Grid extension in German backyards: a game-theory rationale

A substantial extension of the electricity grid seems to be necessary in Germany in the coming decades for technical, economic, and ecological reasons. The increased usage of electricity from environmentally conscious sources is not undisputed and the question of where and how to extend the grid is at the centre of a controversial public discussion. One crucial point in this discussion concerns the fair sharing of the costs and benefits of such an extension. It is necessary to create a fair compensation mechanism. Therefore, an innovative mechanism is proposed in this paper that consists of cooperative game theory as well as auction elements. We interpret the German grid extension as a cooperative cost reduction game that allows the identification of fair cost shares and compensation payments. To solve the problem of non-cooperative behaviour, we propose the involvement of a sealed-bid auction. We show that this novel procedure is incentive compatible.     

Formation of artefacts while sampling emissions of PCDD/PCDF from open burning of biomass

Emission factors for PCDD/PCDF determined from open combustion are used to estimate national emission budgets; therefore, it is important to have confidence in their accuracy. It has been suspected that artefacts may form due to the presence of hot metal surfaces of sampling equipment, thus skewing emission factors. In this study, emissions of PCDD/PCDF from open burning of forest biomass over a brick hearth were sampled. Five experiments were carried out using a portable sampler. Experiments were designed where the key variable, sample hood and inlet temperatures were manipulated. Other variables such as fuel origin, type and density were consistent. The measured concentration of PCDD/PCDF in the smoke samples ranged from 0.01 μg TEQ (t fuel)⁻¹ at the lowest maximum hood temperature (185 °C) to 15 μg TEQ (t fuel)⁻¹ at the highest maximum hood temperature (598 °C). when hood inlet temperatures exceeded 400 °C emission factors were significantly elevated and this is attributed to the formation of artefacts that can cause the over estimation of emission factors. The increase in hood temperature also resulted in a change in the PCDD/PCDF congener and homologue profile of the emissions. For example at the lowest temperature (Fire 1) the PCDD/PCDF ratio measured was 50:1, whereas at the highest temperature (Fire 5) this ratio was about 0.53:1. When the sampler hood and inlet temperatures were kept in the normal operating range of <200 °C, emission factors were comparable to those observed in many previous studies in Australia with emissions dominated by PCDD.     

Improvement of health risk factors after reduction of VOC concentrations in industrial and urban areas

After reductions of fugitive and diffuse emissions by an industrial complex, a follow-up study was performed to determine the time variability of volatile organic compounds (VOCs) and the lifetime cancer risk (LCR). Passive samplers (3 M monitors) were placed outdoors (n?=?179) and indoors (n?=?75) in industrial, urban, and control areas for 4 weeks. Twenty-five compounds including n-alkanes, cycloalkanes, aromatics, chlorinated hydrocarbons, and terpenes were determined by GC/MS. The results show a significant decrease of all VOCs, especially in the industrial area and to a lesser extent in the urban area. The median outdoor concentration of benzene in the industrial area declined compared to the former study, around 85 % and about 50 % in the urban area, which in the past was strongly influenced by industrial emissions. Other carcinogenic compounds like styrene and tetrachloroethylene were reduced to approximately 60 %. VOC concentrations in control areas remained nearly unchanged. According to the determined BTEX ratios and interspecies correlations, in contrast to the previous study, traffic was identified as the main emission source in the urban and control areas and showed an increased influence in the industrial area. The LCR, calculated for benzene, styrene, and tetrachloroethylene, shows a decrease of one order of magnitude in accordance to the decreased total VOC concentrations and is now acceptable according to values proposed by the World Health Organization.     

Application of nanoscale zero valent iron (NZVI) for groundwater remediation in Europe

Purpose  

Nanoscale zero valent iron (NZVI) is emerging as a new option for the treatment of contaminated soil and groundwater targeting mainly chlorinated organic contaminants (e.g., solvents, pesticides) and inorganic anions or metals. The purpose of this article is to give a short overview of the practical experience with NZVI applications in Europe and to present a comparison to the situation in the USA. Furthermore, the reasons for the difference in technology use are discussed.     

