RESUMO
The aim of this study was to evaluate the public and occupational exposure to radon and metal-bearing particles in museums and public buildings located in the city of Rio de Janeiro, Brazil. For this study, four buildings were selected: two historic buildings, which currently house an art gallery and an art museum; and two modern buildings, a chapel and a club. Integrated radon concentration measurements were performed using passive radon detectors with solid state nuclear track detector-type Lexan used as nuclear track detector. Air samplers with a cyclone were used to collect the airborne particle samples that were analyzed by the particle-induced X-ray emission technique. The average unattached-radon concentrations in indoor air in the buildings were above 40 Bq/m(3), with the exception of Building D as measured in 2009. The average radon concentrations in indoor air in the four buildings in 2009 were below the recommended reference level by World Health Organization (100 Bq/m(3)); however, in 2011, the average concentrations of radon in Buildings A and C were above this level, though lower than 300 Bq/m(3). The average concentrations of unattached radon were lower than 148 Bq/m(3) (4pCi/L), the USEPA level recommended to take action to reduce the concentrations of radon in indoor air. The unattached-radon average concentrations were also lower than the value recommended by the European Union for new houses. As the unattached-radon concentrations were below the international level recommended to take action to reduce the radon concentration in air, it was concluded that during the period of sampling, there was low risk to human health due to the inhalation of unattached radon in these four buildings.
Assuntos
Poluentes Radioativos do Ar/análise , Poluição do Ar em Ambientes Fechados/análise , Metais/análise , Radônio/análise , Brasil , Poeira/análise , Exposição Ambiental/análise , Monitoramento Ambiental/métodos , Humanos , Metais/química , Museus , Exposição Ocupacional/análise , Monitoramento de Radiação/métodosRESUMO
We studied the relationship between alpha- and beta-adrenergic agonists and the activity of carbonic anhydrase I and II in erythrocyte, clinical and vessel studies. Kinetic studies were performed. Adrenergic agonists increased erythrocyte carbonic anhydrase as follows: adrenaline by 75%, noradrenaline by 68%, isoprenaline by 55%, and orciprenaline by 62%. The kinetic data indicated a non-competitive mechanism of action. In clinical studies carbonic anhydrase I from erythrocytes increased by 87% after noradrenaline administration, by 71% after orciprenaline and by 82% after isoprenaline. The increase in carbonic anhydrase I paralleled the increase in blood pressure. Similar results were obtained in vessel studies on piglet vascular smooth muscle. We believe that adrenergic agonists may have a dual mechanism of action: the first one consists of a catecholamine action on its receptor with the formation of a stimulus-receptor complex. The second mechanism proposed completes the first one. By this second component of the mechanism, the same stimulus directly acts on the carbonic anhydrase I isozyme (that might be functionally coupled with adrenergic receptors), so that its activation ensures an adequate pH for stimulus-receptor coupling for signal transduction into the cell, resulting in vasoconstriction.
Assuntos
Agonistas alfa-Adrenérgicos/farmacologia , Agonistas Adrenérgicos beta/farmacologia , Anidrases Carbônicas/metabolismo , Catecolaminas/farmacologia , Vasoconstrição/fisiologia , Adulto , Análise de Variância , Animais , Anidrases Carbônicas/isolamento & purificação , Ativação Enzimática , Epinefrina/farmacologia , Eritrócitos/efeitos dos fármacos , Eritrócitos/enzimologia , Humanos , Concentração de Íons de Hidrogênio/efeitos dos fármacos , Isoenzimas/metabolismo , Isoproterenol/farmacologia , Masculino , Metaproterenol/farmacologia , Pessoa de Meia-Idade , Músculo Liso Vascular/efeitos dos fármacos , Norepinefrina/farmacologia , Transdução de SinaisRESUMO
We studied the relationship between alpha- and beta-adrenergic agonists and the activity of carbonic anhydrase I and II in erythrocyte, clinical and vessel studies. Kinetic studies were performed. Adrenergic agonists increased erythrocyte carbonic anhydrase as follows: adrenaline by 75 percent, noradrenaline by 68 percent, isoprenaline by 55 percent, and orciprenaline by 62 percent. The kinetic data indicated a non-competitive mechanism of action. In clinical studies carbonic anhydrase I from erythrocytes increased by 87 percent after noradrenaline administration, by 71 percent after orciprenaline and by 82 percent after isoprenaline. The increase in carbonic anhydrase I paralleled the increase in blood pressure. Similar results were obtained in vessel studies on piglet vascular smooth muscle. We believe that adrenergic agonists may have a dual mechanism of action: the first one consists of a catecholamine action on its receptor with the formation of a stimulus-receptor complex. The second mechanism proposed completes the first one. By this second component of the mechanism, the same stimulus directly acts on the carbonic anhydrase I isozyme (that might be functionally coupled with adrenergic receptors), so that its activation ensures an adequate pH for stimulus-receptor coupling for signal transduction into the cell, resulting in vasoconstriction