This article explores the global threat of metals and metalloids in the environment, using a One Health approach to understand their toxicity. It discusses how human industrial activities, agriculture, and waste production have led to widespread pollution by these substances. The article also examines historical and current examples of poisoning and health effects caused by exposure to metals and metalloids. It highlights the impact of climate change, severe weather events, and wildfires on the distribution and toxicity of these substances. The article emphasizes the importance of considering the interconnectedness of human, organismal, and environmental health through the One Health framework. It also explores the speciation of metals and their effects on microbial, plant, and animal health, as well as their interactions with biological molecules and the development of antimicrobial alternatives. This text is a summary of a special issue that covers various topics related to metal ions and their effects on biological systems. The issue emphasizes the concept of One Health and its relevance to global health.