Concentrations of heavy metals in the western coast of Venezuela are partly driven by anthropogenic influences. To detect metal changes over time, the waters and sediments from 19 sites, across various marine ecosystems, were sampled seven times between 2000 and 2001 and compared with previous studies. The water samples had mean concentrations of Cd, Cu, Pb, and Zn above the guideline values proposed by NOAA as capable of producing chronic effects in the marine biota. In sediments, the mean Cd concentration also exceeded NOAA's Effects Range-Low values for all habitat types, and in sheltered sites, it exceeded NOAA's Effects Range-Median values. The meta-analysis indicated that metal concentrations in water were higher in 2000-2001 than in 1995-1997, with the exception of Pb. In sediments, however, only the concentrations of Cd, Cu, and Pb increased in this period. This increase was particularly noticeable for Cd which, by 2000-2001, showed Igeo values indicating that Morrocoy National Park could be considered strongly to extremely polluted. This increment in the metal concentrations could be associated with: (1) an anomalous precipitation event that occurred at the end of 1999 and which caused a disturbance in the sediment chemistry of most metals and/or (2) an increase in the anthropogenic and natural input of Cd probably associated with the production of fertilizers in the region during the period analyzed. Special attention should be paid to Cd levels in this area as it represents a high toxicological risk for the biota in different habitats.

Polycyclic aromatic hydrocarbons (PAHs) are widespread environmental pollutants produced by incomplete combustion sources such as home heating, biomass burning, and vehicle emissions. PAH concentrations in soils are influenced by source inputs and environmental factors that control loss processes and soil retention. Many studies have found higher concentrations of these pollutants in soils within cities of temperate climates that have a centralized urban core. Less is known about the factors regulating PAH abundance in warm, arid urban ecosystems with low population densities but high traffic volumes. The relative importance of sources such as motor vehicle traffic load and aridland ecosystem characteristics, including temperature, silt, and soil organic matter (SOM) were explored as factors regulating PAH concentrations in soils near highways across the metropolitan area of Phoenix, AZ (USA). Highway traffic is high compared with other cities, with an average of 155,000 vehicles/day. Soils contained low but variable amounts of SOM (median 2.8 ±â€‰1.8% standard deviation). Across the city, median PAH concentrations in soil were low relative to other cities, 523 ±â€‰1,886 μg/kg, ranging from 67 to 10,117 μg/kg. Diagnostic ratio analyses confirmed that the source of PAHs is predominantly fuel combustion (i.e., vehicle emissions) rather than petrogenic, biogenic, or other combustion sources (coal, wood burning). However, in a multiple regression analysis including traffic characteristics and soil properties, SOM content was the variable most strongly related to PAH concentrations. Our research suggests that dryland soil characteristics play an important role in the retention of PAH compounds in soils of arid cities.

This paper focuses on the influence of uranium tailing piles on the contamination of their immediate surroundings. The monitoring was carried out on arable land near Pribram in Central Bohemia, Czech Republic. The monitored arable land is located 600 m northeast of the bottom of the piles. In addition, the high uranium (U) content in the topsoil ranged from 40 to 220 ppm. A former portion of it was found in an exchangeable fraction (49%). Both of these facts make this land unsuitable for agricultural use. The sequential extraction discovered a shift in the U content among sample spots situated in and outside the path of the predominant wind direction. In the first group, uranium binds mainly to Fe/Mn oxides, while in the other samples, U is accumulated in the more mobilizable fractions.

