Abstract: Bioavailability of lead and other heavy metals in the environment may be reduced by addition of microorganisms which sequester lead from the environment in the presence of phosphate. The microorganisms are highly mobile and are, therefore, capable of scavenging a material for lead, which they then sequester. The method basically consists of reducing bioavailability of lead in the environment by addition of Pseudomonas aeruginosa strain CHL004 (ATCC 55937) to said environment in the presence of phosphate which contains at least stoichiometric equivalent amounts of phosphate to lead.