[An experimental study of a microbiological index in the complex setting of standards for lead, copper and zinc in the soil].

Anthropological pollutions falling in the soil by different routes evolve multitude unfavourable consequences for human being and health. The present publication considers a laboratory survey on the influence of lead, copper and zinc by their combined presence in soil onto soil autocleaning ability. The results from the experiments will serve the goals of complex hygiene standards of these three soil pollutants. A number of micro-organisms, relating to soil as an ecological compartment, are tested by two hygienic microbiological methods. The results from experiments point out as maximum permissible concentration (MPC) the following combination of concentrations within the range of the microbiological index: lead--54 mg/kg, copper--90 mg/kg, zinc--165 mg/kg. Concentrations over the above-mentioned have an oppressive effect on saprophytic microflora in higher rate than the observed impact of pathogenic micro-organisms. In conditions of MPC higher than the reached ones the autocleaning ability of the soil is threatened and thus a basis with unfavourable epidemiological indicators is established.