Naturally occurring radionuclides are found throughout the earth's crust, and they form part of the natural background of radiation to which all humans are exposed. Many human activities-such as mining and milling of ores, extraction of petroleum products, use of groundwater for domestic purposes, and living in houses-alter the natural background of radiation either by moving naturally occurring radionuclides from inaccessible locations to locations where humans are present or by concentrating the radionuclides in the exposure environment. Such alterations of the natural environment can increase, sometimes substantially, radiation exposures of the public. Exposures of the public to naturally occurring radioactive materials (NORM) that result from human activities that alter the natural environment can be subjected to regulatory control, at least to some degree. The regulation of public exposures to such technologically enhanced naturally occurring radioactive materials (TENORM) by the US Environmental Protection Agency (EPA) and other regulatory and advisory organizations is the subject of this study by the National Research Council's Committee on the Evaluation of EPA Guidelines for Exposures to Naturally Occurring Radioactive Materials.

"The object of the present work is the publication of researches which I have been carrying on for more than four years on radio-active bodies. I began these researches by a study of the phosphorescence of uranium, discovered by M. Becquerel. The results to which I was led by this work promised to afford so interesting a field that Pierre Curie put aside the work on which he was engaged, and joined me, our object being the extraction of new radio-active substances and the further study of their properties."

Marie Sklodowska Curie was a Polish and naturalized-French scientist who remains today one of the most extraordinary figures in modern physics and chemistry. She was the first person to win two Nobel Prizes (in Physics and in Chemistry) and the first woman scientist to be awarded the Nobel Prize in Physics. After being denied a position at the University of Kraków, due to the common sexism in the academia of the time, she returned to Paris to work together with Pierre Curie. At the end of the 19th century, Henri Becquerel had discovered the new phenomenon of radio-activity (a term later coined by Marie Sklodowska Curie) in uranium salts. Sklodowska Curie built upon this study and made two fundamental discoveries in the field. First, she discovered that radio-activity is a property of certain elements (like uranium and thorium) of the periodic table, and it is not due to the chemical properties of compounds. Second, she discovered two new radio-active elements, polonium and radium. This book presents her address at Vassar College from 1921 and her Ph.D. thesis, defended in 1903 at the Faculty of Science of the Université de la Sorbonne in Paris. Her thesis, described by the examining committee as the best contribution to science ever presented, made Marie Sklodowska Curie the first woman to obtain a doctoral degree in the history of France. Newly translated from the French second edition, it represents a true masterpiece of science and describes in detail her efforts to understand the origin of radioactivity. To appreciate the beauty of her work one has to keep in mind that, at the time, the structure of the atom was largely unknown (the first attempt was made by J.J. Thomson in 1904). Due to high exposure to radiation, she died from aplastic anemia at the age of 66.

The most recent volume in the Drinking Water and Health series contains the results of a two-part study on the toxicity of drinking water contaminants. The first part examines current practices in risk assessment, identifies new noncancerous toxic responses to chemicals found in drinking water, and discusses the use of pharmacokinetic data to estimate the delivered dose and response. The second part of the book provides risk assessments for 14 specific compounds, 9 presented here for the first time.