Soybean [Glycine max (L.) Merr.] cultivars Essex and Forrest that exhibit differences in ozone (O3) sensitivity were used in greenhouse experiments to investigate the role of leaf extracellular antioxidants in O3 injury responses. Charcoal-filtered air and elevated O3 conditions were used to assess genetic, leaf age, and O3 effects. In both cultivars, the extracellular ascorbate pool consisted of 80e98% dehydroascorbic acid, the oxidized form of ascorbic acid (AA) that is not an antioxidant. For all combinations of genotype and O3 treatments, extracellular AA levels were low (1e30 nmol g 1 FW) and represented 3e30% of the total antioxidant capacity. Total extracellular antioxidant capacity was twofold greater in Essex compared with Forrest, consistent with greater O3 tolerance of Essex. The results suggest that extracellular antioxidant metabolites in addition to ascorbate contribute to detoxification of O3 in soybean leaves and possibly affect plant sensitivity to O3 injury.

BACKGROUND, AIM AND SCOPE: Current scientific studies and evaluations clearly show that an increase of urban dust loads, alone or combined with other pollutants und certain meteorological conditions lead to different significant health effects. Premature death, increased hospital admissions and increased respiratory symptoms and diseases as well as decreased lung function can be observed in combination with high pollutant levels. Sensitive groups like elderly people or children and persons with cardiopulmonary diseases such as asthma are more strongly affected. Because of the direct contact between fine particles and lung tissue more information concerning the surface structure (mapping of toxic elements) is required. Materials and Methods:The NanoSims50 ion microprobe images the element composition at the surface of sub-micrometer air dust particles and documents hot spots of toxic elements as a possible threat for human health.Results:The atmospheric fine dust consists of a complex mixture of organic and inorganic compounds. Heavy metals are fixed on airborn particles in the form of hot spots in a nanometer scale. From a sanitary point of view, the hot spots consisting of toxic elements are particularly relevant as they react directly with the lung tissues. Discussion:To what extent particles can penetrate the various areas of the lungs and be deposited there depends on the one hand on their physical characteristics and on the other on breathing patterns and the anatomy of the lung, which is subject to change as the result of growth, ageing or illness. Once inhaled, some particles can reach the pulmonary alveoli and thus directly expose the lung tissues to toxic elements.Conclusions:Especially the mapping of toxic arsenic or heavy metals like copper on the dust particles shows local hot spots of pollution in the dimension of only 50 nanometers.Recommendations and Perspectives:Imaging of elements in atmospheric particles with NanoSIMS will help to identify the material sources.

GOAL, SCOPE AND BACKGROUND: Fragrance preparations or perfumes are used in an increasing variety of applications, as for example washing, cleansing, personal care products, consumer goods or in applications to modify indoor air. However, up to now, little is known to the general or scientific public about their chemical identity and the use pattern of single substances, not even for high production volume chemicals. Some toxicological data are published for a comparatively small number of substances with a focus on sensitisation and dermal effects, while other effects are neglected. Information on ecotoxicity and environmental fate are rare, especially for long-term exposure. Data for a detailed hazard and risk analysis are available in exceptional cases only. According to the current legal situation, fragrance industry is self-regulated, which means that pre-market risk evaluation is not required for most fragrances. Odour and the ability to smell play a major role for wildlife for all taxonomic groups. Reproductive and social behaviour, defence, communication and orientation depend on volatile compounds which can be identical to those used in fragrance preparations. Our interdisciplinary approach leads to the question of whether and, if so, to what extent anthropogenic fragrances may influence life and reproduction of organisms in the environment. MAIN FEATURES: Information from literature on use, exposure and biological effects was combined to analyse the state of knowledge. Following an overview of the amounts of fragrances used in different consumer products and their release into the environment, the roles of odours in nature are shown for a selection of