Nest placement of the giant Amazon river turtle, Podocnemis expansa, in the Araguaia River, Goiás State, Brazil

The giant Amazon river turtle (Podocnemis expansa) nests on extensive sand bars on the margins and interior of the channel during the dry season. The high concentration of nests in specific points of certain beaches indicates that the selection of nest placement is not random but is related to some geological aspects, such as bar margin inclination and presence of a high, sandy platform. The presence of access channels to high platform points or ramp morphology are decisive factors in the choice of nesting areas. The eroded and escarped margins of the beaches hinder the Amazon river turtle arriving at the most suitable places for nesting. Through the years, changes in beach morphology can alter nest distribution.     

Mercury in two fish species from the Paraná river floodplain, Paraná, Brazil

Total mercury concentrations were measured in dorsal muscle tissue of two edible fish species, Prochilodus scrofa 'curimba' and Pseudoplatystoma corruscans 'pintado', respectively detritivorous and carnivorous. Fish species were sampled monthly between February 1993 and January 1994 and bimonthly between April 1994 and February 1995 in three subsystems of Paraná river' system (Ivinhema River/Lake Patos; Baía River/Lake Guaraná and Paraná River/Cortado Channel), between Paraná and Mato Grosso do Sul. Total mercury was determined by HNO3/H2SO4/V2O5 digestion, SnCl2 reduction, and vapour generation method analysis (CGCH 900), adapted to Atomic Absorption Spectrometer (CGAA 7000 ABC). The mean mercury concentrations varied from 82.0 to 310.5 ng g(-1) and from 68 to 294.4 ng g(-1) in 'curimbas' and 'pintados', respectively. Mercury level increases in sexually mature 'curimbas'. Mercury values detected do not exceed the prevailing criteria for issuance of fish consumption advisories (< 500 ng g(-1)).     

Poland’s environment - past,present and future state of the environment in the vistula and odra river basins

In the middle of the last century in the case of many river basins, it became obvious that the targets of the Helsinki-Commission (HELCOM) concerning a 50% reduction of nitrogen and phosphorus inputs to the Baltic Sea had not been reached. Such conclusions could be derived from the observed loads. But the measurements regarding the analysis were not sufficient to determine what the reasons for this report were, what has to be done to fulfil this agreement and to evaluate the time at which the targets can be reached. This contribution presents the current state of Polish surface water quality as well as results of modelling nutrient and heavy metal emissions into the two biggest Polish river basins: Vistula and Odra, which both cover approximately 90% of Poland's territory.     

Parameter precision in the HBV-NP model and impacts on nitrogen scenario simulations in the Rönneå river, southern Sweden

The HBV-NP model is a newly developed water quality model that describes the turnover and fluxes of both nitrogen and phosphorous. It is based on the conceptual precipitation/runoff HBV model. The HBV-NP model was applied for simulation of nitrogen for the R?nne? catchment in southern Sweden. The catchment was divided into 64 subcatchments in the model. Discharge measurements from six stations and nitrogen measurements from 12 stations were used in the calibration of parameters in the model. Eight automatic calibrations were performed with different combinations of time periods, objective functions, and levels of the nitrogen load in the model. A regionally extended interpretation of the Nash-Sutcliffe R2 criterion was used in the calibration. In the evaluation of the criterion, the errors were summed over both time steps and sampling points. Scenario simulations of combined measures for reduction of nitrogen load into the sea by 30% were thereafter performed with the eight sets of parameters established by calibration. The model parameters were not uniquely defined by the calibration. However, the simulated relative reduction of nitrogen load into the sea was relatively insensitive to the choice of parameter set, given the available input sources, variables, and data.     

Replacing the Nile: are anthropogenic nutrients providing the fertility once brought to the Mediterranean by a great river?

Prior to construction of the Aswan High Dam, the annual Nile flood delivered about 7-11 x 10(3) t of biologically available phosphorus (P), at least 7 x 10(3) t of inorganic nitrogen (N), and 110 x 10(3) t of silica (Si) to the Mediterranean coastal waters off Egypt. These nutrients stimulated a dramatic "Nile bloom" of diatoms which supported a productive fishery. After closure of the dam in 1965, flow from the Nile was reduced by over 90%, and the fishery collapsed. It remained unproductive for about 15 years. The fishery began a dramatic recovery during the 1980s, coincident with increasing fertilizer use, expanded agricultural drainage, increasing human population, and dramatic extensions of urban water supplies and sewage collection systems. Calculations of the potential anthropogenic contribution of nutrients (P and N, but not Si) are consistent with the hypothesis that human sewage and agricultural drainage now support the fertility once provided by the Nile, though the nature of the productive ecosystem now supporting the fishery appears to be quite different from the historical one.     

