Heavy Metal Pollution in Iraqi Rivers and Impact on Human and Fish Health: A Review

Abstract

The Euphrates and Tigris rivers are the main vital water sources in Iraq, and therefore many studies have been conducted on them to find out the reasons for their pollution, and the most important sources of pollution are heavy metals. Heavy metals are usually present in nature. Some of them are necessary for life, but they can become toxic through their accumulation in living organisms, as they cannot be eliminated in ecosystems through natural processes, unlike most organic pollutants, where these elements are one of the dangerous pollutants that enter the freshwater environment and cause an imbalance in the ecological system. This is directly or indirectly reflected on the human beings. These elements enter the plant and animal bodies through the soil, water and air which have been categorized by their ability to bio-accumulate in the tissues of animals and elevate their concentration in the tissue and body fluids. Such bioaccumulation causes toxicity to living organisms and may affect human public health. Fishes are the most susceptible among the aquatic animals to the toxicity of heavy metals. They are a basic food source and animal protein, cheap and economical, with a high nutritional value and the human body needs them on a permanent and continuous basis. Fishes are also commonly used in assessing the health of aquatic organisms. This review is focused on the pathological effects of heavy metals in both fishes and humans.