Documentation of bioaerosol concentrations in an indoor composting facility in France

Bioaerosol concentrations were investigated in a totally indoor composting facility processing fermentable household and green wastes to assess their variability. Stationary samples were collected by filtration close to specific composting operations and then were analysed for cultivable mesophilic bacteria, thermophilic bacteria, mesophilic fungi, thermophilic fungi, endotoxins and total airborne bacteria (DAPI-staining). Indoor concentrations exceeded the background levels, between 500 and 5400 EU m(-3) for endotoxins, 10(4) and 10(6) CFU m(-3) for cultivable bacteria and generally below 10(5) CFU m(-3) for airborne cultivable fungi. No significant (p > 0.05) differences were observed between the indoor composting operations. Successive 30 minute bioaerosol samples were collected to investigate the variation of cultivable mesophilic microorganisms over the work shift. Concentrations of mesophilic bacteria and fungi varied up to 1 log unit depending on the time at which they were collected in the day. Total airborne particles, counted using an optical particle counter, were present at up to 10(8) particles m(-3) and several concentration peaks were noted. Values for total airborne bacteria were roughly 70-fold higher than cultivable bacteria. These results raise the question of the sampling strategy (duration of sampling; number of samples to be collected) used in similar studies. They provide new bioaerosol concentration data in a composting facility and suggest that the filtration sampling method might be a useful tool for exposure measurements in that occupational environment.     

Ubiquitination and carbonylation of proteins in the clam Ruditapes decussatus, exposed to nonylphenol using redox proteomics

Ubiquitination and carbonylation of proteins were investigated in the gill and digestive gland of Ruditapes decussatus exposed to NP (nonylphenol) (100 μgL(-1)) using redox proteomics. After 21 d of exposure, clams were dissected and cytosolic proteins of both tissues separated by 2DE SDS-PAGE. Protein expression profiles were tissue-dependent and differently affected by NP exposure. Ubiquitination and carbonylation were also tissue-specific. NP exposure induced significantly more ubiquitinated proteins in gills than in digestive glands, compared to controls. Digestive gland showed a significant higher number of carbonylated proteins than gills after NP exposure. Protein ubiquitination and carbonylation are therefore independent processes. Results showed that NP exposure generated ROS in gill and digestive gland of R. decussatus that significantly altered the proteome. Results also highlighted the advantage of using redox proteomics in the assessment of protein ubiquitination and carbonylation, which may be markers of oxidative stress in R. decussatus.     

An evaluation of the estimation of road traffic emission factors from tracer studies

Road traffic emission factors (EFs) are one of the main sources of uncertainties in emission inventories; it is necessary to develop methods to reduce these uncertainties to manage air quality more efficiently. Recently an alternative method has been proposed to estimate the EFs. In that work the emission factors were estimated from a long term tracer study developed in Ho Chi Minh City (HCMC) Vietnam. A passive tracer was continuously emitted from a finite line source placed in one side of an urban street canyon. Simultaneously, the resulting tracer concentrations were monitored at the other side of the street. The results of this experiment were used to calculate the dispersion factors and afterwards, these dispersion factors were used to estimate the EFs. In this paper we use the Computational Fluids Dynamics (CFD) model WinMISKAM to critically evaluate the proposed methodology.In a first step, we use the results of the tracer study to validate the CFD model. Results show that the model is able to simulate quite well the tracer dispersion in most of the cases. The model is then used to evaluate the effect of varying the source configuration and to correct the EFs. A comparison with available studies shows that the corrected EFs are within the range of the EFs reported in other studies. Finally, the CFD model is used to find a source configuration that better represents the vehicle emissions and that may be used in future studies to estimate the EFs more accurately. Results show that a 200 m line placed in the center of the street would represent very well the vehicle emissions. This work shows that it is possible to accurately estimate the EFs from tracer studies.     

Size-resolved aerosol chemical composition over the Italian Peninsula during typical summer and winter conditions

In the frame of the MIUR-AEROCLOUDS project (Study of Direct and Indirect Aerosol Effects on Climate), night-time and daytime size-segregated aerosol samples were collected concurrently at five different sites (near-city, urban, rural, marine and mountain background sites). The paper reports on the daily evolution of the main aerosol chemical characteristics as a function of particle size in different environments over the Italian Peninsula, spanning from the Po Valley to the south Tyrrhenian coast.Two 4-day intensive observation periods (IOPs) were undertaken in July 2007 and February 2008, under meteorological conditions typical of the summer and winter climate for Italy.In the summer IOP, under stable atmospheric conditions, at the low-altitude continental sites the diurnal evolution of the planetary boundary layer (PBL), induces an atmospheric dilution effect driving the particulate matter (PM) concentrations, while, at the mountain site, it determines the upward motion of polluted air masses from the Po Valley PBL in daytime.The fine fraction was dominated by ammonium salts and carbonaceous matter (water-soluble organic matter, WSOM, and water-insoluble carbonaceous matter, WINCM). High concentrations of ammonium sulphate and WSOM due to enhanced photochemical activity constituted the background aerosol composition over the whole country, whereas, ammonium nitrate and WINCM were more associated to local emissions (e.g. urban site with concentrations peaking in the finest size range due to strong local traffic-related sources of ultrafine particles).During the winter IOP in the Po Valley, the shallow PBL depths and low wind velocity, especially at night, favoured the condensation of semi-volatile species (i.e. organic matter and ammonium nitrate), causing the high fine PM concentration observed at ground level.     

