A rapid approach to rational water pollution control strategies

The formulation of rational wastewater control strategies is becoming increasingly important in many countries where, exploding urbanization, industrialization and/or tourism, often combined with improved standards of living and better awareness of the environmental problems, are resulting in enlarged pollution problems, but also in the availability of expanding financial resources for environmental protection. However, more often than one tends to believe, lack of planning, or planning with limited understanding of the principles involved, has resulted in solutions that are both expensive and incapable of addressing the key problems.As rigorous planning is extremely resource intensive, and for this reason impractical for most study areas, the development of a much simplified analysis procedure, capable of generating rational, near-optimum, strategies and detailed action programs, is required, if proper environmental management is to be widely practiced.In an effort to achieve the above objectives, a systems analysis approach is selected as the most suitable at rationalizing the allocation of available resources and at producing detailed action programs that promote implementation. In the context of this approach, new, easy to use models have been developed, while others, have been selected, adapted and streamlined in their use. The entire problem analysis and strategy synthesis procedures have thus been simplified and defined to a degree appropriate for widespread use, and the resultant procedure is actively promoted by WHO and UNEP.     

Multi-component assessment of worker exposures in a copper refinery. Part 1. Environmental monitoring

The exposure characterisation described in this paper for 135 copper refinery workers (45 females, 90 males) focuses on the concentrations of copper, nickel and other trace elements in the inhalable aerosol fractions, as well as in the water-soluble and water-insoluble subfractions. Some information is also provided on the thoracic and respirable aerosol fractions. Further, results are presented for volatile hydrides of arsenic and selenium released in the copper purification steps of the electrorefining process. For the pyrometallurgical operations, a comparison of the geometric means for the inhalable aerosol fraction indicated that water-soluble copper levels were on average 19-fold higher compared to nickel (p < 0.001) and a significant association was evident between them (r = 0.87, p < 0.001); for the insoluble subfraction, the copper : nickel ratio was 12.5 (p < 0.001) and the inter-element correlation had r = 0.98 and p < 0.001. Although for the electrorefinery workers the relative inhalable concentrations of copper and nickel were not significantly different (p > 0.05), the corresponding inter-element associations were: slope of 7.7, r= 0.54, p < or =0.001 for the water-soluble subfraction and slope of 1.3, r = 0.71 and p < or =0.001 for the water-insoluble subfraction. On average, a good proportion of the inhalable copper and nickel were found in the thoracic (40%) and respirable (20%) aerosol fractions. Cobalt air concentrations were generally low with geometric means and 95% confidence intervals of 3.1 (2.4-4.2)microg m(-3) (pyrometallurgical workers) and 0.3 (0.4-0.5) microg m(-3)(electrorefinery workers). Similarly, the maximum concentrations of cadmium and lead were low, respectively 4 and 25 microg m(-3). Of the hydrides, tellurium and antimony could not be detected, but for the arsenic (arsine) and selenium hydrides measurable exposure occurred for almost all electrorefinery workers, although the levels were generally low at 0.2 microg m(-3).     

In vivo K-shell X-ray fluorescence bone lead measurements in young adults

The (109)Cd K-shell X-ray fluorescence (XRF) technique was used to measure in vivo tibia lead concentrations of 34 young adults living in the state of Vermont (USA) and the province of New Brunswick (Canada). The subjects ranged in age from 18 to 35 years, and had no known history of elevated lead exposure. Measurement parameters were varied, using the same XRF system for both populations. Tibia lead concentrations were low for both groups, with mean values of 0.7 microg lead g(-1) bone mineral (Vermont) and 0.5 microg g(-1)(New Brunswick). No individual measurement exceeded 7 microg g(-1). Mean uncertainty values obtained for the Vermont and New Brunswick subjects were 4.1 microg g(-1) and 2.6 microg g(-1), respectively. Improved measurement uncertainty in the New Brunswick group was attributed to the use of a reduced source-to-skin distance (approximately 5 mm) and a longer measurement time (3600 seconds) using a weaker radioisotope source (< or =0.42 GBq). Measurement uncertainty tended to increase with body mass index. For a given body mass index, female subjects returned a measurement uncertainty approximately 1 microg g(-1) greater than males.     

How Hydrologic Connectivity Regulates Water Quality in River Corridors

Downstream flow in rivers is repeatedly delayed by hydrologic exchange with off‐channel storage zones where biogeochemical processing occurs. We present a dimensionless metric that quantifies river connectivity as the balance between downstream flow and the exchange of water with the bed, banks, and floodplains. The degree of connectivity directly influences downstream water quality — too little connectivity limits the amount of river water exchanged and leads to biogeochemically inactive water storage, while too much connectivity limits the contact time with sediments for reactions to proceed. Using a metric of reaction significance based on river connectivity, we provide evidence that intermediate levels of connectivity, rather than the highest or lowest levels, are the most efficient in removing nitrogen from Northeastern United States’ rivers. Intermediate connectivity balances the frequency, residence time, and contact volume with reactive sediments, which can maximize the reactive processing of dissolved contaminants and the protection of downstream water quality. Our simulations suggest denitrification dominantly occurs in riverbed hyporheic zones of streams and small rivers, whereas vertical turbulent mixing in contact with sediments dominates in mid‐size to large rivers. The metrics of connectivity and reaction significance presented here can facilitate scientifically based prioritizations of river management strategies to protect the values and functions of river corridors.     

