In this paper, we studied the regional aerosol and air quality over an urban location, Pune, India during the period from 8 to 18 November 2012, encompassing a major Indian celebration, namely, Diwali Festival (12–14 November 2012) and also a clean (control) day (9 November 2012). A suit of ground–based measurements, employing solar radiometers (Microtops II and Cimel Sun–sky radiometer), Nephelometer, and satellite observations carried out over the study region have been applied for these investigations. The study revealed many interesting results which include (i) almost four–fold enhancement in AOD and fine mode dominated aerosol size distribution (ASD) during Diwali compared to clean day conditions; (ii) higher columnar water vapor (H2O), nitrogen dioxide (NO2), and lower ozone (O3) during Diwali period; (iii) higher cooling at bottom (–117W m−2) and top of the atmosphere (–33W m−2) and warming (+82W m−2) in the atmosphere during the festival period, (iv) abundance of fine mode anthropogenic scattering particles associated with greater real part and smaller imaginary part of refractive index, and higher single scattering albedo, (v) higher backscattering coefficient revealing intrusion of more aerosol particles, higher depolarization ratio indicating particles of non–spherical nature, presence of water–phase particles, more polluted smoke and dust particles, (vi) greater attenuation and poor horizontal/vertical visibility, and (vii) dominance of urban industrial/biomass burning aerosols among other aerosol types. These results have been compared with concurrent satellite products and found to be consistent. The results have been further explained with local meteorology, back–trajectory analysis and satellite rapid response images.

This baseline study highlights the 210Po and 210Pb concentration in two species of the benthic macroalgae Sargassum from northern Gulf, also known as the ROPME Sea Area (RSA). Within the marine environment, 210Po is initially absorbed from water and concentrated by phytoplankton and macroalgae, and this concentrated 210Po can then readily be passed along to the higher trophic level of the marine food web. The 210Po concentration measured in Sargassum boveanum (22.5–25.6Bqkg−1) was higher than that in Sargassum oligocystum (20.2–22.5Bqkg−1), but is not statistically significant (p>0.064), where as the difference between 210Pb concentrations in Sargassum boveanum (15.3–16.8Bqkg−1) and Sargassum oligocystum (18.4–22.0Bqkg−1) was statistically significant (p>0.019). The measured concentration factor for 210Po in Sargassum in the northern Gulf varied between 0.55 and 1.2×104, values higher to the IAEA recommended value of 1×103. The 210Po enrichment is observed in both the species of Sargassum,210Po/210Pb ratio was >1 at all the stations for all the samples.

Air quality management in urban areas requires the use of advanced modeling tools, able to predict and evaluate the pollution level under different traffic and meteorological conditions. In the present paper, the Artificial Compressibility version of the Characteristic Based Split algorithm (AC–CBS) was used to assess the performance of the Spalart–Allmaras based Detached Eddy Simulation (SA–DES) model, for the calculation of incompressible turbulent flow in different urban street canyon configurations. To our knowledge, the DES version of the SA turbulence model was applied in this work for the first time for the simulation of turbulent flow in a street canyon. The proposed DES model was able to accurately reproduce the turbulent characteristics of the flow compared with results from real street canyon experiments, wind tunnel experiments, and also to that obtained with RANS simulations. These results are very similar to the ones obtained from Large Eddy Simulation (LES) of street canyons flow reported in some recent publications, but with the potential characteristic of reduced computational costs. The DES approach is very promising for the simulation of transient turbulent flows in urban areas when complex three–dimensional domains are considered. The performance of the DES model evaluated for the mean dimensionless streamwise velocity profiles was comparable to that of Reynolds–Averaged Navier–Stokes RANS approach if referred to Hit Rate (HR) validation metric, and even better if referred to Factor of two observation (FAC2) validation metric. An accurate reproduction of the turbulent flow is crucial for urban pollutant dispersion simulations, since the distribution of the pollutant concentrations could differ by order of magnitude in the different points of the street canyon. DES approach results were able to accurately predict the unsteadiness characteristic of the flow, and to reproduce some minor vortex structures, which were not observed in the RANS cases, that will lead to a more accurate reproduction of the pollutant concentrations.

We consider hourly PM10 measurements from 22 monitoring stations located in Basse–Normandie and Haute–Normandie regions (France) and also in the neighboring regions. All considered monitoring stations are either urban background stations or rural ones. The paper focuses on the statistical detection of outliers of the hourly PM10 concentrations from a spatial point of view. The general strategy uses a jackknife type approach and is based on the comparison of the actual measurement with some robust spatial prediction. Two spatial predictions are considered: the first one is based on the median of the concentrations of the closest neighboring stations which directly consider weighted concentrations while the second one is based on kriging increments, instead of more traditional pseudo–innovations. The two methods are applied to the PM10 monitoring network in Normandy and are fully implemented by Air Normand (the official association for air quality monitoring in Haute–Normandie) in the Measurements Quality Control process. Some numerical results are provided on recent data from January 1, 2013 to May 31, 2013 to illustrate and compare the two methods.

