Fate of para-toluenesulfonamide (p-TSA) in groundwater under anoxic conditions: modelling results from a field site in Berlin (Germany)

This article reports on a field modelling study to investigate the processes controlling the plume evolution of para-toluenesulfonamide (p-TSA) in anoxic groundwater in Berlin, Germany. The organic contaminant p-TSA originates from the industrial production process of plasticisers, pesticides, antiseptics and drugs and is of general environmental concern for urban water management. Previous laboratory studies revealed that p-TSA is degradable under oxic conditions, whereas it appears to behave conservatively in the absence of oxygen (O₂). p-TSA is ubiquitous in the aquatic environment of Berlin and present in high concentrations (up to 38 μg L^?1) in an anoxic aquifer downgradient of a former sewage farm, where groundwater is partly used for drinking water production. To obtain refined knowledge of p-TSA transport and degradation in an aquifer at field scale, measurements of p-TSA were carried out at 11 locations (at different depths) between 2005 and 2010. Comparison of chloride (Cl^?) and p-TSA field data showed that p-TSA has been retarded in the same manner as Cl^?. To verify the transport behaviour under field conditions, a two-dimensional transport model was setup, applying the dual-domain mass transfer approach in the model sector corresponding to an area of high aquifer heterogeneity. The distribution of Cl^? and p-TSA concentrations from the site was reproduced well, confirming that both compounds behave conservatively and are subjected to retardation due to back diffusion from water stagnant zones. Predictive simulations showed that without any remediation measures, the groundwater quality near the drinking water well galleries will be affected by high p-TSA loads for about a hundred years.     

An applied methodology for stakeholder identification in transdisciplinary research

In this paper we present a novel methodology for identifying stakeholders for the purpose of engaging with them in transdisciplinary, sustainability research projects. In transdisciplinary research, it is important to identify a range of stakeholders prior to the problem-focussed stages of research. Early engagement with diverse stakeholders creates space for them to influence the research process, including problem definition, from the start. However, current stakeholder analysis approaches ignore this initial identification process, or position it within the subsequent content-focussed stages of research. Our methodology was designed as part of a research project into a range of soil threats in seventeen case study locations throughout Europe. Our methodology was designed to be systematic across all sites. It is based on a snowball sampling approach that can be implemented by researchers with no prior experience of stakeholder research, and without requiring significant financial or time resources. It therefore fosters transdisciplinarity by empowering physical scientists to identify stakeholders and understand their roles. We describe the design process and outcomes, and consider their applicability to other research projects. Our methodology therefore consists of a two-phase process of design and implementation of an identification questionnaire. By explicitly including a design phase into the process, it is possible to tailor our methodology to other research projects.     

Human maternal uniparental disomy for chromosome 16 and fetal development

Two severely growth-retarded fetuses found to have maternal uniparental disomy (UPD) for chromosome 16 and trisomy 16 placental mosaicism both had an unfavourable outcome. Antenatally, the first case was complicated by an unexplained raised maternal serum alpha-fetoprotein concentration, preterm premature rupture of the membranes, and growth retardation detectable at 21 weeks' gestation, whilst the other had an unexplained raised maternal serum human chorionic gonadotrophin level, a two-vessel cord on ultrasound, and cessation of growth at 25 weeks. At post-mortem, both babies had an imperforate anus. Fetal maternal UPD may explain the poor outcome that occurs in some cases of confined placental mosaicism for chromosome 16 and is also associated with specific fetal abnormalities.     

Behaviour and redox sensitivity of antimicrobial residues during bank filtration

The behaviour of residues of antibiotic drugs during bank filtration was studied at a field site in Berlin, Germany, where bank-filtered water is used for the production of drinking water. The neighbouring surface water used for bank filtration is under the influence of treated municipal wastewater. Seven out of 19 investigated antimicrobial residues were found in the surface water with median concentrations between 7 and 151ngL(-1). Out of the seven analytes detected in the surface water only three (anhydroerythromycin, clindamycin and sulfamethoxazole) were found with median concentrations above their limits of quantitation in bank filtrate with a travel time of one month or less. With the exception of sulfamethoxazole, none of the 19 analytes were present in bank filtrate with a residence time larger than one month or in the water-supply well itself. Sulfamethoxazole found with a median concentration of 151ngL(-1) in the surface water was the most persistent of all antimicrobial residues. Nevertheless, it was also removed by more than 98% and only found with a median concentration of 2ngL(-1) in the water-supply well. The degradation of clindamycin and sulfamethoxazole appear to be redox-dependent. Clindamycin was eliminated more efficiently under oxic infiltration conditions while sulfamethoxazole was eliminated more rapidly under anoxic infiltration conditions. A slight preference for an improved degradation under oxic (clarithromycin and roxithromycin) or anoxic (anhydroerythromycin) conditions was also observed for the macrolide antibiotics. Nevertheless, all macrolides were readily removable by bank filtration both under oxic and anoxic conditions.     

