Aluminum is a metal that enters water from natural deposits, industrial processes, and water treatment. It can accumulate in the body over time.

Aluminum is the third most abundant element in Earth's crust, naturally occurring in soil, rocks, and minerals. It enters drinking water through erosion and runoff. Industrial processes, such as mining and manufacturing, can increase aluminum levels in water sources. Ironically, aluminum-based compounds are also used in water treatment to remove impurities. While essential for many applications, long-term exposure to high levels of aluminum in drinking water may pose health risks. Water utilities regularly monitor aluminum concentrations to ensure they remain within safe limits set by regulatory agencies.