Background, aim, and scope Photochemical smog, characterized by high concentrations of O₃ and fine particles, is of great concern in the urban areas, in particular megacities and city clusters like the Pearl River Delta. Materials, methods, and results Ambient ozone (O₃) and its precursors were simultaneously measured at two sites in the Pearl River Delta, namely, Wan Qing Sha (WQS) in Guangzhou and Tung Chung (TC) in Hong Kong, from 23 October to 01 December 2007 in order to explore their potential relationship. Eight high O₃ episode days were identified at WQS and two at TC during the sampling campaign, indicating a more serious O₃ pollution in Guangzhou than in Hong Kong. An observation-based model was employed to determine the ozone-precursor relationship. At both sites, O₃ production was found to be volatile organic compound (VOC)-limited, which is consistent with previous observations. Anthropogenic hydrocarbons played a key role in O₃ production, while reducing nitric oxide emissions aided the buildup of O₃ concentrations. Among VOC species, the summed relative incremental reactivity (RIR) of the top 12 compounds accounted for 89% and 85% of the total RIR at WQS and TC, respectively, indicating that local photochemical O₃ formation can be mainly attributed to a small number of VOC species. Discussion and conclusions A large increment in both simulated HO₂ and O₃ concentrations was achieved with additional input of hourly carbonyl data. This suggested that apart from hydrocarbons, carbonyls might significantly contribute to the O₃ production in the Pearl River Delta.

Background, aim, and scope This review deals with publications concerning the mode of action of Bt proteins and their potential synergism with extrinsic factors. The aim was to assess the impact of those factors especially regarding selectivity and efficacy of Bt toxins and to discuss possible gaps in current risk assessment of genetically engineered plants expressing Bt toxins. Main features The review shows that several extrinsic factors are able to influence the selectivity and efficacy of Bt toxins. The findings are seen as being relevant for risk assessment in Bt plants. This conclusion is derived by discussing current state of knowledge about the mode of action of Bt proteins, unexpected effects on non-target organism, and the way how modified Bt toxins are expressed in genetically engineered plants. Results Several publications have been identified that show that certain factors and synergism can impact efficacy and selectivity of Bt toxins. These extrinsic factors are various and include other Bt toxins or parts from the spore of Bacillus thuringiensis as well as certain enzymes, environmental stress, non-pathogenic microorganisms, and infectious diseases. Discussion Research on the underlying mechanism of observed synergism might help to explain some of the effects found in non-target organisms. In general, possible synergism of Bt toxins with extrinsic factors can be relevant for risk assessment of genetically engineered Bt plants since they expose a modified Bt toxin to the environment under various conditions and over a long period of time. Conclusions Risk assessment of genetically engineered plants should put into question the general assumption of a high selectivity and a linear dose-response relationship in the toxicity of Bt proteins. Both selectivity and efficacy can be influenced by synergism, which can provoke unexpected and undesired effects in non-target organisms. Perspectives It is suggested that systematic research be promoted on synergism between Bt toxins and potential extrinsic factors that could impact the spectrum of susceptible organisms. This research should become a prerequisite for risk assessment of Bt plants.

Purpose The aim of this study was to compare the level of metal contamination in two bays in the middle part of the Eastern Adriatic coastal zone in Croatia using the gills of mussels Mytilus galloprovincialis as indicator tissue. Despite the existing sources of contamination, previous studies with caged mussels only indicated moderate metal contamination of the Kaštela Bay, contrary to the Trogir Bay in which marina and shipyard present a probable source of Cu- and Zn-contamination. Methods The measurements of metallothioneins (MTs) and metals that induce MT synthesis (Cu, Zn, and Cd) were performed in the heat-treated gill cytosol and total proteins (TPs) in the untreated gill cytosol. MTs were determined by differential pulse voltammetry, Cu and Zn by flame atomic absorption spectrometry (AAS), Cd by graphite furnace AAS, and TPs by Bradford spectrophotometric procedure. Results The results collected in four sampling campaigns (autumn periods from 2001 to 2004) indicated that MT levels in mussel gills (expressed on dry mass basis 2.3 ± 0.3 mg g⁻¹) were comparable with basal levels reported in the literature (2.5 ± 0.8 mg g⁻¹). Observed interindividual, temporal, and spatial MT variability could be associated with different confounding factors, such as the time of sampling, total protein concentration, and mussel size rather than cytosolic levels of Cu and Zn. Metal levels, expressed on wet mass basis, in the heat-treated gill cytosol ranged from 1.33 to 11.31 μg g⁻¹ for Zn, from 0.72 to 2.96 μg g⁻¹ for Cu, and from 0.036 to 0.100 μg g⁻¹ for Cd. The highest Zn level was measured at Vranjic (Kaštela Bay)—the site influenced by untreated domestic wastewater, while somewhat increased Zn and the highest Cu levels were found at marina and shipyard locations (Trogir Bay). The highest Cd level was measured at Inavinil (Kaštela Bay). Conclusions The observed association of gill MT levels with several biotic and abiotic factors limits its use as the biomarker of low-level metal exposure. Therefore, the use of the metal concentrations in the heat-treated gill cytosol of Mediterranean mussels should be considered for the assessment of the low-level metal contamination of coastal marine areas.

