Heavy Metal Toxicity

Over 400 years ago, Swiss alchemist and physician Paracelsus (1493-1541) cited: "All substances are poisons; there is none that is not a poison. The right dose differentiates a poison from a remedy." This is often condensed to: "The dose makes the poison." So, why are we overtly anxious about intoxications?In fact, poisons became a global problem with the industrial revolution. Pesticides, asbestos, occupational chemicals, air pollution, and heavy metal toxicity maintain high priority worldwide, especially in developing countries. Children between 0 and 5 years old are the most vulnerable to both acute and chronic poisonings, while older adults suffer from the chronic effects of chemicals. This book aims to raise awareness about the challenges of poisons, to help clinicians understand current issues in toxicology.

It is often said that the “dosage” of any substance determines its remedy or poison effect. Heavy metal sources encompass sewage, pesticides, fertilizers, environmental contamination, occupational exposure/contact through inhalation, ingestion, and skin. Before the advent of technology/the industrial revolution, communicable diseases ravaged the human race but this seems to have given way to non-communicable diseases such as cancers, renal failure, hormonal distortion enzymes, inhibition of fetal growth, and DNA damage causing negative health issues due to heavy metals. This book brings to the fore probably the most recent experimental research/review on heavy metal contamination, remediating techniques, cellular tissue damage, and toxicological and antioxidant effects of heavy metals. It is hoped that its contents will make interesting reading for all.

Highlighted in this compilation of papers is the role and importance of heavy metals in the environment. It provides up-to-date information in a field of active research and progress, where the focus is on effects and interactions between the environment and organisms, as well as contaminant dynamics. Several papers address the impact of heavy metals on our health. The influence of metals on plants is described in an exhaustive study on lichens, which have been widely used as biomonitors for environmental contamination by heavy metals. Metals are also accumulated by animals, as seen in a chapter which focusses on sediment/benthic organism interactions and biomonitoring in fish. Soil interactions are discussed, as well as regional studies of freshwater sediments and the marine environment. The final part of the book addresses a crucial problem: the management of stabilized municipal waste sludges. As a result, the most important and significant recent trends are included, emphasizing interactions with and impacts of heavy metals on humans, animals, plants and soils.

The term “heavy metals” is used as a group name of toxic metals and metalloids (semimetals) causing contaminations and ecotoxicity. In strict chemical sense the density of heavy metals is higher than 5 g/cm3. From biological point of view as microelements they can be divided into two major groups. a. For their physiological function organisms and cells require essential microelements such as iron, chromium (III), cobalt, copper, manganese, molidenium, zinc. b. The other group of heavy metals is toxic to the health or environment. Of highest concern are the emissions of As, Cd, Co, Cu, Hg, Mn, Ni, Pb, Sn, Tl. The toxicity of heavy metals is well known at organizational level, while less attention has been paid to their cellular effects. This book describes the toxicity of heavy metals on microorganisms, yeast, plant and animal cells. Other chapters of the book deal with their genotoxic, mutagenic and carcinogenic effects. The toxicity of several metals touch upon the aspects of environmental hazard, ecosystems and human health. Among the cellular responses of heavy metals irregularities in cellular mechanisms such as gene expression, protein folding, stress signaling pathways are among the most important ones. The final chapters deal with biosensors and removal of heavy metals. As everybody is eating, drinking and exposed to heavy metals on a daily basis, the spirit of the book will attract a wide audience.

This book is concerned with heavy metals, which are considered to be the most hazardous pollutants present in the water system. Heavy metals are extensively studied and their effects on human health are reviewed here. Although several adverse health effects of heavy metals are known for a long time, exposure to heavy metals continues and is even increasing in some parts of the world. This books deals with the source of heavy metals in the environment and possible mitigation measures for metal recovery. The technology available for the detection of heavy metals and the latest remediation techniques are also discussed in detail. In this way, the book also addresses general background to polymers and their composite materials for removal of specific toxic heavy metals from waste water. The different adsorption isotherm models and adsorption mechanism using biosorption methods are also described. The widespread applications of low-value agricultural products, ion-exchange, coagulation, precipitation, flocculation, ultra-filtration and electrochemical methods are mentioned. The book reviews the essential issues and will be of interest to academicians, research scholars and industries. It will be the precious resource for all undergraduate and postgraduate students at institutes and universities.

