Heavy metal pollution in the food chain is a severe environmental issue with consequences for ecosystems and human health. When naturally occurring metal concentrations exceed safe levels, such as copper, zinc, arsenic, cadmium, lead, and mercury, they become toxic. Heavy metals enter the environment through a variety of sources, including industrial operations, wastewater, electronic waste, and agricultural practices. Because of their bioaccumulative and persistent properties, they can spread across trophic levels, poisoning humans, animals, and plants. Heavy metals can lead to kidney failure, neurological illnesses, and developmental issues, as well as damage soil fertility and reduce agricultural yield. Aquatic ecosystems are especially sensitive to metal contamination because people consume polluted seafood and are directly affected by heavy metal deposition in fish and shellfish. Mercury is particularly well known for its powerful biomagnification characteristics, which have resulted in a number of poisoning incidents. To address this issue, remedial techniques such as bioremediation, phytoremediation, and nanotechnology-based methods are under investigation. Genetic engineering advancements offer potential solutions to reduce metal uptake in crops. This book thoroughly examines the causes, effects, and mitigation techniques of toxic metal poisoning, emphasizing the critical importance of sustainable environmental management in protecting public health and global food security.