Essentially deadly: living with toxic elements: Humans and plants have evolved various mechanisms to deal with and even adopt toxic heavy metals.

Abstract

All transition metals are highly toxic to life at low levels, but at the same time some, such as manganese, iron, cobalt, nickel, copper, zinc and molybdenum, are essential micronutrients needed to catalyse key enzymatic reactions. To survive, living organisms have had to evolve mechanisms that either remove such metals from their bodies or detoxify and make use of them metabolically. Many of these mechanisms have been well studied in bacteria, but much less is known about how plants and animals deal with toxic compounds. > Broberg's research also highlights a point common to many toxic compounds […] which is that their metabolic processing can generate dangerous intermediate by‐products Such knowledge is vital for human health because heavy metal contamination is a significant cause of morbidity in certain regions of the world. Such contamination is sometimes natural, but is often the result of human activities that result in high levels of heavy metals in the groundwater. Moreover, some industrial activities—notably metal mining and processing—are particularly dangerous to the health of both workers and people living nearby. This has stimulated work both to assess the impact of exposure to high levels of metals and their salts, and to study the mechanisms of detoxification in humans. In some cases, the proteins and underlying genes involved have been discovered, but it remains unclear to what extent these genes vary between species or even individuals, especially in humans. There was therefore great interest in a recent study of people living in the high Andean village of San Antonio de los Cobres in Argentian [1], who are exposed to natural exceptionally high levels of arsenic, which is extremely toxic and does not seem to have any essential role in living organisms. The study aimed to assess whether natural selection had equipped these people with …