Geological characterization and environmental implications of the placement of the Morelia Dump, Michoacán, Central Mexico

The landfill of Morelia, the capital city of the state of Michoacán in central-western Mexico, is located 12 km west of the city and has operated since 1997 without a structure engineered and designed to control the generation in situ of biogas and leachates. A geological evaluation of the landfill site is presented in this paper. The results indicate that the site lacks ideal impermeable subsurface strata. The subsurface strata consist of highly fractured basaltic lava flows (east-west fault and fracture system trend) and sand-size cineritic material with high permeability and porosity. Geochemical analysis of groundwater from Morelia's municipal aquifer shows a high concentration of heavy metals (Cd, Pb, As) exceeding the Mexican environmental regulations, along with the presence of some organic pollutants (phenols). Analyses of samples of the landfill's permanent leachate ponds show very high concentrations of the same contaminants. Samples were taken from the leachate pond and from nearby water-wells during the rainy season (summer 1997) and the dry season (spring 1997, 1998, and 1999). In all cases, the concentration of contaminants registered exceeded the standards for drinking water of the World Health Organization (American Public Health Association, American Water Works Association, and Water Pollution Control Federation, 2000). Some metal contaminants could be leaching directly from the landfill.     

Melatonin exerts a neuroprotective effect against γ-radiation-induced brain injury in the rat through the modulation of neurotransmitters,inflammatory cytokines,oxidative stress,and apoptosis

Environmental Science and Pollution Research - The current study aimed to investigate the ameliorative effect of melatonin (MLT) against brain injury in rats undergoing whole-body exposure to...     

Haze trends over the United States, 1980–1995

The patterns and trends of haze over the United States for the period of 1980–1995 are presented. Haze measurements are based on human visual range observations at 298 synoptic meteorological stations operated by the United States Weather Service. There was a significant (∼10%) decline in haziness over the 15-yr period. The reductions were evident throughout the eastern United States as well as over the hazy air basins of California. During the same period, in the eastern United States sulfur emissions also declined by about 10%. However, a causality for the reductions has not been established. This report is an update of an earlier survey of haze patterns and trends from 1950 to 1980.     

In situ monitoring of the mutagenic effects of the gaseous emissions of a solid waste incinerator in metropolitan São Paulo, Brazil, using the Tradescantia stamen-hair assay

The present work was designed to determine the potential genotoxicity at the vicinity of a solid waste incinerator in the metropolitan area of S?o Paulo, using the Tradescantia stamen-hair bioassay. Experiments were carried out between December 1998 and April 1999 in four regions (40 pots of plants per site) selected on the basis of their pollution levels predicted by theoretical modeling of the dispersion of the incinerator's plume. The exposure sites were defined as follows: highest level (incinerator); a high level (museum) located 1.5 km from the emission point; a moderate level (school, at a distance of 3.5 km from the incinerator); and a control (at Jaguariúna countryside). The difference in genotoxicity among the groups was statistically significant (p < 0.001). The frequency of mutations observed in the countryside was significantly lower [2.25 +/- 1.55, mean +/- SD (standard deviation)] than that of the sites close to the incinerator. The frequency of mutations measured at the school (3.70 +/- 1.36) was significantly lower than that measured at both the museum (4.89 +/- 1.12) and the incinerator (5.69 +/- 1.34). In conclusion, we found a positive correlation between the spatial distribution of the emissions of the incinerator located in an urban area and the mutagenic events measured by the Tradescantia stamen-hair assay. The in situ approach employed in this study was simple, efficient, and of low cost. No air or chemical extraction of pollutants was necessary for genotoxicity testing as required by other assays.     

Environmental toxicity assessment in the Paraná river delta (Argentina): simultaneous evaluation of selected pollutants and mortality rates of Corbicula fluminea (Bivalvia) early juveniles

Water and sediment samples were collected in the lower Paraná delta at four sites with different levels of exposure to pollution to evaluate the anthropogenic impact through chemical analyses and mortality bioassays. Individual polychlorinated biphenyls, chlorinated pesticides, aliphatic hydrocarbons, polycyclic aromatic hydrocarbons, and heavy metals were measured in waters, porewaters and sediments. The same three phases were also subjected to toxicity assays with straight-hinged juveniles of Corbicula fluminea. Concentrations of several pollutants were above levels recommended for the protection of aquatic life: in waters, Zn, Cu and Cr were 1.6-4.9 times higher, whereas in the sediments Cr was 1.8-3.6, and benzo(a)pyrene was 2.8-5.6 times higher. Pollutant concentrations followed a clear geographic pattern with highest values in the densely populated area of the Reconquista and Luján rivers, lower levels in the San Antonio, and lowest loadings in the remote Paraná de las Palmas. This gradient was adequately matched by the pattern of mortality rates of C. fluminea early juveniles, which were highest in the Reconquista-Luján (40-93%) and lowest (and not significantly different from the control) in the Paraná (3.3-23%). Mortality rates also increased from surface waters (3.3-53%), to porewaters (12-73%), to sediments (23-93%). Although toxicity was probably mainly due to dissolved contaminants, agreement between chemical and biological evidence of pollution was best for the sediment compartment, whereas porewater and surface water showed a higher degree of variability.     

