The chemical elements and human morbidity—water, air and places—a study of natural variability

Abstract

Today it is recognised that the availability and abundance of the chemical elements in man's environment have a direct bearing upon problems of human morbidity. Many biochemical and clinical studies are often only concerned with the elements hydrogen, carbon, nitrogen and oxygen. In recent years interest has been aroused for the remaining elements of the Periodic Table and the manner in which they participate in biological processes. The role of various elements in enzyme reactions has been studied for many years; today a new series of elements have received considerable attention because they have been identified as pollutants. The selection of elements has not always been based upon improvements in basic knowledge, but rather following various types of environmental accidents usually restricted to particular geographical localities. In addition it is recognised that some products of technological progress have become distributed throughout both regional and global environments. Health physics has shown that it is possible to trace the migration of a very large number of radionuclides, arising from both natural and technological processes, through various environments. In this discipline concepts have been developed of critical pathway analysis, the identification of critical sites of deposition, biological damage arising at such sites and the classification of the toxicity of radionuclides for both chronic and acute exposure allowing, when possible, for the chemical form of the elements. Concepts developed for multi-radionuclide study provide a suitable framework in which to consider multi-stable-element distributions in man and the natural environment. An objective of such a study is to determine the manner in which the chemical elements participate in biological processes; in particular their effects upon man and components of his environment. This paper is concerned with the application of multi-element investigations to problems of human morbidity. The multi-element approach provides the investigator with data describing the abundance and distribution of the chemical elements present in samples and also the degree of natural variability in levels. Evaluation of such data provides additional information when inter-relations between the various elements of the Periodic Table are considered. The combined product of the approach provides the necessary information in order that decisions concerning the chemical elements and environmental issues, both scientific and political, can be based upon real knowledge rather than inspired guesses or crude approximations. Multi-element environmental studies are in their infancy, basic technology is available, but there is still the need to develop techniques. This study is mainly concerned with the abundance of the chemical elements in air, water and places and the emphasis in the analysis has been optimised towards precision of assay, rather than accuracy, in order that differences in the abundance of elements in similar matrixes may be favourably compared. Improvement in accuracy presents no serious problems, except perhaps time required for analysis. The role of multi-element facilities is central to many environmental problems and when linked to similar multi-organic analytical techniques provides a very powerful approach. However, in order to obtain maximum benefit the flexibility of analysis provided by instrumentation must be balanced by a flexibility of application so that it is possible to trace the transfer of the elements through natural systems without the hindrance of interdisciplinary barriers. Multi-element analysis is a tool of reconnaissance, to be followed by the application of methods designed to study particular elements in detail. Today there is a need to determine the elements present in a system and how they participate in various components. Too often an element is treated in an abstract manner and concern is expressed for a level which is often natural to the system. Recognition of natural patterns in the abundance of the chemical elements may alleviate some of the concern expressed for the abundance of some elements and also provide a means for recognising patterns which may be identified as not being associated with natural systems.