Mangifera indica as a bioindicator of lead, copper and iron in the vicinity of a metal smelting plant, Bukuru Jos, Nigeria

Abstract

The levels of lead, Pb copper Cu and iron Fe in Mangifera indica leaf and bark and the native soil samples in the vicinity of Makeri smelting plant, Bukuru, Plateau state, were determined using Atomic Absorption
Spectrophotometer (AAS). The aim was to assess the extent of pollution of the environment under study. Results show that the soil pH ranged from 9.40 to 10.17 indicating that the soil samples were generally alkaline with the possible effect of trapping metal ions as hydroxides. The leaf, bark and soil samples gave mean Pb values of 33.40±0.01, 19.25±0.03 and 12.30±0.12ìg/g respectively at a distance of 10 metres from the factory. The corresponding values obtained at a distance of 200 metres were 9.65±0.01, 5.20±0.10 and 11.65±0.0ìg/g for leaf, bark and soil samples respectively. However, at a distance of 400 metres away from the factory, the leaf, bark and soil samples gave 6.03±0.02, 3.10±0.12 and 10.40±0.05ìg/g. The value of Cu was 27.00±0.11, 14.00±0.17 and
43.50±0.15ìg /g in the leaf, bark and soil samples respectively at 10 metres away from the factory, decreasing to 20.00±0.03, 10.85±0.02 and 39.30±0.20ìg/g while at a distance of 400 metres the corresponding values were 19.30±0.22, 8.00±0.13 and 3.00±0.17ìg/g for the leaf, bark and soil samples respectively. The value of Fe was 479.55±0.1ìg/g in the leaf, 116.8±015ìg/g in the bark and 817.11±0.10ìg/g in the soil sample at a distance of 10 metres which decreased to 220.00±0.22, 80.30±0.10 and 749.60±0.13ìg/g respectively at 200metres. The values further decreased to 62.15±0.13, 32.70±0.11 and 655.20±0.21ìg/g in the leaf, bark and soil samples respectively at a distance of 400 metres suggesting that the metal smelting activity of the factory has contributed to high metal load in
the environment.