Lead and cadmium levels in coastal benthic algae (seaweeds) of Tenerife,Canary Islands

Lead and cadmium levels of some species of brown-algae (Phaeophyta) from the mesolittoral (intertidal area) of the Island of Tenerife (central-eastern Atlantic) were determined by Atomic Absorption Spectrometry. The quality control was carried out using a standard "CRM 279 Ulva lactuca".The mean, minimum and maximum concentrations were 11.21, 2.090 and 81.795 microg/g/dw; and 1.13, 0.190 and 5.130 microg/g/dw for lead and cadmium, respectively. The fact that samples registering the highest cadmium concentrations were the same as those which showed the highest lead level corresponding to a sampling station nearby an urban water outlet could be relevant.     

Fractionation of elements by particle size of ashes ejected from Copahue Volcano,Argentina

The volcano Copahue, Neuquén province, Argentina has shown infrequent explosive eruptions since the 18th century. Recently, eruptive activity and seismicity were registered in the period July-October, 2000. As a consequence, ash clouds were dispersed by winds and affected Caviahue village located at about 9 km east of the volcano. Samples of deposited particles from this area were collected during this episode for their chemical analysis to determine elements of concern with respect to the health of the local population and its environment. Different techniques were used to evaluate the distribution of elements in four particle size ranges from 36 to 300 microm. X-ray powder diffraction (XRD) was selected to detect major components namely, minerals, silicate glass, fragments of rocks and sulfurs. Major and minor elements (Al, Ca, Cl, Fe, K, Mg, Mn, Na, S, Si and Ti), were detected by energy dispersive X ray analysis (EDAX). Trace element (As, Cd, Cr, Cu, Hg, Ni, Pb, Sb, U, V and Zn) content was quantified by inductively coupled plasma-mass spectrometry (ICP-MS). Nuclear activation analysis (NAA) was employed for the determination of Ce, Co, Cs, Eu, Hf, La, Lu, Rb, Sc, Sm, Ta and Yb. An enrichment was observed in the smallest size fraction of volcanic ashes for four elements (As, Cd, Cu and Sb) of particular interest from the environmental and human health point of view.     

Analytical approaches to the determination of phosphorus partitioning patterns in sediments

Three methods for phosphorus fractionation in sediments based on chemical extractions have been applied to fourteen aquatic sediment samples of different origin and characteristics. Two of the methods used different approaches to obtain the inorganic fractions. The Hieltjes and Lijklema procedure (HL) uses strong acids or bases, whereas the Golterman procedure (G) uses chelating reagents. The third one, the Standards, Measurements and Testing (SMT) protocol, was proposed in the frame of the SMT Programme (European Commission) which aimed to provide harmonisation and the validation of such methodologies. This harmonised procedure was also used for the certification of the extractable phosphorus contents in a sediment certified reference material (CRM BCR 684). Principal component analysis (PCA) was used to group sediments according to their composition and the three extraction methods were applied to the samples including CRM BCR 684. The data obtained show that there is some correlation between the results from the three methods when considering the organic and the residual fractions together. The SMT and the HL methods are the most comparable, whereas the G method, using a different type of reagent, yields different distribution patterns depending on sample composition. In relation to the inorganic phosphorus, the three methods give similar information, although the distribution between non-apatite and apatite fractions can be different.     

