Metals and cancer

While several metals show at least some evidence of carcinogenicity (see Table 21.1), five metals are classified by the International Agency for Research on Cancer (IARC) as carcinogenic to humans. Arsenic and arsenic compounds, beryllium and 

TABLE 21.1. International Agency for Research on Cancer (IARC) Summary of Metal Carcinogenic Risk to Humans 

Metal (or Process Involving Metal Exposure) Evidence for Carcinogenicity in Humans Evidence for Carcinogenicity in Animals IARC Rating  

Underground hematite mining with Sufficient Sufficient 1 

Implanted foreign bodies of metallic Inadequate Adequate 2B 

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Mankind has used metals for milletmia, but the relation between metals and cancer has only been known for over a century. Only in the past tlnee decades have the tools been available to analyze the molecular and cellular effects of metals on cancer, and only very recently has it been possible to examine the role of free radicals in normal and disease states. Because of their ability to produce free radicals, transition metals provide a nnique means by which to study not only metal-related diseases, but the effects of free radicals on DNA damage, intracellular signaling, and cell-to-cell coimnunication. With the completion of the human genome project and the use of novel technologies snch as genomics and proteomics, it will soon be possible to examine the global effects of free radicals on genes and their expression. 

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