compounds. Existing regulation was analysed to describe the data basis for environmental risk evaluation. Finally, recommendations for further action are derived from these findings. RESULTS: Three main results were elaborated: First, fragrance substances are continuously discharged in large amounts into the environment, especially via the waste water. Second, there are some indications of negative effects on human health or the environment, although the data basis is very thin due to the self regulation of the fragrance industry and the regulatory situation of fragrance substances. Third, many odoriferous substances used by man are identical to those which are signal substances of environmental organisms at very low concentrations, thus giving rise to specific mode of actions in the ecosystem. RECOMMENDATION: For the adequate risk assessments of fragrances, test results on their unspecific as well as their specific effects as signal substances are needed. This would imply prioritisation methods and development of useful test methods for specific endpoints for appropriate risk assessments. Before a comprehensive testing and evaluation of results has been finished, a minimization of exposure should be envisaged. Eco-labelling of products containing acceptable fragrance ingredients could be a first step and provide consumers with the respective information. Transparency concerning the fragrance ingredients used and their biological potency will help to build up confidence between producers and consumers. CONCLUSIONS AND PERSPECTIVES: The interdisciplinary approach, bringing together chemical, biological, toxicological and ecotoxicological data with information provided by manufacturers and with legal and consumer aspects, offers new insights into the field of fragrance substances used in consumer products. The amounts and application fields of fragrance substances increases while fate and effects in the environment are hardly known. The current legal situation is not suited to elucidate the effects of fragrances on human health and the environment sufficiently, especially as it was shown that fragrances may play a considerable role in the ecosystem on the behaviour of organisms. According to the precautionary principle, the lack of knowledge should best be tackled by reducing exposure, especially for compounds such as fragrance substances where no ethical reasons object a substitution by less hazardous chemicals.

BACKGROUND: There has been an increasing concern about the treatment and disposal of contaminated sediment from dredged river, harbor or estuary due to the accumulated toxic organics such as dioxins and inorganics particularly heavy metals like Cr, Pb, Zn, Cu, Hg and Cd. However, considering the huge amount of materials and financial costs involved, any candidate technology must ultimately result to reusable residual by-products. This can only be made possible if the toxic pollutants are removed or stabilized in the raw sediment and then fed back into the materials cycle. Currently, we are developing a pyrolysis process for the commercial-scale cleanup of dioxins and heavy metal-contaminated river sediment to yield reusable char for various economical applications. In this connection, this paper describes our preliminary investigation into the extent of dioxins and heavy metal volatilization from actual contaminated sediment. The stabilization of certain metallic species particularly Cr ions was studied.METHODS: Laboratory scale pyrolysis experiments were conducted using a special horizontal lab-scale pyrolyzer. Sediment samples from Shanghai Suzhou Creek and Tagonoura Harbor were pyrolyzed in the reactor under nitrogen gas at 800°C and different retention times of 30, 60 and 90 min. A constant heating rate of 10°C min-1 was employed. The pyrolysis gas was first allowed to pass through a cold trap to condense the tar. Uncondensed gases were then channeled through a column containing an adsorbent (XAD-2 Resin) for dioxins. Heavy metal concentrations in the initial and final sediment residues were analyzed by ICP (Nippon Jarrel-Ash) following their acid and alkali (for Cr6+) digestion. Dioxins content of the pyrolysis char, tar, and exhaust gases in the dioxin adsorbent were also determined. For comparative purpose, thermal treatment under air flow was conducted.RESULTS: The data for the removal of heavy metals from Suzhou Creek sediment showed very significant reductions in Pb, Zn and Cr6+ content of the sediment at this condition. Percentage removals were 42.4%, 60.8% and 42.2%, respectively. The disappearance of Cr6+ was due to reduction reactions rather than volatilization since the total Cr content remained almost