Antimony: a traffic-related element in the atmosphere of Buenos Aires, Argentina

Vehicular traffic is one of the main sources of antimony in highly populated urban areas like Buenos Aires where an overall traffic density of 1 500 000 vehicles per day (corresponding to 7500 vehicles km(-2)) is estimated. In this context, a study was undertaken to ascertain the levels of Sb and other traffic-related elements (TRE) in the atmosphere of this city. To this end, sixty-seven samples of PM-10 particulate matter were collected during eight days in nine representative sampling sites located downtown Buenos Aires and spread over an area of about 30 km2. The collection of particulate matter was performed on ash-free glass-fibre filters using high volume samplers with PM-10 sampling heads. A combination of aqua regia and perchloric acid was used for leaching metals from filters. The resulting solutions were evaporated and then diluted with 0.1 mol l(-1) HCl. Antimony was determined by inductively coupled plasma-quadrupole mass spectrometry (ICP-QMS) at ng g(-1) levels. Concentrations of Sb varied from 12.9 +/- 0.9 to 375 +/- 23 microg g(-1)(equivalent to 0.87 +/- 0.06 to 15.3 +/- 0.8 ng m(-3)). Statistical analysis was performed on the data set including the measured PM-10 mass and Sb concentrations for the monitored period. Correlations of Sb with other TRE namely, Cu and Mo were also assessed. The highest concentrations of Sb were detected at two sites (Hospital Alemán and Casa Rapallini) located in streets with traffic consisting mostly of passenger cars and showing a "stop-and-go" pattern in peak hours. Antimony levels in the Buenos Aires PM-10 are by far below the level of 0.5 mg m(-3)(for an 8 hour workday, 40 hour work week) set by the US Occupational Safety and Health Administration (OSHA) for occupational exposure. However, monitoring of Sb and other TRE should be carried out in a systematic fashion to detect the possibility of increases in from the present levels.     

Dissolved oxygen content as an index of water quality in San Vicente Bay,Chile (36 degrees 45'S)

The present report describes some effects of industrial and municipal effluents on the waters of San Vicente Bay. Analyses ofthe main substances contained in the fishing industry effluentsuggest rating criteria based on the oxygen saturation of thewater as an assessment of organic pollution. Six cruises were carried out throughout the Bay, from June to December 1996. Watersamples were analyzed for dissolved oxygen, oil and grease content, and sediment samples for organic matter content. Waterparameters (salinity, temperature) were used to characterize theBay's hydrography, and to calculate values for oxygen saturation. The measurements demonstrated a local broad range of oxygen deficit, with a maximum of 45% in the winter to 95% in the spring. In November more than 65% of the Bay's area showed oxygendeficits greater than 40%. Organic matter was unusually high insediments along the northern sector of the Bay. The results suggest that the oxygen depletion was a representative parameterfor establishing a relative scale of water quality in this Bay.     

The behaviour of heavy metals from the Guadalquivir estuary after the Aznalcóllar mining spill: field and laboratory surveys

The spill at `Los Frailes caused a large input of metals intothe riverine, estuarine and coastal ecosystems. Metal behaviourin natural waters can be studied both by performing fieldmeasurements, and by undertaking laboratory simulationexperiments. Here is described the behaviour of the heavymetals Zn, Cd, Pb and Cu in the Guadalquivir estuary usingincubation experiments and the results compared to thoseobtained during field assessments. If the toxic waste water hadbeen discharged untreated into the environment, it could haveraised the heavy metal concentrations in the estuary water tohigh values, such as 20.65 M for Zn and 40 × 10^-3 M for Cd. These values are several times higher than thoseobtained in samples collected in the area during the monitoringof the early impact. The metals present a non-conservative behaviour, with a high loss to waters of low salinity values.     

Environmental and socio-economic evaluation of four different sites for a domestic airport

During World War II, a military airport was built inside the city of Reykjavik. This airport then became the centre of domestic aviation for the whole country. Today, 50 years later, the airport tract has become valuable for urban development. The city government therefore wants the airport relocated. Four different sites have been considered. The first alternative is to maintain the airport in the same place. A second alternative is based on reclaiming land alongside the present airport. A third possible site is in a rugged lava field south of Reykjavik, and the fourth alternative is to move the domestic traffic to Keflavik International Airport about 60 km away. The relocation has become a hot issue in the country. The people living in the countryside want to keep the airport in the same place. On the other hand, people living in Reykjavik see the airport land as valuable potential for urban development close to the city centre. To approach this debate in an orderly fashion, the four sites have been studied from an environmental and socio-economic point of view. The four alternatives are classified by four different categories: (1) economy and capital investment, (2) social impacts, (3) direct environmental consequences, and (4) public safety. Firstly, the last three categories were evaluated and weighted, and all four alternatives graded according to their environmental quality. Secondly, using the results of a separate cost-effectiveness study, a Pareto optimality solution is suggested. Finally, sensitivity analysis was carried out to investigate how the “environmental” factors through their variation can influence the final selection.     

