Environmental pollution

Abstract: Background Recent studies have reported associations between particulate air pollution and daily mortality rates. Population-based, cross-sectional studies of metropolitan areas in the United States have also found associations between particulate air pollution and annual mortality rates, but these studies have been criticized, in part because they did not directly control for cigarette smoking and other health risks. Methods In this prospective cohort study, we estimated the effects of air pollution on mortality, while controlling for individual risk factors. Survival analysis, including Cox proportional-hazards regression modeling, was conducted with data from a 14-to-16-year mortality follow-up of 8111 adults in six U.S. cities. Results Mortality rates were most strongly associated with cigarette smoking. After adjusting for smoking and other risk factors, we observed statistically significant and robust associations between air pollution and mortality. The adjusted mortality-rate ratio for the most po...

Abstract: This extensive report entitled “Climate Change 1995: The Science of Climate Change” is the most comprehensive and up-to-date assessment available for scientific understanding of human influences on the past present and future climate. Its aim is to provide objective information on which to base global climate change that will ultimately meet the aim of the UN Framework Convention on Climate Change. The report includes an overview of the factors governing climate and climate change and quantification of the sources of globally important greenhouse gases and other pollutants arising from human activities. A review of the chemical and biological processes governing their removal from the atmosphere is presented. Also included is an assessment of recent trends in climate during the industrial era which has witnessed the ever-growing impact of human activities on the global environment. The strengths and weaknesses of various climate mathematical models used by researchers for understanding the past and present climate and for calculating possible future climates are assessed. Furthermore the report discusses research aimed at the detection of human influence on the climate of the last century and presents future change projections in global climate and sea level based on a range of scenarios of future emissions of pollutants due to human activity. Finally a list of research and observational priorities needed to improve scientific understanding in key areas is presented.

Abstract: Urban areas are hot spots that drive environmental change at multiple scales. Material demands of production and human consumption alter land use and cover, biodiversity, and hydrosystems locally to regionally, and urban waste discharge affects local to global biogeochemical cycles and climate. For urbanites, however, global environmental changes are swamped by dramatic changes in the local environment. Urban ecology integrates natural and social sciences to study these radically altered local environments and their regional and global effects. Cities themselves present both the problems and solutions to sustainability challenges of an increasingly urbanized world.

Abstract: My lecture spanned not only the hour allocated for it in the morning, but also the first half of the round table that afternoon, where it acted as an introduction to the round table discussion that followed. The break between the two sessions was determined only by administrative and not by scientific matters, and so in this published account, the two may be read as a unit.

Abstract: Diagenesis refers to changes taking place in sediments after deposition. In a theoretical treatment of early diagenesis, Robert Berner shows how a rigorous development of the mathematical modeling of diagenetic processes can be useful to the understanding and interpretation of both experimental and field observations. His book is unique in that the models are based on quantitative rate expressions, in contrast to the qualitative descriptions that have dominated the field. In the opening chapters, the author develops the mathematical theory of early diagenesis, introducing a general diagenetic equation and discussing it in terms of each major diagenetic process. Included are the derivations of basic rate equations for diffusion, compaction, pore-water flow, burial advection, bioturbation, adsorption, radioactive decay, and especially chemical and biochemical reactions. Drawing on examples from the recent literature on continental-margin, pelagic, and non-marine sediments, he then illustrates the power of these diagenetic models in the study of such deposits. The book is intended not only for earth scientists studying sediments and sedimentary rocks, but also for researchers in fields such as radioactive waste disposal, petroleum and economic geology, environmental pollution, and sea-floor engineering.