Metals insolubility reduces bioavailability which is the ability of an organism to take metals into the body. Metals insolubility reduces the toxicity to living organisms. Untreated metals in soil and water can be carcinogenic or cause heavy metals poisoning. Metals are highly soluble and mobile in surface and groundwater. Soluble metals in water severely impact aquatic life and present a significant human health hazard.
Metals are expensive to treat and dispose.