Risk assessments of persistent organic pollutants (POPs) are often based on octanol–water (KOW) partitioning dynamics and may not adequately reflect bioaccumulation in air-breathing organisms. It has been suggested that compounds with low KOW and high octanol–air partitioning (KOA) coefficients have the potential to bioaccumulate in air-breathing organisms, including marine mammals. Here we evaluate differences in concentrations of POPs for two trophically matched Arctic species, spotted seal (Phoca largha) and sheefish (Stenodus leucichthys). We compared concentrations of 108 POPs in matched tissues (liver and muscle) across three ranges of KOW. We found a significant positive correlation between POP concentration and log KOA in spotted seal tissues for low log KOW compounds (log KOW <5.5, p<0.05). This provides further evidence for empirical models and observed bioaccumulation patterns in air-breathing organisms, and highlights the potential for bioaccumulation of these compounds in Arctic marine mammals.

Application of chemical dispersants or mechanical dispersion on surface oil is a trade-off between surface effects (impact of floating oil) and sub-surface effects (impact of suspended oil). Making an informed decision regarding such response, requires insight in the induced change in fate and transport of the oil.We aim to identify how natural, chemical and mechanical dispersion could be quantified in oil spill models. For each step in the dispersion process, we review available experimental data in order to identify overall trends and propose an algorithm or calculation method. Additionally, the conditions for successful mechanical and chemical dispersion are defined.Two commonly identified key parameters in surface oil dispersion are: oil properties (viscosity and presence of dispersants) and mixing energy (often wind speed). Strikingly, these parameters play a different role in several of the dispersion sub-processes. This may explain difficulties in simply relating overall dispersion effectiveness to the individual parameters.

We assessed the effects of 40 ocean outfalls on adjacent macrobenthic invertebrates. Data were obtained from a review of gray and peer-review literature. Different parameters describing the outfall characteristics were compiled (length, maximum depth, treatment level, flow and organic matter mass discharged). Exposure to wave action was represented by significant wave height. The magnitude of the effect was categorized in three impact levels and classified considering different ecological indicators. A theoretical predictive model was formulated in which the lower the organic matter and the higher the energy of the system, the lower the benthic impact. The main conclusion was that the general pattern of the succession of benthic communities brought about by ocean outfalls fits the model of Pearson–Rosenberg but with some deviations i) the probability of a significant impact is much lower, ii) not all the successional stages occur and, iii) the magnitude of the changes are usually lower.

Marine clams Ruditapes philippinarum were exposed under laboratory conditions to sediments sampled at five sites affected by wastewater effluents at the Bay of Cádiz (SW, Spain). Contamination and early biological stress were determined. Metabolism and antioxidant system differed according to seasons. Health status diminished in summer. Metabolism of detoxification, and oxidative effect were related to concentration of metals, PAH, secondary alkane sulfonates (SAS) and antibiotics in winter. Antioxidant system and DNA damage were linked to metals and pharmaceutical products. Phase I and antioxidant system were associated to PAH and SAS in summer. Oxidative stress and effects were related to pharmaceuticals. Phase II was linked to metals and pharmaceuticals. Seasonality of sediment contamination by organic compounds and biological responses was determined. Clams were useful bioindicators, since the set of biomarkers applied was validated as potential tools for sediment quality assessment of wastewater discharges areas.

A three-dimensional circulation model (the Environmental Fluid Dynamic Code) was used to examine the role that physical forcing (river discharge, wind speed and direction) plays in controlling hypoxia in waters adjacent to the Yangtze Estuary. The model assumes that the biological consumption of oxygen is constant in both time and space, which allows the role of physical forcing in modulating the oxygen dynamics to be isolated. Despite of the simplicity of this model, the simulation results showed that it can reproduce the observed variability of dissolved oxygen in waters adjacent to the Yangtze Estuary, thereby highlighting the important role of changes in physical forcing in the variation of hypoxia. The scenarios tested revealed appreciable changes in the areal extent of hypoxia as a function of wind speed and wind direction. Interestingly, well-developed hypoxia was insensitive to river discharge.

The nutrient uptake and release by the mussels in relation with amount of food consumption are emphasised in this research. Results of the study demonstrate that about 16% of the total mass dry weight food consumed by the mussels was released as faeces. The depositions of particulate carbon, nitrogen, and phosphorus in mussel faeces were found to be 26.3, 5.7, and 0.6mg/day/indv respectively. Soluble inorganic nutrients such as NH4+-N (2.5mg/day/indv), and PO43−-P (0.6mg/day/indv) were also released as mussel excretion. The nutrient absorption efficiency for the green mussel body was found to be 65.1% for carbon, 62.1% for nitrogen, and 79.2% for phosphorus. Subsequently, green mussels can remove particulate carbon, nitrogen and phosphorus at 108.1, 13.5, and 4.6mg/day/indv from aquatic systems. Finally, the results can help in estimating the carrying capacity of mussel cultivation without deteriorating the water quality in marine ecosystems.