Predictions of U.K. regulated power station contributions to regional air pollution and deposition: a model comparison exercise

Contributions of the emissions from a U.K. regulated fossil-fuel power station to regional air pollution and deposition are estimated using four air quality modeling systems for the year 2003. The modeling systems vary in complexity and emphasis in the way they treat atmospheric and chemical processes, and include the Community Multiscale Air Quality (CMAQ) modeling system in its versions 4.6 and 4.7, a nested modeling system that combines long- and short-range impacts (referred to as TRACK-ADMS [Trajectory Model with Atmospheric Chemical Kinetics-Atmospheric Dispersion Modelling System]), and the Fine Resolution Atmospheric Multi-pollutant Exchange (FRAME) model. An evaluation of the baseline calculations against U.K. monitoring network data is performed. The CMAQ modeling system version 4.6 data set is selected as the reference data set for the model footprint comparison. The annual mean air concentration and total deposition footprints are summarized for each modeling system. The footprints of the power station emissions can account for a significant fraction of the local impacts for some species (e.g., more than 50% for SO2 air concentration and non-sea-salt sulfur deposition close to the source) for 2003. The spatial correlation and the coefficient of variation of the root mean square error (CVRMSE) are calculated between each model footprint and that calculated by the CMAQ modeling system version 4.6. The correlation coefficient quantifies model agreement in terms of spatial patterns, and the CVRMSE measures the magnitude of the difference between model footprints. Possible reasons for the differences between model results are discussed. Finally, implications and recommendations for the regulatory assessment of the impact of major industrial sources using regional air quality modeling systems are discussed in the light of results from this case study.     

Mapping bundles of ecosystem services reveals distinct types of multifunctionality within a Swedish landscape

Ecosystem services (ES) is a valuable concept to be used in the planning and management of social–ecological landscapes. However, the understanding of the determinant factors affecting the interaction between services in the form of synergies or trade-offs is still limited. We assessed the production of 16 ES across 62 municipalities in the Norrström drainage basin in Sweden. We combined GIS data with publically available information for quantifying and mapping the distribution of services. Additionally, we calculated the diversity of ES for each municipality and used correlations and k-means clustering analyses to assess the existence of ES bundles. We found five distinct types of bundles of ES spatially agglomerated in the landscape that could be explained by regional social and ecological gradients. Human-dominated landscapes were highly multifunctional in our study area and urban densely populated areas were hotspots of cultural services.     

Inventing the future: scenarios, imagination, mastery and control

The complexity of mixed social, behavioral, and natural systems—such as those encountered while analyzing, understanding, and trying to manage aspects of climate change and sustainability, requires more common theoretical frameworks and technical tools than either can bear. How does human activity relate to greenhouse gas emissions, changes in the atmosphere, climate variability, and multiple impacts, outcomes, and effects? Some of the connections can be observed and measured, many cannot. Uncertainties of every conceivable sort can occur. As the time frame into the future extends, uncertainties essentially dominate conventional theories, tools, experiences, habits, processes, and so forth. The scientific consensus linking human activity to climate change is now all but settled according to The Fourth Assessment Report of the Intergovernmental Panel on Climate Change. The consensus says little, however, about who should be doing what and for what reasons under this singular, even unique circumstance. There are no data about the future on which to rely. We are challenged to imagine many different and possible “futures” as humankind seeks to exert its mastery and control. This essay considers and then weaves together several basic issues, ideas, and topics: complexity, the concept of human intentionality, several means used to exert control in organizations and social systems, and different methods being used to imagine, invent, and communicate the future.     

Phytoremediation: The uptake of metals and metalloids by rhodes grass grown on metal‐contaminated soil

An experiment was performed to examine the phytoremediation potential of Rhodes grass (Chloris gayana Kunth cv. ‘Pioneer’). The study sought to determine substrate tolerance, biomass production, and plant uptake of antimony (Sb), arsenic (As), cadmium (Cd), lead (Pb), silver (Ag), and zinc (Zn). The plants were grown on weight percent mixtures (5 percent, 15 percent, 25 percent, 35 percent, 50 percent) of a vertisol soil and base‐metal mine tailings (7–2,040 μg/g As, ≥ 30 μg/g Cd, 30–12,000 μg/g Pb, and 72–4,120 μg/g Zn). The 5 percent and 15 percent amendment of mine tailings increased the biomass production of Rhodes grass (from 0.1 g/plant to ≈ 3.5 g/plant) without appreciably elevating plant concentrations of the elements. Plant growth decreased by greater than 50 percent for the substrate containing greater than 25 percent tailings (3,023 μg/g Pb and 1,084 μg/g Zn). Reduced biomass production coincided with maximal Zn uptake by Rhodes grass (249.8 μg/g), indicating tailings induced phytotoxicity. The total concentrations of metals and metalloids tolerated by Rhodes grass in the plant‐growth medium indicated hypertolerance to elevated As, Pb, and Zn concentrations. Partial extraction of the plant‐growth medium determined that plant‐available Pb was ten times higher than Ag, As, Cd, and Zn availability. However, Rhodes grass accumulated low levels of Pb, in addition to As and Cd, over the experimental range, indicating low fodder toxicity risk to browsing livestock. This study concludes that if there are no invasive species issues associated with conservation land uses, Rhodes grass is well suited to metalliferous mined land revegetation and would therefore be highly effective for such programs in subtropical and tropical Australia. © 2005 Wiley Periodicals, Inc.     

