Some heavy metals are either essential nutrients (typically iron, cobalt, and zinc), or relatively harmless (such as ruthenium, silver, and indium) but can be toxic in large amounts or certain forms.
Some heavy metals are either essential nutrients (typically iron, cobalt, and zinc), or relatively harmless (such as ruthenium). Some heavy metals are either essential nutrients (typically iron, cobalt, and zinc), or relatively harmless (such as silver). Some heavy metals are either essential nutrients (typically iron, cobalt, and zinc), or relatively harmless (such as indium). Some heavy metals can be toxic in large amounts. Some heavy metals can be toxic in certain forms.