A greenhouse pot experiment was conducted in Agrinion, Greece, in 2009, using a Randomized Block Design. Treated Municipal Wastewater (TMWW) in five levels was applied to Brassica oleracea var. Capitata (cabbage) in four replications. The experiment aimed at investigating the effect of TMWW on: (a) the interrelationships of cabbage plant parts (roots, stems, leaves, and heads) heavy metal content, with the respective dry matter yield. (b) The relationship between each individual soil bioavailable diethylenetriaminepentaacetic acid (DTPA extractable) heavy metal, with the dry matter (dm) yield of the abovementioned cabbage plant parts. The heavy metals of cabbage plant parts dry matter were significantly related negatively and statistically with the respective dry matter yield. Similarly, the soil available DTPA-extractable heavy metals were generally negatively affecting the dry matter yield of roots, stems, leaves, and heads. Conversely, Co, Cr, and Cd were found to be positively associated with the dry matter yield increase of the aforementioned plant parts. This effect was indirect, probably being due to contribution in essential elements by the synergistic interactions of these heavy metals with plant nutrients, such as Ca, Mg, Fe, and Mn.

Poly(acrylamide-acrylic acid-dimethylaminoethyl methacrylate) P(AAm-AA-DMAEMA) resin was prepared by the template copolymerization. PAAm was used as a template for the copolymerization of DMAEMA and AA in aqueous solution using gamma rays. The adsorption of indigo carmine and eriochrome black-T anionic dyes from aqueous media on P(AAm-AA-DMAEMA) has been investigated. The adsorption behavior of this resin has been studied under different adsorption conditions: dye concentrations (50–500 mg l−1), contact times, temperature (30–55°C), and pH values (2–7). The amount of dye adsorbed increased with increasing resin content, but it had a little change with temperature and decreased slightly with increasing pH. Adsorption data of the samples were modeled by the pseudo-first-order and pseudo-second-order kinetic equations in order to investigate dye adsorption mechanism. It was found that the adsorption kinetics of the resin followed a pseudo-second-order model with rate constant (k 2) of 2.5 × 10−3 and 1.8 × 10−2 g (mg−1 min−1) for indigo carmine and eriochrome black-T, respectively. Equilibrium isotherms were analyzed using the Langmuir and Freundlich isotherms. It was seen that the Freundlich model fits the adsorption data better than the Langmuir model.

Nitrogen compounds generated by anthropogenic combustion deposits in forest watersheds and induce nitrogen saturation of the area. Because excess nitrogen is derived from atmospheric deposition, this action is expected to uniformly affect a wide area of forest soils. Geographically, heterogeneous nitrate concentration of stream water within a small area has been attributed to the tree type, geological setting and tree cut. In this article, we hypothesized that the effect of the atmospheric nitrogen deposition in the forest watershed may vary within a small area, and that such variation is induced by the degree of air mass containing a high concentration of nitrogen deposition of combustion origin. We measured major ion concentrations, including nitrate, nitrite oxygen and nitrogen stable isotope of nitrate sampled at 24 water streams in the Chichibu region, which is 50–100 km from the Tokyo metropolitan area. The nitrate concentration showed a wide range (25.6–237 μmol L−1) within 300 km2, which was explained sufficiently by the air mass advection path and its contact with the mountain’s surface. The nitrate concentration showed a significant positive correlation with chloride (r = 0.73; p < 0.001). As chloride originates outside of the Chichibu region, the positive correlation between two ions showed that the nitrate concentration of the stream water was affected by the nitrogen compound from the Tokyo Metropolitan area as a form of atmospheric deposition. Between the nitrate concentration and the stable isotope ratio of oxygen of nitrate, there was a positive correlation until nitrate concentration of 100 μmol L−1. When the nitrate is over 100 μmol L−1, δ18O shows a stable value of ca. 5.7‰. This indicates that the nitrification proceeds when the nitrate concentration was low to middle, but the reaction slowed when the nitrate concentration became high. Oxygen stable isotope of nitrate along with a set of nitrate concentrations can be used as a good indicator of nitrogen saturation.

