Irritation of the eyes, nose, and throat can also occur if undiluted TCE is ingested. Generally, minor negative effects that result from one or several exposures to TCE disappear when exposure ends. Some harmful health effects may persist after long-term TCE exposure. Zinc is one of the most widely used metals in the world. It is used both alone, to coat other metals, and combined with other metals to form alloys such as brass and bronze.
Zinc compounds occur naturally in the air, soil, and water, and are present in all foods.
Our bodies need small amounts of zinc, but in large doses it can be harmful. Zinc mostly enters the environment from smelting and refining operations, and is usually found in surface water and groundwater. Zinc may also enter the soil in discharges from industrial operations and in the natural breakdown of zinc ore deposits. Zinc is carried into the air as dust and fumes from zinc production facilities, automobile emissions, fuel combustion, and soil erosion. Garbage incineration, coal combustion, and smelters are also major sources of airborne zinc.