Metals are important environmental pollutants and their toxicity is a problem of increasing significance for ecological, nutritional, and environmental reasons. These pollutants, ultimately derived from a growing number of diverse anthropogenic sources (industrial effluents and wastes, urban runoff, sewage treatment plants, boating activities, agricultural fungicide runoff, domestic garbage dumps, and mining operations), have progressively affected more and more different ecosystems. Even agricultural lands are progressively becoming enriched of metals due to long-term use of phosphatic fertilizers, sewage sludge application, dust from smelters, industrial waste and bad watering practices in agricultural lands. Among these metals, Cu, Fe, Mn, Mo and Zn are pivotal micronutrients, while Ag, As, Cd, Cr, Hg, Pb, Sb and V and are non-essential for plants and have no known function as nutrients and seem to be more or less toxic to all plants and microorganisms. Sodium excess deserves particular attention. Several agricultural lands are indeed becoming familiar with the problem of salinization, due to the use of fresh water which contains a high level of NaCl or due to intensive fertilization, especially in arid and semi-arid environments characterized by poor rainfalls. Overall, the presence of both essential and non-essential metals in the atmosphere, soil and water, in excessive amounts, can cause serious problems to all organisms. Knowledge of plant-metal interactions is important for the safety of the environment, but also for reducing the risks associated with the introduction of trace metals into the food chain. Although intense research has been conducted during the last 30 years, many aspects remain to be clarified concerning the effect of metals in higher plants. Our goal for this book is to critically review existing literature related to the specific effects of different metals in plants, as well as to provide new evidence about plant-metal interactions in order to clarify mechanisms of metal uptake, translocation, and partitioning and the effect of metal toxicity. Consequences related to accumulation of metals in food products have been described. Physiological and biochemical mechanisms adopted by plants to cope with metal excess and possible implications for phytoremediation of metal-contaminated soils are also discussed. Therefore, we believe that this book will provide a comprehensive overview regarding some aspects of metal toxicity in plants and it will be useful for scientist working in this field of research, but it will also be of practical interest to environmentalists, policy-makers, and resource managers working on the topic. We wish to thank all the authors who joined this book project by contributing their valuable work. Lastly, we extend our sincere thanks to Nova Science Publishers for their efficient support.

Experts explore the influence of trace metals on the pathogenesis of infectious diseases. Many parts of the world in which common infectious diseases are endemic also have the highest prevalence of trace metal deficiencies or rising rates of trace metal pollution. Infectious diseases can increase human susceptibility to adverse effects of metal exposure (at suboptimal or toxic levels), and metal excess or deficiency can increase the incidence or severity of infectious diseases. The co-clustering of major infectious diseases with trace metal deficiency or toxicity has created a complex web of interactions with serious but poorly understood health repercussions, yet has been largely overlooked in animal and human studies. This book focuses on the distribution, trafficking, fate, and effects of trace metals in biological systems. Its goal is to enhance our understanding of the relationships between homeostatic mechanisms of trace metals and the pathogenesis of infectious diseases. Drawing on expertise from a range of fields, the book offers a comprehensive review of current knowledge on vertebrate metal-withholding mechanisms and the strategies employed by different microbes to avoid starvation (or poisoning). Chapters summarize current, state-of-the-art techniques for investigating pathogen-metal interactions and highlight open question to guide future research. The book makes clear that improving knowledge in this area will be instrumental to the development of novel therapeutic measures against infectious diseases. Contributors M. Leigh Ackland, Vahid Fa Andisi, Angele L. Arrieta, Michael A. Bachman, J. Sabine Becker, Robert E. Black, Julia Bornhorst, Sascha Brunke, Joseph A. Caruso, Jennifer S. Cavet, Anson C. K. Chan, Christopher H. Contag, Heran Darwin, George V. Dedoussis, Rodney R. Dietert, Victor J. DiRita, Carol A. Fierke, Tamara Garcia-Barrera, David P. Giedroc, Peter-Leon Hagedoorn, James A. Imlay, Marek J. Kobylarz, Joseph Lemire, Wenwen Liu, Slade A. Loutet, Wolfgang Maret, Andreas Matusch, Trevor F. Moraes, Michael E. P. Murphy, Maribel Navarro, Jerome O. Nriagu, Ana-Maria Oros-Peusquens, Elisabeth G. Pacyna, Jozef M. Pacyna, Robert D. Perry, John M. Pettifor, Stephanie Pfaffen, Dieter Rehder, Lothar Rink, Anthony B. Schryvers, Ellen K. Silbergeld, Eric P. Skaar, Miguel C. P. Soares, Kyrre Sundseth, Dennis J. Thiele, Richard B. Thompson, Meghan M. Verstraete, Gonzalo Visbal, Fudi Wang, Mian Wang, Thomas J. Webster, Jeffrey N. Weiser, Günter Weiss, Inga Wessels, Bin Ye, Judith T. Zelikoff, Lihong Zhang