The Establishment of Marine Protected Areas in Senegal: Untangling the Interactions Between International Institutions and National Actors

International institutions, understood as sets of rules contained in international agreements, are aimed at orienting national governments towards specific policy options. Nevertheless, they can determine a change in national policies and practices only if states are willing and capable of incorporating international obligations into their national legislations and ensuring their application and enforcement in areas that follow completely under national jurisdiction. The establishment of marine protected areas promoted by international agreements as a tool for the protection of marine resources represents an interesting case for revealing the complex interactions between international institutions and national actors. Particularly, the establishment of these areas in Senegal shows the salience of domestic constellations of actors who may support or undercut national commitments to international regimes: political elites, bureaucracies, the general public and target groups. By anchoring the empirical analysis to an actor-centred institutionalist perspective, the article explains how dynamic constellations of actors can distort the penetration of international objectives in the national policy framework. Different constellations of national actors can indeed bend international institutions at different moments: during the formulation of a new law in line with international obligations; in the definition of its implementation framework; and in the enforcement of national policies.     

Carbon and nitrogen stocks and nitrogen mineralization in organically managed soils amended with composted manures

The use of composted manures and of legumes in crop rotations may control the quality and quantity of soil organic matter and may affect nutrient retention and recycling. We studied soil organic C and N stocks and N mineralization in organically and conventionally managed dryland arable soils. We selected 13 extensive organic fields managed organically for 10 yr or more as well as adjacent fields managed conventionally. Organic farmers applied composted manures ranging from 0 to 1380 kg C ha yr and incorporated legumes in crop rotations. In contrast, conventional farmers applied fresh manures combined with slurries and/or mineral fertilizers ranging from 200 to 1900 kg C ha yr and practiced a cereal monoculture. Despite the fact that the application of organic C was similar in both farming systems, organically managed soils showed higher C and similar N content and lower bulk density than conventionally managed soils. Moreover, organic C stocks responded to the inputs of organic C in manures and to the presence of legumes only in organically managed soils. In contrast, stocks of organic N increased with the inputs of N or C in both farming systems. In organically managed soils, organic N stocks were less mineralizable than in conventional soils. However, N mineralization in organic soils was sensitive to the N fixation rates of legumes and to application rate and C/N ratio of the organic fertilizers.     

Analysing the influence of different street vegetation on traffic-induced particle dispersion using microscale simulations

Urban vegetation can be viewed as compensation to the environmental drawbacks of urbanisation. However, its ecosystem function is not well-known and, for urban planning, vegetation is mainly considered as an element of urban design. This article argues that planning practice needs to re-examine the impact of vegetation cover in the urban fabric given our evaluation of vegetation's effects on air quality, including the dispersion of traffic-induced particles at street level. Using the three-dimensional microclimate model ENVI-met?, we evaluate these effects regarding the height-to-width ratio of streets flanked by buildings and the vertical and horizontal density of street vegetation. Our results reveal vegetation's effect on particle dispersion through its influence on street ventilation. In general, vegetation was found to reduce wind speed, causing inhibition of canyon ventilation and, consequently, an increase in particle concentrations. Vegetation was also found to reduce wind speed at crown-height and to disrupt the flow field in close vicinity to the canopy. With increasing height-to-width ratio of street canyons, wind speed reduction increases and the disturbance of the flow impacts across a canyon's entire width. We also found that the effect is more pronounced in configurations with poor ventilation, such as the low wind speed, perpendicular inflow direction, and in deep canyons cases.     

The quest for eco-social efficiency in biofuels production in Brazil

Equating eco-efficiency with the business link to sustainable development is clearly limited, especially with the new paradigms brought up by Corporate Social Responsibility, which has shown that the private sector’s contribution to sustainable development can go far beyond the sphere of pollution control. It is necessary to give eco-efficiency a broader meaning so that it can support the quest for sustainable development. This requires the inclusion of social aspects, leading to a kind of eco-social efficiency. The present paper illustrates this idea by comparing Brazilian production and use of ethanol from sugarcane, in the context of the National Alcohol Program (Proalcool), with biodiesel production and use, in the context of the Biodiesel National Program (PNPB). Despite the problems presented, PNPB was designed to encourage companies to align productivity concerns with social ones, what could be the beginning of the here called eco-social efficiency.