The Use of Atmospheric Dispersion Models in Risk Assessment Decision Support Systems for Pesticides

In the evaluation of potentially adverse effects oforganic chemicals such as pesticides on theenvironment the atmosphere may play an important role.After its release to the atmosphere the chemical willbe transported/dispersed in the atmosphere and finallyit will be removed either by atmospheric-chemicaldestruction or by deposition to the underlying soil orsurface water. In a risk assessment decision supportsystem both ambient concentrations and depositionfluxes must be known to evaluate the risk of directexposure (inhalation) or the risk of soil and watercontamination caused by deposition. This paperdiscusses the use of atmospheric dispersion models insuch risk assessment decision support systems.     

Effects of municipal solid waste compost and sewage sludge on chemical and spectroscopic properties of humic acids from a sandy Haplic Podzol and a clay loam Calcic Vertisol in Portugal

The effects of amendment with municipal solid waste compost (MSWC) and anaerobically digested sewage sludge (SS) on the compositional and structural features of soil humic acids (HAs) were investigated. For this purpose, HAs were isolated from MSWC, SS, and two different Portuguese soils, a sandy Haplic Podzol and a clay loam Calcic Vertisol, which were either unamended or amended with MSWC or SS at a rate of 60tha(-1). The isolated HAs were analyzed for elemental and acidic functional group composition, and by ultraviolet/visible, Fourier transform infrared (FT IR), and fluorescence spectroscopies. The application of MSWC and especially SS to soils determined an increase of C, N, H, and S contents and E(4)/E(6) ratios (i.e., ratios of absorbances at 465 and 665nm), and a decrease of O, COOH, and phenolic OH contents and C/N, C/H, and O/C ratios of soil HAs. The FT IR and fluorescence results showed that the organic amendments, especially SS, caused an increase of the aliphatic character and a decrease of the degrees of aromatic polycondensation, polymerization, and humification of amended soil HAs. Both MSWC and SS affected more markedly the clayey soil HAs than the sandy soil HAs, possibly due to less extended mineralization processes and the protective action of clay minerals on amended soil HAs.     

Urban Domestic Gardens (XIV): The Characteristics of Gardens in Five Cities

Domestic gardens make substantial contributions to the provision of green space in urban areas. However, the ecological functions provided by such gardens depend critically on their configuration and composition. Here, we present the first detailed analysis of variation in the composition of urban gardens, in relation to housing characteristics and the nature of the surrounding landscape, across different cities in the United Kingdom. In all five cities studied (Belfast, Cardiff, Edinburgh, Leicester, and Oxford), garden size had an overwhelming influence on garden composition. Larger gardens supported more of the land-use types recorded, in greater extents, and were more likely to contain particular features, including tall trees and mature shrubs, areas of unmown grass and uncultivated land, vegetable patches, ponds, and composting sites. The proportional contribution of non-vegetated land-uses decreased as garden area increased. House age was less significant in determining the land-use within gardens, although older houses, which were more likely to be found further from the urban edge of the city, contained fewer hedges and greater areas of vegetation canopy >2 m in height. Current UK government planning recommendations will ultimately reduce the area of individual gardens and are thus predicted to result in fewer tall trees and, in particular, less vegetation canopy >2 m. This might be detrimental from ecological, aesthetic, social, and economic stand points.     

Effects of long-term soil amendment with sewage sludges on soil humic acid thermal and molecular properties

Sewage sludges are frequently used as soil amendments due to their high contents of organic matter and nutrients, particularly N and P. However, their effects upon the chemistry of soil humic acids, one of the main components of the soil organic matter, need to be more deeply studied in order to understand the relation between organic matter structure and beneficial soil properties. Two sewage sludges subjected to different types of pre-treatment (composted and thermally dried) with very different chemical compositions were applied for three consecutive years to an agricultural soil under long-term field study. Thermal analysis (TG–DTG–DTA) and solid-state ¹³C NMR spectroscopy were used to compare molecular and structural properties of humic acids isolated from sewage sludges, and to determine changes in amended soils. Thermally dried sewage sludge humic acids showed an important presence of alkyl and O/N-alkyl compounds (70%) while composted sludge humic acids comprised 50% aromatic and carbonyl carbon. In spite of important differences in the initial chemical and thermal properties of the two types of sewage sludges, the chemical and thermal properties of the soil humic acids were quite similar to one another after 3 years of amendment. Long-term application of both sewage sludges resulted in 80–90% enrichment in alkyl carbon and organic nitrogen contents of the soil humic acid fraction.     

