High levels of arsenic remain even years after use is discontinued. Also, soils near smelters contain high arsenic levels. I. Volatilization and methylation of dimethylarsinic acid and methylation of arsenate and arsenite occurs in soil. Other compounds that may be methylated are tellurium and lead. A. pH can be changed by microbial activity 1.
Lichens produce aromatic acids.
Fulvic and humic acids also involved. B. Redox can be altered by microbial activity. Specific elements that become solubilized include silica, calcium, magnesium, aluminum, cobalt, nickel, lead, potassium, and others. Solubilization is enhanced by organic inputs. Examples of interactions between microorganisms and minerals.