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Abstract(s)
O radão é um gás radioativo e apresenta vários isótopos ( átomos cujo núcleo tem o mesmo numerp atómico “Z”) sendo os três principais: O radão (222Rn) resultante do decaimento do urânio (238U), o actinão (219Rn) com origem na desintegração do actínio (227Ac) e o torão (220Rn) produto do decaimento do tório (232Th). Este gás liberta-se dos solos e rochas, dos materiais de construção e da água. As suas concentrações mais elevadas ocorrem, geralmente, em rochas graníticas (plutónicas) sendo mais baixas em rochas sedimentares como os calcários. O gás radão é indetetável aos sentidos do ser humano, uma vez que é isento de cor, odor ou sabor, sendo necessário recorrer a equipamento especializado para medir a sua concentração.
O seu estado físico permite uma grande mobilidade em relação a outros elementos radioativos. Uma vez liberto das rochas, este gás tende a concentrar-se em espaços fechados como minas subterrâneas, habitações e outros edifícios. A sua concentração no interior dos locais e a sua posterior desintegração representam um grande risco para a saúde humana, sendo apontado como a segunda maior causa de cancro do pulmão a seguir ao tabaco.
O Decreto-Lei n.º 118/2013, resulta da transposição para o direito nacional, da Diretiva n.º 2010/31/EU, referente ao desempenho energético dos edifícios. Este decreto integra num único documento o sistema de certificação energético dos edifícios e os respetivos regulamentos, e ainda, a política de qualidade do ar interior. De forma a dar cumprimento às alterações impostas pelo decreto de lei, é publicada a Portaria n.º 353-A/2013, que determina os valores mínimos de caudal de ar novo por espaço, bem como os limiares de proteção e as condições de referência para os poluentes do ar interior. Esta portaria estabelece um limiar de proteção de 400 Bq/m3 para o Radão e a obrigatoriedade de análise de radão em edifícios construídos em zonas graníticas, nomeadamente nos distritos de Braga, Vila Real, Porto, Guarda, Viseu e Castelo Branco.
O presente trabalho tem como objetivo o estudo da contribuição de algumas tintas, habitualmente utilizados na construção civil, para a concentração de radão em interiores. O caso prático do presente estudo consiste na medição da emissão de radão por parte de algumas tintas e permeabilidade ao mesmo. Para esse efeito, foram fabricados provetes em acrílico, sendo que no seu interior foram colocados detetores passivos CR39 sensíveis ao radão, de forma a medir as concentrações deste.
Radon is a radioactive gas and has several isotopes (atoms whose nucleus has the same atomic number "Z"), with the three main ones being: radon (222Rn) resulting from the decay of uranium (238U), actinion (219Rn) from the disintegration of the actin (227Ac) and the thorium (220Rn) product of thorium decay (232Th). This gas is released from soils and rocks, building materials and water. Its highest concentrations occur generally in granite (plutonic) rocks and are lower in sedimentary rocks such as limestones. Radon gas is undetectable to the human senses, since it is free of color, odor or taste, and it is necessary to use specialized equipment to measure its concentration. Its physical state allows a great mobility in relation to other radioactive elements. Once released from the rocks, this gas tends to focus on enclosed spaces such as underground mines, dwellings and other buildings. Its concentration inside the sites and its subsequent disintegration represent a great risk to human health, being pointed out as the second biggest cause of lung cancer after tobacco. Decree-Law no. 118/2013 results from the transposition into Portuguese law of the Directive 2010/31/EU on the energy performance of buildings. This decree integrates in a single document the system of energy certification of the buildings and the respective regulations, as well as the indoor air quality policy. In order to comply with the changes imposed by the decree of law,the Ordinance no. 353-A/2013 is publicated, which determines the minimum values of new air flow per space, as well as the protection thresholds and the reference conditions for indoor air pollutants. This ordinance establishes a protection threshold of 400 Bq/m3 for Radão and the obligation of radon analysis in buildings built in granitic zones, namely in Braga, Vila Real, Porto, Guarda, Viseu and Castelo Branco districts. The present work has the objective of studying the contribution of some paints, usually used in civil construction, to the concentration of radon indoors. The practical case of the present study consists in the measurement of the emission of radon by some paints and its permeability. For this purpose, acrylic specimens were manufactured, and radiant sensitive passive CR39 detectors were placed in the interior to measure their concentrations.
Radon is a radioactive gas and has several isotopes (atoms whose nucleus has the same atomic number "Z"), with the three main ones being: radon (222Rn) resulting from the decay of uranium (238U), actinion (219Rn) from the disintegration of the actin (227Ac) and the thorium (220Rn) product of thorium decay (232Th). This gas is released from soils and rocks, building materials and water. Its highest concentrations occur generally in granite (plutonic) rocks and are lower in sedimentary rocks such as limestones. Radon gas is undetectable to the human senses, since it is free of color, odor or taste, and it is necessary to use specialized equipment to measure its concentration. Its physical state allows a great mobility in relation to other radioactive elements. Once released from the rocks, this gas tends to focus on enclosed spaces such as underground mines, dwellings and other buildings. Its concentration inside the sites and its subsequent disintegration represent a great risk to human health, being pointed out as the second biggest cause of lung cancer after tobacco. Decree-Law no. 118/2013 results from the transposition into Portuguese law of the Directive 2010/31/EU on the energy performance of buildings. This decree integrates in a single document the system of energy certification of the buildings and the respective regulations, as well as the indoor air quality policy. In order to comply with the changes imposed by the decree of law,the Ordinance no. 353-A/2013 is publicated, which determines the minimum values of new air flow per space, as well as the protection thresholds and the reference conditions for indoor air pollutants. This ordinance establishes a protection threshold of 400 Bq/m3 for Radão and the obligation of radon analysis in buildings built in granitic zones, namely in Braga, Vila Real, Porto, Guarda, Viseu and Castelo Branco districts. The present work has the objective of studying the contribution of some paints, usually used in civil construction, to the concentration of radon indoors. The practical case of the present study consists in the measurement of the emission of radon by some paints and its permeability. For this purpose, acrylic specimens were manufactured, and radiant sensitive passive CR39 detectors were placed in the interior to measure their concentrations.
Description
Keywords
Decreto-Lei 118/2013 Detetor Passivo Radão Radioativo Saúde Tintas