Environmental Impact of Heavy Metals

*Muhammad Mudassir Usman, Shamsu Shuaibu Bala and K. Hamza*

### **Abstract**

Heavy metals cause toxicity in biological systems by bonding to Sulfhydryl groups and producing reactive oxygen species (ROS). Many international organizations established a standard regarding the presence of heavy metals in the environment, food, and drinking water as a result of numerous harmful effects on humans and animals observed. This study aimed to determine the level of heavy metal concentrations and water quality in the Romi River, where some heavy metals concentrations (Iron 0.89 mg/L and Nickel 0.36 mg/L) exceeded the WHO maximum standard limits (Nickel 0.02 mg/L and 0.030 mg/L). The mean concentrations of the metal's chromium, iron, nickel, and zinc with standard deviation were found to be: 0.100.1 mg/L, 0.890.1 mg/L, 0.060.1 mg/L, and 0.200.1 mg/L, respectively. This study revealed that the contamination occurs as a results of effluents release into the river thereby causing many harmful effect to the community around them.

**Keywords:** contamination, concentration, environment, heavy metals & toxicity, environmental pollution

### **1. Introduction**

Water pollution occurs in both rural and urban areas in Nigeria. Many factories in Nigeria are located on river banks and use the rivers as open sewers for their effluents. It is important to note that some of these heavy metals are required for proper biochemical function. Metals such as lead, chromium, and arsenic, on the other hand, can be toxic when consumed in small or large amounts. In general, the ionic form of a metal is more toxic because it can form toxic compounds with other ions. Electron transfer reactions with oxygen can produce toxic oxyradicals [1, 2].

Water contamination endangers other resources, such as fisheries, and land resources, for example, have already suffered significantly. The majority of environmental pollution is caused by anthropogenic sources, specifically domestic and industrial activities [1, 2]. Failure to halt further deterioration of environmental quality may jeopardize the health of a large proportion of the population, with serious political and socioeconomic consequences [3, 4].

Heavy metal exposure has increased as a result of anthropogenic, industrial, and agricultural activity as well as modern industrialization, all of which have negative

impacts on human health. The environmental concern of hazardous metal contamination of water and air affects hundreds of millions of people worldwide. Heavy metal pollution in food is a problem for both human and animal health. In this context, the concentration of heavy metals in air, food, and water sources is evaluated [3]. Among the numerous toxins in the environment, metals can exist naturally and stay in the ecosystem. As a result, human exposure to metals is unavoidable, and some researchers have found that the toxicity of metals varies depending on gender [4]. Biological systems may typically react to them by losing one or more electrons, releasing metal cations that are affine to the nucleophilic sites of essential macromolecules. Several acute and long-term harmful effects of heavy metals have an impact on several human organs. Examples of the adverse effects of heavy metal toxicity include cancer, gastrointestinal and kidney dysfunction, nervous system diseases, skin lesions, vascular damage, immune system malfunction, and birth defects. The cumulative effects of simultaneous exposure to two or more metals have been reported [5–7].

Heavy consequences such abdominal cramping, bloody diarrhea, and kidney failure can occur after exposure to high doses of heavy metals, especially lead and mercury [5, 6]. Contrarily, low-dose exposure poses a subtle and unnoticed risk unless it is consistently experienced, at which point its side effects, such as neuropsychiatric illnesses characterized by exhaustion, anxiety, and negative effects, may be identified.