Introduction The effect of oceanic CO₂ sequestration was examined exposing a deep-sea bacterium identified as Vibrio alginolyticus (9NA) to elevated levels of carbon dioxide and monitoring its growth at 2,750 psi (1,846 m depth). Findings The wild-type strain of 9NA could not grow in acidified marine broth below a pH of 5. The pH of marine broth did not drop below this level until at least 20.8 mM of CO₂ was injected into the medium. 9NA did not grow at this CO₂ concentration or higher concentrations (31.2 and 41.6 mM) for at least 72 h. Carbon dioxide at 10.4 mM also inhibited growth, but the bacterium was able to recover and grow. Exposure to CO₂ caused the cell to undergo a morphological change and form a dimple-like structure. The membrane was also damaged but with no protein leakage.

Background, aim and scope Landfill gas (LFG) tends to escape from the landfill surface even when LFG collecting systems are installed. Since LFG leaks are generally a noticeable percentage of the total production of LFG, the optimisation of the collection system is a fundamental step for both energy recovery and environmental impact mitigation. In this work, we suggest to take into account the results of direct measurements of gas fluxes at the air-cover interface to achieve this goal. Materials and methods During the last 5 years (2004-2009), 11 soil gas emission surveys have been carried out at the Municipal Solid Waste landfill of Legoli (Peccioli municipality, Pisa Province, Italy) by means of the accumulation chamber method. Direct and simultaneous measurements of CH₄ and CO₂ fluxes from the landfill cover (about 140,000 m²) have been performed to estimate the total output of both gases discharged into the atmosphere. Three different data processing have been applied and compared: Arithmetic mean of raw data (AMRD), sequential Gaussian conditional simulations (SGCS) and turning bands conditional simulations (TBCS). The total amount of LFG (captured and not captured) obtained from processing of direct measurements has been compared with the corresponding outcomes of three different numerical models (LandGEM, IPCC waste model and GasSim). Results Measured fluxes vary from undetectable values (<0.05 mol m⁻² day⁻¹ for CH₄ and <0.02 mol m⁻² day⁻¹ for CO₂) to 246 mol m⁻² day⁻¹ for CH₄ and 275 mol m⁻² day⁻¹ for CO₂. The specific CH₄ and CO₂ fluxes (flux per surface unit) vary from 1.8 to 7.9 mol m⁻² day⁻¹ and from 2.4 to 7.8 mol m⁻² day⁻¹, respectively. Discussion The three different estimation methodologies (AMRD, SGCS and TBCS) used to evaluate the total output of diffused CO₂ and CH₄ fluxes from soil provide similar estimations, whereas there are some mismatches between these results and those of numerical LFG production models. Isoflux maps show a non-uniform spatial distribution, with high-flux zones not always corresponding with high-temperature areas shown by thermographic images. Conclusions The average value estimated over the 5-year period for the Legoli landfill is 245 mol min⁻¹ for CH₄ and 379 mol min⁻¹ for CO₂, whereas the volume percentage of CH₄ in the total gas discharged into the atmosphere varies from 29% to 51%, with a mean value of 39%. The estimated yearly emissions from the landfill cover is about 1.29 × 10⁸ mol annum⁻¹ (2,100 t year⁻¹) of CH₄ and 1.99 × 10⁸ mol annum⁻¹ (8,800 t year⁻¹) of CO₂. Considering that the CH₄ global warming potential is 63 times greater than that of CO₂ (20 a time horizon, Lashof and Ahuja 1990), the emission of methane corresponds to 130,000 t annum⁻¹ of CO₂. Recommendations and perspectives The importance of these studies is to provide data for the worldwide inventory of CH₄ and CO₂ emissions from landfills, with the ultimate aim of determining the contribution of waste disposal to global warming. This kind of studies could be extended to other gas species, like the volatile organic compounds.