unchanged. Other heavy metals such as Cu, Fe and Ni showed very minimal reductions. Nonetheless, Toxicity Characteristics Leaching Procedure (TCLP) tests confirmed that these residual heavy metals were rather stable in the pyrolysis char. Reduction of toxic Cr6+ at 42.2% has also been achieved by pyrolysis (with N2) as opposed to the more than 580 % increase in Cr6+ observed during thermal oxidation (with air).DISCUSSION: Pyrolysis also remove toxic organics particularly dioxins from the sediment. For the total dioxins, removal percentage of 99.9999% was achieved even at the lowest retention time of 30 min. Almost all polychlorinated dibenzo-p-dioxine (PCDDs) and polychlorinated dibenzo-furans (PCDFs) were removed at any retention time. The TEQs detected from the solid residues were mainly contributed by dioxin-like PCBs, yet these were present in relatively trace quantities. At the shortest retention time of 30 min, only 0.000085 pg-TEQ g-1 of polychlorinated biphenyls (PCBs) was detected in the pyrolysis char. Furthermore, the residual PCBs have very low toxicity ratings and none of the highly toxic PCBs, which were initially present in the sediment such as 3,3',4,4',5-PeCB and 3,3',4,4'5,5'-HxCB, were detected in the char. Results further confirmed that most of the dioxins that were removed were transferred to the gas phase so that volatilization may be considered as the main mechanism for their removal.CONCLUSION: Some heavy metals particularly Pb and Zn can be volatilized under N2 pyrolysis at 800oC. Pyrolysis also prevented the formation of more toxic Cr6+ ions and at the same time resulted to its reduction by around 42.2% contrast to the 580% increase during thermal oxidation. PCDDs and PCDFs have been removed and were not formed in the solid products over the retention time range of 30-90 min at 800°C. Dioxin-like PCBs mostly remained and a retention time of 30 min was found sufficient for its maximum removal. RECOMMENDATIONS AND PERSPECTIVE: . With the above results, a temperature of 800oC at a retention time of 30 min is sufficient for the removal of total dioxins and some heavy metals by volatilization. It is however necessary to destroy the dioxins as well as recover heavy metals in the gas phase. Stability of remaining heavy metals in the char also needs to be confirmed by leaching tests. These are the major concerns, which we are currently evaluating to establish the feasibility of our proposed large scale pyrolysis system for sediment treatment.

- DOI: http://dx.doi.org/10.1065/espr2006.04.299 Goal, Scope and Background This paper describes a statistical modelling approach, suggested as a policy tool in the Athens area for the assessment of the emissions reduction level required to meet the air quality standards for two criteria air pollutants, namely CO and NO2. Methods. More than ten years of hourly CO and NOx-NO2 concentration data measured by the monitoring network of the Hellenic Ministry for the Environment, Physical Planning and Public Works were analyzed and the original dataset has been reduced using a data evaluation procedure. Results and Discussion Seasonal pollutant concentration trends suggested that the reduction of CO and NOx concentrations observed in the beginning of the '90s is almost entirely attributed to the increase of the catalyst-equipped cars during this period. The numerical parameters of an empirical model relating EU standard exceedances with mean annual concentrations were defined and the model was validated using datasets from years that were not used for the estimation of these parameters. This model was used in conjunction with a roll-back equation as a policy tool for the assessment of the effect of different CO and NOx emissions reduction scenarios on air quality standard compliance for CO and NO2. Results predicted with this empirical modelling approach were assessed with monitored data averaged over a 3-year period, giving satisfactory results. Conclusion A methodology suggested for assessing the effects of different emissions reduction scenarios on air quality standard attainment was successfully applied for CO and NO2 in the Athens area. Recommendation and Perspective The proposed methodology can provide a useful tool for the evaluation of policies already in progress as well as the development of future policies for emissions reduction in urban areas with similar characteristics, aiming at air quality standard compliance on a timely manner. Such a methodology could be applied in other urban areas of Greece characterized by dense traffic, therefore assisting the development of national policies in relation to air pollutants for which standard exceedances occur.

