The effects of dissolved organic matter and pH on sampling rates for polar organic chemical integrative samplers (POCIS)

The effect of solution pH and levels of dissolved organic matter (DOM) on the sampling rates for model pharmaceuticals and personal care products (PPCPs) and endocrine disrupting substance (EDS) by polar organic chemical integrative samplers (POCIS) was investigated in laboratory experiments. A commercially available POCIS configuration containing neutral Oasis HLB (hydrophilic-lipophilic balance) resin (i.e. pharmaceutical POCIS) and two POCIS configurations prepared in-house containing MAX and MCX anion and cation exchange resins, respectively were tested for uptake of 21 model PPCPs and EDS, including acidic, phenolic, basic and neutral compounds. Laboratory experiments were conducted with dechlorinated tap water over a pH range of 3, 7 and 9. The effects of DOM were studied using natural water from an oligotrophic lake in Ontario, Canada (i.e. Plastic Lake) spiked with different amounts of DOM (the concentration of dissolved organic carbon ranged from 3 to 5 mg L⁻¹ in uptake experiments). In experiments with the commercial (HLB) POCIS, the MCX-POCIS and the MAX-POCIS, the sampling rates generally increased with pH for basic compounds and declined with pH for acidic compounds. However, the sampling rates were relatively constant across the pH range for phenols with high pKa values (i.e. bisphenol A, estrone, estradiol, triclosan) and for the neutral pharmaceutical, carbamazepine. Thus, uptake was greatest when the amount of the neutral species in solution was maximized relative to the ionized species. Although the solution pH affected the uptake of some model ionic compounds, the effect was by less than a factor of 3. There was no significant effect of DOM on sampling rates from Plastic Lake. However, uptake rates in different aqueous matrixes declined in the order of deionized water > Plastic Lake water > dechlorinated tap water, so other parameters must affect uptake into POCIS, although this influence will be minor. MAX-POCIS and MCX-POCIS showed little advantage over the commercial POCIS configuration for monitoring in natural waters.     

Atmospheric mercury monitoring survey in Beijing,China

With the aid of one industrial, two urban, two suburban, and two rural sampling locations, diurnal patterns of total gaseous mercury (TGM) were monitored in January, February and September of 1998 in Beijing, China. Monitoring was conducted in six (two urban, two suburban, one rural and the industrial sites) of the seven sampling sites during January and February (winter) and in four (two urban, one rural, and the industrial sites) of the sampling locations during September (summer) of 1998. In the three suburban sampling stations, mean TGM concentrations during the winter sampling period were 8.6, 10.7, and 6.2 ng/m3, respectively. In the two urban sampling locations mean TGM concentrations during winter and summer sampling periods were 24.7, 8.3, 10, and 12.7 ng/m3, respectively. In the suburban-industrial and the two rural sampling locations, mean mercury concentrations ranged from 3.1-5.3 ng/m3 in winter to 4.1-7.7 ng/m3 in summer sampling periods. In the Tiananmen Square (urban), and Shijingshan (suburban) sampling locations the mean TGM concentrations during the summer sampling period were higher than winter concentrations, which may have been caused by evaporation of soil-bound mercury in warm periods. Continuous meteorological data were available at one of the suburban sites, which allowed the observation of mercury concentration variations associated with some weather parameters. It was found that there was a moderate negative correlation between the wind speed and the TGM concentration at this suburban sampling location. It was also found that during the sampling period at the same site, the quantity of TGM transported to or from the sampling site was mainly influenced by the duration and frequency of wind occurrence from certain directions.     

Sharing conservation burdens fairly

We examined how, from the point of view of justice, the burdens of paying for conservation should be shared. I resisted simple answers to the question of who should pay for conservation that lean on a single moral principle. I identified 3 relevant principles that relate to who causes conservation challenges, who has greater capacity to carry burdens, and who stands to benefit from conservation. I argue for a distinctive pluralist framework for allocating conservation burdens that grants a proper role to all 3 principles. A multistep process can be used to put the framework into practice. First, identify cases in which conservation is necessary. Second, consider whether people knew or could have been expected to anticipate the consequences of their activities and whether they had reasonable alternatives to acting the way they did. Third, turn to facts about benefits; when no culprit for conservation challenges can be found, ask who benefits from acts of conservation. In the second and third stages, consideration must also be given to ability to pay.     

COVID-19: the impact of a global crisis on sustainable development teaching

Environment, Development and Sustainability - The COVID-19 pandemic has caused a global crisis, one which also influences the ways sustainability is being taught at universities. This paper...     