Background, aim, and scope Organoarsenical-containing animal feeds that promote growth and resistance to parasites are mostly excreted unchanged, ending up in nearby wastewater storage lagoons. Earlier work documented the partial transformation of organoarsenicals, such as, 3-nitro-4-hydroxyphenylarsonic acid (roxarsone) to the more toxic inorganic arsenate [As(V)] and 3-amino-4-hydroxyphenylarsonic acid (3-AHPAA). Unidentified roxarsone metabolites using liquid chromatography coupled to inductively coupled plasma mass spectrometry (LC/ICP-MS) were also inferred from the corresponding As mass balance. Earlier batch experiments in our laboratory suggested the presence of organometallic (Cu) complexes during relevant roxarsone degradation experiments. We hypothesized that organocopper compounds were complexed to roxarsone, mediating its degradation in field-collected swine wastewater samples from storage lagoons. The objective of this study was to investigate the role of organometallic (Cu) complexes during roxarsone degradation under aerobic conditions in swine wastewater suspensions, using electrospray ionization mass spectrometry (ES-MS). Materials and methods Two swine wastewater samples differing in % solids content and total recoverable Cu concentrations were reacted with 500 ppb of roxarsone under aerobic conditions for 16 days. LC/ICP-MS and ES-MS were used for As speciation analyses, and characterization of metal-organoarsenical complexes in swine wastewater subsamples, respectively. Results and discussion An organocopper roxarsone metabolite was found only in the high-Cu wastewater sample, suggesting the role of Cu in roxarsone degradation under aerobic conditions. The organocopper metabolite was not found in the low-Cu wastewater sample, because roxarsone did not undergo degradation under aerobic conditions even after 16 days. Conclusions Aerobic degradation of organoarsenicals (roxarsone) has not been documented before. Preliminary dataset from this study illustrates the direct and/or indirect association of particulate Cu in catalyzing roxarsone degradation under aerobic conditions in samples with high % solids content. Recommendations and perspectives Concerns regarding the degradation of roxarsone in wastewater to the more toxic inorganic As may be partially linked to the presence of particulate Cu. The presence of Cu in wastewater-suspended particle surfaces has never been coupled before to organoarsenicals degradation reactions, thus, further studies are needed to elucidate the related reaction mechanisms and pathways. Water depth-dependent solid particle distribution profiles in wastewater storage lagoons could provide empirical evidence towards the design of effective degradation practices for nitrophenol-containing compounds, such as, organoarsenical-containing antibiotics, or explosive munitions compounds.

Background, aim, and scope Arthropods, with over a million species described, are ubiquitous throughout different environments. Knowledge of their responses to human impact is crucial for understanding and predicting changes in ecosystem structure and functions. Our aim was to investigate the general patterns and to identify sources of variation in changes of the diversity, abundance and fitness of terrestrial arthropods (including Arachnida, Collembola and Insecta) in habitats affected by point polluters. Main features We found 134 suitable studies which were published between 1965 and 2007. These data came from impact zones of 74 polluters in 20 countries with the largest representation from Russia (28 polluters), Poland (12 polluters) and the USA (six polluters). The database allowed calculation of 448 effect sizes (i.e. relative differences between measurements taken from polluted and control sites) on the effects of various point polluters like non-ferrous industries, aluminium plants, cement, magnezite, fertilising and chemical plants, power plants, iron- and steel-producing factories. We used meta-analysis to search for general effects and to compare between polluter types and arthropod groups, and linear regression to describe the latitudinal gradient and to quantify relationships between pollution and arthropod responses. Results The overall effect of pollution on arthropod diversity did not differ from zero. However, species richness of soil arthropods (both living on the soil surface and within the soil) tended to decrease, and species richness of herbivores to increase, near point polluters. Abundance of terrestrial arthropods near point polluters decreased in general. This decrease resulted from strong adverse effects on soil arthropods, especially on decomposers and predators. Densities of herbivores increased, but a number of research biases that we discovered in published data may have led to overestimation of the latter effect. The dome-shaped density pattern along pollution gradients was discovered only in 5% of data sets. Among herbivores, only free-living defoliators and sap-feeders demonstrated higher densities in polluted sites; the effects of pollution on other guilds were not significant. Near the polluters, conifers suffered higher increase in damage from herbivores than deciduous woody plants and herbs. Overall effect of pollution on arthropod performance was negative; in particular, individuals from polluted sites were generally smaller than individuals from control sites. This negative effect weakened with increase in duration of the pollution impact, hinting evolution of pollution resistance in populations inhabiting polluted sites. Stepwise regression analysis demonstrated that pollution-induced changes in both the density and performance of arthropods depended on climate of the locality. Negative effects on soil fauna increased with increase in annual precipitation; positive effects on herbivore population density increased with