Geraldo Stachetti Rodrigues

RENEWABLE ENERGY : ECONOMIC AND ENVIRONMENTAL ISSUES

This article analyzes the potential of various renewable or solar energy technologies to supply the United States with its future energy needs. Diverse renewable technologies are assessed in terms of their land requirements, environmental benefits and risks, economic costs, and a comparison of their advantages. In addition a projection of the amount of energy that could be supplied by solar energy is made. Topics covered include: assessment of renewable energy technologies; biomass energy systems; liquid fuels; ethanol; methanol; hydrogen; hydroelectric systems; wind power; photovoltaics; solar thermal conversion systems; passive heating and cooling of buildings; comparing solar power to coal and nuclear power; transition to solar energy and other alternatives. 84 refs.

Exploring the clastogenic effects of air pollutants in São Paulo (Brazil) using the Tradescantia micronuclei assay

This study was designed to determine the clastogenicity of particulate matter (aerodynamic diameter smaller than 10 microm) in the urban polluted air in the city of São Paulo. The Tradescantia-micronucleus (Trad-MCN) assay was used throughout this study to evaluate the clastogenicity of the extracts of the particulate matter. Tradescantia pallida (Rose) Hunt. cv. purpurea, an indigenous cultivar, was used in the Trad-MCN assay. The efficacy of this plant material for the Trad-MCN assay was validated with dose-response studies using formaldehyde and beta radiation. Dose-response curves were established with these known mutagens. The extracts of the PM10 particles at concentrations between 5 and 50 ppm induced a dose-related increase in MCN frequencies. The results indicate that T. pallida is equally sensitive to mutagens as the standard Tradescantia clone 4430 or 03 and the particulate matter in the urban air are clastogenic to the chromosomes of this plant. Inhalation of these particles by urban dwellers may affect their health by inducing similar genetic damage.

Sistema integrado de avaliação de impacto ambiental aplicado a atividades do Novo Rural

O objetivo deste trabalho foi apresentar o sistema de Avaliacao Ponderada de Impacto Ambiental de Atividades do Novo Rural (APOIA-NovoRural), que consiste de um conjunto de planilhas eletronicas (plataforma MS-Excel) que integram 62 indicadores da performance ambiental de uma atividade economica em um estabelecimento rural. Cinco dimensoes de avaliacao foram consideradas: ecologia da paisagem, qualidade ambiental (atmosfera, agua e solo), valores socioculturais, valores economicos e gestao e administracao. Os indicadores foram construidos em matrizes de ponderacao, nas quais dados quantitativos, obtidos em campo e laboratorio, foram automaticamente transformados em indices de impacto, expressos graficamente. O indice de impacto de cada indicador foi traduzido a um valor de utilidade, empregando-se funcoes e coeficientes especificamente derivados para cada indicador. Os valores de utilidade foram agregados para compor o Indice de Impacto Ambiental da atividade avaliada. Os resultados da avaliacao permitem ao produtor/administrador averiguar quais atributos da atividade podem estar desconformes com seus objetivos de sustentabilidade e ao tomador de decisoes a indicacao de medidas de fomento ou controle das atividades, segundo planos de desenvolvimento local; proporcionam, ainda, uma unidade de medida objetiva de impacto para auxiliar na qualificacao e certificacao de atividades agropecuarias.

An environmental impact assessment system for agricultural R&D

Abstract A strategic planning process has been implemented at the Brazilian Agricultural Research Agency (Embrapa) to introduce sustainable agriculture concepts in all steps of Research and Development (R&D). An essential part of the devised mission statement called for the impact assessment of all technology innovation resulting from R&D, under field conditions (ex-post). However, methods for impact assessment of technology innovations at the farmstead level appropriate for the institutional context were lacking. The environmental impact assessment (EIA) system (AMBITEC-AGRO) developed to attend that demand is composed by a set of weighing matrices constructed in an electronic spreadsheet. Impact indicators are evaluated in the field in an interview/survey, and weighed according to their spatial scale and importance toward effecting environmental impacts. The results of these weighing procedures are expressed graphically in the assessment spreadsheets. Finally, the indicator evaluations are composed into an Environmental Impact Index for the agricultural technology innovation.

Pollen mother cells of Tradescantia clone 4430 and Tradescantia pallida var. purpurea are equally sensitive to the clastogenic effects of X-rays

The Tradescantia micronucleus test is a sensitive bioassay for mutagenesis that may be employed both under field and laboratory conditions. This test has been standardized mostly on the basis of the results obtained with clone 4430. However, this clone is not well adapted to tropical weather, frequently showing problems with growth and flowering. In addition, it is attacked by parasites and insects, a fact that limits its use in field studies aiming at the biomonitoring of air pollution. In the city of São Paulo, Tradescantia pallida (Rose) Hunt. var. purpurea Boom is widely distributed as an ornamental plant in gardens and along roadsides and streets, mostly because of its natural resistance and its easy propagation. In this report, we present dose-response curves indicating that the sensitivity of T. pallida and clone 4430 to X-radiation (1, 10, 25 and 50 cGy) is similar. The results confirm our previous suggestion that T. pallida represents a good alternative for in situ mutagenesis testing in tropical regions, especially biomonitoring studies in which the exposure conditions may not be fully controllable.