Improving collection efficiency through remote monitoring of charity assets

Collection costs associated with servicing a major UK charity’s donation banks and collecting unsold goods from their retail shops can account for up to 20% of the overall income gained. Bank and shop collections are commingled and are typically made on fixed days of the week irrespective of the amounts of materials waiting to be collected. Using collection records from a major UK charity, this paper considers what vehicle routing and scheduling benefits could accrue if bank and shop servicing requirements were monitored, the former using remote sensing technology to allow more proactive collection scheduling. A vehicle routing and scheduling algorithm employing tabu search methods was developed, and suggested time and distance savings of up to 30% over the current fixed schedules when a minimum bank and shop fill level of between 50% and 60% was used as a collection trigger. For the case study investigated, this led to a potential revenue gain of 5% for the charity and estimated CO₂ savings of around 0.5 tonnes per week across the fleet of six heterogeneous vehicles.     

Background level of risk determines the intensity of predator neophobia in juvenile convict cichlids

Behavioural ecology is rife with examples of prey animals that are able to adjust the intensity of their anti-predator response to match background risk levels. Often, preys need experience with predators before they will invest in costly anti-predator responses. This means that prey animals often fail to respond to predators during their first encounter. Recently, we have shown that prey raised under high-risk conditions may exhibit avoidance of potential predation cues independent of experience (neophobia). Such phenotypically plastic neophobic predator responses may reduce the initial costs of learning ecologically relevant threats while maintaining sufficient behavioural plasticity to respond to variation in local conditions. Here, we test if induced neophobia results in threat-sensitive behavioural trade-offs in response to a novel chemosensory cue. Our first experiment shows that while juvenile convict cichlids (Amatitlania nigrofasciata) pre-exposed to high (but not low) risk conditions exhibited predator avoidance to a novel odour (rainbow trout, Oncorhynchus mykiss), the response intensity was not influenced by the concentration of trout odour detected. Our second experiment demonstrated that the intensity of anti-predator response towards a novel predator cue was dependent upon the level of background risk. Convict cichlids pre-exposed to high-risk conditions showed stronger responses than those pre-exposed to low-risk conditions, while cichlids pre-exposed to intermediate-risk conditions exhibited intermediate response intensities. Together, these data demonstrate that background levels of risk and not the concentration of novel cues detected shape the induced neophobic response pattern of juvenile convict cichlids.     

An integrated modeling framework for performing environmental assessments: Application to ecosystem services in the Albemarle-Pamlico basins (NC and VA, USA)

The U.S. Environmental Protection Agency uses environmental models to inform rulemaking and policy decisions at multiple spatial and temporal scales. As decision-making has moved towards integrated thinking and assessment (e.g. media, site, region, services), the increasing complexity and interdisciplinary nature of modern environmental problems has necessitated a new generation of integrated modeling technologies. Environmental modelers are now faced with the challenge of determining how data from manifold sources, types of process-based and empirical models, and hardware/software computing infrastructure can be reliably integrated and applied to protect human health and the environment.In this study, we demonstrate an Integrated Modeling Framework that allows us to predict the state of freshwater ecosystem services within and across the Albemarle-Pamlico Watershed, North Carolina and Virginia (USA). The Framework consists of three facilitating technologies: Data for Environmental Modeling automates the collection and standardization of input data; the Framework for Risk Assessment of Multimedia Environmental Systems manages the flow of information between linked models; and the Supercomputer for Model Uncertainty and Sensitivity Evaluation is a hardware and software parallel-computing interface with pre/post-processing analysis tools, including parameter estimation, uncertainty and sensitivity analysis. In this application, five environmental models are linked within the Framework to provide multimedia simulation capabilities: the Soil Water Assessment Tool predicts watershed runoff; the Watershed Mercury Model simulates mercury runoff and loading to streams; the Water quality Analysis and Simulation Program predicts water quality within the stream channel; the Habitat Suitability Index model predicts physicochemical habitat quality for individual fish species; and the Bioaccumulation and Aquatic System Simulator predicts fish growth and production, as well as exposure and bioaccumulation of toxic substances (e.g., mercury).Using this Framework, we present a baseline assessment of two freshwater ecosystem services-water quality and fisheries resources-in headwater streams throughout the Albemarle-Pamlico. A stratified random sample of 50 headwater streams is used to draw inferences about the target population of headwater streams across the region. Input data is developed for a twenty-year baseline simulation in each sampled stream using current land use and climate conditions. Monte Carlo sampling (n = 100 iterations per stream) is also used to demonstrate some of the Framework's experimental design and data analysis features. To evaluate model performance and accuracy, we compare initial (i.e., uncalibrated) model predictions (water temperature, dissolved oxygen, fish density, and methylmercury concentration within fish tissue) against empirical field data. Finally, we ‘roll-up’ the results from individual streams, to assess freshwater ecosystem services at the regional scale.     

A case study of GM maize gene flow in South Africa

In order to thank Prof. Dr. Hans-Toni Ratte on the occasion of his retirement for his outstanding experimental and modelling merits in the field of ecotoxicology and ecology and his personal 65th anniversary on November 25th this article will present a laudation.