increases in both mean July temperature and annual precipitation. Discussion We detected effects of research methodology on the outcome of published studies. Many of them suffer from research bias—the tendency to collect data on organisms or under conditions in which one has an expectation of detecting significant effects. Pseudoreplicated studies (one polluted site contrasted to one control site) frequently reported larger effects than replicated studies (several polluted sites contrasted with several control sites). These methodological flaws especially influenced herbivory studies; we conclude that increase in herbivory in both heavily and moderately polluted habitats is not as frequent as it was earlier suggested. In contrast, the decrease in abundance of predators is likely to be a widespread phenomenon. Thus, our analysis supports the hypothesis that pollution may favour herbivore populations by creating an enemy-free space. Consistent declines in abundance of soil arthropods in impact zones of different polluters suggest that this group can potentially be used in bioindication of pollution-induced changes in terrestrial ecosystems. Conclusions Main effects of pollution on arthropod communities (decreased abundance of decomposers and predators and increased herbivory) may have negative consequences for structure and services of entire ecosystems. Responses of arthropods to pollution depend on both temperature and precipitation in such a way that ecosystem-wide adverse effects are likely to increase under predicted climate change. Recommendations and perspectives Our analysis confirmed that local severe impacts of industrial enterprises on biota are well-suited to reveal the direction and magnitude of the biotic effects of aerial pollution, as well as to explore the sources of variation in responses of organisms and communities. Although we analysed the effects of point polluters, our conclusions can be applied to predict consequences of pollution impacts on regional and even global scales. We argue that possible interactions between pollution and climate should be accounted for in the analyses of global change impacts on biota.

Background, aim, and scope To stimulate the national economy, a so-called “gold week” comprising May Day and National Day has been put in force by the government, and the first golden-week holiday began on October 1, 1999. Statistical data show that about 15,000 visitors were received each day by Emperor Qin's Terra-Cotta Museum during just such a gold week period. To evaluate the effects of tourism on indoor air, airborne samples were collected by the sedimentation plate method for 5 min during the “Oct. 1” gold week period of 2006, and both composition and changes of airborne bacteria and fungi in indoor/outdoor air in the museums were investigated. Materials and methods Airborne microbes were simultaneously collected by means of gravitational sedimentation on open Petri dishes. Three parallel samples were collected at the same time each day, and samples were subsequently incubated in the lab. Microbiology media were prepared before each experiment by a professional laboratory. Concentrations were calculated and presented as average data of colony-forming units per cubic meter of air (CFU/m³). Results The results show that (1) 13 bacterial genera and eight genera of fungi were identified from indoor and outdoor air at Emperor Qin's Terra-Cotta Museum during “Oct. 1” gold week in 2006. The bacterial groups occupied 61%, the fungi groups occupied 36%, and others occupied 3% of the total number of isolated microorganism genera. (2) As for the comparison of indoor and outdoor samples, the average concentrations of fungi were higher during the afternoon (13:00) than for the morning (09:00). The average concentrations of bacteria in indoor air were higher during the afternoon (13:00) than for the morning (9:00), and in outdoor air, they were lower during the afternoon (13:00) than for the morning (9:00). (3) The average concentrations of five dominant groups of bacteria and three dominant groups of fungi were higher during the afternoon (13:00) than for the morning (9:00) in the indoor air, but the average concentrations of fungi were higher and those of bacteria were lower during the afternoon than for the morning, for outdoor air. (4) As for the comparison of indoor samples, the bacterial daily concentrations and fungal daily concentrations were higher during the afternoon (13:00) than those for the mornings (9:00) over the 10 days. For the comparison of outdoor samples, the bacterial concentration was lower, and the fungal concentrations were higher during the afternoon (13:00) than those for the morning (9:00) over the 10 days. Discussion The results also show that the numbers of airborne bacteria and fungi had a daily character in indoor air and were higher in the afternoon. The airborne microbe concentrations were found to be similar to residential indoor values from other reports; the indoor museum maximum of microbial concentrations was 90 CFU/m³ and did not exceed the Chinese indoor bioaerosol guideline. However, microorganisms may fall on the surface of display items as a result of particle sedimentation and would, as such, be capable of degrading objects by way of their secretions, e.g., enzymes and organic acids. Therefore, the right steps should be taken to prevent any deterioration in the quality of displayed artifacts. Conclusions The results show that museum air was affected by human activity; therefore, it is imperative that the number of visitors be strictly limited and that windows be opened regularly to avoid air pollution. Recommendations and perspectives The data provide a significant scientific basis for indoor air quality control and museum scientific management. It is recommended that the number of visitors be strictly limited.

