What is often the first sign of Zinc poisoning?

Nausea is frequently the first sign of zinc poisoning and can occur shortly after exposure. This symptom arises primarily because zinc affects the gastrointestinal system; it can irritate the stomach lining and lead to symptoms such as nausea and vomiting. In cases of acute zinc toxicity, these gastrointestinal effects are typically the most immediate and prevalent symptoms experienced by individuals.

Other potential symptoms may manifest later, such as fever, which can result from an immune response or infection, or respiratory distress, which is less commonly associated with zinc toxicity. Vision changes could occur in more severe or prolonged exposure situations but are not typical immediate signs. Therefore, nausea serves as a clear and early indicator of zinc poisoning, aligning with what is known about how the body reacts to excessive zinc intake.