Heavy Metals Pollution Of Soil Toxicity And Phytoremediation Techniques

The rapid industrialization and intensive agricultural activities over the last few decades have resulted in accumulation of various pollutants in the environment chiefly soil which has led to the accumulation of heavy metals. The indiscriminate release of heavy metals into the soil and waters is a major health concern worldwide because of their potential reactivity toxicity mobility and as they cannot be broken down to non-toxic forms and therefore has long-lasting effects on the ecosystems. Some metals such as manganese copper zinc and nickel are important in very small amounts and beneficial to plants and animals for their growth and optimum performance but high concentrations of all these metals have strong toxic effects and pose an environmental threat and causes toxicity in biological systems such as humans animals and plants. Many of them are toxic even at very low concentrations and they are not only cytotoxic but also carcinogenic and mutagenic in nature. Source of Contamination of soils with toxic heavy metals through mining operations discharge of industrial effluents intensive chemicalization of agriculture based on pesticides fertilizers and disinfectant etc. is of great concern. In order to make the environment healthier for human beings contaminated soils need to be rectified to make them free from heavy metals. There are some conventional remediation technologies to clean polluted areas specifically soils contaminated with metals. These methods are expensive time consuming and environmentally devastating. Recently phytoremediation as a cost effective and environmentally friendly technology has been developed in which plants are used to remediate the toxic heavy metals polluted areas by using specific metallophytes. These plants are known as hyperaccumulators. Phytoremediation is becoming an important tool for decontaminating soil water and air by detoxifying extracting hyperaccumulating andor sequestering contaminants especially at low levels where using current methods costs exceed effectiveness. In this paper it was reviewed sources environmental impacts factors affecting heavy metals bioavailability in plants and phytoremediation techniques of soil heavy metal contamination.