ABSTRACT
Ubiquitous in the biosphere, aluminum is the most plentiful of metals. Physical contact with elemental aluminum or aluminum salts, whether topical, respiratory, or oral, is unavoidable. The skin, lung, and gastrointestinal tract are very effective barriers to aluminum absorption; there is no conclusive evidence that the metal performs any essential function in the animal organism, and in healthy human subjects the kidneys effectively excrete the amounts absorbed through the diet. Consequently, the only population at risk from aluminum toxicity are patients with chronic renal failure, where excessive accumulation leads to skeletal weakness. Traditionally, aluminum was considered relatively nontoxic, but increasing evidence suggests some negative interactions with important biological processes, such as the formation of DNA crosslinks (1), modification of enzyme activity, including those vital for neurotransmission (2,3), and competitive combination with calmodulin (4).
