Heavy metal accumulation by selected plant species along the national highway: a case study of Udaipur, Rajasthan, India

Abstract

ABSTRACTA detailed research was conducted to find out the heavy metal accumulation by plant species at the roadside. Bioconcentration, bioaccumulation and translocation factors were estimated in 10 individuals of each investigating plant species. The plant and soil samples used in the research were collected along the National Highway-76 from Chittorgarh to Udaipur, Rajasthan, India. The concentration of cadmium and lead in roadside soil, plant roots, stems and leaves shows a correlation. The highest bioconcentration factor of Cd and Pb was 0.22 ± 0.04 and 0.13 ± 0.02 estimated in Bougainvillea spectabilis Willd. The highest translocation factor of Cd was 1.30 ± 0.50 in Pongamia pinnata L., and the highest translocation factor of Pb was 1.63 ± 0.45 estimated for Nerium oleander L. The average concentrations of Cd and Pb were 11.35 ± 1.60 and 223.70 ± 68 mg kg−1 in investigated roadside soil. The average concentrations of accumulated Cd and Pb in B. spectabilisWilld. were 2.38 ± 0.49, 1.97 ± 0.51, 3.07 ± 0.78 and 29.34 ± 7.82,18.96 ± 5.62, 37.75 ± 12.93 mg kg−1 in roots, stems and leaves, respectively. The decreasing order of bioaccumulation factor of cadmium in plants was B. spectabilis Willd.>Butea monosperma (Lam.) Taub>Calotropis procera (Ailton) Dryand>N. oleander L.>P. pinnata L. The decreasing order of bioaccumulation factor of lead in plants was B. spectabilis Willd.>P. pinnataL.>B. monosperma (Lam.) Taub>C. procera (Ailton) Dryand>N. oleander L. The B. spectabilis Willd. was identified as a rhizofiltration tool of heavy metals such as Cd and Pb with higher bioconcentration factor. P. pinnata L. for Cd and N. oleander L. for Pb were revealed for phytoextraction technology with high translocator factor to accumulate and eliminate these toxic elements from soil.