Particle deposition,resuspension and phosphorus accumulation in small constructed wetlands

To improve understanding of phosphorus (P) retention processes in small constructed wetlands (CWs), we analysed variations in sediment deposition and accumulation in four CWs on clay soils in east-central Sweden. Sediment deposition (in traps) generally exceeded the total suspended solids (TSS) load suggesting that resuspension and wetland base erosion were important. This was confirmed by quantification of particle accumulation (on plates) (1–23 kg m^?2 year^?1), which amounted to only 13–23% of trap deposition. Spatial mean P concentrations in accumulated sediment on plates (0.09–0.15%) were generally similar to temporal mean P concentrations of particles in water (0.11–0.15%). Deposition/accumulation was minor in one wetland with high hydraulic load (400 m year^?1), suggesting that such small wetlands are not efficient as particle sinks. Economic support for CWs are given, but design and landscape position are here demonstrated to be important for effective P retention.     

Moving beyond the conceptual: specificity in regional climate change adaptation actions for biodiversity in South East Queensland,Australia

While many scientific assessments have been recommending general strategies for biodiversity conservation under climate change, translation of these recommendations into specific actions and practice has been limited. Focusing on two biomes, rainforest and wetlands in biodiverse South East Queensland, Australia, we demonstrate how general principles can be translated into specific actions for stakeholders and responsible agencies. We synthesize research that is contextualizing protection of refugia and habitat connectivity, establishing baseline data sets to detect change and developing strategic conservation planning scenarios to adjust reserve boundaries or situate new reserves. This has been achieved by coupling spatial information on biological assets (i.e. ecosystems and species) with future climate scenarios and process models to anticipate movement of critical habitats. Conservation planning software is also being used to prioritize investment to meet specific objectives. This approach is enabling us to identify at-risk biological assets, opportunities to ameliorate threats and obstacles to delivering regional adaptation actions. A larger total reserved area is needed, with proactive planning to capture areas further inland and along watercourses. Major obstacles include conflict between urbanization and priorities for habitat conservation and the need for greater levels of investment for monitoring programmes and to protect landward shifted wetlands on private land.     

Use of macroinvertebrate assemblages for assessing performance of stabilization ponds treating effluents from sugarcane and molasses processing

Wastewater discharge from sugarcane processing is a significant pollutant of tropical aquatic ecosystems. For most developing countries, monitoring of the level of pollutants is done mostly through chemical analysis, but this does not reflect potential impacts on aquatic assemblages. In addition, laboratory facilities for accurate concentration measurements are often not available for regular monitoring programs. In this study, we investigated the use of benthic macroinvertebrates for biological monitoring in western Kenya. Benthic macroinvertebrates were sampled in stabilization ponds treating wastewater from sugarcane- and molasses-based processing plants to assess their composition and abundance in relation to different concentrations of chemical variables. Optimum concentrations and tolerance values were identified for various taxa, and a biotic index was developed that combined tolerance values (ranked between 0 and 10) for the various macroinvertebrate taxa. A succession in composition and distribution of macroinvertebrate taxa was observed from the inlet to the outlet of the pond systems. Diptera dominated in the first ponds that had high concentrations of chemical oxygen demand (COD), biological oxygen demand (BOD₅), and nutrients, while intolerant Ephemeroptera, Plecoptera, and Trichoptera (EPT) appeared as the concentrations dropped in subsequent ponds. The effluent quality was classified as “good,” “fair,” and “poor,” corresponding with biotic index value ranges 0–3.50, 3.51–6.50, and 6.51–10, respectively. During validation, the index grouped sites with respect to levels of measured environmental variables. The study revealed that the developed biotic index would help in monitoring the quality of sugarcane processing and molasses effluents before release into recipient aquatic ecosystems, replacing the need for costly chemical analyses.     

An Alternative Approach to Photochemical Ozone Creation Potentials Applied under European Conditions

ABSTRACT

Photochemical ozone creation potential (POCP) values for 83 different volatile organic compounds (VOCs), including CO and CH₄, were calculated under different environmental conditions representative for Europe. These calculations show that variations in POCP values are large between different types of chemical environments and that POCP values for VOCs should be presented as ranges instead of single values. POCP ranges are based on the extremes of the POCP values and are defined with the intention to include all POCP values an individual VOC will obtain in any European environment where O₃ formation is of environmental concern. The POCP ranges indicate large differences in O₃ production between individual VOCs, which justifies the use of this ranking scale instead of treating all VOCs as a homogeneous group of species in abatement strategies.

Both the average O₃ production over 96 hr and the maximum contribution to the O₃ concentration were studied. The most efficient O₃ producers were found to be iso-prene, 2-methyl-2-butene, and acrolein. As a group, the alkenes are the most potent O₃ producers, followed by higher alkanes and then the aromatics. The calculated values show a good agreement with previously calculated POCP values under northern European conditions.     

