Evaluation Of The Impact Of Heavy Metals And Total Petroleum Hydrocarbons Contamination On Roadside Soils, In Edo State

Heavy metals and Total Petroleum Hydrocarbon (TPH) contaminations were evaluated on roadside surface soils along Benin-Auchi road in Ekpoma, Edo State. The Control and contaminated samples were collected at sampling depth of 0 -15cm and 15 – 30 cm from along the roadside soils and a total of 12 samples were collected which were then taken to the laboratory and analysed for Heavy metals and Total Petroleum Hydrocarbons in the content. The mean values of samples were calculated and the control was compared with the samples from the various sites. The mean concentration of heavy metals on highway roadsides soils was 4309.21mg/kg Fe; 15.70mg/kg Cu: 0.15mg/kg Cd: 2.55mg/kg Cr: 123.01mg/kg Mn; 0.77mg/kg Ni: 0.38mg/kg Pb and 3734.21mg/kg Fe: 10.47mg/kg Cu; 0.08mg/kg Cd; 1.23mg/kg Cr; 183.71mg/kg Mn:0.30mg/kg Ni: 0.15 mg/kg Pb in the control soils. TPH for road side soils was 1599.26mg/kg and was far higher than that from the control (31.88mg/kg) which indicated that roadsides soils were more exposed to high levels of heavy metal and TPH contamination. Notwithstanding, the levels were below some established critical levels for TPH, copper, nickel, chromium, manganese and lead. It follows that these metals are not sufficiently high to cause serious damage on humans and plants, but if they gradually slip into neighbouring farms, they will enter the food chain resulting in serious health risk. Therefore, there is an urgent need for legislative measures to minimise the indiscriminate disposal of oil contaminated residues, vehicle emissions, road traffic and air pollution.