Heavy metal pollution is a significant environmental issue with serious biotoxic effects on humans. Heavy metals such as lead (Pb), cadmium (Cd), zinc (Zn), mercury (Hg), arsenic (As), and others are essential in small amounts but can be toxic at higher concentrations. These metals are released into the environment through natural and anthropogenic sources, including mining, industrial activities, and automobile exhausts. Once released, they can leach into water and soil, leading to pollution that affects ecosystems and human health. Heavy metals are persistent in the environment and can accumulate in living organisms through food, water, and air. They are absorbed by plants and animals, leading to bioaccumulation and biomagnification in the food chain. This results in increased toxicity in higher trophic levels, including humans. Exposure to heavy metals can occur through various routes, including occupational exposure in mining and industrial settings, and through consumer products containing heavy metals. The biotoxic effects of heavy metals are due to their interference with normal biochemical processes in the body. When ingested, they form stable compounds with biomolecules such as proteins and enzymes, disrupting their functions and leading to various health issues. Symptoms of heavy metal poisoning include gastrointestinal disorders, neurological damage, kidney dysfunction, and respiratory problems. Lead, for example, is particularly toxic and can cause severe damage to the nervous system, especially in children. The paper reviews the sources, occurrence, and chemical behavior of heavy metals in the environment, as well as their biotoxic effects on humans. It emphasizes the importance of understanding the mechanisms of heavy metal toxicity and the need for preventive measures to reduce exposure and pollution. The paper also highlights the importance of regulatory limits and the need for proper management of heavy metal pollution to protect human health and the environment.Heavy metal pollution is a significant environmental issue with serious biotoxic effects on humans. Heavy metals such as lead (Pb), cadmium (Cd), zinc (Zn), mercury (Hg), arsenic (As), and others are essential in small amounts but can be toxic at higher concentrations. These metals are released into the environment through natural and anthropogenic sources, including mining, industrial activities, and automobile exhausts. Once released, they can leach into water and soil, leading to pollution that affects ecosystems and human health. Heavy metals are persistent in the environment and can accumulate in living organisms through food, water, and air. They are absorbed by plants and animals, leading to bioaccumulation and biomagnification in the food chain. This results in increased toxicity in higher trophic levels, including humans. Exposure to heavy metals can occur through various routes, including occupational exposure in mining and industrial settings, and through consumer products containing heavy metals. The biotoxic effects of heavy metals are due to their interference with normal biochemical processes in the body. When ingested, they form stable compounds with biomolecules such as proteins and enzymes, disrupting their functions and leading to various health issues. Symptoms of heavy metal poisoning include gastrointestinal disorders, neurological damage, kidney dysfunction, and respiratory problems. Lead, for example, is particularly toxic and can cause severe damage to the nervous system, especially in children. The paper reviews the sources, occurrence, and chemical behavior of heavy metals in the environment, as well as their biotoxic effects on humans. It emphasizes the importance of understanding the mechanisms of heavy metal toxicity and the need for preventive measures to reduce exposure and pollution. The paper also highlights the importance of regulatory limits and the need for proper management of heavy metal pollution to protect human health and the environment.