Photochemical transformations of tetrabromobisphenol A and related phenols in water

A method was developed for studies of the phototransformation at UV irradiation of aqueous solutions of tetrabromobisphenol A (TBBPA), tribromobisphenol A (TriBBPA), tetrachlorobisphenol A (TCBPA), 2,4-dichlorophenol at various pHs as well as 2-chlorophenol, 2-bromophenol, 3,4-dichlorophenol and bisphenol A at pH 11. The absorbance spectra of the compounds and the emission spectra of the light-source were determined and used to calculate disappearance quantum yields of the photochemical reactions that were taking place. No major differences between the disappearance quantum yields of TBBPA and TCBPA were observed at pH 10, while the disappearance quantum yield of TriBBPA was approximately two times higher. The rate of decomposition of TBBPA was six times higher at pH 8 than at pH 6. Identification of the degradation products of TBBPA and TriBBPA, by GC-MS analysis and by comparison to synthesised reference compounds, indicated that TBBPA and TriBBPA decompose via different mechanisms. Three isopropylphenol derivatives; 4-isopropyl-2,6-dibromophenol, 4-isopropylene-2,6-dibromophenol and 4-(2-hydroxyisopropyl)-2,6-dibromophenol, were identified as major degradation products of TBBPA while the major degradation product of TriBBPA was tentatively identified as 2-(2,4-cyclopentadienyl)-2-(3,5-dibromo-4-hydroxyphenyl)propane.     

Emissions from a controlled fire in municipal solid waste bales

Environmental and safety aspects of seasonal storage of baled municipal solid waste to be used as fuel for energy production (waste fuel), was investigated and experiments were carried out on burning of bales. The flammability, combustion processes and emissions were studied by simulating, in small-scale, potential effects of a possible fire in full-scale bale storage area. Despite the high water content and the high density of the bales, after setting fire, the bales burned well, even though no risk for self-ignition exists. The following parameters of the combustion product were measured continuously: O2, CO2, CO, SO2, NO, NO2, NOx, THC, smoke gas rate and the temperature of the smoke. Soot particles in the smoke were collected and analysed for Hg, Pb, Cd, As, Ni, Cr, Mn, Cu, Co, Sb and V concentrations. The analysis of the moisture content, concentrations of Hg, Cd, HCl, HF, HBr, NH3, polyaromatic hydrocarbons (PAH), chlorinated and brominated dioxins (PCDD/F and PBrDD/F, respectively) were carried out. It was found that the PCDD/F levels (TEQs) varied according to the system used: 12.53 ng (I-TEF-88)/Nm3; 14.09 ng (I-TEF-99)/Nm3; 13.86 ng (Eadons)/Nm3. The PAH concentration was 3.04 microg/Nm3. The contents of the metals in the smoke (with the exceptions of Pb and Cd with mean values of 1.74 and 0.36 mg/m3, respectively) were below the limit values established by the Swedish Ministry of Environment for emissions from incineration plants [Swedish Ministry of Environment, (2002:1060), F?rordning 2002:1060 om avfallsf?rbr?nning. Available from http://www.notisum.se/rnp/SLS/LAG/20021060.HTM]/EU-directive [(2000/76/EC), Directive 2000/76/EC, of the European Parliament and of the Council of 4 December 2000 on the Incineration of Waste. http://www.Scotland. gov.uk/library5/environment/iecda.pdf]. The HCl concentration was 10 times higher than the limit value (mean value of 99 mg/m3).     

Persistent organochlorine pollutants in children working at a waste-disposal site and in young females with high fish consumption in Managua, Nicaragua

The aim of this study was to assess persistent organochlorine pollutant (POP) levels in serum collected from children (11-15 years old) working and sometimes also living at the municipal waste-disposal site in Managua, located at the shore of Lake Managua, and in nonworking children living both nearby and also far away from the waste-disposal site. The influence of fish consumption was further evaluated by assessing POPs levels in serum from young women (15-24 years old) with markedly different patterns of fish consumption from Lake Managua. 2,2-bis(4-chlorophenyl)-1,1,1-trichloro-ethane (4,4'-DDT) and 2,2-bis(4-chlorophenyl)-1,1-dichloro-ethene (4,4'-DDE), gamma-hexachlorocyclohexane (gamma-HCH), polychlorinated biphenyls, pentachlorophenol, and polychlorobiphenylols were quantified in all samples. In general, the levels observed were higher than those reported in children from developed countries, such as Germany and United States. Toxaphene, aldrin, dieldrin, and beta-HCH could not be identified in any sample. The children working at the waste-disposal site had higher levels of POPs compared with the nonworking reference groups. In children not working, there were also gradients for several POPs, according to vicinity to the waste-disposal site. Moreover, in children, as well as in young women, there were gradients according to fish consumption. The most abundant component was 4,4'-DDE, but at levels still lower than those reported in children from malarious areas with a history of recent or current application of 4,4'-DDT for vector control.     

