Evaluation of Chemical Properties and Heavy Metals Status of Fluted Pumpkin (Telfairia occidentalis) in a Soil along Build up Traffic Road, Port Harcourt, Nigeria

The study was conducted along University of Port Harcourt - Choba, heavily built traffic road, to evaluate the impact of vehicular activities on heavy metals lead (Pb), Cadmium (Cd) and Zinc (Zn) on soil and Fluted Pumpkin. Three traverses of 50 meters apart were cut along University of Port Harcourt - Choba major road, composite soil samples collected from each of the traverse cuts at distances of (0- 5) and 15 meters while the control samples were collected from 100 meters away at a depth of 0-15 and 15-30 cm respectively. Plant tissue samples (roots, stems and shoots) of Telfairia occidentalis were collected from each of the traverses, while control plant sample was taken at 100 meters away from the road. A total of 18 composite soil samples and four plant samples were collected. All the samples were analyzed for Pb, Cd and Zn using Atomic Absorption Spectrophotometer (AAS). Result of the study showed that the content of Pb in plant tissue was significantly (P<0.05) higher in traverse one over control and exceeded the maximum permissible limit of 0.3mg/kg Pb in vegetable while in traverses 2 and 3, the concentration of Pb falls within the maximum permissible limit. Uptake of Zn in the plant tissue were significantly (P<0.05) higher than control in all the traverse  and was within the maximum permissible limit of 99.4mg/kg Zn. Cadmium was not detected in traverse  2 and control but the value recorded in traverse 1 falls within the maximum permissible level of 0.2mg/kg Cd. The study revealed that the three heavy metals in soil samples significantly (P<0.05) increased over the control samples in all the traverses sampled. The concentrations of all the metals decrease with increase in distance from the road. Soil samples collected at 0-5 meters distance away from the traffic area had higher concentrations than the samples collected at 15- and 100-meters distances from the road side. The study also revealed that the concentrations of the three heavy metals decreased with increase in soil depth. Soil chemical properties investigated were significantly higher in samples in direct proximity to roadside than the control.