This is the first study on the dinoflagellate cysts inAlgerianwaters and in Mellah Lagoon (SouthWesternMediterranean), located  within a protected reserve. In total, 42 species of dinocysts belonging to 7 orders, 12 families and 23 genera, were identified in the  26 superficial sediment samples from Mellah Lagoon. The distribution of dinocysts in the sediment of this lagoon is heteroge- neous. Indeed, their abundance oscillates between 1 and 315 cysts g−1 dry sediment (DS). Cyst morphotype assemblages were dominated by a few numbers of species: Alexandrium minutum (15.87%), Gonyaulax verior (9.81%), Protoperidinium spp.  (7.74%), Alexandrium affine (7.05%), Scrippsiella trochoidea (6.67%), and Alexandrium pseudogonyaulax (6.19%). There is a  positive correlation between the density of cysts and the depth (r = 0.61; p < 0.05), organic matter (r = 0.70; p < 0.05), water  content (r = 0.71; p < 0.05), and the fine fraction of sediment (r = 0.74; p < 0.05). Surprisingly, although the Mellah Lagoon is  almost semi-closed, it holds an important specific richness in dinocysts (42 species) higher than others observed in Mediterranean  lagoons. However, cyst abundances are low compared to other lagoons in the Mediterranean Sea. Finally, the presence of  dinocysts of Alexandrium catenella/tamarense, A. minutum, and Gymnodiniumcatenatum associated to paralytic shellfish toxins,  A. pseudogonyaulax which produces goniodomin A, also Protoceratium reticulatum and Gonyaulax spinifera complex which  produce yessotoxins, needs to implement a monitoring programto prevent a potential human intoxication due to the consumption of contaminated sea products by these potent neurotoxins.

This chapter presents general aspects of polycyclic aromatic hydrocarbons (PAHs) as environmental pollutants and synthesizes information on the presence and levels of PAHs in the coasts and deep sea throughout the world. PAHs are a large group of compounds formed of two or more fused benzene rings or, in some cases, a pentagonal ring. PAHs are solid at room temperature and characterized by low steam pressures and low water solubility, as well as high melting and boiling points. PAHs can originate from three possible sources: petrogenic, pyrolytic and natural. Although PAHs can occur naturally, anthropogenic activities are generally considered the major source of PAHs released into the environment. PAHs can be introduced into marine environments by different ways: spillage of fossil fuels, ship traffic, atmospheric depositions, urban runoff, and municipal and industrial wastewater discharge. PAHs associated with sediments are considered to be less bioavailable to organisms and therefore less toxic for aquatic biota than PAHs dissolved in seawater. | Fil: Oliva, Ana Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Argentino de Oceanografía. Universidad Nacional del Sur. Instituto Argentino de Oceanografía; Argentina | Fil: Ronda, Ana Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Argentino de Oceanografía. Universidad Nacional del Sur. Instituto Argentino de Oceanografía; Argentina. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia; Argentina | Fil: Girones, Lautaro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Argentino de Oceanografía. Universidad Nacional del Sur. Instituto Argentino de Oceanografía; Argentina | Fil: Orazi, Melina Mirta. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Argentino de Oceanografía. Universidad Nacional del Sur. Instituto Argentino de Oceanografía; Argentina | Fil: Recabarren Villalón, Tatiana Valentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Argentino de Oceanografía. Universidad Nacional del Sur. Instituto Argentino de Oceanografía; Argentina | Fil: Marcovecchio, Jorge Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Argentino de Oceanografía. Universidad Nacional del Sur. Instituto Argentino de Oceanografía; Argentina. Universidad FASTA "Santo Tomas de Aquino"; Argentina. Universidad Tecnológica Nacional. Facultad Regional Bahía Blanca; Argentina. Academia Nacional de Ciencias Exactas, Físicas y Naturales; Argentina | Fil: Arias, Andres Hugo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Argentino de Oceanografía. Universidad Nacional del Sur. Instituto Argentino de Oceanografía; Argentina. Universidad Nacional del Sur. Departamento de Química; Argentina

International audience | Zinc (Zn) and lead (Pb) concentrations were measured in 173 samples collected in soils under forest, wetland, and arable land around a Zn smelter plant that stopped activity in the 1960s. The adopted sampling strategy consisted in collecting 0–30-cm-depth samples from all soils, tilled or not, in order to harmonize the analyzed soil volume to that of plowed soils. Airborne deposition was modeled as a function of the distance from the pollution source and of land use. The Zn/Pb concentration ratios in the surface layer remarkably contrasted 3–4, 1.5–2, and ~ 0.5 for arable, wetland, and forest soils, respectively, independently from the distance to the emission source, while total Zn and Pb concentrations, taken separately, were only slightly discriminant. For metal pollution sites originating from former industrial activity, Zn/Pb concentration ratios determined on relevant soil samples represent a powerful indicator that provides easy and rapid information in real field conditions on time-related input/output dynamics of mobile and less-mobile metal pollutants, and hence, on interactions between pollutants and soils under different land use conditions.

