Accumulation of Heavy Metals and Metalloid in Foodstuffs from Agricultural Soils around Tarkwa Area in Ghana, and Associated Human Health Risks.

Nesta Bortey-Sam,Julius Fobil,Mayumi Ishizuka,Osei Akoto,Yoshinori Ikenaka,Shouta Nakayama,Elvis Baidoo,Hazuki Mizukawa

doi:10.3390/ijerph120808811

Abstract

This study was carried out to assess the extent of heavy metals and metalloid accumulation from agricultural soils to foodstuffs (viz, M. esculenta (cassava) and Musa paradisiaca (plantain)) around thirteen neighboring communities within Tarkwa, Ghana; and to estimate the human health risk associated with consumption of these foodstuffs. Concentrations of As, Cd, Co, Cr, Cu, Ni, Pb, and Zn were measured with an inductively coupled plasma–mass spectrometer and mercury analysis was done using a mercury analyzer. From the results, 30% of cassava samples collected, contained higher concentrations of Pb when compared to Codex Alimentarius Commission standard values. Bioconcentration factor indicated that Ni had higher capacity of absorption into food crops from soil than the other heavy metals. For both children and adults, the target hazard quotient (THQ) of Pb in cassava in communities such as Techiman, Wangarakrom, Samahu, and Tebe (only children) were greater than 1, which is defined as an acceptable risk value. This indicated that residents could be exposed to significant health risks associated with cassava consumption.

Highlights

There has long been concerns about heavy metals and metalloids pollution because of their stability and non-biodegradability in environmental media as well as their toxicity to plants, animals, and humans [1].Soil is the primary reservoir for heavy metals in the atmosphere, hydrosphere, and biota, and plays a fundamental role in the overall metal cycle in nature [2]
The objectives of the present study were to assess the extent of heavy metal and metalloid accumulation from soils to foodstuffs commonly grown in agricultural areas in Tarkwa; study the relation between bioconcentration factor (BCF), soil pH and soil organic matter (SOM); and evaluate the potential human health risks of toxic metal exposure to residents in Tarkwa through consumption of foodstuffs
The geometric mean (GM) concentrations of metals from the thirteen communities decreased in the order, Zn (37) > Cr (16) > Cu (5.1) > Pb (4.8) > As (3.8) > Ni (2.2) > Co (1.3) > Hg

Summary

Introduction

There has long been concerns about heavy metals and metalloids pollution because of their stability and non-biodegradability in environmental media as well as their toxicity to plants, animals, and humans [1].Soil is the primary reservoir for heavy metals in the atmosphere, hydrosphere, and biota, and plays a fundamental role in the overall metal cycle in nature [2]. There has long been concerns about heavy metals and metalloids pollution because of their stability and non-biodegradability in environmental media as well as their toxicity to plants, animals, and humans [1]. Vegetables/foodstuffs take up heavy metals and/or metalloids by absorbing them from contaminated soils, as well as from deposits on parts of the crop exposed to air from polluted environments [9]. The amount of heavy metals that move from soil into plants can be measured by “the transfer factor”; this factor is defined as the ratio that exists between the concentrations of metals in the plant and that in soil This transfer factor could be different for different plant species and will change as soil physical and chemical properties are altered. Plants having a transfer factor greater than 1 are categorized as hyperaccumulators, whereas those with transfer factor less than 1 are termed as non-accumulators [13]

Objectives

Methods

Results

Conclusion