Effects on the function of Arctic ecosystems in the short- and long-term perspectives

Historically, the function of Arctic ecosystems in terms of cycles of nutrients and carbon has led to low levels of primary production and exchanges of energy, water and greenhouse gases have led to low local and regional cooling. Sequestration of carbon from atmospheric CO2, in extensive, cold organic soils and the high albedo from low, snow-covered vegetation have had impacts on regional climate. However, many aspects of the functioning of Arctic ecosystems are sensitive to changes in climate and its impacts on biodiversity. The current Arctic climate results in slow rates of organic matter decomposition. Arctic ecosystems therefore tend to accumulate organic matter and elements despite low inputs. As a result, soil-available elements like nitrogen and phosphorus are key limitations to increases in carbon fixation and further biomass and organic matter accumulation. Climate warming is expected to increase carbon and element turnover, particularly in soils, which may lead to initial losses of elements but eventual, slow recovery. Individual species and species diversity have clear impacts on element inputs and retention in Arctic ecosystems. Effects of increased CO2 and UV-B on whole ecosystems, on the other hand, are likely to be small although effects on plant tissue chemisty, decomposition and nitrogen fixation may become important in the long-term. Cycling of carbon in trace gas form is mainly as CO2 and CH4. Most carbon loss is in the form of CO2, produced by both plants and soil biota. Carbon emissions as methane from wet and moist tundra ecosystems are about 5% of emissions as CO2 and are responsive to warming in the absence of any other changes. Winter processes and vegetation type also affect CH4 emissions as well as exchanges of energy between biosphere and atmosphere. Arctic ecosystems exhibit the largest seasonal changes in energy exchange of any terrestrial ecosystem because of the large changes in albedo from late winter, when snow reflects most incoming radiation, to summer when the ecosystem absorbs most incoming radiation. Vegetation profoundly influences the water and energy exchange of Arctic ecosystems. Albedo during the period of snow cover declines from tundra to forest tundra to deciduous forest to evergreen forest. Shrubs and trees increase snow depth which in turn increases winter soil temperatures. Future changes in vegetation driven by climate change are therefore, very likely to profoundly alter regional climate.     

Evaluation criteria for AIS 1 neck injuries in frontal impacts--a parameter study combining field data and Madymo modeling

Two situations with an expected higher AIS 1 neck injury rate in frontal impact were compared to a reference situation using a Madymo human body model in three different sitting postures and four different crash pulses. The two situations were reduced occupant weight and occupant with initial forward arm resistance, respectively. Occupant neck motion phases were identified and corresponding possible evaluation criteria were evaluated within the phases. Typical neck kinematics was seen for the two different situations. Occupants of lower weight had a more extended neck in the initial protraction phase and also a generally more pronounced upper neck link angle. Occupants with initial arm resistance had generally greater lower neck link angle at the time when the upper neck link angle was straight. No evaluation criteria reflected the anticipated AIS 1 neck injury rate consistently. In the initial protraction phase, NICmin correlated to expected injury outcome in almost half of the cases. In the protraction-flexion shift phase, Nkm, Nij, upper neck shear force and neck tension force reflected anticipated severity outcome to some extent. In the flexion phase, upper and lower neck extension correlated to anticipated AIS 1 neck injury rate only to a minor extent. The different sitting postures were more influential than the different crash pulses, emphasizing the importance of not only considering the spectra of impact severity but also differences in sitting postures in safety system development and evaluation.     

气候变化与紫外线B辐射对北极苔原和极地荒漠生态系统的影响重要发现和扩展总结

引言 北极已成为对当前气候波动和预计的全球变暖增强的影响进行评估的重要地区.原因有以下几个方面:①在过去几十年中北极经历了大幅度的变暖过程(温度平均升高3℃,而在许多地区温度升高了4～5℃);②气候预测表明气候呈现持续变暖趋势,在2080年之前年平均气温升高4～5℃;③近期的气候变暖正在影响北极的环境和经济,这些影响还会加大,并对生活方式、文化及生态系统造成影响;④北极的变化可能会影响到地球上的其它地区.     

基本原理,概念及评估办法

引言 人们普遍认为,全球气候变暖在北极将进一步放大,由于平流层臭氧修复的可能延误,紫外线B(UV-B)辐射可能继续增加,北极环境及其居民可能特别易受这类环境变化的影响.上述共识促进了对气候变化影响的国际评估工作.北极气候影响评估(ACIA)是一项为时4年的研究,结果出版了一篇重要的科研报告[1]并产生了其他的成果.在本文以及本期Ambio专刊下面的文章中,我们提供了报告中针对北极陆地生态系统(从树线群落交错带到极地荒漠)的部分研究成果.