Determination of Heavy Metals in Soil around Amasoma Community in Bayelsa State, Nigeria

Aims: Anthropogenic activities such as crude oil exploration and exploitation has led to the suspicion of heavy metals contamination in the study area. This study investigated the concentration of zinc, nickel, lead and cadmium in the soil extracted from the area where Scent Leaf (Ocimum gratissimum) and Pawpaw tree (Carica papaya) are grown in Amassoma community, Bayelsa State, Nigeria. Study Design: Scent leaf (Ocimum gratissimum) and Pawpaw tree (Carica papaya) soils from where these plants are grown were randomly collected for heavy metal analysis from within Amassoma community in Southern Ijaw Local Government Area of Bayelsa State, Nigeria Place and Duration of Study: This study was carried out in Biological Sciences, Faculty of Science, Niger Delta University, Wilberforce Island, Amassoma, Bayelsa State between March 2019 to September 2019 Methodology:  Scent leaf (Ocimum gratissimum) and Pawpaw tree (Carica papaya) soils were digested and analyzed for heavy metals using Atomic Absorption Spectrophotometer (AAS, model S471096). The method used was wet-ashing method for the analysis. Results: the concentrations of Lead (Pb), Nickel (Ni), Cadmium (Cd), and Zinc (Zn), in pawpaw soil and scent leaf soil. From the sample data analysis, the average lead (Pb) contents in pawpaw soil and scent leaf soil were 1.283 mg/kg and 1.44 mg/kg respectively. The average Cadmium (Cd) in pawpaw soil and scent leaf soil were 0.256 mg/kg and 0.256 mg/kg respectively. The average Nickel (Ni) compositions in pawpaw soil and scent leaf soil were 4.71 mg/kg and 5.09 mg/kg respectively. While the Average Zinc (Zn) in pawpaw soil and scent leaf soil is 2.280 mg/kg and 2.160 mg/kg respectively. The soil analyzed for heavy metals were below the threshold target values recommended by the WHO. Conclusion: The Scent leaf (Ocimum gratissimum) and Pawpaw tree (Carica papaya) soils analyzed for heavy metals were below the permissible limit recommended by WHO for soil safety. The result from the present study revealed that there may not be soil contamination as a result of the selected heavy metals, however, It is recommended that caution should be taken in regulating the anthropogenic activities that may tend to elevate the level of heavy metals in the surrounding to prevent contamination of soil over time which could be detrimental to the health of the populace.