In situ assessment of pesticide genotoxicity in an integrated pest management program I-Tradescantia micronucleus assay

The genotoxicity induced by pesticides applied in an integrated pest management (IPM) program was evaluated with the Tradescantia micronucleus assay (Trad-MCN). Three pesticide application rates were prescribed as follows: (a) Low, no field pesticide spray; (b) Medium, IPM test rate: banded cyanazine plus metolachlor (2.7 kg a.i. and 2.3 l a.i./ha of herbicides, respectively); and (c) High, a preventative pesticide application program: broadcast cyanazine plus metolachlor (same application rates as above) plus chlorpyrifos (1 kg a.i./ha of insecticide). The Trad-MCN was employed for the assessment of (a) the formulated compounds, singly and in combinations; (b) pesticide residues extracted from soils sampled before and after application, and (c) in situ exposures (14-h exposure to pesticide-sprayed field). All pesticides showed clastogenic potency at doses between 10 and 50 ppm. Aqueous extracts of the two pesticide-sprayed soils were clastogenic, but the unsprayed soil extracts were not. Plants exposed in situ to pesticide-sprayed soils (inside a chamber receiving vapors from the soil) also showed significant increases in micronuclei frequency in relation to controls exposed to unsprayed soil. In general, there was no significant reduction in the genotoxic effects from the High to the Medium treatment levels of the IPM program. This suggests that the reduction in pesticide application rates attained with the implementation of the proposed IPM program was not sufficient to abate the genotoxicity of the pesticides, as perceived with the sensitive assays employed. The results indicate that replacing genotoxic compounds may be the only effective remediation measure to eliminate the risks imposed by mutagenic compounds in the agricultural environment.

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

ABSTRACT The present work was designed to determine the potential genotoxicity at the vicinity of a solid waste incinerator in the metropolitan area of Sâo 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 incinerators 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 Jaguariuna 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.

In situ monitoring of mutagenicity of air pollutants in São Paulo City using Tradescantia-SHM bioassay

The Tradescantia stamen hair mutation assay (Trad-SHM) was employed for assessing the environmental mutagenesis in two areas of Sao Paulo City. The study sites were defined as follows: 1) Celso Garcia Avenue, an industrial area on the outskirts of the urban center (Belem neighborhood), with an average daily traffic volume of 8,750 vehicles; 2) Doutor Arnaldo Avenue, in downtown area (Pinheiros neighborhood), with a mostly residential and business offices occupation, with an average daily traffic volume of 46,125 vehicles. The negative control (background) site is located in the city of Jaguariuna, 138 km from Sao Paulo, in an area of low atmospheric pollution. The mutation frequency observed for Belem was similar to the background for clone 4430, whereas plants exposed in Pinheiros showed significant increases in mutation rate. Positive correlation was observed between mutation frequency and the levels of particulate matter in the atmosphere. This indicated a relationship between mutation frequency and the amount of atmospheric pollution present at the exposure sites in Sao Paulo City, with special reference to vehicular emissions.

Biological Response of Tradescantia Stamen-hairs to High Levels of Natural Radiation in the Poços de Caldas Plateau

A presente politica de protecao radiologica esta baseada na hipotese de linearidade da relacao dose-efeito, da qual derivam os procedimentos de protecao e o estabelecimento de limites aceitaveis de exposicao. Embora tal politica possa ser considerada conservadora e eficiente, ha controversias quanto a aplicabilidade da hipotese de linearidade quando efeitos geneticos sao considerados, especialmente para exposicoes a doses reduzidas presentes em areas com altos niveis de radiacao natural, o que justifica estudos adicionais. O Planalto de Pocos de Caldas e considerado um dos locais da Terra de maior radiatividade natural, e o objetivo do presente estudo foi aplicar um teste muito sensivel de avaliacao de mutagenese (o ensaio da mutacao em pelos estaminais de Tradescantia) para averiguar in situ as respostas biologicas induzidas pela radiacao natural. A inducao de mutagenese foi avaliada em ambientes apresentando taxas de exposicao a radiacao gamma variando de 1,5mR.min-1 a 100mR.min-1.Os resultados indicam que a radiacao presente na maioria dos ambientes estudados nao foi suficiente para induzir aumentos significativos na taxa de mutacao, mesmo neste bioensaio muito sensivel.

In situ assessment of pesticide genotoxicity in an integrated pest management program : II. Maize waxy mutation assay

The mutagenicity induced by pesticides applied in an integrated pest management (IPM) program was evaluated in situ with the maize forward waxy mutation bioassay. Three pesticide application rates were prescribed as follows: (1) Low--no field pesticide spray; (2) Medium--IPM test rate: banded cyanazine plus metolachlor (2.7 kg a.i. and 2.3 l a.i./ha of herbicides, respectively); and (3) High--a preventative pesticide application program: broadcast cyanazine plus metolachlor (same application rates as above) plus chlorpyrifos (1 kg a.i./ha of insecticide). In general, there was no significant reduction in the genotoxic effects from the high to the medium treatment levels of the IPM program. This suggests that the reduction in pesticide application rates attained with the implementation of the proposed IPM program was not sufficient to abate the genotoxicity of the pesticides. The results indicate that replacing genotoxic compounds may be the only effective remediation measure if concern about environmental mutagenesis were to result in changes in agricultural management.