Modified SBA-15 mesoporous silica for heavy metal ions remediation

N-Propylsalicylaldimino-functionalized SBA-15 mesoporous silica was prepared, characterized and used as an adsorbent for heavy metal ions. The organic-inorganic hybrid material was obtained using successive grafting procedures of SBA-15 silica with 3-aminopropyl-triethoxysilane and salicylaldehyde, respectively. For comparison an amorphous silica gel was functionalized using the same procedure. The structure and physicochemical properties of the materials were characterized by means of elemental analysis, X-ray diffraction (XRD), nitrogen adsorption-desorption, thermogravimetric analysis and FTIR spectroscopy. The organic functional groups were successfully grafted on the SBA-15 surfaces and the ordering of the support was not affected by the chemical modification. The behavior of the grafted solids for the adsorption of heavy metals ions from aqueous solutions was investigated. The hybrid materials showed high adsorption capacity and high selectivity for copper ions. Other ions, such as nickel, zinc, and cobalt were adsorbed by the modified SBA-15 material. The adsorbent can be regenerated by acid treatment without altering its properties.     

Editorial: Special issue on composite sampling

Environmental and Ecological Statistics -     

The Accuracy of Mortality Reporting in Displaced Persons Camps During the Post-emergency Phase

For humanitarian organisations, accurate data are essential to identify emerging health problems and determine programme needs. We visited 45 post-emergency phase displaced persons camps and collected three months' mortality data which we compared with organisations' routine mortality reports. Organisations reported 612 deaths and we identified 741 deaths, for a mortality-reporting ratio, defined as the number of organisation-reported deaths divided by the number of investigator-identified deaths, of 83 per cent. For the majority of camps which under-reported deaths, mortality reporting ratios were significantly higher for women than men, and for camps with central mortality registers rather than those without. In the few camps which over-reported deaths, these occurred primarily among children younger than five years of age, probably due to the inclusion of abortions and stillbirths. Despite the overall under-reporting of deaths by humanitarian organisations, the existing health information systems appear to estimate mortality rates adequately in these post-emergency camps. However, organisations should improve the precision and completeness with which they report the characteristics of deaths in order to provide valuable data to target their programmes at the most vulnerable people.     

Immediate and long-term assistance following the bombing of the US Embassies in Kenya and Tanzania

On 7 August 1998 truck bombs destroyed the US Embassies in Kenya and Tanzania.(1) The response in both countries was characterised by an absence of incident command, limited pre-hospital care, a disorganised hospital response and a lack of transportation for those injured. In the next five years USD 50 million was provided by the United States Agency for International Development (USAID) to alleviate the resulting suffering, support reconstruction and strengthen disaster preparedness capacity in the two countries. These two programmes have enhanced awareness of disaster management issues, improved training capacity, built response structures and provided material resources. Their design and implementation provide lessons for future disasters in developing countries. The assistance programmes evolved very differently. In Kenya the programme largely excluded the public sector and the potential for government coordination, while the Tanzanian programme concentrated heavily on central government and regional hospital structures-largely omitting the non-governmental or civil society sector. Excluding key stakeholders raises concerns about programme sustainability and the ability to respond effectively to future emergencies.     

Assessment of the pollution impact on biomarkers of effect of a freshwater fish

Changes in biomarkers of fish captured from stressed environments may represent a reliable tool in revealing sublethal effects of the pollutants found in aquatic ecosystems. The response patterns of selected biochemical and morphological variables biomarkers of effect were assessed in adult females of an indigenous teleost Cnesterodon decemmaculatus, caught at a polluted site (San Francisco) of the Reconquista river (Buenos Aires, Argentina). Combined field-caging experiments with controlled laboratory exposure to clean media were performed. The biochemical parameters measured were specific activities of gill (Na+ + K+)-ATPase, liver AlaAT and AspAT, and brain AChE; LSI and CF were also calculated. The changes in gill (Na+ + K+)-ATPase and liver AlaAT activities of fish captured in the field in most cases were reversible after transfer to clean media. The results were interpreted in association with the physicochemical profile of the water samples taken simultaneously with the capture of the fish. Results suggested the suitability of the test species used as tools in environmental monitoring programs of risk assessment.