Assessment of heavy metals bioaccumulation and health risk in crops grown in farmlands around mining sites in Gwana, Alkaleri lga, Bauchi state, Nigeria

Siman Mikin,Harami Malgwi Adamu,Mohammed Abdullahi Shibdawa

doi:10.14419/ijac.v9i1.31547

Abstract

Analysis was carried out on farm crops (Guinea corn, Millet and Beans) collected from adjourning farmlands around mining area of Gwana in Alkaleri Local Government Area, Bauchi State. Their heavy metal concentrations were determined and quantified using Atomic Absorption Spectroscopy (AAS). The heavy metal characterization revealed the presences copper, iron, lead, manganese, nickel and zinc in the farm crops. The mean values of the elements that where obtain for copper, iron, lead, manganese, nickel, silver and zinc by AAS are 33.90, 12.00, 71.43, 12.56, 4.40, 0.60 and 101.96 mg/kg, respectively. From the Analysis of variance (ANOVA) used to compare these levels of heavy metals in the crops, it showed that there was a significant difference in their concentration. Exposure assessment and risk characterization of the heavy metals present in the farm crops showed that the mean values of the bioaccumulation coefficient for the elements of copper, iron, lead, manganese, nickel, silver and zinc are1.24, 0.03, 1.68, 0.80,1.64, 0.89 and 1.21 respectively. The estimated daily intake rate for the elements of copper, iron, lead, manganese, nickel and zinc are 1.17 to 1.28 mg/kg, 0.03 to 0.04 mg/kg, 0.06 to 0.011 mg/kg, 1.39 to 1.96 mg/kg, 1.92 to 3.14 mg/kg and 1.18 to 1.26 mg/kg respectively. The hazard quotient for the elements of copper, iron, lead, manganese, nickel and zinc are 0.57â€“1.31, 0.01â€“0.02, 22.95â€“32.50, 0.07â€“0.12, 0.02â€“0.26 and 0.32â€“0.40 respectively. The carcinogenic risk for the elements of lead and nickel are 0.0003â€“0.0011 and 0.0006â€“0.0089 respectively. It is hereby recommended that the farm crop samples from within the catchment areas understudy should be subjected to clinical trials to evaluate the extent of the damage it can cause on body tissues.Â Â

Highlights

Mining of solid minerals has been identified as a major entry point of heavy metals into the environment polluting its various components such as soil, water and air (Tsafe et al, 2012)
Owing to the fact that land is a scare resources, there is a worrisome trend of putting reclaimed lands within the vicinity abandoned mining sites to agricultural use thereby increasing the level of bioaccumulation of the heavy metals by the plants and Hazard Risk by the end consumers
The heavy metal concentrations in the digest were determined at the Center for Energy Research and Development, Abubakar Tafawa Balewa University Bauchi, using the Atomic Absorption Spectrophotometer

Summary

Introduction

Mining of solid minerals has been identified as a major entry point of heavy metals into the environment polluting its various components such as soil, water and air (Tsafe et al, 2012) In the soil these heavy metals are either accumulated within its matrix, or where they are liable, are transferred amongst its various strata, until they are taken up by plants. Once in these plants, they climb up the food chain posing serious health risk to living organisms (Idzelis et al, 2004). There seemed to be a problem of environmental alteration, ecosystem and agricultural land destruction which prompted the researcher to investigate the depth of these environmental impacts

Methods

Results

Conclusion