Urban and industrial activities are major sources of pollution to marine environments. Sediments can act as sink and reservoir for a wide range of contaminants, including heavy metals. Environmental quality assessment in this compartment can provide useful information to control pollution in coastal areas. Lately, implementation of Environmental Legislative Frameworks within the European Community is increasing awareness about the importance of marine sediment quality in order to achieve a “Good Environmental Status.” In this work, the study of superficial marine sediments allowed assessment of source and fate of heavy metals in a semi-enclosed deep embayment that is subjected to severe anthropogenic activities. Results indicated that accumulation of heavy metals takes place mainly in proximity to anthropogenic sources (industrial area and harbors), but pollution can also spread to greater depths affecting the whole ecosystem. Multivariate statistics helped identify source and fate of several elements, showing evidence of pollutants transfer from urban wastewaters, industrial effluents, and atmospheric emissions to marine sediments. Results provided useful information for the implementation and development of Environmental Management Strategies under European Legislative Frameworks.

The levels of radioactive contamination by artificial radiocesium (137Cs) were evaluated in sediments and the commonest species of water plants. Specimens were collected from a range of biotopes along the Pinios River and its tributaries, during the years 1998 and 2010. The 137Cs concentrations within the above period clearly indicate that this radionuclide still decrease in the River Pinios. A marked decrease is also observed in comparison to our previous results in 1993. 137Cs concentration activities in the sediment are higher than in the plant material. In general, roots showed greater 137Cs concentration than leaves, while stems showed the lowest concentration. Significant differences in 137Cs concentrations were found among different species growing under similar environmental conditions. 137Cs content in collected aquatic plants was in the descending order: Ceratophyllum demersum L. > Myriophyllum spicatum L. > Paspalum pasalodes Scribner > Cladophora glomerata L. > Cyperus longus L. > Potamogeton nodosus Poiret. A comparison of the studied stations indicated that the southwest side of Thessalia plain, where the first two initial sampling stations of the Pinios River and the tributaries Enipeas and Kalentzis are situated, was highly contaminated. Low 137Cs concentrations were observed in the Titarisios tributary, originated from the northeast part of Thessalia plain, behind Mt. Olympus and the last sampling stations of the Pinios River.

The ForSAFE-VEG model was used to investigate the impacts of climate change and air pollution scenarios on soil chemistry and ground vegetations composition. In particular, the model involves a ground vegetation model incorporating plant changes to ambient site conditions in terms of climate and chemistry, but the model also incorporate competition between the different plant groups. The model was validated against observed values and reproduced observations of tree growth, soil chemistry, and ground vegetation compositions to satisfaction. The results show that the ground vegetation reacts strongly to changes in air pollution, in particular nitrogen as well as to climate change with major shifts in plant composition. A procedure for estimating critical loads for nitrogen, using ground vegetation biodiversity as criterion, was tested and the method seems operable. It suggests that if we want to protect the present biodiversity of the ground vegetation, this will face significant difficulties because of permanent climate change that induced changes in the ecosystem. We conclude that the reference state for ground vegetation biodiversity is rather to be sought for in the future, hopefully using models, than in the past or present.

Toxicity of Hg2+ was determined in two strains of Euglena gracilis var. bacillaris: the wild-type (B) and a streptomycin-resistant strain (Smr). Cells were cultured under 12-h dark/12-h light regime or under continuous darkness. In the dark/light cultures, cellular growth was severely diminished in the B strain by Hg2+, whereas only a slight decrease was attained in the Smr strain; Hg2+ also affected the photosynthetic and respiratory activities of the B strain, but not those of Smr strain. Under continuous darkness, cellular growth of both strains was lower than under dark/light cycles, but it was inhibited by Hg2+ to a much lesser extent. Cell culture by 5 days under continuous dark or by 8 days of dark/light cycles resulted in a higher intracellular content of mercury in B strain than in Smr strain. In contrast, in both culture conditions, the fraction of mercury removed from medium by B strain was lower than that attained by Smr strain, whereas the ability to bio-transform (reduce) Hg2+ was two times higher in the mutant strain. The results suggested that Smr strain cells acquired an ability to remove Hg2+ from the medium, which was not associated to accumulation and which conferred protection against mercury.