Investigators have long recognized the importance of certain elements, commonly called "minerals," in the diet of humans and animals and in the soil that supports plants, in that these elements are essential for the life or optimum health of the organisms. Deficiencies of 20 to 24 elements in animals and man and of 13 to 18 elements in plants have been recognized. At the same time, an understanding of the responses of these organisms to the insult of toxic concentrations of these and other elements also has been of interest. More recently, concern has arisen regarding the effects of an organism's exposure to the more subtle chronic and subchronic concentrations of certain elements that industrial and other human activities are releasing into the environment.

The population explosion that began in the 1960s has been accompanied by a decrease in the quality of the natural environment, e.g. pollution of the air, water and soil with essential and toxic trace elements. Numerous poisonings of people and animals with highly toxic anthropogenic Hg and Cd in the 20th century prompted the creation of the abiotic environment, mainly in developed countries. However, the system is insufficient for long-term exposure to low concentrations of various substances that are mainly ingested through food and water. This problem could be addressed by the monitoring of sentinels – organisms that accumulate trace elements and as such reflect the rate and degree of environmental pollution. Usually these are long-lived vertebrates – herbivorous, omnivorous and carnivorous birds and mammals, especially game species. This book describes the responses of the sentinels most commonly used in ecotoxicological studies to 17 trace elements.

Diet and Health examines the many complex issues concerning diet and its role in increasing or decreasing the risk of chronic disease. It proposes dietary recommendations for reducing the risk of the major diseases and causes of death today: atherosclerotic cardiovascular diseases (including heart attack and stroke), cancer, high blood pressure, obesity, osteoporosis, diabetes mellitus, liver disease, and dental caries.

FROM THE PREFACE The main objective of composting is to transform organic materials into a stable usable product. Often organic materials which may have limited beneficial use in their raw state or have regulatory disposal constraints can be transformed by composting into marketable products. The limits on beneficial reuse may be regulations or they may be due to the potential for materials to be putrescible or pathogenic. Composting can be a solution for each of these. The implementation of composting on a large scale (in contrast to home or backyard composting) involves materials handling. Technological implementation of composting must be consistent with the biological demand of the system. If the biological system is violated, conditions will not be optimized for composting, and problems such as odor generation, insufficient aeration or moisture, or a combination of these conditions may result. Past problems and closure of facilities have been largely due to violations of the biological systems. Product quality with respect to particle size, inclusions, moisture content and other physical aspects are a function of engineering design. A well designed system must have the biological and engineering principles in harmony at all times.