BACKGROUND, AIM AND SCOPE: Air quality is an field of major concern in large cities. This problem has led administrations to introduce plans and regulations to reduce pollutant emissions. The analysis of variations in the concentration of pollutants is useful when evaluating the effectiveness of these plans. However, such an analysis cannot be undertaken using standard statistical techniques, due to the fact that concentrations of atmospheric pollutants often exhibit a lack of normality and are autocorrelated. On the other hand, if long-term trends of any pollutant's emissions are to be detected, meteorological effects must be removed from the time series analysed, due to their strong masking effects. MATERIALS AND METHODS: The application of statistical methods to analyse temporal variations is illustrated using monthly carbon monoxide (CO) concentrations observed at an urban site. The sampling site is located at a street intersection in central Valencia (Spain) with a high traffic density. Valencia is the third largest city in Spain. It is a typical Mediterranean city in terms of its urban structure and climatology. The sampling site started operation in January 1994 and monitored CO ground level concentrations until February 2002. Its geographic coordinates are W0º22'52\ N39º28'05\ and its altitude is 11 m. Two nonparametric trend tests are applied. One of these is robust against serial correlation with regards to the false rejection rate, when observations have a strong persistence or when the sample size per month is small. A nonparametric analysis of the homogeneity of trends between seasons is also discussed. A multiple linear regression model is used with the transformed data, including the effect of meteorological variables. The method of generalized least squares is applied to estimate the model parameters to take into account the serial dependence of the residuals of this model. This study also assesses temporal changes using the Kolmogorov-Zurbenko (KZ) filter. The KZ filter has been shown to be an effective way to remove the influence of meteorological conditions on O3 and PM to examine underlying trends. RESULTS: The nonparametric tests indicate a decreasing, significant trend in the sampled site. The application of the linear model yields a significant decrease every twelve months of 15.8% for the average monthly CO concentration. The 95% confidence interval for the trend ranges from 13.9% to 17.7%. The seasonal cycle also provides significant results. There are no differences in trends throughout the months. The percentage of CO variance explained by the linear model is 90.3%. The KZ filter separates out long, short-term and seasonal variations in the CO series. The estimated, significant, long-term trend every year results in 10.3% with this method. The 95% confidence interval ranges from 8.8% to 11.9%. This approach explains 89.9% of the CO temporal variations. DISCUSSION: The differences between the linear model and KZ filter trend estimations are due to the fact that the KZ filter performs the analysis on the smoothed data rather than the original data. In the KZ filter trend estimation, the effect of meteorological conditions has been removed. The CO short-term component is attributable to weather and short-term fluctuations in emissions. There is a significant seasonal cycle. This component is a result of changes in the traffic, the yearly meteorological cycle and the interactions between these two factors. There are peaks during the autumn and winter months, which have more traffic density in the sampled site. There is a minimum during the month of August, reflecting the very low level of vehicle emissions which is a direct consequence of the holiday period. CONCLUSIONS: The significant, decreasing trend implies to a certain extent that the urban environment in the area is improving. This trend results from changes in overall emissions, pollutant transport, climate, policy and economics. It is also due to the effect of introducing reformulated gasoline. The additives enable vehicles to burn fuel with a higher air/fuel ratio, thereby lowering the emission of CO. The KZ filter has been the most effective method to separate the CO series components and to obtain an estimate of the long-term trend due to changes in emissions, removing the effect of meteorological conditions. RECOMMENDATIONS AND PERSPECTIVE: Air quality managers and policy-makers must understand the link between climate and pollutants to select optimal pollutant reduction strategies and avoid exceeding emission directives. This paper analyses eight years of ambient CO data at a site with a high traffic density, and provides results that are useful for decision-making. The assessment of long-term changes in air pollutants to evaluate reduction strategies has to be done while taking into account meteorological variability.

