Pollution of the biosphere with toxic metals has accelerated dramatically since the beginning of the industrial revolution. The primary sources of this pollution are the industrial eifluents, burning of fossil fuels, mining and smelting of metalliferous ores, municipal wastes, fertilizers, pesticides, sewage etc. Toxic metal contamination of soil, aqueous waster streams and ground water poses a major environmental and human health problem, which is still in need of an effective and affordable technological solution. Unfortunately, heavy metals cannot be chemically degraded. In many ways living plants can be compared to solar driven pumps, which can extract and concentrate certain elements from their environment. Certain plants have the ability to accumulate heavy metals (which have no known biological function) such as Cd, Cr, Ni, Pb, Co, Ag, Se and Hg. At present, phytoremediation of metals may be approaching commercialization. Additional short term advances in phytoremediation are likely to come from the selection of more efficient plant varieties and soil amendments and from optimizing agronomic practices used for plant cultivation. Major long term improvements in phytoremedlation should come when scientists isolate genes from various plants, which can enhance the metal accumulation. However, biology alone cannot make phytoremediation work. In recent years, cooperative research has been conducted by scientists in fields such as soil science, genetics, chemistry, botany and microbiology for developing new technology. As the research matures, It is likely that we will see phytoremediation become an applied technology with in a few years.
