The contamination of the environment with heavy metals originating from improperly managed waste is an escalating issue with serious consequences for ecosystems and human health. Industrial, electronic, and household wastes are primary sources of metals like lead, mercury, cadmium, arsenic, and chromium. Poor waste disposal practices enable these metals to contaminate air, water, soil, and the food chain. Rapid industrialization and urban expansion, especially in developing nations, exacerbate the problem through mismanaged waste streams. Disposal in uncontrolled landfills and incineration without proper safeguards leads to leaching of metals into soil and groundwater, and emissions of toxic fumes. This paper examines the key sources of heavy metals, identifies activities such as metallurgy, chemical manufacturing, electrical equipment production, battery usage, sewage sludge handling, coal-fired power generation, waste incineration, and household waste. Agricultural practices, particularly pesticide and fertilizer waste, are also highlighted. The analysis provides insights essential for policymakers, waste managers, and stakeholders to devise strategies for mitigating heavy metal contamination