Background, Aim and Scope The article is focused on dioxin, furan, PCB and organochlorine pesticide monitoring in the surface waters of the Central European, protected natural reserve Krivoklatsko, under the UNESCO programme Man and Biosphere. Persistent compounds are presently transported via different means throughout the entire world. This contamination varies significantly between sites. This raises the question of what constitutes the naturally occurring background levels of POPs in natural, unpolluted areas, but which are close to industrialised regions. Information of real background POP contamination can be of high value for risk assessment management of those sites evidently polluted and for the defining of de-contamination limits. Preserved areas should not be seen as isolated regions in which the impacts of human activities and natural factors are either unexpected or overlooked. Every ambient region, even those protected by a law or other means, are still closely connected to neighbouring human developed and impacted areas, and are therefore subject to this anthropogenic contamination. These areas adjacent to natural reserves are sources of diverse substances, via entry of air, water, soil and/or biota. After an extended period of industrial activities, organochlorine pollutants, even those emitted in trace concentrations have reached detectable levels. For future research and for the assessment of environmental changes, present levels of contamination would be of high importance. This work publishes data of the contamination with organochlorine pollutants of this natural region, where biodiversity and ecological functions are of the highest order. Materials and Methods: Semipermeable membrane devices (SPMDs) were utilised as the sampling system. SPMDs were deployed in two small creeks and one water reservoir selected in the central part of the Krivoklatsko Natural Reserve, where it could be expected that any possible contamination by POPs would be lowest. The exposed SPMDs were analysed both for chemical contents of POPs and for toxicity properties. The chemical analyses of dibenzo-dioxins, dibenzo-furans, PCBs and OCPs were analysed by GC/MS/MS on GCQ or PolarisQ (Thermoquest). Toxicity bioassays were performed on the alga Desmodesmus subspicatus, bacteria Vibrio fischeri and crustacean Daphnia magna. All toxicity data were expressed as the effective volume Vtox. Vtox is a toxicity parameter, the determination of which is independent of SPMD deployment time and pre-treatment dilution (unlike, for example, the EC50 of the SPMD extract). Results: The following chemical parameters were monitored: 1) tetra, penta, hexa and hepta dibenzo-p-dioxins and furans; 2) all those detectable from tri- through deca-polychloriated biphenyls (PCBs) and 3) a group of organochlorine pesticides: hexachlorobenzene and isomers of hexachlorocyclohexane, DDE, DDD and DDT. The concentrations of dioxins and furans on the assessed sites varied from under detection levels up to 7 pg.l-1; PCBs were detected in a sum concentration up to 2.8 ng.l-1; and organochlorine pesticides up to 346 pg.l-1. The responses of bioassays used were very low, with the values obtained for Vtox being under 0.03 l/d. Discussion: Toxicity testing showed no toxicity responses, demonstrating that the system used is in coherence with the ecological status of the assessed sites. Values of Vtox were under the critical value - showing no toxicity. The PCA of chemical analysis data and toxicity responses resulted in no correlations between these two groups of parameters. This demonstrated that the present level of contamination has had no direct adverse effects on the biota. Conclusions: The concentration values of six EPA-listed, toxic dioxins and sums of tetra-hepta dioxins; nine EPA toxic dibenzofurans and the sums of tetra-hepta bibenzofurans are presented together with all tri-deka PCBs and organochlorine pesticides (alfa-, beta-, gama-, delta-HCH, HCB, opDDE, ppDDE, opDDD, ppDDD, opDDT, ppDDT). These values represent possible current regional natural background values of these substances monitored within the Central European region, with no recorded adverse effects on the freshwater ecosystem (up until the present time). Recommendations and Perspectives: Assessment of dioxins, furans and other organochlorine compounds within natural reserves can be important for the monitoring of human-induced impacts on preserved areas. No systematic monitoring of these substances in areas not directly affected by industry has generally been realised. There is a paucity of data of the presence of any of these substances within natural regions. Further monitoring of contamination of both soil and biota by dioxins and furans in preserve regions is needed and can be used for future monitoring of man-made activities and/or accidents. Semipermeable membrane devices proved to be a very good sampling system for the monitoring of trace concentrations of ambient organochlorine compounds. Toxicity evaluation using the Vtox concept demonstrated that those localities assessed expressed no toxicity.

"Artificial neural networks (ANNs), which are parallel computational models, comprising of interconnected adaptive processing units (neurons) have the capability to predict accurately the dispersive behavior of vehicular pollutants under complex environmental conditions. This book aims at describing step-by-step procedure for formulation and development of ANN based VP models considering meteorological and traffic parameters. The model predictions are compared with existing line source deterministic/statistical based models to establish the efficacy of the ANN technique in explaining frequent dispersion complexities in urban areas. The book is very useful for hardcore professionals and researchers working in problems associated with urban air pollution management and control."--Jacket.