Heavy Metal Tolerance

by

Robert S. Boyd, Nishanta Rajakaruna

• LAST REVIEWED: 30 September 2013
• LAST MODIFIED: 30 September 2013
• DOI: 10.1093/obo/9780199830060-0137

Introduction

The operation of biological systems is challenged by various environmental factors that interfere with or interrupt biological processes (creating stress). Some heavy metals have important physiological roles, but high doses of these essential heavy metals or exposure to other heavy metals that lack physiological roles in organisms may create stress through interference with the function of enzymes or with the information-coding molecules (DNA or RNA) in cells. Some organisms are less susceptible to these effects than others, and this heavy metal tolerance has become an important example of core biological concepts such as adaptation and evolution. Heavy metal tolerance is also of interest because organisms can be tolerant to more than one stress: understanding this phenomenon (termed “co-tolerance” or “cross-tolerance”) can provide insights into the mechanisms of tolerance and allow applications of this knowledge in solving environmental problems. Heavy metal tolerance also has vital practical and applied aspects, since human industry relies greatly on various metals (some of which are quite toxic) and these industries have resulted in pollution that can have severe impacts on the health of humans, other organisms, and entire ecosystems. Current studies explore the physiological mechanisms of heavy metal tolerance in many groups of organisms, investigate its underlying genetic basis, and use that knowledge to create genetically engineered organisms that may be useful to solve environmental problems caused by heavy metal pollution.

General Overviews

General information on heavy metal tolerance is often included in sources that cover heavy metal toxicity, as tolerance is essentially the ability of organisms to avoid the toxic effects of heavy metals. The toxicological literature is vast, but Anderson, et al. 2005 is a good example of a general resource that can provide toxicological information on heavy metals. A general toxicological text, such as Stine and Brown 1996, can provide a helpful introduction to underlying principles and approaches of toxicology. Heavy metals are generally found at relatively small concentrations in organisms, and Pais and Jones 1997 and Kabata-Pendias 2010 provide useful summaries on specific heavy metals and their interactions with soils and biota. A number of edited volumes have chapters that cover particular aspects of heavy metal tolerance: a recent example targeting cellular mechanisms affected by heavy metals is Bánfalvi 2011. Pollution by heavy metals is an important environmental problem, and sources that focus on heavy metal pollution often contain information about heavy metal tolerance (Sánchez 2008 is a recent example). Finally, there are sources that focus on a specific group of organisms and provide overviews that are taxonomically limited to that group. For example, Shaw 1990 and Gupta and Sandallo 2011 focus on heavy metal tolerance (or toxicity) in plants, a group that has been heavily researched, partly because of the applied uses of heavy metal tolerant plants in restoration and phytoextraction/phytomining operations.

• Anderson, Bruce, Ann de Peyster, Shayne C. Gad, et al., eds. 2005. Encyclopedia of toxicology. 2d ed. Amsterdam: Elsevier.

  A four-volume set that contains over eleven hundred entries on an extensive set of subjects relevant to toxicology, including entries on individual heavy metals.

• Bánfalvi, Gáspár, ed. 2011. Cellular effects of heavy metals. New York: Springer.

  DOI: 10.1007/978-94-007-0428-2

  A collection of sixteen chapters on aspects of heavy metal toxicity, the book includes a useful introductory chapter on general cellular effects of heavy metals. Other chapters focus on specific metals or experimental systems that reflect the expertise of the contributors.

• Gupta, Dhamendra K., and Luisa M. Sandallo, eds. 2011. Metal toxicity in plants: Perception, signaling and remediation. London: Springer.

  Recent summary of advances in the study of metal toxicity (and its opposite, tolerance), this book includes twelve chapters on a wide variety of topics including physiology, new advances stemming from “omics” approaches (transcriptomics, proteomics, metabolomics), gene expression, and applied fields such as phytoextraction using metal tolerant plants.

• Kabata-Pendias, Alina. 2010. Trace elements in soils and plants. 4th ed. Boca Raton, FL: CRC Press.

  Highlights the role that anthropogenic factors play in changing the heavy metal and other trace element status in soils and plants. Chapters cover natural/background levels of biologically relevant heavy metals in soils and plants, chemical phenomena relevant to the mobility of heavy metals, and the remediation of heavy metal–contaminated soils.

• Pais, István, and J. Benton Jones Jr. 1997. The handbook of trace elements. Boca Raton, FL: St. Lucie.

  Provides an overview of trace elements in biology, and then lists each of forty-one trace elements and provides a summary of its concentration in various materials (soil, water, foods, fertilizers) as well as in plants and animals.

• Sánchez, Mikel L., ed. 2008. Causes and effects of heavy metal pollution. New York: Nova Science.

  An edited volume covering a wide range of topics regarding heavy metal pollution, the book is a good example of a volume on pollution. It includes information in some chapters pertinent to heavy metal tolerance.

• Shaw, A. Jonathan, ed. 1990. Heavy metal tolerance in plants: Evolutionary aspects. Boca Raton, FL: CRC Press.

  This extensive treatment summarizes ecological, physiological, and evolutionary aspects of heavy metal tolerance research in plants, fungi, protists, and animals. The twenty-one chapters provide a useful synthesis of the heavy metal tolerance literature prior to 1990.

• Stine, Karen E., and Thomas M. Brown. 1996. Principles of toxicology. Boca Raton, FL: CRC Press.

  An example of a general toxicology text, it covers the breadth of toxicology, from molecular/cellular to physiological and to environmental/ecological levels.