AND HUMAN HEALTH DIVISION
CLINICAL CHEMISTRY SECTION, COMMISSION ON TOXICOLOGY
"Heavy metals" a meaningless term? (IUPAC Technical
John H. Duffus
The Edinburgh Centre for Toxicology, 43 Mansionhouse
Road, Edinburgh EH9 2JD, Scotland, United Kingdom
Abstract: Over the past two decades, the term "heavy metals"
has been widely used. It is often used as a group name for metals and
semimetals (metalloids) that have been associated with contamination
and potential toxicity or ecotoxicity. At the same time, legal regulations
often specify a list of "heavy metals" to which they apply.
Such lists differ from one set of regulations to another and the term
is sometimes used without even specifying which "heavy metals"
are covered. However, there is no authoritative definition to be found
in the relevant literature. There is a tendency, unsupported by the
facts, to assume that all so-called "heavy metals" and their
compounds have highly toxic or ecotoxic properties. This has no basis
in chemical or toxicological data. Thus, the term "heavy metals"
is both meaningless and misleading. Even the term "metal"
is commonly misused in both toxicological literature and in legislation
to mean the pure metal and all the chemical species in which it may
exist. This usage implies that the pure metal and all its compounds
have the same physicochemical, biological, and toxicological properties,
which is untrue. In order to avoid the use of the term "heavy metal",
a new classification based on the periodic table is needed. Such a classification
should reflect our understanding of the chemical basis of toxicity and
allow toxic effects to be predicted.
** Corresponding author.
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> erratum (Pure
Appl. Chem. 75(9), 1357, 2003)
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