Resource Use Rates and Efficiency as Indicators of Regional Sustainability: an Examination of Five Countries

We examine trends from 1970 to the mid 1990's of some variables related to development and sustainability for Costa Rica, Korea, Mexico, the Netherlands and the United States: first, by calculating energy and agricultural efficiencies over time, second, by examining the environmental impacts of economic activities, and third, by estimating ecological footprints. We find that many "optimistic" arguments about sustainability have been misleading, and that there is little or no indication that we are becoming any more sustainable or even efficient. Total quality-corrected energy consumption has increased for all five countries and the renewable energy portion is decreasing. The efficiency of turning energy into both agricultural production and GDP has declined for all countries except for the US. In general, there is a remarkable linearity between resource use and economic and agricultural production over all countries and all years, suggesting severe biophysical constraints to sustainable objectives. On the other hand, per capita ecological footprints have decreased somewhat in Costa Rica, Mexico, and the United States, while national ecological footprints have tended to remain constant except for Korea. While there has been a reduction of specific pollutants in the United States, some of this has been achieved by exporting heavy manufacturing industries. We conclude that continued population and economic growth in each country is likely to make the achievement of any kind of sustainability increasingly unlikely. Sustainability, if that is desirable, requires a very different approach than what we have undertaken to date.     

Intertidal endolithic fauna and it's relationship to the mineralogical,physical and chemical characteristics of the substrate

Mineral composition, granulometry, cohesion, relative and absolute density, and the pH of samples of the Santa Elena sedimentary rock shoal (37°5602 S; 58°1135 W; Argentina) were determined in order to relate the endolithic fauna with the properties of the substrate. Twenty three samples were collected in December 1987, applying a systematic sampling method to an intertidal area of 5 500 m². The mineral composition was determined using x-ray diffraction. Cohesion was determined by visual evaluation of the disintegration of the sample following various periods of immersion in water and by recording the resistance to compressive fracture according to the American Society for Testing and Materials (ASTM) standard. The ASTM standard was also followed for measurement of absolute and relative densities and porosity. The rock was ground up in distilled water and the pH of the resulting liquid measured over a period of 24 h. The data were analysed using numerical taxonomy, and in a supplementary study a granulometric analysis was attempted using five representative samples. The endolithic species selected were: the sipunculanThemiste petricola; the polychaetesPolydora sp. andPherusa sp., and the bivalvesLithophaga patagonica, Petricola patagonica, Saxicava solida, Barnea lamellosa, andPholadidea darwini. The mineral analysis indicated heterogeneous composition and spatial distribution characteristic of a loess. In terms of cohesion, the substrate displayed varying degrees of disintegration, with resistance ranging from zero to very high (254.6 kg/cm²). The endolithic faunaThemiste petricola, Polydora sp.,Pherusa sp.,Lithophaga patagonica, Petricola patagonica, andSaxicava solida were found in areas of low to very high cohesion, with or without calcite. The Pholadidae were found in areas of zero to low cohesion, with absence or traces of calcite. This study indicates the important role of cohesion in determining the distribution of the endolithic fauna.     

Economic viability study of a separate household waste collection in a developing country

This article reports a study of the economic viability of a separate household waste collection project, and considers its social and environmental benefits. The study was developed from the database obtained through the pilot project on separate collections in João Pessoa, the capital of Paraíba, in the northeast region of Brazil. The pilot project had been supported by the local municipal council since September 2000. The methodology applied to this study of economic viability is based on the economic quantification of the benefits and costs involved in the process of a separate collection of household waste. The benefits to the environment, owing to the reduction of the final disposal of household waste, were also evaluated. The results of this research are encouraging for the benefit cost relation (B/C) of both the quantified economic components and the environmental aspects. The values found for the relation B/C ranged from 1.27 to 1.77 depending on the economic quantification of the direct and indirect benefits to the components involved in the project, i.e., the waste collectors, the municipal council, the sellers of recycled material, and the recycling industry.