Exposure of workers in mineral processing industries in Brazil

The mining, milling and processing of uranium and thorium bearing minerals may result in radiation doses to workers. A preliminary survey pilot program, that included six mines in Brazil (two coal mines, one niobium mine, one nickel mine, one gold mine and one phosphate mine), was launched in order to determine the need to control the radioactive exposure of the mine-workers. Our survey consisted of the collection and analysis of urine samples, complemented by feces and air samples. The concentrations of uranium, thorium and polonium were measured in these samples and compared to background data from family members of the workers living in the same dwelling and from residents from the general population of Rio de Janeiro. The results from the coal mines indicated that the inhalation of radon progeny may be a source of occupational exposure. The workers from the nickel, gold and phosphate mines that were visited do not require a program to control internal radiological doses. The niobium mine results showed that in some areas of the industry exposure to thorium and uranium might occur.     

Mullet and gudgeon liver histopathology and macroinvertebrate indexes and metrics upstream and downstream from a wastewater treatment plant (Febros River—Portugal)

The increased pollution in ecosystems reinforces the importance of both chemical monitoring and biological monitoring of streams and rivers, as an effective water quality-based approach to assess aquatic ecosystem health. In this study, gudgeon (Gobio gobio) and mullet (Mugil cephalus) liver histopathology (biomarker) and some macroinvertebrate community indexes and metrics (bioindicator) were used to evaluate the effect of the wastewater treatment plant (WWTP) of Febros (Avintes) in Febros River water quality and ecosystem health. Regarding macroinvertebrate communities, the Belgian Biotic Index (BBI) and Iberian Biological Monitoring Working Party (IBMWP) indexes suggested that Febros water was slightly polluted, even though the worst situation was found downstream the WWTP discharge. Concerning community metrics, upstream percent of individuals in five numerically dominant taxa (80%) was slightly more superior than the downstream (78%). The presence of intolerant or sensible individuals, determined by percent of Ephemeroptera, Plecoptera, and Trichoptera individuals and number of Ephemeroptera, Plecoptera, and Trichoptera families metrics, was higher upstream WWTP, reflecting a better water quality. The histopathology shows the presence of hepatic lesions in gudgeon and mullet. The statistical analysis of the lesion gradation showed that only necrosis was significantly higher in gudgeon captured downstream the WWTP, while differences were not observed for mullet. The multivariate analysis of data confirmed the existence of differences in hepatic lesions between gudgeon and mullet and between sampling sites. Regarding macroinvertebrate community, this analysis showed that the organic contamination reflected by the BBI and IBMWP indexes values was a determinant factor in the spatial distribution of macroinvertebrates. This work showed that the study of different biological organization levels can be used for a better assessment of ecosystem ecological integrity and can be used as a tool to reveal anthropogenic activity effects in macroinvertebrate diversity and in fish liver pathology from Febros River.     

Effect of variations in the redox potential of Gleysol on barium mobility and absorption in rice plants

Two assays were designed to obtain information about the influence of redox potential variations on barium mobility and bioavailability in soil. One assay was undertaken in leaching columns, and the other was conducted in pots cultivated with rice (Oryza sativa) using soil samples collected from the surface of Gleysol in both assays. Three doses of barium (100,300 mg kg⁻¹ and 3000 mg kg⁻¹-soil dry weight) and two redox potential values (oxidizing and reducing) were evaluated. During the incubation period, the redox potential (Eh) was monitored in columns and pots until values of −250 mV were reached. After the incubation period, geochemical partitioning was conducted on the barium using the European Communities Bureau of Reference (BCR) method. Rainfall of 200 mm d⁻¹ was simulated in the columns and in the planting of rice seedlings in the pots. The results of the geochemical partitioning demonstrated that the condition of reduction favors increased barium concentrations in the more labile chemical forms and decreased levels in the chemical forms related to oxides. The highest barium concentrations in leached extracts (3.36 mg L⁻¹) were observed at the highest dose and condition of reduction at approximately five times above the drinking water standard. The high concentrations of barium in the soil did not affect plant dry matter production. The highest levels and accumulation of barium in roots, leaves, and grains of rice were found at the highest dose and condition of reduction. These results demonstrate that reduction leads to solubilization of barium sulfate, thereby favoring greater mobility and bioavailability of this element.     

Economic assessment of managing processionary moth in pine forests: a case-study in Portugal

This paper assesses the private and social profitability of current strategies for managing processionary moth (Thaumetopoea pityocampa) in Portuguese pine forests, looking at economic and environmental costs and benefits. Costs include the expenses for forest treatment and the social costs of threats to human health (dermatitis amongst others); benefits are assessed in terms of both revenue and social benefits such as carbon fixation and recreation. The evaluation was done using Cost Benefit Analysis (CBA) as an analytical framework. While this tool is currently applied to forest and environmental assessment and specific applications to pest management strategies are to be found in agricultural economics, rather few attempts have been made in the field of forest pest management. In order to assess and compare with--without options, a case-study was analysed for the Setúbal Peninsula, south of Lisbon, an area where extensive stands of maritime pine (Pinus pinaster) grow. The exercise has shown that CBA can be a valuable tool for assessing the economic and social profitability of pest management. The results demonstrate that the loss of revenues in the no-management option is not sufficient to make pest management profitable for private forest owners in the short-term. Conversely, a social profit is gained as pest management minimizes health risks for humans and avoids possible recreational losses.     

Assessment of heavy metals in the particulate matter of two Brazilian metropolitan areas by using <Emphasis Type="BoldItalic">Tillandsia usneoides</Emphasis> as atmospheric biomonitor

Purpose  

The aims of this paper were to quantify the heavy metals (HM) in the air of different sites in Rio de Janeiro (RJ) and Salvador (SA) using Tillandsia usneoides (Bromeliaceae) as a biomonitor, and to study the morphology and elemental composition of the air particulate matter (PM) retained on the Tillandsia surface.     

