Heavy Metal (Zinc) in Cultivated Vegetable Plants Irrigated by Industrial Effluent: Polarographically in Jaipur (India)
Author : Dr. Ashok Kumar
Abstract :
Heavy metals (HM) represent a group of metallic elements and metalloids characterized by a relatively density higher than 5 g/cm3, an atomic number greater than 20. It is a matter of utmost concern that present time agriculture is being threatened constantly by the decline in already depleted resources particularly in soil and water because of increasing population, rapid pace of urbanization and environmental pollution due to industrial mismanagement.
The accumulation of heavy toxic metals above the permissible limit in the industrial waste water can modify the microbial characteristic, and plant growth. Heavy metals are the natural constituent of the earth crust. Several of the heavy metals are essential to the human being. The sources of heavy metal introduction into the environment are mining, piping, combustion of by products and human activities. Heavy metals present in trace amounts are quite beneficial to the human life.
Presence of heavy toxic elements in the soil irrigated with waste water leads to negative influence on the quality of vegetables and fruits with respect to their taste and smell. Thus, knowledge and understanding of chemical composition of soil and water of any region is very essential. The toxic metal concentration can reduce soil fertility and their increased input to food chain leads to the accumulation in food stuff and hence can threaten human health.
Polarographic methods have been used for determination of zinc in selected plant species cultivated irrigating with industrial wastewater in Jaipur. The half wave potential E, was characteristic for zinc identification and diffusion current was proportional to concentration of metals in foodstuffs. The study revealed the presence of heavy metals in most vegetable foodstuffs exceeding permissible limits of UK, WHO and Indian Standards. The method used is reproducible, rapid and can be used in food technology for quality control and human health.
Keywords :
Polarographic method, half wave potential, zinc, plant species