Agriculture is critical to the economies of developing countries. It is the basic source of food supply and a major contributor to economic development. But there is a cost. Today, agricultural water pollution undermines economic growth and threatens the environmental and physical health of millions of people around the world. The annual social and economic costs of agricultural water pollution could reach trillions of dollars. Yet the issue receives scant attention in global research and debate.

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Chemical contaminants are released from mining, domestic and industrial effluents into an aquatic environment. Sediments (n = 10) were collected with an Eckman grab at ten stations in the Densu Estuary for ecological risk assessment. The spatial distribution of organic characteristics and ecological risk of metals—zinc, lead, copper, mercury, iron, and manganese in sediment—were analyzed using standard methods. The organic parameters occurred in the ranges, as follows: % C, 0.76 to 2.05, % TN, 0.06 to 0.015; % TP, 0.44 to 1.38; and C/N, 12.31 to 34.81. The ranges of metal concentrations (mg/kg) were as follows: Fe, 201.10 to 720.90; Mn, 40.10 to 152.70; Zn, 7.3 to 158.3; Pb, 1.9 to 84.7; Cu 3.4 to 23.0; and Hg, 0.01 to 0.05. The mean concentration of metals in the sediment were Fe > Mn > Pb > Zn > Cu > Hg. The highest mean concentration of Fe suggested redox conditions in the Densu Estuary. There is a low contamination factor (CF) for five metals (Zn, Hg, Fe, Cu, and Mn) (CF < 1) to high contamination of Pb (3 < CF ≤ 6). The average Pb concentration was above local and geological backgrounds, suggesting an anthropogenic source of pollution from industrial and domestic effluents and agrochemicals. The sediment was extremely enriched by Pb (EF > 50) with a positive index of geoaccumulation (0 < Igeo ≤ 2) than other metals. There is considerable to a very high degree of contamination (DC) (3 ≤ DC ≥ 6) of metals in the sediment of Densu Estuary. The potential ecological risk index (≤ 40 PERI < 80) suggested a very low to moderate ecological risk of metal pollution. The study provides baseline knowledge on geochemical contamination in tropical estuarine systems for the development of effective chemical control strategies towards sustainable management of coastal waters.

Estuaries serve as nursery grounds for many marine fish species. However, increasing human activities within estuaries and surrounding areas lead to significant habitat quality degradation for the juveniles. In recent years, plastic pollution has become a global environmental issue as plastic debris are found in all aquatic environments with potential adverse impacts on marine biota. Given the important ecological role of estuaries and implications of microplastics (MP) in ecosystems, here we assess the occurrence, number, size, and polymer types of MP ingested by wild and caged juvenile European flounder (Platichthys flesus). We deployed caged fish for 1 month at five sites in three estuaries in the eastern English Channel. The Seine estuary, heavily impacted by manmade modifications and one of the most contaminated estuaries in Europe, was compared to two smaller estuaries (Canche and Liane) less impacted by industrial activities. We found that juvenile flounders (7–9 cm) were vulnerable to plastic ingestion. Seventy-five percent of caged fish and 58% of wild caught fish had the presence of MP items in their digestive tract. Fibers (69%) dominated in the fish’s digestive tract at all sites. An average of 2.04 ± 1.93 MP items were ingested by feral juvenile flounder and 1.67 ± 1.43 by caged juvenile flounder. For the caged fish, the three sites impacted by wastewater treatment plant (Liane, Le Havre harbor, and Rouen) were those with the highest percentage of individuals that has ingested MP items. Most of the isolated items were fibers and blue in color. Polymers identified by micro Raman spectroscopy were polycaprolactam, polyethylene terephthalate, and polyurethane. Although other environmental factors may have affected caged fish condition and mortality, we found no significant correlation with the number of ingested MP. However, the high occurrence of MP ingested by juvenile fish on nursery grounds raises concerns on their potential negative effects for fish recruitment success and population renewal. Finally, this study describes, for the first time, the feasibility of using caged juvenile fish as an assessing tool of MP contamination in estuarine nursery grounds.