Heavy-metal pollution assessment in the coastal lagoons of Jacarepaguá, Rio de Janeiro, Brazil

The Jacarepaguá lagoon receives the waste from 239 industries and domestic sewage. Bottom sediment analysis revealed that metal pollution is not spread over the lagoons but restricted to the discharge areas of the main metal-carrier rivers. Metal concentrations in superficial water showed the following concentrations values in ng/ml: Zn, 9.63+/-3.59; Pb, 0.61+/-0.43; Cu, 0.94+/-0.45; Mn, 12.7+/-8.0. Metal concentration in fish (average of seven different species) presented the following results, in mg/kg wet weight: Cr, 0.08+/-0.01; Cu, 0.4+/-0.15; Zn, 4.6+/-3.4; Fe, 2.4+/-1.3; Mn, 0.4+/-0.3. These results imply, considering fish consumption rate and the RfD (USEPA Reference Dose), that the local population is not exposed to undue health risks. Metal concentrations in the water may, however, increase due to their dissolution induced by pH and redox changes in the sediments.     

Toxicity of water and sediment in a small urban river (Store Vejleå, Denmark)

The urban stream Store Vejle? (Denmark), which receives discharges of urban runoff, was investigated using a combination of biological toxicity tests and chemical analysis. The urban stormwater and road runoff gave low, but statistically significant, effects on the reproduction of the alga Pseudokirchneriella subcapitata. In all pre-concentrated water samples toxic effects were found and differences in toxicity depending on time and location of sampling were identified. Undiluted pore water samples from sediments collected in the stream were all toxic towards the algae and dilutions from 4 to 14 times were needed compared to a pore water sample from an unpolluted stream where a dilution factor of only 1.6 was required. A qualitative correlation between the toxicity of the pore water and the degree of pollution as evidenced by the metal concentration was observed, but statistically significant correlations could not be established by ranking procedures of, e.g. metal content or PAH-concentrations versus the observed toxicity.     

Trends in exceedances of the ozone air quality standard in the continental United States, 1980–1998

In 1997, the United States National Ambient Air Quality Standard (NAAQS) for ozone was revised from a 1-h average of 0.12 parts per million (ppm) to an 8-h average of 0.08 ppm. Analysis of ozone data for the ensemble of the contiguous United States and for the period 1980–1998 shows that the average number of summer days per year in exceedance of the new standard is in the range 8–24 in the Northeast and in Texas, and 12–73 in southern California. The probability of exceedance increases with temperature and exceeds 20% in the Northeast for daily maximum temperatures above 305 K. We present the results of several different approaches to analyzing the long-term trends in the old and new standards over the continental United States from 1980 to 1998. Daily temperature data are used to resolve meteorological variability and isolate the effects of changes in anthropogenic emissions. Significant negative trends are found in the Northeast urban corridor, in the Los Angeles Basin and on the western bank of Lake Michigan. Temperature segregation enhances the detection of negative trends. Positive trends occur at isolated sites, mostly in the Southeast; a strong positive trend is found in Nashville (Tennessee). There is some evidence that, except in the Southwest, air quality improvements from the 1980s to the 1990s have leveled off in the past decade.     

A study of the particulate matter PM10 composition in the atmosphere of Chillán, Chile

Inhalable particulate matter (PM10) concentrations were measured over 24-h intervals at six different urban sites in the city of Chillán from September 2001 to April 2003. Sampling locations were selected to represent central city, commercial, residential, and industrial portions of the city. Chemical composition of PM10 was performed to samples of 47 mm diameter Teflon membranes within the city of Chillán. The spatial and temporal variability of the chemical composition of PM10 was evaluated taking into account additional data from meteorology and further air pollutants. The majority of PM mass was comprised of carbon, nitrate, sulfate, ammonium, and crustal components but in different proportion on different days and at different sites. The chemical analyses showed that carbonaceous substances and crustal material were the most abundant component of PM10 during the winter and summer, respectively. The concentrations of PM10 were higher during the cold season than during the warm season. The PM10 concentrations were higher in the downtown area of the city of Chillán, where also the chemical composition was more variable due to urban traffic and other anthropogenic sources.     

A multivariate statistical analysis of the composition of rainwater near Cubatão, SP, Brazil

With the aim of estimating the chemical composition of bulk precipitation (wet + dry) in Cubat?o, rainwater samples were collected at several localities in the Cubat?o region from May 1984 to October 1985. The levels of some inorganic ions (Na+, Ca2+, K+, Mg2+, Cl-, SO4(2-), NH4+, PO4(3-)) were measured by atomic absorption spectrophotometry, turbidimetry and titration analysis. Correlation and Fisher discrimination indices, principal component and varimax loading and scores were determined in the multivariate statistical data treatment. The results showed that ionic concentrations in rainwater from Vila Parisi are significantly higher than those of Cubat?o Centro, Santos and Serra do Mar. The ionic compositions of the Vila Parisi rainwater seem to be mainly determined by local anthropogenic activities (industrial pollution). Besides the influence of this factor on water quality, there is also a natural oceanic contribution involving Cl- and Na+ at the other locations.     

Economic,ecological, and health aspects of β-diketonate application in the process of water purification

Environmental Science and Pollution Research - Water pollution is a constant challenge for humanity. Sustainable economic development and environmental protection through a green economy structure...