease of the amount of contaminant in the solid and non-aqueous liquid phases, increasing the amount in the other phases.     

Seagrass (Posidonia oceanica) monitoring in western Mediterranean: implications for management and conservation

The seagrass Posidonia oceanica is extensively monitored in Mediterranean coastal waters and is an ideal candidate for an eco-regional assessment of the coastal ecosystem. The aim of this study is to evaluate the potential of P. oceanica as eco-regional indicator for its assessment at the scale of Mediterranean basin. For this purpose, regional and national P. oceanica monitoring programmes are identified, and their data and metadata are collected and compared in terms of objectives, strategies, sampling designs and sampling methods. The analysis identifies a number of issues concerning data quality, reliability and comparability. In particular, the adoption of different sampling designs and methods may introduce relevant errors when comparing data. The results of this study stress the necessity of carefully planning monitoring programmes. Moreover, it highlights that the adoption of a number of common tools would facilitate all Mediterranean monitoring activities and allows an optimisation of management efforts at an eco-regional scale.