Assessment, Accumulation, Toxicity and Importance of Heavy Metals in Agricultural Soil and Living System - Review

Adugna Bayata

doi:10.11648/j.ajep.20200906.11

Abstract

Heavy or toxic metals are metals which are harmful beyond the permissible level to human health and are heavier in density than water by more than five times. Living organisms require varying amounts of heavy metals. Heavy metals like copper, manganese, cobalt, iron, zinc and molybdenum are required by living organisms in a small amount. Soil is a crucial component of rural and urban environments, and in both places land management is the key to soil quality. This paper review was aimed to touch the accumulation, assessment and importance of some heavy metals in agricultural soils and to understand the present situation and the impact of heavy metal contamination of soils in the world, in this review, compare and analyze the contamination of various cities/countries, and explore background, impact and remediation methods of heavy metal contamination of soils. Their accumulation in crops and pollution to soil can decrease crop yield, quality and cause detrimental effect to human health through food chain. Heavy metals can enter to human through inhalation, ingestion, body contact and skin absorption. In recent years, with the development of the global economy, both type and content of heavy metals in the soil caused by human activities have gradually increased, resulting in the deterioration of the environment.

Highlights

Heavy metals are natural constituents of earth crust and they are generally found in low concentration
Heavy metals in soils have been considered as powerful tracers for monitoring impact of anthropogenic activity such as industrial emission, vehicular emission, and atmospheric deposited
From the study it was reported higher concentrations of arsenic in farmed soils than other land use; higher cadmium and copper concentration in horticultural soil than other land uses which could be as a result of applied fertilizer impurities while lead concentrations were generally higher in horticultural soils followed by orchard, vineyards, market gardens, with pastoral soils having the lowest concentration [21]

Summary

Introduction

Heavy metals are natural constituents of earth crust and they are generally found in low concentration. Heavy metals in soils have been considered as powerful tracers for monitoring impact of anthropogenic activity such as industrial emission (cement plant, fossil fuel and coal combustion chemical plants), vehicular emission, and atmospheric deposited. These lead to emission of heavy metals into the air and their subsequent deposition into soils [3]. One of the most important sources of air pollution is vehicle emission Metals such as Fe, Cu and Zn are essential components of many alloy, pipes, wires and tires in motor vehicles and are released into the roadside environment as a Adugna Bayata: Assessment, Accumulation, Toxicity and Importance of Heavy Metals in Agricultural Soil and Living System - Review result of mechanical abrasion [5]

Heavy Metal Persistence in Soil and Living Organisms

Importance of Heavy Metals

Accumulation of Heavy Metal in Soil

Findings

Conclusion