Aquatic microcosm assessment of the effects of tylosin on Lemna gibba and Myriophyllum spicatum

Tylosin is a macrolide antibiotic commonly used for therapeutic treatment and prophylaxis in livestock. As part of a larger ecotoxicological study, the potential phytotoxic effects of tylosin on the rooted macrophyte Myriophyllum spicatum and the floating macrophyte Lemna gibba were assessed under semi-field conditions using 15 12 000-L microcosms. Concentrations of 0, 10, 30, 300 microg/L (n = 3), and 600, 1000, and 3000 microg/L (n = 1) were evaluated as part of separate ANOVA and regression analyses over an exposure period of 35 days. Fate of tylosin was monitored over time in the highest three treatments, where dissipation followed pseudo-first order kinetics with associated half-lives ranging from 9 to 10 days. For both M. spicatum and L. gibba, tylosin was found to cause no biologically significant changes to any endpoint assessed compared to controls at a Type I error rate of 0.1. However, subsequent power analyses revealed that there was generally insufficient power to declare that there were no significant differences at a Type II error rate of 0.2. Conclusions concerning biologically significant impacts were therefore further assessed based on other statistical criteria including comparisons of percent differences between replicated treatments and controls, minimum significant and minimum detectable differences, and coefficients of variation. Based on these criteria, at an ecological effect size of >20% change, tylosin was concluded to elicit no biologically or ecologically significant toxicity to M. spicatum or L. gibba. A hazard quotient assessment indicated that tylosin poses little risk to either species of macrophyte, with an HQ value calculated to be nearly three orders of magnitude below 1 (0.002).     

An assessment of the sensitivity and reliability of the relative reduction factor approach in the development of 8-hr ozone attainment plans

The updated regulatory framework for demonstrating that future 8-hr ozone (O3) design values will be at or below the National Ambient Air Quality Standards (NAAQS) provides guidelines for the development of a State Implementation Plan (SIP) that includes methods based on photochemical modeling and analytical techniques. One of the suggested approaches is the relative reduction factor (RRF) for estimating the efficacy of emission reductions. In this study, the sensitivity of model-predicted responses towards emission reductions to the choice of meteorology and chemical mechanisms was examined. While the different modeling simulations generally were found to be in agreement on whether predicted future-year design values would be above or below the NAAQS for 8-hr O3 at a majority of the monitoring locations in the eastern United States, differences existed for a small percentage of monitors (approximately 6.4%). Another issue investigated was the ability of the attainment demonstration procedure to predict changes in monitored O3 design values. A retrospective analysis was performed by comparing predicted O3 design values from model simulations using emission estimates for 1996 and 2001 with monitored O3 design values for 2001. Results indicated that an average gross error of approximately 5 ppb was present between modeled and observed design values and that, at approximately 27% of all sites, model-predicted and observed design values disagreed as to whether the design value was above or below the NAAQS. Retrospective analyses such as the one presented in this study can provide valuable insights into the strengths and limitations of modeling and analysis techniques used to predict future design values over time periods of a decade or more for the purpose of developing SIPs. Furthermore, such analyses could provide avenues for improvement and added confidence in the use of the RRF approach for addressing attainment of the NAAQS.     

Dibenzo-p-dioxins in the environment from ceramics and pottery produced from ball clay mined in the United States

Processed ball clay samples used in the production of ceramics and samples of the ceramic products were collected and analyzed for the presence and concentration of the 2,3,7,8-Cl substituted polychlorinated dibenzo-p-dioxins and -furans (PCDDs/PCDFs). The processed ball clay had average PCDD concentrations of 3.2 ng/g toxic equivalents, a congener profile, and isomer distribution consistent with those found previously in raw ball clay. The PCDF concentrations were below the average limit of detection (LOD) of 0.5 pg/g. The final fired ceramic products were found to be free of PCDDs/PCDFs at the LODs. A consideration of the conditions involved in the firing process suggests that the PCDDs, if not destroyed, may be released to the atmosphere and could represent an as yet unidentified source of dioxins to the environment. In addition, the PCDDs in clay dust generated during manufacturing operations may represent a potential occupational exposure.     

Partielle Ordnung

Zusammenfassung  Sollen Chemikalien oder Umweltbelastungen ?kotoxikologisch beurteilt werden, so erfordert die Komplexit?t ?kosystemarer Zusammenh?nge, da? Bewertungsverfahren Informationen m?glichst nicht aggregieren soilten. Es gibt keine ?kologisch begründete, allgemein verwendbare Zielfunktion. Die Technik, dennoch beispielsweise Chemikalien miteinander vergleichen zu k?nnen, beruht auf der Verallgemeinerung des Ordnungsbegriffs und der Visualisierungsmethode durch Hasse-Diagramme. Am Beispiel von sechs Chemikalien wird das Verfahren erl?utert und gezeigt, da? ungünstige Einstufungen von Chemikalien verschiedene Ursachen haben k?nnen, die dann auch unterschiedliche ?kotoxikologische Konsequenzen bewirken.      

