Radon in air and water

Radon is a natural radioactive gas that you cannot see, smell, or taste and that can only be detected with special equipment. It is produced by the radioactive decay of radium, which in turn is derived from the radioactive decay of uranium. Uranium is found in small quantities in all soils and rocks, although the amount varies from place to place. Radon decays to form radioactive particles that can enter the body by inhalation. Inhalation of the short-lived decay products of radon has been linked to an increase in the risk of developing cancers of the respiratory tract, especially of the lungs. Breathing radon in the indoor air of homes contributes to about 15,000 lung cancer deaths each year in the United States and 1,100 in the UK (HPA 2009). Only smoking causes more lung cancer deaths

Progressive Collapse Analysis of a Typical Super-Tall Reinforced Concrete Frame-Core Tube Building Exposed to Extreme Fires

A number of disastrous incidents have indicated that extreme fires can act as a trigger event to initiate the progressive collapse of reinforced concrete (RC) structures. Hence, research on progressive collapse risks of RC structures under extreme fires is most important. However, limited studies have been undertaken in the fire-induced progressive collapse of tall and super-tall RC buildings. Hence, a high-performance finite element model was developed for this study to simulate the mechanical behavior of RC members in fire-induced progressive collapse. Fiber beam and multi-layer shell elements were used, in conjunction with appropriate material constitutive laws and elemental failure criteria under high temperature conditions. Extreme fire scenarios were also considered, based on the actual fire-induced progressive collapse events of the WTC towers and the Windsor Tower. The simulation results indicated that a progressive collapse of a super-tall building was triggered by the flexural failure of the peripheral columns, approximately 7 h after being exposed to fire. The bending deformations of the peripheral columns increased significantly, due to the outward thermal expansion of the upper floors and the inward contraction of the lower floors, a result of the fire-induced damage. The results also revealed that, when multiple stories are subjected to fire, the internal forces in the components are redistributed in the horizontal and vertical directions by way of the Vierendeel truss mechanism, leading to a maximum increase (of approximately 100%) of the axial forces in the columns. The present work identified the mechanisms of the fire-induced progressive collapse of a typical RC super-tall building, and provided an effective analysis framework for further research on the fire safety of tall and super-tall RC buildings.No Full Tex

Condicionantes socioeconômicos e geográficos do acesso à mamografia no Brasil, 2003-2008 Socioeconomic and geographic constraints to access mammography in Brasil, 2003-2008

Este estudo examinou os efeitos de características da população e geográficas na chance de mamografia, no Brasil em 2003 e 2008. A partir do Suplemento Saúde da Pesquisa Nacional por Amostra de Domicílios, foram analisados os padrões de mamografia em mulheres com 25 anos ou mais, por meio de razão de prevalências, e em mulheres com 40 anos ou mais, por meio de regressão logística multivariada, incluindo o local de residência e a distribuição geográfica da oferta. Entre as mulheres com 50-69 anos, 54,6% relataram ter feito mamografia, em 2003, e 71,5%, em 2008. A chance de realização do exame é maior entre as de 50 a 69 anos, aumenta com a renda familiar e escolaridade, dentre as casadas, para as que consultaram médico e têm plano de saúde. Residir em área metropolitana triplica a chance de mamografia. Comparado com a região Norte, residentes das demais regiões têm chances maiores e a distância influencia negativamente a realização do exame. No período, a cobertura aumentou na faixa etária alvo da política nacional, com redução das desigualdades de renda e de escolaridade. A ampliação do acesso parece mais ligada às políticas de aumento de renda e inclusão social, e à ampliação da oferta de exames na rede pública e conveniada, do que ao aumento do número de mamógrafos.<br>This study examined the effect of population characteristics and geographic location of residences and services on the odds of receiving a mammography in 2003 and 2008. Patterns of mammography use were analyzed using data from the Health Supplements of the National Household Sample Survey for women aged over 25, using prevalence ratios, and for women over 40 using multivariate logistic regression, correcting for complex sample design effects. In 2003, 54.6% of women of 50-69 years of age reported having had a mammography, in 2008, 71.5%. The odds are higher for those 50 to 69 years old, and increase with family income, education, being married, having consulted a doctor and having health insurance. Living in a metropolitan area trebles the chance of mammography. Compared to the Northern region, residents in all other regions have greater odds, greater distances decrease the odds. Coverage increased in the age range targeted by national policy, and inequalities due to income and education on access to mammography were reduced but regional convergence was not marked. Increased access seems to relate more to policies of income distribution and social inclusion, and to the availability of the examination in the Unified Health System, than to an increasing number of mammography units