Partitioning of persistent organic pollutants (POPs) between human serum and breast milk: A literature review

The literature was reviewed to assess the relationship between the lipid adjusted concentration in human serum and breast milk (expressed as the serum/milk ratio) of a broad range of POPs in paired samples. Thirteen studies were identified, including seven studies that reported serum/milk ratios for polychlorinated dibenzo-dioxins and -furans (PCDD/Fs), ten for polychlorinated biphenyls (PCBs), five for polybrominated diphenyl ethers (PBDEs), and five for organochlorine pesticides (OCPs). Mean serum/milk ratios ranged between 0.7 and 25 depending on the compound and congener. For PCDD/Fs, PCBs and PBDEs, a clear trend of increasing mean serum/milk ratio by increasing molar volume, hydrophobicity and number of halogen substitutes was observed. The mean serum/milk ratios reported by the 13 studies summarized here will aid comparison between human POPs exposure studies using either serum or milk samples. More studies are needed to allow a valid comparison between data obtained from analysis of breast milk and serum samples for a broader range of POPs. Furthermore such studies may shed light on compound specific factors as well as other determinants that may affect the partitioning and partition kinetics of POPs between serum and breast milk.     

Concentrations of PFOS, PFOA and other perfluorinated alkyl acids in Australian drinking water

Perfluorinated alkyl acids (PFAAs) are persistent environmental pollutants, found in the serum of human populations internationally. Due to concerns regarding their bioaccumulation, and possible health effects, an understanding of routes of human exposure is necessary. PFAAs are recalcitrant in many water treatment processes, making drinking water a potential source of human exposure. This study was conducted with the aim of assessing the exposure to PFAAs via potable water in Australia. Sixty-two samples of potable water, collected from 34 locations across Australia, including capital cities and regional centers. The samples were extracted by solid phase extraction and analyzed via liquid chromatography/tandem mass spectrometry for a range of perfluoroalkyl carboxylates and sulfonates. PFOS and PFOA were the most commonly detected PFAAs, quantifiable in 49% and 44% of all samples respectively. The maximum concentration in any sample was seen for PFOS with a concentration of 16 ng L⁻¹, second highest maximums were for PFHxS and PFOA at 13 and 9.7 ng L⁻¹. The contribution of drinking water to daily PFOS and PFOA intakes in Australia was estimated. Assuming a daily intake of 1.4 and 0.8 ng kg⁻¹ bw for PFOS and PFOA the average contribution from drinking water was 2-3% with a maximum of 22% and 24% respectively.     

Triclosan in individual human milk samples from Australia

Triclosan is a chlorinated phenol ether that has been in widespread use as a broad-spectrum antibacterial agent for four decades. When compared to the limited international data available on human body burden of triclosan, results from a pooled blood study suggested that triclosan concentrations in Australia were a factor two higher than observed in Sweden. This study determined triclosan levels in individual human milk samples (n = 151) collected between 2002 and 2005 from primiparous Australian mothers. It provided the first report of population triclosan levels and individual variation in Australia and gave a measure of infant exposure via breast feeding. The distribution of triclosan concentration was positively skewed, with 7.2% of the samples below the LOQ, 66% with a concentration of less than or equal to 1.0 ng g⁻¹ fresh weight and the remaining samples above 1 ng g⁻¹ reaching a maximum concentration of 19 ng g⁻¹ fresh weight. The mean and median triclosan concentrations were 1.3 ± 2.7 ng g⁻¹ f.w. and 0.26 ng g⁻¹ f.w., respectively. The results of this study showed high variability in triclosan concentrations between individuals and no correlations with maternal age (p = 0.094), maternal weight (p = 0.971) or infant age at the time of sample collection (p = 0.621). A large number of samples contained low or non-quantifiable concentrations of triclosan and so, in Australia, ubiquitous background exposure due to environmental sources is low. This means that body burden can be influenced by an individual’s use of triclosan containing product. Given that triclosan containing product use is continuing, it is important that monitoring in both humans and the environment is continued and that triclosan containing products are adequately labeled so that an individual can choose to avoid exposure.