Biology Doesn’t Eliminate Metals, It Manages Them

In contaminated soils, it’s tempting to believe that once microbes are added, the metals are “gone.” The reality is more nuanced.

First, metals don’t disappear.

• Microbes dilute metals by spreading them across many binding sites.

• They diffuse metals by secreting extracellular polymers and precipitating them into less mobile forms.

• But unless plants extract those metals into biomass, the total pool remains in the soil.

Second, microbes are living systems.

• To keep binding metals, they must stay alive.

• That requires water and a regular supply of organic matter — food scraps, greenwaste, compost.

• When microbes die, the metals they held can be released and mobilized again, undoing the stabilization.

Third, restoration is a process, not a one‑time fix.

Biology offers resuscitation and diffusion effects that reduce toxicity and risk, but only if we sustain the microbial workforce. Just as humans need meals every day, soils need ongoing organic inputs to keep their microbial communities active and protective.

The takeaway: Contaminated soils aren’t “cured” with a single treatment. They’re managed through continuous care, turning waste into the food that keeps microbes working for us.