Utilisation of single added fatty acids by consortia of digester sludge in batch culture

Inocula derived from an anaerobic digester were used to study (i) their potential for methane production and (ii) the utilisation rates of different short chain fatty acids (SCFAs) by the microbial community in defined media with mono-carbon sources (formic-, acetetic-, propionic-, butyric acid) in batch culture. It could be demonstrated that the microbial reactor population could be transferred successfully to the lab, and its ability to build up methane was present even with deteriorating biogas plant performance. Therefore, this reduction in performance of the biogas plant was not due to a decrease in abundance, but due to an inactivity of the microbial community. Generally, the physico-chemical properties of the biogas plant seemed to favour hydrogenotrophic methanogens, as seen by the high metabolisation rates of formate compared with all other carbon sources. In contrast, acetoclastic methanogenesis could be shown to play a minor role in the methane production of the investigated biogas plant, although the origin of up to 66% of methane is generally suggested to be generated through acetoclastic pathway.     

Milk ejection solicitations and non-nutritive nursings: an honest signaling system of need in domestic pigs?

In domestic pigs, about 20% of nursing episodes end without milk transfer (non-nutritive nursings, NNNs). The function of NNNs has not been satisfactorily explained yet. Here, we suggest that NNNs may be a part of an honest signaling system that enables the sow to provide more frequent nutritive nursings (NNs) to those litters that can prove their need through exceptionally frequent milk ejection solicitations. We further propose that the system is kept stable through the accelerating costs attached to the solicitation in the form of NNNs. Based on this hypothesis, we predicted that (P1) with an increasing number of all nursings (ALL = NNNs + NNs) the number of NNs should increase and that (P2) with an increasing number of ALL the proportion of NNNs should increase. We tested P1 and P2 using a meta-analysis applied to data from eight studies that recorded the number of NNs and NNNs in domestic pigs. We confirmed both P1 (NNs increasing with ALL) and P2 (proportion of NNNs increasing with ALL). In combination, these results show a steeply accelerating cost of each additional nutritive nursing that piglets instigate. This cost sets limits to the piglets' ability to solicit higher maternal investment through more frequent nursing solicitations.     

Dietary exposure to dioxin-like compounds in three age groups: results from the Flemish environment and health study

Lipophilic contaminants are present in the environment and bioaccumulate in the food chain. Therefore, their intake via animal fat of various sources was assessed for three age groups of the Flemish population, participating in a large biomonitoring program of the Flemish government. In total, 1636 adolescents (14-15 years), 1186 mothers (18-44 years), and 1586 adults (50-65 years) participated in the study and completed a semi quantitative food frequency questionnaire. Individual consumption data were combined, via a so-called simple distribution approach, with recent data on polychlorinated dibenzo-p-dioxins/furans and dioxin-like polychlorinated biphenyls, measured via the chemical-activated luciferase gene expression (CALUX) bio-assay in food items available on the Flemish market. The median (95th percentile) estimated intakes of dioxin-like contaminants were 2.24 (4.61), 2.09 (4.26), and 1.74 (3.53) pg CALUX-TEQ kg(-1) bw d(-1) for, respectively adolescents, mothers and adults. These data are in the same range as those found in other European studies. The CALUX-TEQ results of respectively 59.8%, 53.7% and 36.2% of the adolescent, mother and adult population exceed the tolerable weekly intake (TWI) of 14 pg WHO-TEQ kg(-1) bw w(-1), as derived by the Scientific Committee on Food [Scientific Committee on Food, 2001. Opinion of the Scientific Committee on Food on the Risk Assessment of Dioxins and Dioxin-like PCBs in Food, CS/CNTM/DIOXIN/20 final Brussels, Belgium]. The main contributors of dioxin-like substances are fish and seafood (25-43% of the total intake), added fats (22-25% of the total intake) and dairy products (17-20% of the total intake).     

Survival of selected pathogens in diluted sludge of a thermophilic waste treatment plant and in NaCl-solution under aerobic and anaerobic conditions

Decimal reduction times (DRT or D-value) of Campylobacter jejuni, Salmonella enterica (formerly Salmonella choleraesuis) serovar Senftenberg, Escherichia coli, and Listeria monocytogenes were determined in two different matrices, diluted fermenter sludge (DFS) and 0.95% NaCl-solution (NaCl) at 50 degrees C, both under aerobic and anaerobic conditions. Depending on aeration, matrix composition, and the respective organism, the D-values varied between 10min and more than 15h. Generally the viability of bacteria decreased faster in DFS compared to NaCl-solution and under aerobic compared to anaerobic conditions. After 24h no viable cells could be detected in DFS, both under aerobic as well as under anaerobic conditions, whereas viable cells were still found in NaCl solutions. In both matrices the detection limits determined by means of PCR-based and classical microbiological methods were compared and pointed to lower detection limits of the latter methods. Results of the present investigation show that test organisms were far from surviving several days in DFS whereas hydraulic retention times normally used for thermophilic anaerobic digestion are in the range of 2 weeks. However, an underestimation of survival rates of the test organisms seems probable when applying aerobic standard methods.