Heavy Metal Bioaccumulation by Eisenia fetida, Cynodon dactylon and Vigna radiata in Single, Bi and Tri-Metal Soil Systems

Rapid industrialization and consequent anthropogenic activities has magnified heavy metal pollution in the environment as whole, especially in soil systems. It has enhanced the risk of entering of heavy metals in food chain resulting in aggravated health hazards in the higher bios including humans, which has become a serious environmental concern. Additionally, the metal causing soil contamination may be redistributed regionally and globally in other environmental segments with consequent environmental hazard. Though bioremediation techniques including phytoremediation, employing bioaccumulative nature of metals are favored by scientists but heighten the health risks on passing through food-webs. The present short-term study evaluates risks of metal bioaccumulation while soil is decontaminated through sole phytoremediation or integrated with vermicomposting technology. The bioaccumulation experiments were designed with an edible crop-Vigna radiata, a fodder species-Cynodon dactylon and a soil building worm species Eisenia fetida for the short exposure periods of 7 and 14 days. Soils were spiked either with each of lead, cobalt and nickel alone or in combination of two or all three metals. The results show positive risk correlation between metals accumulation in considered biospecies employed for soil decontamination.