Urban air pollution is one of the most important environmental problems nowadays. Understanding urban pollution is rather challenging due to different factors that produce a strongly heterogeneous pollutant distribution within streets. Observed concentrations depend on processes occurring at a wide range of spatial and temporal scales, complex wind flow and turbulence patterns induced by urban obstacles and irregular traffic emissions. The main objective of this paper is to model particulate matter dispersion at microscale while considering the effects of mesoscale processes. Computational Fluid Dynamic (CFD) PM10 simulations were performed taking into account high spatial resolution traffic emissions from a microscale traffic model and inlet vertical profiles of meteorological variables from Weather Research and Forecasting (WRF) model. This modelling system is evaluated by using meteorological and PM10 concentration data from intensive experimental campaigns carried out on 25th February and 6th July, 2015 in a real urban traffic hot-spot in Madrid. The effect of uncertainties in the inlet profiles from mesoscale input data on microscale results is assessed. Additionally, the importance of the sensible surface heat fluxes (SHF) provided by WRF and the selection of an appropriate turbulent Schmidt number in the dispersion equation are investigated. The main conclusion is that the modelling system accurately reproduces PM10 dispersion imposing appropriate inputs (meteorological variables and SHF) and a suitable turbulent Schmidt number. Better agreement is found for simulation with a low turbulent Schmidt number. This approach improves the standard microscale modelling alone because more realistic boundary conditions and mesoscale processes are considered.

Local regressions have been widely employed for decomposing atmospheric data series. However, the use of local quadratic regressions is less extended. The current paper is grounded on the hypothesis that local linear regressions are able to capture CO2 and CH4 temporal evolution equally as well as quadratic linear regressions. Thus, the current paper pursues the following goals: (1) to quantify the temporal variability of both gases by using the local linear and local quadratic regression method; (2) to analyse the main statistics of the detrended series over time; (3) to compare results between the local linear and local quadratic regression method. Minimum mixing ratios in late summer and maximum in winter were detected for both gases. Atmospheric increases of an average of 1.98 ppm year−1 for CO2 and 11 ppb year−1 for CH4 were found when applying the local linear regression method. Alternatively, an increase of 2.24 ppm year−1 for CO2 and around 10.34 ppb year−1 for CH4 was obtained when the local quadratic regression method was applied. The Pearson correlation coefficients (0.21–0.40) showed acceptable values due to the large amount of available data. Statistically significant differences for the initial and the smoothed trend, as well as statistically significant differences for the seasonal component, were reported when comparing the local linear with the local quadratic method. Overall, both methods proved easy to apply and both provided acceptable data accuracy.

In vitro assays were used to determine the effects of aqueous fine particulate matter (PM₂.₅) extracts on different homogenates of rat organs. The PM₂.₅ collected from two regions (Seropédica and Duque de Caxias) in Rio de Janeiro, Brazil, were used to evaluate different oxidative damages and redox state. Two PM₂.₅ extract concentrations (concentrate and 10x dilution) were evaluated using rat tissue homogenates (heart, lung, liver, and kidney). Measurements of total antioxidant capacity (ACAP), lipid peroxidation levels (LPO), reduced glutathione concentrations (GSH), activity of glutamate cysteine ligase (GCL), activity of glutathione S-transferase (GST) and catalase (CAT) were performed. Most PM₂.₅ aqueous extract concentrations contain numerous metals (e.g. Li, Ti, Fe, Cu, Cd, Sr, among others), which reduced ACAP and generated LPO in most tissue homogenates. Besides this, GST activity decreased in liver and lung, increasing in kidney and heart homogenates. GCL activity increased in lung, liver and kidney and undergo decrease in the heart homogenate. All concentrations of PM₂.₅ evaluated decreased GSH levels. PM₂.₅ concentrations for both sites (regions) raised catalase activity in most tissue homogenates except in the liver. In vitro toxicity of the PM₂.₅ in different tissues, presented an ability to interact with cellular antioxidant defense system, causing depletion of the sulfhydryl stocks, resulting in the damage of biological molecules and inducing oxidative imbalance.