Factores de riesgo psicosociales en el consumo de tabaco de los adolescentes: estados de ánimo negativos, grupo de iguales y estilos parentales

Existe una multiplicidad de factores que pueden afectar el riego del consumo de tabaco en la adolescencia. Mediante el análisis de estos factores de manera conjunta podemos desentrañar la relevancia específica que cada uno de ellos tiene en la conformación de la conducta individual de los adolescentes. El objetivo de esta investigación es profundizar en el conocimiento sobre la relación entre el consumo de tabaco en la adolescencia y variables socio-demográficas y socio-emocionales. Contamos con una muestra representativa de 2.289 adolescentes catalanes (15-18 años) que participaron en el Panel de Familias e Infancia. Se han realizado modelos de regresión para determinar la asociación estadística de los diferentes estados de ánimo (tristeza, nerviosismo y soledad), características del grupo de iguales y estilos parentales, con el consumo de tabaco. Los resultados indican que el comportamiento adictivo es más probable cuando los adolescentes muestran estados de ánimo negativos, controlando por variables socio-demográficas y otros factores de riesgo. Entre estos factores adicionales, los estilos parentales autoritativos reducen el riesgo del consumo de tabaco en comparación con la parentalidad autoritaria, permisiva y negligente. El consumo generalizado de tabaco en el grupo de iguales es el factor de riesgo que tiene una asociación más alta con el comportamiento individual del adolescente.

Consumo de tabaco en el lugar de trabajo: interacciones entre fumadores y no fumadores respecto al cumplimiento de la normativa

Aprofitant l'aparició de la nova llei sobre la prohibició de fumar en els espais laborals, exposen els resultats d'una investigació en que s'analitzaven les interaccions entre fumadors i no fumadors, les diferents reaccions

Recuperação de 241Am de para-raios e detectores de fumaça

A method is described for recovering and purifying 241Am from lightning-conductors and smoke detectors. The method is based on the precipitation of silver, as AgCl, the main impurity, and extraction of americium with TBP. Further purification with ion-exchange resin is also used. The results have shown that by this method the americium is obtained with high purity.

Eletrocatálise e poluição ambiental

This work considers mainly the problem of environmental pollution due to the production of energy by burning fossil fuels, particularly in urban vehicles. Electrochemical energy conversion is proposed as a partial solution to this problem, through the use of hydrogen in fuel cells. In both the production of hydrogen by electrolysis and in the electrochemical processes in fuel cells, the key factor is electrocatalysis. The concept of electrocatalysis, the production of catalysts and supported catalysts and their use in practical systems for the conversion of energy is discussed.

Distribuição de coprostanol (5beta(H)-colestan-3beta-ol) em sedimentos superficiais da Baía de Guanabara: indicador da poluição recente por esgotos domésticos

A critical evaluation is presented on the use of faecal sterols for the identification of sewage contamination in Guanabara Bay. Sediments were collected from 8 stations in the bay selected as representative of different contamination levels. GC/MS determination of faecal sterols gave: coprostanol, 335 - 40000 ng g-1; coprostanone, 112-4136 ng g-1; cholesterol, 1407-7800 ng g-1; cholestanol, 2011 - 10900 ng g-1 and cholestanone, 655-7954 ng g-1. The observed concentration is in accordance with the presence of known pollution sources, however, concentration ratios of different sterols species produced unclear results evidently influenced by primary production and microbial processes.

Propagação da poluição atmosférica por flúor nas águas subterrâneas e solos de regiões próximas às indústrias de fertilizantes (Rio Grande, RS)

Fluoride concentration was determined in rainwater, ground water and soil in the zone of fertilizer industry in the city of Rio Grande. In contaminated rainwater fluorine concentration was registered up to the value of 4,4 mg.L-1. Fluorine concentration in the shallow ground water in general reflects its distribution in the atmosphere, but cannot be used as marker of atmosphere contamination in the urban area due to dissolving influence of residential effluents. The 0,01% HCl extracts from the set of surface soil samples demonstrates fluoride distribution in the zone of influence of industrial emissions, which coincides to the numerical simulation of fluorides dispersion in the air.

Avaliação de poluição do ar por chumbo particulado: uma abordagem geoquímica

High lead concentrations up to 5478 mg kg-1 were detected in dry atmospheric precipitations in Rio Grande city and adjacent area. Lead anomalies cover up to 30% of the study area. Lead concentration measurement in dry atmospheric precipitation and suspended particulate matter provides a possibility to detect concentrations above lead threshold in the air. The most impacted areas are fishermen's villages. The most possible source of lead in the air is uncontrolled sub industrial activity of local population

Poluição química relacionada ao ar de interiores no Brasil

During the last two decades there has been increasing concern within the scientific community related to the effects of indoor air quality on health. Changes in building design devised to improve energy efficiency and new synthetic building materials have contributed to increase pollutant concentrations. These factors have generated poor air quality and caused the development of a lot of symptoms known as Sick Building Syndrome (SBS). In Brazil, there are few studies in this area, collected in this review to support researches and awareness of the need to adopt preventive measures to reach a better quality for the Indoor Environment.

