The world is a dirty place and getting dirtier all the time. The reasons for this ever-increasing lack of cleanliness are not hard to find, being basically caused by the actions of the six billion people who inhabit the planet. The needs of the people for air, water, food, housing, clothing, heating, materials, oil, gas, minerals, metals, chemicals, and so forth have, over the centuries, given rise to a variety of environmental problems that have been exacerbated or been newly created by the industrialization of the world, the increase in population, and the increase in longevity of the population. The costs of cleaning even fractions of the known environmental problems are truly enormous, as detailed in the volume Environmental Risk Analysis (I. Lerche and E. Paleologos, 2001, McGraw-Hill). The chances of causing new environmental problems, and their associated costs of clean up, are equally challenging in terms of anthropogenic influences and also of the natural environmental problems that can be triggered by humanity. This volume discusses many examples of environmental problems that have occurred and that are still ongoing. The volume also considers the effects in terms of sickness and death of fractions of the population of the planet caused by such environmental problems.