Levels and seasonal variations of organochlorine pesticides in urban and rural background air of southern Ghana

Urban, suburban and rural background air samples were collected in southern Ghana in 2008 employing polyurethane foam disc passive air samplers (PAS). PAS were analysed for organochlorine pesticides (OCPs), namely hexachlorocyclohexanes (α-, β-, γ- and δ-hexachlorocyclohexane), dichlorodiphenyltrichloroethane including metabolites (o,p'- and p,p'-DDT, DDE and DDD), hexachlorobenzene, pentachlorobenzene, aldrin, dieldrin, endrins (endrin, endrin aldehyde and endrin ketone), isodrin, heptachlors (heptachlor, heptachlor epoxide A and heptachlor epoxide B), chlordanes (α-, β-chlordane, oxychlordane and trans-nonachlor), endosulfans (α- and β-endosulfan and endosulfan sulphate), methoxychlor and mirex using a gas chromatograph coupled to a mass spectrometer. The levels of OCPs ranged for the individual pesticides from below limit of quantification to 750 pg m(-3) (for α-endosulfan), and current agricultural application seemed to be the main primary source of most abundant pesticides. Re-volatilization of previously used pesticides from contaminated soils could not be ruled out either as potential secondary source of contamination, especially in warm and dry seasons and periods of intensive agricultural activities. Higher atmospheric concentrations were observed in November and December during the dry season compared to lower concentrations observed in June, July and August when the country experiences heavy rains. The highest seasonal variation was observed for currently used pesticides as α-endosulfan. A p,p'-DDT/p,p'-DDE ratio suggested recent inputs of fresh technical DDT.     

The impact of ambient ozone on mountain spruce forests in the Czech Republic as indicated by malondialdehyde

Malondialdehyde (MDA), a product of lipid peroxidation and biomarker of oxidative stress, is measured over the long term in spruce Picea abies needles under real conditions in three Czech mountain border areas. The trends presented collate the MDA content in spruce needles with ambient ozone, temperature and precipitation as casual, and defoliation as a subsequent factor for the period 1994-2006. We have found the overall decreasing trends in MDA and defoliation. The highest MDA and defoliation are recorded in the Jizerske, the lowest in the Krusne hory Mts. Out of the examined variables the MDA is predicted best by mean temperature in vegetation season, median of O₃ concentrations and AOT40; these three variables account for 34% of MDA1 and 36% of MDA2 variability. Our hypothesis that higher ambient O₃ exposure results in higher MDA contents in P. abies needles under real conditions has not been approved.     

Trace element concentrations in soils along urbanization gradients in the city of Wien, Austria

Urban soil is an important component of urban ecosystems. This study focuses on heavy metal contamination in soils of Wien (Austria) and results are compared to those for a few large European cities. We analysed the elemental contents of 96 samples of topsoil from urban, suburban and rural areas in Wien along a dynamic (floodplain forest) and a stable (oak–hornbeam forest) urbanization gradient. The following elements were quantified using ICP-OES technique: Al, As, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Pb, P, S and Zn. For heavy metals PI (pollution index) values were used to assess the level of pollution. The PI values indicated high level of pollution by Pb in the suburban and rural area of stable gradient and in the urban area of dynamic gradient; moderate level of pollution was indicated for Cd in the urban area of stable gradient. The level of pollution was moderate for Co in the suburban and rural area of the stable gradient, and for Cu in suburban area of stable gradient, and urban area of dynamic gradient. The pollution level of Zn was moderate in all areas. Urban soils, especially in urban parks and green areas may have a direct influence on human health. Thus, the elemental analysis of soil samples is one of the best ways to study the effects of urbanization. Our results indicated that the heavy metal contamination was higher in Wien than in a few large European cities.     

