Heavy metals can be emitted into environment by both natural and anthropogenic sources, mainly mining and industrial activity. Human exposure occurs through all environmental media. Infants are more susceptible to the adverse effects of exposure. Increasing attention is now being paid to the mental development of children exposed to heavy metals. The purpose of this book is to evaluate the existing knowledge on intellectual impairment in children exposed to heavy metals in their living environment and to identify the research needs in order to obtain a clearer picture of the situation in countries and regions at risk, in which the economy is closely related to metallurgy and heavy metals emission, and to recommend a strategy for human protection. In greater detail the main objectives could be formulated as follows: to review the principal sources of single, and complex mixtures of, heavy metal pollutants in the environment; to identify suitable methodology for chemical analyses in the environment and in humans; to evaluate the existing methods for measuring mental impairment, including their reliability and validity; to recommend a standard testing protocol to be used in future research; to assess the future role of environmental heavy metal pollution in countries and regions at risk and its effects on children’s neurological development; to recommend a prevention strategy for protecting children’s health and development.

Trace metals occur as natural constituents of the earth's crust, and are ever present constituents of soils, natural waters and living matter. The biological significance of this disparate assemblage of elements has gradually been uncovered during the twentieth century; the resultant picture is one of ever-increasing complexity. Several of these elements have been demonstrated to be essential to the functions of living organisms, others appear to only interact with living matter in a toxic manner, whilst an ever-decreasing number do not fall conveniently into either category. When the interactions between trace metals and plants are considered, one must take full account of the known chemical properties of each element. Consideration must be given to differences in chemical reactivity, solubility and to interactions with other inorganic and organic molecules. A clear understanding of the basic chemical properties of an element of interest is an essential pre-requisite to any subsequent consideration of its biological significance. Due consideration to basic chemical considerations is a theme which runs through the collection of chapters in both volumes.

In the past two decades there has been an increasing public awareness of the hazards that exist from the contamination of the environment by toxic substances. 'Heavy metals' and the terrestrial environment are but one facet of the impact of toxic substances on the natural environment, and the use of biological materials for indicating the occurrence of, and continually monitoring the presence of, these materials is a specific topic which is of considerable interest to a diverse range of individuals, organisations and disciplines. It was our intention when we first en visaged this book that it should contain a description of a range of circumstances in which biological monitoring techniques have been employed in the terrestrial environment and that it should be seen as a practical text which dealt with the merits, shortcomings and suitability of biological monitoring materials. Monitoring is, however, a manifold process. It serves not only to provide information on past and present concentrations of toxic materials in various components of the environ ment, but also to provide information on the processes of environmental release, transport, accumulation and toxicity. Indeed, this may be one of the greatest virtues of biological monitoring over other forms of monitor ing. According to the skill of the staff employed in the monitoring procedure, the information that is accrued can have a vastly different value.

Following a description of the various sources and factors influencing the contents of heavy metal pollution in post-catastrophic and agricultural soils, subsequent chapters examine soil enzymes and eggs as bio-monitors, lead adsorption, the effects of arsenic on microbial diversity, and the effects of Mediterranean grasslands on abandoned mines. A third section focuses on the adaptation strategies used by plants and bacteria, such as Pinus sylvestris in industrial areas, and the rhizosphere in contaminated tropical soils and soil treated with sewage sludge. Further topics addressed include strategies of bioremediation, e.g. using transgenic plants as tools for soil remediation. This new volume on heavy metals in soil will be of interest to researchers and scholars in microbial and plant biotechnology, agriculture, the environmental sciences and soil ecology.

Heavy-metal contamination is one of the world's major environmental problems, posing significant risks to agro-ecosystems. Conventional technologies employed for heavy-metal remediation have often been expensive and disruptive. This book provides comprehensive, state-of-the-art coverage of the natural, sustainable alternatives that use a wide range of biological materials in the removal/detoxification of heavy metals, consequently leading to the improvement of crops in these soils. Novel, environmentally friendly and inexpensive solutions are presented based on a sound understanding of metal contamination and the roles of plants and microbes in the management of these toxic soils. Written by worldwide experts, the book provides not only the necessary scientific background but also addresses the challenging questions that require special attention in order to better understand metal toxicity in soils and its management through bioremediation.

The term "Heavy Metal" is somewhat imprecise, but includes most metals with an atomic number greater than twenty, but excludes alkali metals alkaline earths, lanthanum andactinides. Human civilization started with the accidental discovery of - especially Copper. Since then living organisms have taken long strides with the help of metals.

Heavy metal and metalloid contamination of groundwater and surface water ecosystems involves important policy-related and ethical issues besides its more well-known scientific aspects. Heavy Metal and Metalloid Contamination of Surface and Underground Water: Environmental, Policy, and Ethical Issues has brought these three dimensions under a single volume. The book presents an updated status of the nature and extent of heavy metal and metalloid contamination of water and discuss its future implications. In Section I, the book provides a state-of-the-art review of research findings on entry, storage, and release, human health risks, and the uptake and accumulation by freshwater biota and the toxic effects experienced by them. The book also provides information on the bioremediation of heavy metals and metalloids, and the possible effects of climate change on their distribution and toxicity. Section II of the book throws light on the policies and legislations adopted in several countries to deal with the vexed issue of metal contamination of waters in both historical and current perspectives. Special emphasis has been given to the contamination of drinking water and its attendant implications for human health. The book also treats the relevance and applications of Integrated Water Resources Management (IWRM), which forms the backbone of the water policies of several countries. In Section III, discussions focus on ethical issues rising out of heavy metal and metalloid contamination of water, and on the different ethical approaches and principles in both indigenous and other societies. Features: A systematic overview of the major facets of heavy metal and metalloid contamination of water Compilation and analysis of the latest research in the subject area Ample case studies in all chapters that highlight specific problems Review of policy and legislation for the control of heavy metal pollution of water Water ethics in indigenous societies This book will be a vital resource for students and research scholars in the field of environmental science, ecotoxicology, and pollution studies.