Heavy metal contamination is a critical environmental and public health issue, resulting from the presence of toxic metals like lead, mercury, cadmium, and arsenic in the environment. These metals, with high density and toxicity even in trace amounts, enter ecosystems through natural geological processes and various anthropogenic activities, including industrial emissions, agricultural practices, and improper waste disposal. Heavy metals can contaminate soil, water, air, and food, affecting ecosystems and posing severe health risks to humans through pathways like bioaccumulation and biomagnification in food chains. For instance, soil contamination impacts crops, while polluted water bodies affect aquatic life, leading to contaminated seafood. Human exposure to heavy metals is linked to numerous health problems, including neurotoxicity, kidney damage, respiratory issues, and an increased risk of cancers. Heavy metal contamination also disrupts ecosystem balance, degrading soil quality and biodiversity and harming aquatic life. Effective management requires stringent regulations on industrial emissions, improved waste disposal practices, and the promotion of environmental education to raise awareness about contamination risks. Remediation strategies, such as phytoremediation and community-based monitoring, are also critical to mitigate contamination in affected areas. Addressing this issue is particularly pressing in Nigeria, where water bodies, including the Niger River and Lagos Lagoon, face high levels of heavy metal contamination from industrial discharges and urban runoff. Collaborative efforts focusing on stricter enforcement of environmental standards, public health interventions, and community education are essential to reduce heavy metal pollution and its health and environmental impacts.