Sulfur and oxygen isotope tracing in zero valent iron based In situ remediation system for metal contaminants

In the present study, controlled laboratory column experiments were conducted to understand the biogeochemical changes during the microbial sulfate reduction. Sulfur and oxygen isotopes of sulfate were followed during sulfate reduction in zero valent iron incubated flow through columns at a constant temperature of 20 ± 1 °C for 90 d. Sulfur isotope signatures show considerable variation during biological sulfate reduction in our columns in comparison to abiotic columns where no changes were observed. The magnitude of the enrichment in δ³⁴S values ranged from 9.4‰ to 10.3‰ compared to initial value of 2.3‰, having total fractionation δS between biotic and abiotic columns as much as 6.1‰. Sulfur isotope fractionation was directly proportional to the sulfate reduction rates in the columns. Oxygen isotopes in this experiment seem less sensitive to microbial activities and more likely to be influenced by isotopic exchange with ambient water. A linear relationship is observed between δ³⁴S and δ¹⁸O in biotic conditions and we also highlight a good relationship between δ³⁴S and sulfate reduction rate in biotic columns.     

Towards a general relationship between climate change and biodiversity: an example for plant species in Europe

Climate change is one of the main factors that will affect biodiversity in the future and may even cause species extinctions. We suggest a methodology to derive a general relationship between biodiversity change and global warming. In conjunction with other pressure relationships, our relationship can help to assess the combined effect of different pressures to overall biodiversity change and indicate areas that are most at risk. We use a combination of an integrated environmental model (IMAGE) and climate envelope models for European plant species for several climate change scenarios to estimate changes in mean stable area of species and species turnover. We show that if global temperature increases, then both species turnover will increase, and mean stable area of species will decrease in all biomes. The most dramatic changes will occur in Northern Europe, where more than 35% of the species composition in 2100 will be new for that region, and in Southern Europe, where up to 25% of the species now present will have disappeared under the climatic circumstances forecasted for 2100. In Mediterranean scrubland and natural grassland/steppe systems, arctic and tundra systems species turnover is high, indicating major changes in species composition in these ecosystems. The mean stable area of species decreases mostly in Mediterranean scrubland, grassland/steppe systems and warm mixed forests.     

TiO₂-based nanoparticles released in water from commercialized sunscreens in a life-cycle perspective: structures and quantities

This work investigates the physical-chemical evolution during artificial aging in water of four commercialized sunscreens containing TiO₂-based nanocomposites. Sunscreens were analyzed in terms of mineralogy and TiO₂ concentration. The residues formed after aging were characterized in size, shape, chemistry and surface properties. The results showed that a significant fraction of nano-TiO₂ residues was released from all sunscreens, despite their heterogeneous behaviors. A stable dispersion of submicronic aggregates of nanoparticles was generated, representing up to 38 w/w% of the amount of sunscreen, and containing up to 30% of the total nano-TiO₂ initially present in the creams. The stability of the dispersion was tested as a function of salt concentration, revealing that in seawater conditions, a major part of these nano-TiO₂ residues will aggregate and sediment. These results were put in perspective with consumption and life cycle of sunscreens to estimate the amount of nano-TiO₂ potentially released into AQUATIC environment.     

Time needed to evacuate the Netherlands in the event of large-scale flooding: strategies and consequences

On 30 May 2008, the Government of the Netherlands informed the national parliament about the effectiveness of preventive evacuation of coastal and river areas in case of flooding. Analysis of a case study showed that it is impossible to evacuate coastal areas preventively within a 48-hour time span preceding a worst credible scenario flood caused by a storm surge. This fact illustrates the need for alternative evacuation strategies, such as vertical evacuation (evacuating to safe havens, inside the flood zone) or shelter-in-place (hiding), to reduce loss of life and the impact of the evacuation. This paper defines these strategies and demonstrates, by returning to the case study used by the Dutch government, that they require different measures, methods of approach, and crisis management processes. In addition, it addresses the need for flexible and scalable preparation so that after detecting and understanding the threat, authorities and citizens can make decisions about different evacuation strategies.     

