The article investigates the toxic effects of mercury and its compounds on living organisms and examines various methods for detecting mercury in food and water. It highlights mercury’s historical recognition as a poison, its persistence in the environment due to both natural and anthropogenic sources, and its severe health effects, including neurological, respiratory, and immune system damage. Mercury, especially in organic forms like methylmercury, accumulates in the body and is highly toxic even in small amounts. The study evaluates detection techniques including atomic absorption spectroscopy (AAS), inductively coupled plasma optical emission spectroscopy (ICP-OES), and colorimetry. These methods were applied to food and water samples, showing that mercury levels in tested waters remained within permissible limits. The paper emphasizes the importance of accurate mercury detection to ensure food safety and public health, and it discusses both the challenges and effectiveness of different analytical approaches.