The antifungal activity of the leaf gland volatile oil of sweet gale (Myrica gale) (Myricaceae)

Summary The antifungal activity of volatile oil obtained from the leaves of sweet gale (Myrica gale) has been investigated. Fungi, isolated from the leaves ofM. gale, were grown in liquid medium containing the oil and its effect on biomass production was gauged. The oil inhibited growth of all species of fungi to greater or lesser extent. Sesquiterpenes were more active than monoterpenes, and among the sesquiterpenes germacrone was marginally more active than -elemenone. These results support the proposition that the volatile oil ofM. gale has a role in resistance to fungal pathogens.     

Connectivity of Streams and Wetlands to Downstream Waters: An Integrated Systems Framework

Interest in connectivity has increased in the aquatic sciences, partly because of its relevance to the Clean Water Act. This paper has two objectives: (1) provide a framework to understand hydrological, chemical, and biological connectivity, focusing on how headwater streams and wetlands connect to and contribute to rivers; and (2) briefly review methods to quantify hydrological and chemical connectivity. Streams and wetlands affect river structure and function by altering material and biological fluxes to the river; this depends on two factors: (1) functions within streams and wetlands that affect material fluxes; and (2) connectivity (or isolation) from streams and wetlands to rivers that allows (or prevents) material transport between systems. Connectivity can be described in terms of frequency, magnitude, duration, timing, and rate of change. It results from physical characteristics of a system, e.g., climate, soils, geology, topography, and the spatial distribution of aquatic components. Biological connectivity is also affected by traits and behavior of the biota. Connectivity can be altered by human impacts, often in complex ways. Because of variability in these factors, connectivity is not constant but varies over time and space. Connectivity can be quantified with field‐based methods, modeling, and remote sensing. Further studies using these methods are needed to classify and quantify connectivity of aquatic ecosystems and to understand how impacts affect connectivity.     

Making the sustainable more sustainable: public transport and the collaborative spaces of policy translation

This paper investigates where and how sustainable transport goals are translated into public transport planning and operations. The case where this is explored is the Regional Public Transport Authority (RPTA) in Stockholm, Sweden. By drawing upon recent discussions on policy translation and political–administrative relationships, sustainable transport is found to be translated in two different collaborative spaces in the RTPA. In the market side of the authority, which is mainly preoccupied with procurement of traffic and compliance issues, sustainable transport is translated into quantitative goals (including biofuels, emissions, noise, etc.) and mechanically reproduced from the politicians via the civil servants to the private operators. In the planning side of the authority, sustainability measurements have been hard to quantify and the challenge to integrate land-use and transport planning is resolved in an organic manner, in specific projects, between the strategic transport planners in the RPTA and the land-use planners in the municipalities, at a distance from the politicians’ involvement. Throughout the RPTA, sustainable transport has broadened to also include social sustainability, although this has been difficult to translate into quantitative measurements, which is the desired mode of governance by the politicians.     

Expert judgment and uncertainty regarding the protection of imperiled species

Decisions concerning the appropriate listing status of species under the U.S. Endangered Species Act (ESA) can be controversial even among conservationists. These decisions may determine whether a species persists in the near term and have long‐lasting social and political ramifications. Given the ESA's mandate that such decisions be based on the best available science, it is important to examine what factors contribute to experts’ judgments concerning the listing of species. We examined how a variety of factors (such as risk perception, value orientations, and norms) influenced experts’ judgments concerning the appropriate listing status of the grizzly bear (Ursus arctos horribilis) population in the Greater Yellowstone Ecosystem. Experts were invited to complete an online survey examining their perceptions of the threats grizzly bears face and their listing recommendation. Although experts’ assessments of the threats to this species were strongly correlated with their recommendations for listing status, this relationship did not exist when other cognitive factors were included in the model. Specifically, values related to human use of wildlife and norms (i.e., a respondent's expectation of peers’ assessments) were most influential in listing status recommendations. These results suggest that experts’ decisions about listing, like all human decisions, are subject to the use of heuristics (i.e., decision shortcuts). An understanding of how heuristics and related biases affect decisions under uncertainty can help inform decision making about threatened and endangered species and may be useful in designing effective processes for protection of imperiled species.     

Sparrow Modeling to Understand Water‐Quality Conditions in Major Regions of the United States: A Featured Collection Introduction1

Preston, Stephen D., Richard B. Alexander, and David M. Wolock, 2011. SPARROW Modeling to Understand Water‐Quality Conditions in Major Regions of the United States: A Featured Collection Introduction. Journal of the American Water Resources Association (JAWRA) 47(5):887‐890. DOI: 10.1111/j.1752‐1688.2011.00585.x     

Greenhouse effect of clusterization of CO2 and CH4 with atmospheric moisture

Carbon dioxide and methane are major compounds involved in global warming. The process of CO₂ and CH₄ molecules absorption by water clusters was investigated by the molecular dynamics method. The frequency spectra of dielectric permittivity for systems consisting of (H₂O) _n , (CO₂) _i (H₂O)₁₀ and (CH₄) _i (H₂O)₁₀ clusters mixed in various proportions were determined. The IR radiation absorption spectra of these systems were calculated and compared. Also, the radiating power of these systems was established. The capture of greenhouse gases’ molecules by ultra disperse water media reduces the ability of the media to absorb the Earth’s radiation, i.e., it reduces the greenhouse effect.