Environmental damage — environmental expenditure 2: Statistical evidence on the Federal Republic of Germany

Summary In part one of this paper (The Environmentalist,1990, pp.301–309) it was shown that conventional economic accounting does not reveal the actual damage to the natural environment, although an ever-increasing share of the Gross National Product is being spent for environmental protection activities. In this, part two of the paper, on the basis of acceptable conventions, the results of an empiric research on defensive expenditures in the GNP are presented, again taking the Federal Republic of Germany as an example. The authors would like to see more research of this type in order to understand better the environmental impacts and the structural deficiencies of modern industrial society. Dr Christian Leipert and Professor Udo E. Simonis have contributed frequently toThe Environmentalist (see 1989, pp.171–183; 1990, pp.25–38; 1990, pp.301–309). Dr Leipert is research fellow, Dr Simonis is research professor at the environmental policy unit of the Science Center Berlin.     

Einsatz der Hasse-Diagrammtechnik zur vergleichenden Bewertung von aquatischen Wirkungstests

In eine ?kotoxikologische Bewertung von Schadstoffen müssen die Ergebnisse von Wirkungstests einflie?en. Die Qualit?t der Bewertung im ?kosystemaren Kontext steht und f?llt mit der ?kosystemaren Qualit?t der Tests. In der vorliegenden Arbeit wird eine Bestandsaufnahme aquatischer Wirkungstests (unabh?ngig von bestehenden legislativen Vorgaben) vorgenommen, und es werden die Ergebnisse in einer Tabelle zusammengestellt, die Einsatzbereiche, Anwendbarkeit für mathematische Wirkungsmodellierung und ?kosystemare Relevanz enth?lt. Die hieraus resultierende Tabelle ist schwer zu überblicken und Zusammenh?nge zwischen bestimmten Wirkungstests sind kaum überschaubar. So ist auch eine Einstufung der aquatischen Wirkungstests ohne zus?tzliche mathematische Hilfsmittel schwierig. Hier wird gezeigt, wie anhand der Technik derHasse-Diagramme die Einstufung der Wirkungstests nach ihrer Qualit?t erleichtert wird. Es zeigt sich u.a., da? es keinen Test gibt, der alle Anforderungen gleichzeitig erfüllt. Einerseits gibt es sechs Tests, die — nach ihren Einsatzbereichen und nach ihrer Umsetzbarkeit für die mathematische Modellierung beurteilt — zwar optimal sind, aber keine ?kosystemare Relevanz aufweisen. Andererseits gibt es zwei Tests, die besonders ausgezeichnet sind: Einer (Test 8), der drei Einsatzbereiche aufweist und gleichzeitig sowohl für die mathematische Modellierung geeignet, als auch ?kosystemar relevant ist, und einer, der in zwei anderen Einsatzbereichen positiv beurteilt wurde und noch ?kosystemar interessant ist (Test 54). Es zeigt sich, da? zwischen Tests mit breitem Einsatzbereich und solchen, die ?kosystemar relevant sind, eine Lücke klafft. An evaluation of pollutants depends on the ecotoxicological quality of the effect tests carried out. In this paper a compilation of aquatic tests is given independently on administration needs. The results are summarized in a table listing fields of application, importance for mathematical modelling and ecological relevance. The table includes 55 tests and 8 attributes characterizing each tests The interpretation of the results listed in this table is hardly feasible. An appropriate tool to rank the tests is the technique ofHasse-diagrams. Using this tool it can be deduced that no test fulfills all demands. There are six tests which are optimal with respect to applicability and mathematical modelling. However, they have no relevance for ecosystems. Only two tests are optimal with respect to ecotoxicology, There is still a gap between tests with a wide field of applications and those tests which are relevant with respect to ecotoxicology.     

Contributions of global and regional sources to mercury deposition in New York State

A modeling system that includes a global chemical transport model (CTM) and a nested continental CTM (TEAM) was used to simulate the atmospheric transport, transformations and deposition of mercury (Hg). Three scenarios were used: (1) a nominal scenario, (2) a scenario conducive to local deposition and (3) a scenario conducive to long-range transport. Deposition fluxes of Hg were analyzed at three receptor locations in New York State. For the nominal scenario, the anthropogenic emission sources (including re-emission of deposited Hg) in New York State, the rest of the contiguous United States, Asia, Europe, and Canada contributed 11-1, 25-9, 13-19, 5-7, and 2-5%, respectively to total Hg deposition at these three receptors. Natural sources contributed 16-4%. The results from the local deposition and long-range transport scenarios varied only slightly from these results. However, there are still uncertainties in our understanding of the atmospheric chemistry of Hg that are likely to affect these estimates of local, regional and global contributions. Comparison of model simulation results with data from the Mercury Deposition Network suggests that local and regional contributions may currently be overestimated.