Background, aim and scope Opposite interests must coexist in coastal areas: the presence of significant cities and urban centres, of touristic and recreational areas, and of extensive shellfish farming. To avoid local pollution caused by treated wastewaters along the Northern Adriatic coast (Friuli Venezia-Giulia and Veneto regions), marine outfall systems have been constructed. In this study, the application of a numerical dispersion model is used to support the traditional monitoring methods in order to link information concerning the hydrodynamic circulation and the microbiological features, to evaluate possible health risks associated with recreational and coastal shellfish farming activities. The study is a preliminary analysis of the environmental impact of wastewater treatment plants (WWTPs) with submarine discharge outfalls. It also could be useful for the water profile definition according to the Directive 2006/7/EC on the quality of bathing water and for the integrated areal analysis (Ostoich et al. 2006), to define the area of influence of each submarine discharge point. Materials and methods Historical data on discharges of the considered WWTPs were recovered and evaluated. Data on discharges' control for Veneto region (WWTPs of Lido and Cavallino) were produced by the WWTPs' manager Veritas Laboratory service, while data for the WWTPs of Friuli Venezia-Giulia region were produced by the regional environmental protection agency in the institutional control activity following official methods. The hydrodynamic model used in this work is the three-dimensional version of the finite element model SHYFEM, developed at ISMAR-CNR (Marine Science Institute of the Italian National Research Council) in Venice (Umgiesser et al. J Mar Syst 51:123-145, 2008). Results and discussion Numerical simulations have been carried out with the 3D version of the finite element model SHYFEM for 3 months during autumn 2007 to evaluate the bacterial pollution dispersion along the coasts of Veneto and Friuli Venezia-Giulia regions, prescribing meteo-marine forcings and concentration values at the points corresponding to the positions of the submarine outfalls. Model results show that during autumn 2007 the discharges of the submarine outfalls of the Venice province seem to have no impact on the surface water quality, while there are some visible effects in the Gulf of Trieste. This reflects the behaviour of the experimental data collected by ARPAV and ARPA FVG and monitoring campaigns both on water and shellfish quality. Further results have been elaborated to identify the area of influence of each discharge point; scenarios were developed with imposed concentrations. The results seem to highlight that the two discharges of the Veneto region are not noticeable, while the discharges of the Gulf of Trieste (in particular the Servola and Barcola ones) are perceptible. Conclusions This study represents a new step towards the study of the microbiological pollution dispersion and impact due to the discharges of the submarine outfalls of the Veneto and Friuli Venezia-Giulia regions (nine considered discharge points). With the 3D version of the finite element model SHYFEM, the information obtained from the hydrodynamic circulation has been linked to the classical methods of analysis, to assess possible risks connected to the microbiological parameter Escherichia coli. Recommendations and perspectives In future studies the time scale for microbiological parameters' decay could be linked to various environmental parameters such as light climate, temperature, and salinity. Interesting information would come from the study of new scenarios with different configurations of the discharge of the pipelines and/or the treatment plants and in particular from the improvements of the 3D version of the SHYFEM model, to take the stratification process into account which occurs during spring-summer, since the Northern Adriatic Sea is a very complex ecosystem, both as physical and ecological processes.