DETECTING REDUCTIONS IN SEDIMENT LOADS ASSOCIATED WITH OHIO'S CONSERVATION RESERVE ENHANCEMENT PROGRAM1

ABSTRACT: Small systematic changes in loads or concentrations of water quality constituents are difficult to detect against the background of short term fluctuations (“noise”) that result from weather and climate effects. Minimum Detectable Change Analysis (MDCA) uses prior knowledge of a water quality constituent to determine how much change must occur (e.g., from implementation of conservation practices) for the change to be statistically significant. In this paper we use MDCA to determine whether the goal of the Ohio Lake Erie Conservation Reserve Enhancement Program (CREP), to reduce sediment loads by an average of 6 percent over 10 years, represents a large enough change to be detected. We conclude that this amount of change is unlikely to be detected as statistically significant, even with the high frequency sampling program planned for evaluating it. The minimum detectable change ranges from about 7 to 9 percent for three different rivers.     

Breaking the dogma: PCB-derived semiquinone free radicals do not form covalent adducts with DNA,GSH, and amino acids

Covalent bond formations of free radical metabolites with biomolecules like DNA and proteins are thought to constitute a major mechanism of toxicity and carcinogenesis. Glutathione (GSH) is generally accepted as a radical scavenger protecting the cell. In the present study, we investigated a semiquinone radical (SQ^●-) metabolite of the semivolatile 4-chlorobiphenyl, using electron paramagnetic resonance spectroscopy, and oxygen consumption. Proton nuclear magnetic resonance (¹H NMR) and liquid chromatography–mass spectrometry (LC-MS) were also employed to elucidate the radical interaction with DNA, amino acids, and GSH. We found that DNA and oligonucleotides stabilized SQ^●- by electron delocalization in the π-stacking system, resulting in persistent radical intercalated, rather than forming a covalent bond with SQ^●-. This finding was strongly supported by the semiempirical calculation of the semioccupied molecular orbital and the linear combination of the atomic orbitals, indicating 9.8 kcal mol^?1 energy gain. The insertion of SQ^●- into the DNA strand may result in DNA strand breaks and interruption of DNA replication process or even activate radical mediated secondary reactions. The presence of amino acids resulted in a decrease of the electron paramagnetic resonance (EPR) signal of SQ^●- and correlated with their isoelectric points. The pH shifts the equilibrium of the dianions of hydroquinone and influenced indirectly the formation of SQ^●-. Similar findings were observed with GSH and Cys. GSH and Cys functioned as indirect radical scavengers; their activities depend on their chemical equilibria with the corresponding quinones, and their further reaction via Michael addition. The generally accepted role of GSH as radical scavenger in biological systems should be reconsidered based upon these findings, questioning the generally accepted view of radical interaction of semiquinones with biologically active compounds, like DNA, amino acids, proteins, and radical scavengers like GSH.     

Critical Review of Exposure and Effects: Implications for Setting Regulatory Health Criteria for Ingested Copper

Environmental Management - Decades of study indicate that copper oral exposures are typically not a human health concern. Ingesting high levels of soluble copper salts can cause acute...     

Pediatrician attitudes, knowledge, and practice behavior regarding teen driving safety

Problem

Each year about 4,000 teens ages 16-19 die on U.S. roads. Injury prevention counseling is recommended as a valuable and cost-effective part of routine health supervision. This study describes pediatrician knowledge and practice regarding teen driving safety.

Methods

A 31-item self-administered survey was mailed to pediatricians.

Results

160 of 392 pediatricians (41%) completed the survey. During a health supervision visit 93% of pediatricians reported discussing seat belt use, 89% impaired driving, 54% teen licensing laws, and 16% parent teen contract. Half reported having a teen in their practice killed in a crash.

Conclusions

A majority surveyed report discussing and counseling teens on first wave teen driver safety issues (seat belts, alcohol use), but most do not discuss graduated driver licensing laws or related issues. Impact on Industry: Broadly adopted, this inexpensive counseling approach, could lead to reductions in teen motorvehicle crash injuries.     

Relative influence of environmental factors and fishing on coral reef fish assemblages

Understanding whether assemblages of species respond more strongly to bottom-up (availability of trophic resources or habitats) or top-down (predation pressure) processes is important for effective management of resources and ecosystems. We determined the relative influence of environmental factors and predation by humans in shaping the density, biomass, and species richness of 4 medium-bodied (10–40 cm total length [TL]) coral reef fish groups targeted by fishers (mesopredators, planktivores, grazer and detritivores, and scrapers) and the density of 2 groups not targeted by fishers (invertivores, small fish ≤10 cm TL) in the central Philippines. Boosted regression trees were used to model the response of each fish group to 21 predictor variables: 13 habitat variables, 5 island variables, and 3 fishing variables (no-take marine reserve [NTMR] presence or absence, NTMR size, and NTMR age). Targeted and nontargeted fish groups responded most strongly to habitat variables, then island variables. Fishing (NTMR) variables generally had less influence on fish groups. Of the habitat variables, live hard coral cover, structural complexity or habitat complexity index, and depth had the greatest effects on density, biomass, and species richness of targeted fish groups and on the density of nontargeted fishes. Of the island variables, proximity to the nearest river and island elevation had the most influence on fish groups. The NTMRs affected only fishes targeted by fishers; NTMR size positively correlated with density, biomass, and species richness of targeted fishes, particularly mesopredatory, and grazing and detritivorous fishes. Importantly, NTMRs as small as 15 ha positively affected medium-bodied fishes. This finding provides reassurance for regions that have invested in small-scale community-managed NTMRs. However, management strategies that integrate sound coastal land-use practices to conserve adjacent reef fish habitat, strategic NTMR placement, and establishment of larger NTMRs will be crucial for maintaining biodiversity and fisheries.