Heavy metals and its impact in vegetable crops

Environmental pollution is rapidly booming worldwide. The soil contaminated with heavy metals like lead Cr, Mn, Fe, Ni, Cu, Zn, Cd, Pb and Hg has serious environmental problems since these metals are non-essential and toxic to plants and animals and have significant toxic effect on human being health. Recently due to various anthropogenic activities such as mining, industrialization and agricultural activities like application of pesticides, fungicides and fertilizers, heavy metals are released in to the soil, water and atmosphere. These released heavy metals enter into the plant system through various physiological process and it affects the plant growth and development. The concentration of heavy metals in the environment varies due to various activities and it becomes toxic when it reaches above the permissible limits. The possible introduction of these elements has contributed to the increasing occurrence of heavy metals in the ecosystem through their direct ingestion from contaminated soils, consumption of vegetables grown on the contaminated soils or drinking wastewater that has percolated through such soils. Vegetables are grown all over the world for human needs and relished as nutritional supplement. Accumulation of heavy metals occurs only when the vegetable crops are cultivated in heavy metal contaminated environment, as a result these heavy metals enters into the food chain. When heavy metals contaminated vegetables are consumed by human beings it causes various severe health ailments. These heavy metals not only affect the plants and human beings, it also affects the nutrient status of soil, soil health, water source and also other aquatic living organisms. There are various remediation processes to reduce the level of heavy metals from these sources. This paper aims to review the different heavy metal accumulation and its impact in vegetable crops .