Introduction to Heavy Metal Toxicity in Mammals

Abstract

Throughout biologic evolution, living forms have incorporated into biochemical constituents those available metals that had physical and chemical properties suitable for carrying out the functions of life. The progress of evolution is a response to the ever-changing environment. Animal requirements for certain metals are a direct outgrowth of this association. Our knowledge of trace-metal requirements for mammalian growth, development, general health, and reproduction is growing rapidly as intense research progresses (Hopps, 1972). Certain metals that previously were considered to be toxicants are now considered essential nutrients. At the same time, increased concern and effort are extended to problems of metal toxicity and safety in man and other mammals. The actual and potential problems of metal toxicity are often examined with too-limited knowledge by environmentalists and by those in the news media who suggest when and where technology must stop in order to preserve the immediate environment of endangered species. Experiments readily show that any compound is harmful if given in excess! Science and technology allow man considerable control of his immediate environment, but the earth-inhabitant continuum cannot be denied. The secret of survival, therefore, is not to absolutely prohibit the use of any chemical, but to utilize each chemical rationally.