Some metals are essential for life and are naturally available in our food and water.
In addition to metals essential for life, drinking water may contain metals which cause chronic or acute poisoning. This water enters larger water bodies which we then use as resources for drinking water. Contamination of our water resources by poisonous metals occurs largely due to human activity. These activities include industrial processes, such as electronics and mining, agricultural activities, and discarding of wastes in landfills. This means that public water supplies are monitored for these metals regularly.