This book presents state-of-the-art knowledge related to concerns about methylmercury (MeHg) in the soil-rice system. It covers increasing concerns about human exposure to methylmercury through the consumption of Hg-contaminated rice and shows the global contamination of soil and how Hg can be mobilized, immobilized, methylated, and demethylated in soils. The authors present the biogeochemical process through which rice plants accumulate Hg. This book comprehensively displays the biogeochemical behavior of Hg in paddy soils and rice plants, as well as the current remediation technologies to mitigate Hg risks from paddy soil ecosystems. Features: Provides cutting-edge knowledge on mercury in paddy field ecosystems Discusses the key biogeochemical transformation processes of mercury in soil Explains the accumulation processes of mercury in rice plants Includes case studies on how to inhibit mercury accumulation in rice plants Shows the application of Hg stable isotope traces in paddy soil-rice field studies Intended for researchers, graduate students, and professionals working in fields such as Geochemistry, Agronomy, and Environmental Science and Engineering, this book will be an important resource for anyone interested in Hg contamination in soils and rice and the related risk for human and environmental health.

Mercury is widespread in our environment. Methylmercury, one organic form of mercury, can accumulate up the aquatic food chain and lead to high concentrations in predatory fish. When consumed by humans, contaminated fish represent a public health risk. Combustion processes, especially coal-fired power plants, are major sources of mercury contamination in the environment. The U.S. Environmental Protection Agency (EPA) is considering regulating mercury emissions from those plants. Toxicological Effects of Methylmercury reviews the health effects of methylmercury and discusses the estimation of mercury exposure from measured biomarkers, how differences between individuals affect mercury toxicity, and appropriate statistical methods for analysis of the data and thoroughly compares the epidemiological studies available on methylmercury. Included are discussions of current mercury levels on public health and a delineation of the scientific aspects and policy decisions involved in the regulation of mercury. This report is a valuable resource for individuals interested in the public health effects and regulation of mercury. The report also provides an excellent example of the implications of decisions in the risk assessment process for a larger audience.

Major portion of the planet earth is covered by seas and oceans representing 96.5% of the planet’s water, playing a detrimental role in sustaining the plant including crop diversity and productivity for human consumption. Water resources contain both soluble and transition metals, which are easily absorbed by plants through roots as a first point of contact and subsequently play important physiological and biological functions in plants. Transition metals such as copper (Cu), iron (Fe), manganese (Mn) and zinc (Zn) contribute to the plant productivity by playing key functional roles in the photosynthesis. In addition, to their major role in regulating the plant productivity, they also play an important role by acting as homeostatic regulators in uni-parentally inherited chloroplasts and maintains the flow of the electron transfer. It is worthwhile to mention that they play a critical role as transporters, which acts as electron balancing units for managing the electrostatic potential across the membranes. In contrast, some metals such as Cd, As play a significant role in inducing the stress mechanism and influencing either directly or in-directly Haber-Weiss reactions either through the production of the reactive oxygen species (ROS) or through the membrane damage thus leading to leakage of membrane transporters. However, besides playing a detrimental role as transporters in plant system, excessive accumulation of these metals due to the increasing contamination in the marginal soil and water are posing important threats to the plant system. Realizing the toxic effects of the metals, several physiological evidences have been laid for the credence of the metal toxicity and their concurrent effect on plant productivity. Increasing effects of the metals as toxicants can have three adverse effects on the populations: population can move, persist via local adaptation or phenotypic plasticity, or die. Next generation sequencing studies have revolutionized our abilities to detect the changes in expression profiles across an array of genes, which can in-turn help to develop early markers of metal induced stress. Plant Metallomics and Functional Omics: A System-Wide Perspective focuses on the applications of the system wide understanding of the biological and functional interplay occurring at the juncture of the metalloid induced stress and toxicity. The main goal of this book is to familiarize the readers with the most up-to-date information on metal-induced physiological changes in plant species.

This book provides the fundamentals, recent developments, and future research needs for critical mercury transformation and transport processes, as well as the experimental methods that have been employed in recent studies. The coverage discusses the environmental behavior and toxicological effects of mercury on organisms, including humans, and provides case studies at the end of each chapter. Bringing together information normally spread across several books, this text is unique in covering the entire mercury cycle and providing a baseline for what is known and what uncertainties remain in respect to mercury cycling.

Mercury (Hg) is a global pollutant that knows no environmental boundaries. Even the most stringent control of anthropogenic Hg sources will not eliminate exposure given its ubiquitous presence. Exposure to Hg occurs primarily via the food chain due to MeHg’s accumulation in fish. Latest US statistics indicate that 46 States have fish consumption advisories. In addition, Hg is a common pollutant in hazardous waste sites, with an estimated 3-4 million children living within one mile of at least one of the 1,300+ active hazardous waste sites in the US. The effects on intellectual function in children prenatally exposed to MeHg via maternal fish consumption have been the subject of two on-going major, prospective, longitudinal studies in the Seychelles and the Faroe Islands. It is important to recognize that the risk for MeHg exposure is not limited only to islanders with high fish consumption. This book will provide state-of-the-art information to the graduate student training in toxicology, risk assessors, researchers and medical providers at large. It is aimed to bring the reader up to date on contemporary issues associated with exposure to methylmercury, from its effects on stem cells and neurons to population studies.

ACKNOWLEDGEMENTS xiv PART I MERCURY AND HUMAN HEALTH B. WHEATLEY and S. PARADIS I Exposure of Canadian Aboriginal Peoples to Methylmercury 3-11 M. GIRARD and C. DUMONT I Exposure of James Bay Cree to Methylmercury during Pregnancy for the Years 1983-91 13-19 M. RICHARDSON, M. MITCHELL, S. COAD and R. RAPHAEL I Exposure to Mercury in Canada: A Multimedia Analysis 21-30 M. RICHARDSON, M. EGYED and D. J. CURRIE I Human Exposure to Mercury may Decrease as Acidic Deposition Increases 31-39 L. E. FLEMING, S. WATKINS, R. KADERMAN, B. LEVIN, D. R. AVYAR, M. BIZZIO, D. STEPHENS and J. A. BEAN I Mercury Exposure in Humans through Food Consumption from the Everglades of Florida 41-48 J. M. GEARHART, H. J. CLEWELL III, K. S. CRUMP, A. M. SHIPP and A. SILVERS I Pharmacokinetic Dose Estimates of Mercury in Children and Dose-Response Curves of Performance Tests in a Large Epidemiological Study 49-58 I. SKARE I Mass Balance and Systemic Uptake of Mercury Released from Dental Amalgam Fillings 59-67 J. DELLINGER, N. KMIECIK, S. GERSTENBERGER and H. NGU I Mercury Contamina tion of Fish in the Ojibwa Diet: I. Walleye Fillets and Skin-On versus Skin-Off Sampling 69-76 J. DELLINGER, L. MALEK and M. BEATTIE I Mercury Contamination of Fish in the Ojibwa Diet: II. Sensory Evoked Responses in Rats Fed Walleye 77-83 H. AKAGI, O. MALM, F. J. P. BRANCHES, Y. KINJO, Y. KASHIMA, J. R. D. GUIMARAES, R. B. OLIVEIRA, K. HARAGUCHI, W. C. PFEIFFER, Y.

An up-to-date overview of the characterization, risk assessment and remediation of mercury-contaminated sites. The book summarizes, for the first time, works from Europe, Russia and the American continent, and review chapters are supplemented by detailed, international case studies.