A poluição gerada por máquinas de combustão interna movidas à diesel - a questão dos particulados. Estratégias atuais para a redução e controle das emissões e tendências futuras

The exhaust emissions of vehicles greatly contribute to environmental pollution. Diesel engines are extremely fuel-efficient. However, the exhaust compounds emitted by diesel engines are both a health hazard and a nuisance to the public. This paper gives an overview of the emission control of particulates from diesel exhaust compounds. The worldwide emission standards are summarized. Possible devices for reducing diesel pollutants are discussed. It is clear that after-treatment devices are necessary. Catalytic converters that collect particulates from diesel exhaust and promote the catalytic burn-off are examined. Finally, recent trends in diesel particulate emission control by novel catalysts are presented.

Distribuição de mercúrio total como indicador de poluição urbana e industrial na costa brasileira

The monitoring of the pollution status of the Brazilian coast is hampered by the lack of a consistent environmental indicator. We propose Hg as an environmental proxy to anthropogenic pollution of coastal regions due to its absence in the Brazilian geology, its ubiquity in anthropogenic effluents, and its toxicity. Available data suggest Hg "backgrounds" in coastal sediments of 1-10 ng g-1, in the East and 15-30 ng g-1 in the South. We suggest short sediment cores to establish these values estimating a geo-accumulation index to compare all areas. The distribution of index values showed the majority of southern coast at least moderately contaminated whereas many eastern areas are still pristine.

Risk perception and stages of smoking acquisition = Percepción de riesgo y etapas de iniciación en el consumo de tabaco

The purpose of this descriptive survey was to investigate the risk perceptions of smoking in a sample of 1,510 Spanish adolescents(49.1% males; mean age = 14.03; SD = 1.28). In addition, the present research categorised adolescents into one of the fourstages of smoking acquisition, as described by the Transtheoretical Model of Change (TMC): Precontemplation (notthinking about trying smoking in the next 6 months), Contemplation (thinking about trying smoking in the next 6 months), Preparation (thinking about starting smoking in the next 30 days) and Action (smokers), by gender and age. The results showed that age and risk perceptions are important variables in the progression through the stages of change towards regular tobacco consumption (Action stage). These results clearly demonstrate the importance of starting antismoking campaigns at an early age to prevent smoking acquisition or the thought of starting in the near future. These findings also highlight the need to continuously remind adolescents about the negative consequences of smoking

Poluição das águas por herbicidas utilizados no cultivo do arroz irrigado na região central do estado do Rio Grande do Sul, Brasil: predição teórica e monitoramento

This article presents an evaluation of the pollution of river water by herbicides used in the culture of irrigated rice in Rio Grande do Sul State, Brazil. Firstly, a theoretical evaluation was made using the approaches suggested by EPA-USA, the "Groundwater Ubiquity Score" index and the Goss method to estimate the pollution possibilities. Afterwards, a monitoring program was established for the rivers of the area from 2001 to 2003 to investigate the presence of herbicide residues. The results indicate that the herbicides clomazone and propanil are the ones with larger presence and frequency in the analyzed samples. The theoretical forecast was confirmed by the results of the monitoring program.

Uso de agrotóxicos em cana-de-açúcar na bacia do Rio Corumbataí e o risco de poluição hídrica

The state of São Paulo is the main Brazilian consumer of pesticides. Sugar cane, which uses a great amount of these products, is extensivelly cultivated in this state, such as in the Corumbataí river basin, an important source of water for the region. In order to implement an efficient and low-cost monitoring program, the temporal characterization of the use of pesticides on sugar cane in this basin was performed. After knowing the seasonal trends of consumption, a better choice of sampling time, became possible. The combination of data from this survey with partitioning indices, average doses and toxicological classifications showed to be important for defining the pesticides to be included in the monitoring program.

Estudo da decomposição térmica de propelente sólido compósito de baixa emissão de fumaça

The thermal decomposition of hydroxyl-terminated polybutadiene (HTPB)/ammonium nitrate (AN) based propellants, so called smokeless formulations, and raw materials were investigated by differential scanning calorimetry (DSC) and thermogravimetry (TG). The thermoanalytical profile of different components and of propellant were evaluated and the Arrhenius parameters for the thermal decomposition of the propellant sample were determined by the Ozawa method. The kinetic parameters of the thermal decomposition of propellant samples were determined by DSC measurements. The values obtained for activation energy (Ea) and pre-exponential factor were 163 kJ mol-1 and 1.94x10(6) min-1.

Efeitos da poluição atmosférica (litorânea e industrial) em isoladores da rede elétrica da região metropolitana de Salvador

The performances of eight kinds of insulators from electrical distribution lines in Salvador-BA, Brazil, were evaluated considering the chemical and physical local environmental pollution. The parameters that were chosen as characteristic for the insulators' properties were leakage current and partial electrical discharge. A data storage processing system and a communication link to the lab were built for data acquisition. The results show that the main contribution to the poor performance of the insulators is settleable magnetite particulate matter on the insulator in addition to the long term wetness time, t4.