The possible origin of Zostera noltii in the Canary Islands and guidelines for restoration

Seagrasses and their habitat are declining worldwide. Zostera noltii in the Canary Islands has been drastically reduced, mainly by anthropogenic disturbance, to three small surviving patches in a single harbor in Lanzarote. A previous genetic study, using neutral microsatellite markers, revealed that these patches consist of a single clonal individual. Here, an assignment test, using microsatellite data, was used to locate the most likely population of origin from a set of possible donor populations. Our results show that the Moulay Bousselham population in northern Morocco is assigned as the most likely population of origin (88%), although the probability of being at one generation time distance is low (2.7%). This result, however, allows locating the most closely related stands that may be the most successful donor populations for future restoration based on shoot or seed transplantation.     

Effect of light supply on CO2 capture from atmosphere by Chlorella vulgaris and Pseudokirchneriella subcapitata

Carbon dioxide (CO₂) is one of the primary greenhouse gases that contribute to climate change. Consequently, emission reduction technologies will be needed to reduce CO₂ atmospheric concentration. Microalgae may have an important role in this context. They are photosynthetic microorganisms that are able to fix atmospheric CO₂ using solar energy with efficiency ten times higher than terrestrial plants. The objectives of this study were: (i) to analyse the effect of light supply on the growth of Chlorella vulgaris and Pseudokirchneriella subcapitata; (ii) to assess the atmospheric CO₂ capture by these microalgae; and (iii) to determine the parameters of the Monod model that describe the influence of irradiance on the growth of the selected microalgae. Both microalgae presented higher growth rates with high irradiance values and discontinuous light supply. The continuous supply of light at the highest irradiance value was not beneficial for C. vulgaris due to photooxidation. Additionally, C. vulgaris achieved the highest CO₂ fixation rate with the value of 0.305 g-CO₂ L^?1 d^?1. The parameters of the Monod model demonstrated that C. vulgaris can achieve higher specific growth rates (and higher CO₂ fixation rates) if cultivated under higher irradiances than the studied values. The presented results showed that microalgal culture is a promising strategy for CO₂ capture from atmosphere.     

Development of a local carbon dioxide emissions inventory based on energy demand and waste production

This paper describes the study that led to the development of a carbon dioxide emissions matrix for the Oeiras municipality, one of the largest Portuguese municipalities, located in the metropolitan area of Lisbon. This matrix takes into account the greenhouse gas (GHG) emissions due to an increase of electricity demand in buildings as well as solid and liquid wastes treatment from the domestic and services sectors. Using emission factors that were calculated from the relationship between the electricity produced and amount of treated wastes, the GHC emissions in the Oeiras municipality were estimated for a time series of 6 yr (1998-2003). The obtained results showed that the electricity sector accounts for approximately 75% of the municipal emissions in 2003. This study was developed to obtain tools to base options and actions to be undertaken by local authorities such as energy planning and also public information.     

Estrogenic activity removal of 17beta-estradiol by ozonation and identification of by-products

This work investigated the degradation of a natural estrogen (17beta-estradiol) and the removal of estrogenic activity by the ozonation process in three different pHs (3, 7 and 11). A recombinant yeast assay (YES assay) was employed to determine estrogenic activity of the ozonized samples and of the by-products formed during the ozonation. Ozonation was very efficient for the removal of 17beta-estradiol in aqueous solutions. High removals (>99%) were achieved with low ozone dosages in the three different pHs. Several by-products were formed during the ozonation of 17beta-estradiol. However, only a few compounds could be identified and confirmed. Different by-products are formed at different pHs, which is probably due to different chemical pathways and different oxidants (O(3) and OH radical). The by-products formed at pH 11 were 10epsilon-17beta-dihydroxy-1, 4-estradieno-3-one (DEO) and 2-hydroxyestradiol, which were not formed in pH 3. Only testosterone could be observed in pH 3, whereas at pH 7 all three by-products were found. At pH 7 and 11 the applied ozone dosages were not enough to remove all the estrogenicity from samples, even though the 17beta-estradiol residual concentration for these two pHs was lower than at pH 3. Higher estrogenicity was detected at pH 11. An explanation to this fact may be that oxidation via OH radical forms more by-products with estrogenic activity. Probably, the formation of 2-hydroxyestradiol at pHs 7 and 11 is contributing to the residual estrogenicity of samples ozonized at these pHs. In this work, complete removal of estrogenic activity was only obtained at pH 3.     

Using Baetidae Species as Biological Indicators of Environmental Degradation in a Brazilian River Basin

The Ephemeroptera family Baetidae is one of the most specious families in the Neotropical region and a great effort to improve the taxonomy of this group has been made over the last 10 years in South America. Such studies now enable the development of biomonitoring tools at species-level in the region. A total of 2,199 baetids were collected from seven sampling sites, collected three times (autumn, winter and summer), representing an environmental gradient, draining an area of Atlantic Forest remnants. We describe the mesohabitat of nine Baetidae species and evaluate their responses to environmental degradation and water chemistry by means of biological measures (richness and abundance) and multivariate analysis (Canonical Correspondence Analysis), in order to assess their potential capacity as indicators of these impacts. Most species were found predominantly associated with stony substrates, but some were associated with pool litter, and one species was found predominantly in riffle litter substrate. Species distribution was influenced by the environmental gradient. Based on the CCA ordination, we were able to identify which species were found in pristine versus the most impaired areas, therefore enabling us to establish the sensitivity of each species.