Brominated flame retardants and organochlorines in the European environment using great tit eggs as a biomonitoring tool

Large-scale studies are essential to assess the emission patterns and spatial distribution of organohalogenated pollutants (OHPs) in the environment. Bird eggs have several advantages compared to other environmental media which have previously been used to map the distribution of OHPs. In this study, large-scale geographical variation in the occurrence of OHPs, such as polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and organochlorine pesticides (OCPs), was investigated throughout Europe using eggs of a terrestrial residential passerine species, the great tit (Parus major). Great tit eggs from 22 sampling sites, involving urban, rural and remote areas, in 14 European countries were collected and analysed (5-8 eggs per sampling site). The environmentally most important congeners/compounds of the analysed pollutants were detectable in all sampling locations. For PCBs, PBDEs and OCPs, no clear geographical contamination pattern was found. Sum PCB levels ranged from 143 ng/g lipid weight (lw) to 3660 ng/g lw. As expected, PCB concentrations were significantly higher in the sampled urban compared to the remote locations. However, the urban locations did not show significantly higher concentrations compared to the rural locations. Sum PBDEs ranged from 4.0 ng/g lw to 136 ng/g lw. PBDEs were significantly higher in the urbanized sampling locations compared to the other locations. The significant, positive correlation between PCB and PBDE concentrations suggests similar spatial exposure and/or mechanisms of accumulation. Significantly higher levels of OCPs (sum OCPs ranging from 191 ng/g lw to 7830 ng/g lw) were detected in rural sampling locations. Contamination profiles of PCBs, PBDEs and OCPs differed also among the sampling locations, which may be due to local usage and contamination sources. The higher variance among sampling locations for the PCBs and OCPs, suggests that local contamination sources are more important for the PCBs and OCPs compared to the PBDEs. To our knowledge, this is the first study in which bird eggs were used as a monitoring tool for OHPs on such a large geographical scale.     

New roles for farming in a differentiated countryside: the Portuguese example

Throughout Europe, the role of farming as the private provider of public goods and services increasingly valuated by society is today generally acknowledged. Furthermore, in the turn towards rural development concerns, multifunctionality as an attribute of rural space has emerged, justifying the territorial approach of farming. The situation facing the multifunctionality demand is nevertheless not the same in all European regions, which by all means is getting strengthened in the transition towards post-productivism. In some regions, there is a productivist orientation and production has a dominant economic role, while others will need to be supported on other functions to survive economically and socially, or may be best suited to environmental functions alone. The vocation of the rural territories is different, and thus also the functions they are able to support. This paper discusses the concept of multifunctionality of the rural areas, and defines a possible methodological approach towards the identification of the different types of rural areas in Europe, based on the identification of ideal types, through the analysis of selected indicators. The empirical application has been developed for the Portuguese Ministry of Agriculture, aiming at assessing the differentiated characteristics and dynamics of the Portuguese rural territory. Analyzing data from 1990 and 2000, at municipal level, three dimensions have been considered: the land cover, the agricultural sector and the rural community. Combining the three analyses, it was possible to identify different vocations of the rural space, and the role that farming could have in the future for the multifunctionality of the territory. Accordingly, the municipalities have been grouped in types, pre-defined as ideal types. This was a first attempt to understand the differentiation of the rural territory in Portugal. For decision-making it should be further developed. It nevertheless shows that there is clear differentiation concerning the possible landscape functions to be developed between regions and a possible way to assess. It also shows that a territorial approach to agriculture may be the key for the maintenance of the sector in many areas where production by itself, as it has been know until now, may be severely threatened.     

Mapping of tritium emissions using absorption vapour samplers

Püspökszilágy Radioactive Waste Treatment and Disposal Facility (RWTDF) is a typical near-surface engineered repository designated to store low- and intermediate-level wastes from various institutes, research facilities and hospitals in Hungary. Two automatic combined ¹⁴C–tritium sampling units installed at the facility sample the air 2 m above surface. The one installed near the vaults detects tritium (T) activities two orders of magnitude higher than the far reference sampling unit. To localize the T emissions, 19 small absorption vapour samplers filled with silica gel were settled onto the ground surface. After the saturation of the silica gel, the water was recovered and its T concentration was measured with a low-background liquid scintillation counter. The absorption vapour samplers are cheap, simple and easy-to-use. We present the samplers and the T distribution map constructed from the data, which helps to localize the T emission.