南非志愿举措的发展

采取少数几个小的志愿步骤 南非的志愿举措大部分是由于公司经营所在的不确定法规环境的结果.环境立法的确存在,但过去执法不力,这部分地由于工业界和政府都认为增长和就业机会是与环境管理相冲突的,而且前者优于后者.希望随着可持续发展的信息得到更好的理解,那些冲突类别将成为过去的事情.     

Determinants of maternal and fetal exposure and temporal trends of perfluorinated compounds

In recent years, some perfluorinated compounds (PFCs) have been identified as potentially hazardous substances which are harmful to the environment and human health. According to limited data, PFC levels in humans could be influenced by several determinants. However, the findings are inconsistent. In the present study, perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA), and perfluorononanoic acid (PFNA) were measured in paired maternal and cord serum samples (N?=?237) collected between 1978 and 2001 in Southern Sweden to study the relationship between these and to investigate several potential determinants of maternal and fetal exposure to PFCs. Time trends of PFCs in Swedish women were also evaluated. The study is a part of the Fetal Environment and Neurodevelopment Disorders in Epidemiological Research project. PFOS, PFOA, and PFNA levels (median) were higher in maternal serum (15, 2.1, and 0.24 ng/ml, respectively) than in cord serum (6.5, 1.7, and 0.20 ng/ml, respectively). PFC levels were among the highest in women originating from the Nordic countries and the lowest in women from the Middle East, North Africa, and sub-Saharan Africa. Multiparous women had lower serum PFOA levels (1.7 ng/ml) than primiparous women (2.4 ng/ml). Maternal age, body mass index, cotinine levels, and whether women carried male or female fetuses did not affect serum PFC concentrations. Umbilical cord serum PFC concentrations showed roughly similar patterns as the maternal except for the gestational age where PFC levels increased with advancing gestational age. PFOS levels increased during the study period in native Swedish women. In summary, PFOS levels tend to increase while PFOA and PFNA levels were unchanged between 1978 and 2001 in our study population. Our results demonstrate that maternal country of origin, parity, and gestational age might be associated with PFC exposure.     

Science-practice interactions linked to climate adaptation in two contexts: municipal planning and forestry in Sweden

This paper examines the science-practice interface in the process of adapting to climate change in society. This paper analyses science-based stakeholder dialogues with climate scientists, municipal officers and private individual forest owners in Sweden, and examines how local experts both share scientific knowledge and experience and integrate it into their work strategies and practices. The results demonstrate how local experts jointly conceptualise climate adaptation, how scientific knowledge is domesticated among local experts in dialogue with scientific experts, the emergence of anchoring devices, and the boundary-spanning functions that are at work in the respective sectors.     

Fourth WHO-coordinated survey of human milk for persistent organic pollutants (POPs): Belgian results

Persistent organic pollutants (POPs) are chemicals that accumulate in the food chain and are toxic to humans and wildlife. The fourth World Health Organization (WHO) survey on POP levels in human milk (2006-2009) aims to provide baseline and trend information on human exposure to POPs. So far Belgium participated in all three previous rounds (1988, 1992, 2001). Whereas the first three rounds focused on determination of dioxins and PCBs in pooled (mixed) samples, the fourth survey comprised the analyses of individual milk samples for nine "basic POPs" (chlorinated pesticides and indicator PCBs) and of pooled milk samples for "basic POPs", "advanced POPs" (dioxins and dioxin-like PCBs) and "optional POPs" (polybrominated diphenylethers [PBDEs], polybrominated dioxins and dibenzofurans [PBrDD/F], mixed halogenated dioxins and dibenzofurans [PXDD/F] and hexabromocyclododecane [HBCD]). For the Belgian participation human milk samples were collected during the summer of 2006 from 197 women between 18 and 30 years old distributed over all Belgian provinces. The individual samples were analyzed in a Belgian Laboratory for "basic" POPs. A pooled sample was made from 178 individual samples and analyzed by the WHO Reference Laboratory for the "basic, advanced and optional" POPs. The results indicate that most organochlorinated pesticides banned 25-30 years ago were below or around detection limits in Belgian human milk samples although DDE was still found at low levels in all samples. Over the last five years the levels of marker PCBs and PCDD/Fs in Belgian human milk decreased, respectively, by 58% and 39%. For some of the other emerging or older compounds recent international data are needed to allow comparison. This shows the importance of international studies as run by WHO.     

Temporal pessimism and spatial optimism in environmental assessments: An 18-nation study

The personal assessments of the current and expected future state of the environment by 3232 community respondents in 18 nations were investigated at the local, national, and global spatial levels. These assessments were compared to a ranking of each country's environmental quality by an expert panel. Temporal pessimism (“things will get worse”) was found in the assessments at all three spatial levels. Spatial optimism bias (“things are better here than there”) was found in the assessments of current environmental conditions in 15 of 18 countries, but not in the assessments of the future. All countries except one exhibited temporal pessimism, but significant differences between them were common. Evaluations of current environmental conditions also differed by country. Citizens' assessments of current conditions, and the degree of comparative optimism, were strongly correlated with the expert panel's assessments of national environmental quality. Aside from the value of understanding global trends in environmental assessments, the results have important implications for environmental policy and risk management strategies.